M. Malone v. WCAB (City of Philadelphia) ( 2021 )


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  •            IN THE COMMONWEALTH COURT OF PENNSYLVANIA
    Michael Malone,                                :
    Petitioner        :
    :
    v.                        :   No. 22 C.D. 2020
    :   Submitted: September 4, 2020
    Workers’ Compensation Appeal                   :
    Board (City of Philadelphia),                  :
    Respondent            :
    BEFORE:       HONORABLE RENÉE COHN JUBELIRER, Judge
    HONORABLE MICHAEL H. WOJCIK, Judge
    HONORABLE ELLEN CEISLER, Judge
    OPINION NOT REPORTED
    MEMORANDUM OPINION BY
    JUDGE COHN JUBELIRER                               FILED: January 6, 2021
    Michael Malone (Claimant) petitions for review of the Order of the Workers’
    Compensation Appeal Board (Board) that affirmed a Workers’ Compensation
    Judge’s (WCJ) Decision and Order (Decision), denying Claimant’s Claim Petition
    on the basis that Claimant did not establish that he suffers from an occupational
    disease, as that term is defined in Section 108 of the Workers’ Compensation Act
    (Act), 77 P.S. § 27.1.1 On appeal, Claimant argues the WCJ erred in denying his
    Claim Petition because uncontradicted evidence shows that his injury is an
    occupational disease, he is entitled to a presumption that his injury is work related,
    1
    Act of June 2, 1915, P.L. 736, as amended, added by Section 1 of the Act of October 17,
    1972, P.L. 930, 77 P.S. § 27.1.
    the WCJ accepted that he was exposed to carcinogens during his work, and the City
    of Philadelphia (Employer) did not rebut that presumption. Based on the credited
    evidence, Claimant has not established that his injury is an occupational disease
    entitling him to a presumption that his injury is work related, and he has not
    otherwise established that his injury was caused by his work. Accordingly, we
    affirm the Board’s Order.
    I.     BACKGROUND
    Claimant was diagnosed with prostate cancer in October 2010. (Mar. 2, 2018
    WCJ Decision, Finding of Fact (FOF) ¶ 1.n.) On May 18, 2012, Claimant filed the
    Claim Petition, alleging that his prostate cancer is an occupational disease caused by
    “[d]irect exposure to . . . carcinogens while working as a [f]irefighter” for
    Employer’s Fire Department.2 (Claim Petition at 1-2, Certified Record (C.R.) Item
    2.) In the Claim Petition, Claimant sought medical benefits and total disability
    benefits for the period from May 6, 2011, to June 20, 2011. (Id.) Employer filed an
    Answer denying that Claimant suffered any injury or disease that was causally
    related to his employment. (Answer to Claim Petition at 1, C.R. Item 4.) It also
    asserted that Claimant did not provide Employer with the required notice of the
    injury.3 (Id. at New Matter – Affirmative Defenses.)
    A. Proceedings Before the WCJ
    2
    Claimant also filed a Penalty Petition, which the WCJ later denied in her September 2,
    2014 Decision. (Certified Record (C.R.) Items 5, 11 at 9.) Claimant did not challenge that portion
    of the WCJ’s Decision, and, as such, the Penalty Petition is not at issue on appeal.
    3
    The WCJ issued an initial decision on September 2, 2014, in which the WCJ agreed with
    Employer that Claimant did not provide timely statutory notice of his injury as required under
    Section 311 of the Act, 77 P.S. § 631, and denied the Claim Petition. On appeal, the Board
    reversed, concluding that Claimant had provided Employer with timely statutory notice of his
    injury. Accordingly, the Board remanded the matter to the WCJ for a decision on the merits.
    Employer does not appeal this decision by the Board, and, therefore, we will not discuss it further.
    2
    1. Testimony of Claimant
    The WCJ held multiple hearings on the Claim Petition, at which live and
    deposition testimony was presented. Claimant first testified at the initial hearing
    held on July 2, 2012, as follows.4          (Reproduced Record (R.R.) at 1500-01.)5
    Claimant worked for Employer from 1983 to 2011 as a firefighter and lieutenant.
    (Id. at 1503-04.)     At the time he was hired, Claimant underwent a physical
    examination that showed no signs of cancer. (Id. at 1503-05.) Throughout his
    employment, on at least five separate occasions, he underwent similar examinations
    without signs of cancer. (Id. at 1504.) During most of his tenure with Employer, he
    was assigned to work at fire stations at which at least two diesel-powered vehicles
    were present. (Id. at 1505.) After Claimant joined Employer’s Ladder 20 in 2009,
    Employer installed a system to capture diesel fuel emissions, but no such system was
    in place at any of Claimant’s previous work locations. (Id. at 1506.) Claimant stated
    that he often noticed diesel fuel emissions present in indoor air at the stations where
    he worked, as evidenced by black soot on the walls and ceilings. (Id.) Throughout
    his career, Claimant was present in enclosed spaces of the firehouses while the diesel
    engines in the vehicles were routinely run at the beginning of each shift, and where
    diesel exhaust was present. (Id. at 1507-08.)
    Claimant further testified that he has only a minimal family history of cancer,
    and no family history of prostate cancer.           (Id. at 1531-33.)      He smoked for
    approximately 30 years, but quit in 2008. (Id. at 1518.) Claimant responded to
    hundreds of fires over the course of his career with Employer. (Id. at 1512, 1538.)
    4
    Claimant’s testimony can be found on pages 1500-1546 of the Reproduced Record and
    is summarized in the WCJ’s March 2, 2018 Decision in Finding of Fact ¶ 1.
    5
    The Reproduced Record page numbers are not followed by a small “a” as required
    by Pennsylvania Rule of Appellate Procedure 2173, Pa.R.A.P. 2173, and thus are not followed by
    a small “a” herein.
    3
    At many of those fires, Claimant sometimes wore a self-contained breathing
    apparatus (SCBA), which provides clean, breathable air to the wearer for a limited
    time. (Id. at 1509-10, 1513.) Employer’s requirements for the use of SCBA, and
    Claimant’s use thereof, increased over the course of his career. (Id. at 1511-13.)
    Throughout his career, however, there were various firefighting activities involving
    exposure to smoke for which Claimant was not required to wear, and did not wear,
    an SCBA. (Id.) Accordingly, Claimant testified, he endured at least some exposure
    to smoke without an SCBA at “[a]ll of” the fires to which he responded. (Id. at
    1513.) Some of the fires to which Claimant responded involved exposures to
    polychlorinated biphenyls (PCBs) and asbestos. (Id. at 1521-22.) Often, soot would
    be present when he coughed or blew his nose, even days after responding to a fire.
    (Id. at 1514.) Claimant responded to a fire, at which he was exposed to smoke
    without an SCBA, one or two months before his cancer diagnosis in October 2010.
    (Id. at 1512, 1528.) In May 2011, Claimant underwent surgery to treat his prostate
    cancer, after which he was unable to work for a period of six weeks. (Id. at 1515-
    16.) He then retired from his work as a firefighter and did not return to work for
    Employer following the surgery. (Id. at 1516.) In June 2012, Claimant received a
    report prepared by Barry L. Singer, M.D., a board-certified oncologist, concerning
    the potential work-relatedness of Claimant’s cancer. (Id. at 1517.) Prior to receiving
    Dr. Singer’s report, Claimant never had been informed by a doctor that his cancer
    might have been related to his firefighting work. (Id.)
    2. Reports of Barry L. Singer, M.D., and Virginia M. Weaver, M.D.
    In support of the Claim Petition, Claimant presented two reports by physicians
    concerning his exposure to carcinogens at work and the potential results thereof.
    4
    Claimant first presented a report by Dr. Singer.6 After reviewing Claimant’s medical
    history, Dr. Singer concluded that Claimant’s “exposure to carcinogens while
    working for [Employer] was a substantial contributing factor in the development of
    his prostate cancer.” (R.R. at 3.) As to the sources of such carcinogens, Dr. Singer
    identified Claimant’s exposure at fires to smoke, dust, and soot without an SCBA,
    and diesel exhaust from trucks at the stations where Claimant worked. (Id. at 1-2.)
    Smoke contains several substances identified by the International Agency for
    Research on Cancer (IARC) as “Group 1 carcinogens,” meaning they have been
    definitively confirmed to cause cancer in humans. (Id. at 3; see id. at 6.) IARC
    Group 1 carcinogens “in smoke include arsenic, asbestos, benzene, benzo(a)pyrene,
    1,3-betadiene, formaldehyde[,] and soot.” (Id. at 3.) Additionally, common IARC
    Group 2A carcinogens (which are shown to be likely human carcinogens) found in
    smoke include creosote, PCBs, polycyclic aromatic hydrocarbons, and styrene. (Id.;
    see id. at 6.) Dr. Singer noted that Claimant had no family history of prostate cancer.
    (Id. at 3.) He also identified several scientific studies linking prostate cancer to
    firefighting. (Id.)
    Claimant next presented a report by Virginia M. Weaver, M.D., a professor
    of environmental health sciences and medicine at Johns Hopkins University.7 Dr.
    Weaver opined that, based on her review of research on occupational exposure,
    firefighters are exposed to many recognized carcinogens, including numerous IARC
    Group 1 carcinogens. (Id. at 5-8.) These exposures occur during firefighting
    activities where smoke is present. (Id. at 6-7.) Although firefighters sometimes use
    6
    This initial report by Dr. Singer can be found on pages 1-4 of the Reproduced Record and
    is summarized in the WCJ’s March 2, 2018 Decision in Finding of Fact ¶ 3.
    7
    Dr. Weaver’s report can be found on pages 5-10 of the Reproduced Record and is
    summarized in the WCJ’s March 2, 2018 Decision in Finding of Fact ¶ 4.
    5
    personal protective equipment to reduce their exposure, that equipment is only
    partially effective even when used correctly. (Id. at 8-9.) Such equipment is often
    not used at all when firefighters are in the presence of smoke. (Id.) Dr. Weaver also
    identified diesel exhaust at fire stations and asbestos from buildings as additional
    means of carcinogen exposure for firefighters. (Id. at 6-8.) Dr. Weaver noted a
    study that shows increased incidence of cancer among those exposed to diesel
    exhaust. (Id. at 7.) She did not offer an opinion on the causal connection between
    carcinogens and prostate cancer in particular.
    3. Report and Testimony of Tee L. Guidotti, M.D.
    Employer presented the deposition testimony and report of Tee L. Guidotti,
    M.D., who is board certified in internal medicine, pulmonary medicine, and
    occupational medicine.8 (Id. at 1034-35.) Dr. Guidotti also has a nonmedical degree
    in toxicology, has training in epidemiology, and has conducted research on cancer
    risk among firefighters. (Id. at 1035-36, 1040-42.) Dr. Guidotti evaluated and
    opined on Dr. Singer’s methodology and the validity of his expert opinions. He
    stated that Dr. Singer’s method for reviewing and relying on the various
    epidemiologic studies Dr. Singer cited was not a sufficient method for determining
    general causation, i.e., whether a certain carcinogen is capable of causing a certain
    type of cancer. (Id. at 1084-85.) Dr. Guidotti discussed the importance of using a
    particular methodology when investigating whether a given agent causes a specific
    disease. (Id. at 1040, 1046-47.) Upon reviewing Dr. Singer’s opinions, Dr. Guidotti
    could not discern any methodology employed by Dr. Singer, nor did Dr. Guidotti
    believe that Dr. Singer gathered enough evidence to render an opinion on the
    8
    Dr. Guidotti’s testimony and report can be found on pages 1025-1433 of the Reproduced
    Record and are summarized in the WCJ’s March 2, 2018 Decision in Finding of Fact ¶ 5.
    6
    etiology of any particular disease. (Id. at 1046-47, 1053, 1098.) He also noted that
    IARC Group 1 carcinogens are each related to different types of cancer, and that Dr.
    Singer did not appear to discuss which of those listed carcinogens are related to
    which types of cancer. (Id. at 1087-90.) Dr. Guidotti opined that Dr. Singer had not
    sufficiently reviewed information on general causation in order to offer an opinion
    about specific causation, i.e., the cause of Claimant’s cancer in particular, which was
    the same opinion Dr. Singer offered in numerous other cases involving prostate
    cancer in firefighters. (Id. at 1429-30.)
    Dr. Guidotti further testified that a claimant’s history of smoking can present
    a confounding variable that inhibits the assessment of whether occupational
    exposures significantly contributed to the claimant’s disease.           (Id. at 1109.)
    Additionally, cigarette smoke contains some of the same carcinogens to which
    firefighters are exposed on the job and can compound the health effects of work-
    related exposure. (Id. at 1109-11.) Dr. Guidotti acknowledged, however, that a
    claimant’s smoking history should not result in the automatic denial of a claim or
    the conclusion that there is no causal connection between his work and his cancer,
    but it should be considered to be a potentially significant causal factor. (Id. at 1116-
    17.) Concerning prostate cancer in particular, Dr. Guidotti opined that, although
    other types of cancer have a marked association with firefighting, prostate cancer is
    “much more a disease of aging than it is of external influences[,]” and he did not
    believe there is sufficient evidence to conclude that firefighting significantly elevates
    prostate cancer risk. (Id. at 1378-79.)
    4. Responsive Report and Testimony of Dr. Singer
    In response to Dr. Guidotti’s report and testimony criticizing Dr. Singer’s
    methodology and opinions, Claimant presented an additional report by, and the
    7
    deposition testimony of, Dr. Singer.9 Dr. Singer acknowledged Dr. Guidotti’s focus
    on epidemiologic studies, but emphasized that epidemiology is only one component,
    among others, that he considers when offering an opinion in firefighter cancer cases.
    (Id. at 233-34.) Dr. Singer explained that, when he described Claimant’s firefighting
    work as a substantial contributing factor in Claimant’s development of prostate
    cancer, he meant to convey his opinion that “but for the exposures to known human
    carcinogens encountered during [Claimant’s] service, he would not have developed
    the cancer when it was diagnosed.” (Id. at 235.) In direct response to Dr. Guidotti’s
    criticism that he failed to identify a specific carcinogen linked to prostate cancer, Dr.
    Singer stated that he did identify many specific carcinogens to which firefighters are
    exposed. (Id.) He opined that, among these, “prostate cancer has been associated
    with arsenic, [Polycyclic aromatic hydrocarbons (]PAH’s[)], and phthalates[,]”
    which are IARC Group 1 carcinogens, and he cited several scientific studies in
    support of that statement. (Id. at 235-36.) He explained, however, that a focus on a
    single carcinogen may not be appropriate, given that exposure to multiple
    carcinogens (as occurs with firefighters) can produce a synergistic increase in cancer
    risk. (Id. at 235.)
    Dr. Singer reemphasized what he views as a significant body of epidemiologic
    evidence of increased rates of prostate cancer among firefighters. (Id. at 235-36.)
    In support of this view, he cited several meta-analyses of cancer among firefighters,
    including one analysis by Grace LeMasters, Ph.D., published in 2006 (LeMasters
    Report), which both he and Dr. Guidotti had discussed in their earlier reports and
    9
    Dr. Singer’s responsive report, dated December 19, 2012, can be found on pages 233-237
    of the Reproduced Record. His accompanying deposition testimony is summarized, along with
    his responsive report, in the WCJ’s March 2, 2018 Decision in Finding of Fact ¶ 6 and can be
    found on pages 46-1024 of the Reproduced Record.
    8
    testimony. (Id.) On cross-examination, Dr. Singer admitted that some cases of
    prostate cancer in firefighters are not caused by work-related exposure, but by other
    factors. (Id. at 499-502.) However, he maintained his opinion that, for many
    firefighters, their exposure to carcinogens through their work contributes to their
    development of prostate cancer, including by causing them to develop it at an earlier
    age than they otherwise would. (Id. at 931.)
    5. Report of Janet L. Stanford, Ph.D.
    Finally, Employer introduced a report by Janet L. Stanford, Ph.D., an
    epidemiologist who studies prostate cancer.10            Dr. Stanford explained that
    observational studies have identified several risk factors that are associated with
    prostate cancer. (Id. at 1434.) These “include age, race/ethnicity, and family history
    of prostate cancer.” (Id.) The median age of diagnosis with prostate cancer is 67.
    (Id.) Diagnosis at a younger age does not necessarily suggest an environmental
    cause, because diseases with genetic causes tend to present at an earlier age. (Id. at
    1435.) Dr. Stanford admitted that she is not an occupational epidemiologist qualified
    to address the connection between occupational exposures and prostate cancer. (Id.)
    She opined, however, that the literature she reviewed suggests that about 42% of
    prostate cancer etiology is related to genetics, while about 58% is related to
    environmental factors, such as occupational exposure, alcohol use, and smoking.
    (Id.) Prostate cancer is a complex disease that often has multiple factors in its
    causation.   (Id.)   These multiple factors—such as genetics and environmental
    exposure—can interact with each other, producing a causal effect greater or less than
    each produces individually. (Id.) The extent to which such interaction occurs in
    10
    Dr. Stanford’s report can be found on pages 1434-1494 of the Reproduced Record and
    is summarized in the WCJ’s March 2, 2018 Decision in Finding of Fact ¶ 7.
    9
    prostate cancer cases has not been well studied. (Id.) Therefore, Dr. Stanford
    concluded, “it is possible to estimate a likelihood that an exposure” to carcinogens
    is associated with prostate cancer, but it is not possible definitively to prove that
    certain carcinogens cause prostate cancer. (Id.)
    B. March 2, 2018 WCJ Decision
    In the March 2, 2018 Decision, the WCJ found that Claimant did not establish
    that his prostate cancer was caused by his work as a firefighter and denied the Claim
    Petition. In doing so, the WCJ found Claimant’s testimony wholly credible, noting
    that Employer did not dispute Claimant’s description of his firefighting duties and
    experiences, presumably including the exposure to smoke and diesel exhaust of
    which Claimant testified. (Mar. 2, 2018 WCJ Decision, FOF ¶ 8.) Concerning the
    medical testimony, the WCJ found that Claimant’s evidence did not establish that
    any IARC Group 1 carcinogens are known to cause prostate cancer. (Id. ¶ 9.) On
    this issue, the WCJ found Employer’s medical expert witness, Dr. Guidotti, credible
    and Claimant’s expert, Dr. Singer, not credible. (Id.) The WCJ explained:
    Dr. Singer mentions the [IARC] Group 1 carcinogens as cancer[-
    ]causing agents, but his testimony on this issue is vague at best as [it]
    pertains to prostate cancer in general and [is] not credible to establish
    that prostate cancer is caused by Group 1 carcinogens. Dr. Guidotti
    explained in detail the different accepted scientific methodologies used
    in determining how to analyze whether a particular substance is a
    cancer-causing agent, and Dr. Singer did not use any of these methods
    but rather relied on articles and his own assumptions when
    assessing . . . claimants’ affidavits in the various cases he reviewed.
    This Judge finds Dr. Guidotti’s explanation as to the methodology to
    be used in analyzing whether a[n IARC] Group 1 carcinogen is a known
    cause of a particular type of cancer more credible than Dr. Singer’s
    contrary opinions, to the extent any were expressed, because Dr.
    Guidotti is trained in epidemiology, has a degree in toxicology[,] and is
    board certified in internal medicine, pulmonary medicine[,] and internal
    medicine.
    10
    (Id.) Based on her refusal to credit Dr. Singer’s testimony, as described above, the
    WCJ concluded that Claimant failed to demonstrate that IARC Group 1 carcinogens
    have been shown to cause prostate cancer, and, thus, he was not entitled to the
    statutory presumption that his firefighting caused his cancer. (Id. ¶ 10.)
    The WCJ did not credit Dr. Singer’s testimony that Claimant’s exposure to
    carcinogens through his firefighting work was a substantial contributing factor in his
    development of prostate cancer. (Id.) Once again, the WCJ credited Employer’s
    witness over Dr. Singer, noting Dr. Stanford’s opinion that the established risk
    factors for prostate cancer are age, race/ethnicity, and family history. (Id.) The WCJ
    found specifically that
    Dr. Stanford is better qualified to answer the question of whether
    prostate cancer could be caused by firefighting than Dr. Singer, and her
    opinion that such causal connection has not been shown is more
    credible than Dr. Singer’s opinion that Claimant’s work is a substantial
    contributing causative factor in his development of prostate cancer.
    (Id.) The WCJ further found that Dr. Singer’s medical “opinion has no credible
    scientific or epidemiologic basis.”     (Id.)   Based on these findings, the WCJ
    concluded that Claimant failed to establish that he contracted prostate cancer as a
    result of his work and denied the Claim Petition. (Mar. 2, 2018 WCJ Decision,
    Conclusion of Law ¶ 2.)
    C. December 24, 2019 Board Opinion
    Claimant appealed the WCJ’s Decision to the Board, which affirmed. The
    Board, noting that the WCJ credited the testimony of Dr. Guidotti and Dr. Stanford,
    declined to disturb those credibility determinations given a WCJ’s discretion to
    accept or reject the testimony of any witness, including any expert witnesses. Based
    on the WCJ’s determination that Dr. Singer’s testimony was not credible, the Board
    11
    determined that Claimant failed to meet his initial burden of proving that IARC
    Group 1 carcinogens can cause prostate cancer. The Board reasoned that, because
    Claimant failed to meet this burden of establishing general causation, the burden
    never shifted to Employer to rebut a presumption regarding the specific cause of
    Claimant’s cancer. The Board concluded that, “as there was no credible evidence to
    establish Claimant’s initial burden of proof, the WCJ’s finding that Claimant failed
    to meet his burden entitling him to benefits for prostate cancer was supported by
    substantial, competent evidence.” (Dec. 24, 2019 Board Op. at 14.) The Board also
    determined that, contrary to Claimant’s argument, the WCJ did not capriciously
    disregard the LeMasters Report, on which Dr. Singer relied, given that the WCJ
    actually discussed it but declined to credit it along with Dr. Singer’s other testimony.
    Claimant now petitions this Court for review.11
    II. PARTIES’ ARGUMENTS
    On appeal, Claimant argues that the Board and the WCJ erred by
    misinterpreting Claimant’s burden of proof when analyzing the evidence in support
    of the Claim Petition. (Claimant’s Brief (Br.) at 23.) Claimant acknowledges that,
    in seeking compensation for an occupational disease, as defined in Section 108(r) of
    the Act, 77 P.S. § 27.1(r),12 he must make a threshold showing of general
    causation—in this case, that his type of cancer, prostate cancer, can be caused by an
    11
    In reviewing a decision of the Board, “[o]ur review is limited to determining whether an
    error of law was committed, whether necessary findings of fact are supported by substantial
    evidence, and whether constitutional rights were violated.” McDermott v. Workers’ Comp. Appeal
    Bd. (Brand Indus. Servs., Inc.), 
    204 A.3d 549
    , 554 n.9 (Pa. Cmwlth. 2019).
    12
    Section 108(r) establishes, as an occupational disease, “[c]ancer suffered by a firefighter
    which is caused by exposure to a known carcinogen which is recognized as a Group 1 carcinogen
    by the [IARC].” 77 P.S. § 27.1(r). Section 108(r) was added by Section 1 of the Act of July 7,
    2011, P.L. 251.
    12
    IARC Group 1 carcinogen. (Id. at 24.) He asserts that he provided uncontradicted
    scientific evidence, i.e., the testimony and opinion of Dr. Singer, and the LeMasters
    Report and other studies upon which Dr. Singer relied, showing that specific IARC
    Group 1 carcinogens are capable of causing prostate cancer. (Id. at 24-27.) Claimant
    insists that this evidence was sufficient to carry his initial burden, thus demonstrating
    that he suffered from an occupational disease. (Id. at 27.) Claimant then emphasizes
    that, by crediting Claimant’s testimony, the WCJ accepted that Claimant established
    the other elements necessary to trigger an evidentiary presumption, pursuant to
    Section 301(f) of the Act, 77 P.S. § 414,13 that his specific cancer was caused by his
    work. (Id. at 27-28.)
    Alternatively, Claimant argues that he established entitlement to the
    evidentiary presumption of compensability through Section 108(n) of the Act, 77
    P.S. § 27.1(n),14 by showing an association and causal relationship between the
    13
    Section 301(f) was added to the Act by Section 2 of the Act of July 7, 2011, P.L. 251,
    and provides, in pertinent part, as follows:
    Compensation pursuant to cancer suffered by a firefighter shall only be to those
    firefighters who have served four or more years in continuous firefighting duties,
    who can establish direct exposure to a carcinogen referred to in section
    108(r) relating to cancer by a firefighter and have successfully passed a physical
    examination prior to asserting a claim under this subsection or prior to engaging in
    firefighting duties and the examination failed to reveal any evidence of the
    condition of cancer. The presumption of this subsection may be rebutted by
    substantial competent evidence that shows that the firefighter’s cancer was not
    caused by the occupation of firefighting. . . . The presumption provided for under
    this subsection shall only apply to claims made within the first three hundred weeks
    [after the last date of employment in an occupation or industry to which a claimant
    was exposed to the hazards of disease].
    77 P.S. § 414.
    14
    Section 108(n) establishes, as occupational diseases, “[a]ll other diseases (1) to which
    the claimant is exposed by reason of his employment, and (2) which are causally related to the
    (Footnote continued on next page…)
    13
    occupation of firefighting and prostate cancer through the LeMasters Report. (Id. at
    29-30.) Claimant contends that the WCJ ignored the LeMasters Report, which was
    clear error. Finally, Claimant argues that Employer’s evidence did not identify a
    non-work-related cause of Claimant’s cancer and, therefore, was not sufficient to
    rebut the evidentiary presumption applicable under the Act. (Id. at 31-34.) He
    claims, therefore, that the WCJ and the Board erred in denying and dismissing the
    Claim Petition based on Employer’s evidence. (Id. at 35.)
    Employer responds that this Court is bound by the WCJ’s credibility
    determinations, including her decision not to credit Dr. Singer’s expert opinion, and
    cannot overturn or disturb that determination. (Employer’s Br. at 6.) Employer
    emphasizes that a showing of general causation, under Section 108(r) of the Act, is
    a necessary precondition to considering the rebuttable presumption provided in
    Section 301(f) of the Act. (Id. at 7-9.) Because the WCJ found that Claimant did
    not make the initial general causation showing, Employer argues, the rebuttable
    presumption was never truly an issue, and the burden never shifted to Employer to
    show a non-work-related cause of Claimant’s cancer. (Id. at 5.) In other words,
    Employer takes the position that, because Claimant never credibly demonstrated that
    IARC Group 1 carcinogens can cause prostate cancer, his exposure to those
    carcinogens never became relevant, even if it was credibly demonstrated. (Id. at 10.)
    Employer asserts that the WCJ did not err or abuse her discretion in declining to
    credit Dr. Singer regarding Claimant’s initial burden, and the Board did not err in
    giving deference to that credibility determination. (Id. at 12-13.) Employer does
    not address Claimant’s argument that he demonstrated occupational disease under
    Section 108(n) of the Act.
    industry or occupation, and (3) the incidence of which is substantially greater in that industry or
    occupation than in the general population. . . .” 77 P.S. § 27.1(n).
    14
    III. DISCUSSION
    To prevail on a claim petition, a claimant bears “the burden of establishing
    the right to compensation and all of the elements necessary to support an award.”
    Rife v. Workers’ Comp. Appeal Bd. (Whitetail Ski Co.), 
    812 A.2d 750
    , 754 (Pa.
    Cmwlth. 2002). Section 301(a) of the Act, 77 P.S. § 431, provides that “[e]very
    employer shall be liable for compensation for personal injury to . . . each employe,
    by an injury in the course of his employment . . . .” Section 301(c)(2) of the Act, 77
    P.S. § 411(2), defines the phrase “injury arising in the course of his employment” to
    include an “occupational disease,” as that term is defined under Section 108 of the
    Act. Thus, an injury satisfying the definition of “occupational disease” under
    Section 108 is a compensable injury under the Act. To assist claimants who assert
    they suffer from an occupational disease in demonstrating the elements necessary to
    support an award, the Act contains a generally applicable evidentiary presumption
    regarding the cause of a claimant’s occupational disease. Section 301(e) of the Act,
    77 P.S. § 413,15 provides that
    [i]f it be shown that the employe, at or immediately before the date of
    disability, was employed in any occupation . . . in which the
    occupational disease is a hazard, it shall be presumed that the employe’s
    occupational disease arose out of and in the course of his employment,
    but this presumption shall not be conclusive.
    The definition of “occupational disease” was amended by Act 46 of 201116 to add
    Section 108(r), which expanded the term “occupational disease” to include “[c]ancer
    suffered by a firefighter which is caused by exposure to a known carcinogen which
    is recognized as a Group 1 carcinogen by the [IARC].” 77 P.S. § 27.1(r). Act 46
    15
    Section 301(e) was added to the Act by Section 3 of the Act of October 17, 1972, P.L.
    930.
    16
    Act of July 7, 2011, P.L. 251, No. 46.
    15
    also added Section 301(f) of the Act, 77 P.S. § 414, which imposes additional
    conditions on the presumption of Section 301(e) as it relates to the occupational
    disease of cancer suffered by a firefighter. Under Section 301(f), a firefighter is
    entitled to benefits for the occupational disease of cancer, as defined in Section
    108(r) of the Act, provided the firefighter can show: (1) employment for four or
    more years in continuous firefighting duties; (2) direct exposure to an IARC Group
    1 carcinogen; and (3) the firefighter passed a physical examination prior to engaging
    in firefighting duties that did not reveal any evidence of cancer. 77 P.S. § 414. Once
    the claimant shows these elements and the presumption of causation applies, the
    employer can rebut the presumption through “substantial competent evidence that
    shows that the firefighter’s cancer was not caused by the occupation of
    firefighting.”17 Id.
    Importantly, when evaluating whether a claimant has met his burden under
    the Act, “[t]he WCJ is the ultimate fact finder and has complete authority for making
    all credibility” and evidentiary weight determinations. Rife, 
    812 A.2d at 755
    . It is
    well-settled that a “WCJ may reject the testimony of any witness in whole or in part,
    even if that testimony is uncontradicted.” Hoffmaster v. Workers’ Comp. Appeal Bd.
    (Senco Prods., Inc.), 
    721 A.2d 1152
    , 1156 (Pa. Cmwlth. 1998). Where the WCJ is
    required to assess the credibility of deposition testimony, the WCJ must articulate
    objective bases for crediting one witness’s deposition testimony over another
    witness’s deposition testimony. Daniels v. Workers’ Comp. Appeal Bd. (Tristate
    Transp.), 
    828 A.2d 1043
    , 1053-54 (Pa. 2003).
    17
    In addition to the three conditions discussed above, Section 301(f) requires the firefighter
    to have filed his claim within 300 weeks of his last day of employment as a firefighter in order to
    qualify for the rebuttable presumption provided in Section 301(f). Here, it is clear and undisputed
    that Claimant filed the Claim Petition within 300 weeks of his last day of employment as a
    firefighter.
    16
    A. Section 108(r) of the Act
    The Pennsylvania Supreme Court has clarified the process by which a
    claimant may avail himself or herself of the evidentiary presumption found in
    Section 301(f) based on a Section 108(r) claim. See City of Phila. Fire Dep’t v.
    Workers’ Comp. Appeal Bd. (Sladek), 
    195 A.3d 197
     (Pa. 2018) (Sladek II). In Sladek
    II, the claimant had worked for Employer as a firefighter and brought a claim petition
    seeking compensation for malignant melanoma. In support of his claim petition,
    that claimant also introduced testimony by Dr. Singer, who opined that the
    claimant’s exposure to carcinogens through his work for Employer was a substantial
    contributing factor in his development of skin cancer. Id. at 201. Dr. Singer also
    opined that malignant melanoma could be caused by the IARC Group 1 carcinogens
    arsenic and soot. Id. at 202. Employer introduced the testimony of Dr. Guidotti,
    who gave testimony very similar to his testimony in this case, criticizing Dr. Singer’s
    methodology and opinions. Unlike in the instant matter, however, the WCJ in Sladek
    II credited Dr. Singer’s testimony and opinions, declined to credit Dr. Guidotti’s
    testimony, and granted the claim petition. Id. at 202-03. The Board affirmed the
    WCJ’s decision, and Employer appealed to this Court. We vacated the Board’s
    decision and remanded for further proceedings. We held, in part, that “[i]t was
    incumbent upon [the c]laimant to prove that his malignant melanoma is a type of
    cancer caused by the Group 1 carcinogens to which he was exposed in the
    workplace” in order to establish that his cancer was an occupational disease under
    Section 108(r) of the Act. City of Phila. Fire Dep’t v. Workers’ Comp. Appeal Bd.
    (Sladek), 
    144 A.3d 1011
    , 1021-22 (Pa. Cmwlth. 2016) (en banc) (second emphasis
    added), rev’d, Sladek II. We also specifically rejected the Board’s reasoning that the
    17
    claimant met his initial burden simply by demonstrating he suffered from cancer
    generally and had been exposed to at least one IARC Group 1 carcinogen.
    Our Supreme Court reversed and remanded to the Board. Sladek II, 195 A.3d
    at 210. In so doing, the Court explained that the Act divides litigation by firefighters
    for cancer claims into “discrete stages.” Id. at 207. First, the claimant must carry
    an initial burden under Section 108(r). This initial burden, which concerns general
    causation only, is not a heavy one, and the claimant need only “establish a general
    causative link between the claimant’s type of cancer and a Group 1 carcinogen.” Id.
    at 208. “In other words, the claimant must produce evidence that it is possible that
    the carcinogen in question caused the type of cancer with which the claimant is
    afflicted.” Id. Next, the claimant must show that the claimant meets the other three
    conditions to the presumption in Section 301(f) of the Act, i.e., four or more years
    of service, direct exposure to an IARC Group 1 carcinogen, and a cancer-free
    physical exam prior to engaging in firefighting work. Id. at 207. If the claimant
    makes these showings, the claimant benefits from the presumption in Section 301(f),
    and the burden shifts to the employer to prove that the claimant’s cancer was caused
    by something other than the claimant’s work as a firefighter. Id. The Court noted
    that “epidemiological evidence is clearly relevant and useful in” evaluating general
    causation at the initial burden stage. Id. at 208.18 The Court therefore directed the
    Board on remand to determine whether Dr. Singer’s testimony satisfied the standard
    18
    A majority of our Supreme Court joined in this portion, i.e., Part I, of the Sladek II
    opinion regarding the initial burden stage. See Sladek II, 195 A.3d at 199 (“Justice Donohue
    delivers the Opinion of the Court with respect to Part I [(concerning a claimant’s initial burden of
    demonstrating an occupational disease under Section 108(r))], announces the judgment of the
    Court, and delivers an opinion with respect to Part II [(rebutting the presumption of compensability
    under Section 301(f)),] joined by Justices Baer and Todd[.]” (italics omitted)).
    18
    set forth in Frye v. United States, 
    293 F. 1013
     (D.C. Cir. 1923),19 and stated that if
    it did not, the claimant could not carry his initial burden as to general causation under
    Section 108(r) of the Act. Sladek II, 195 A.3d at 210. Crucially, for the instant case,
    the Court also noted that, even if Dr. Singer’s testimony satisfied the Frye standard,
    the fact finder was free to find “that Dr. Guidotti’s opinion is more credible on the
    question of general causation.” Id. In that situation, “the epidemiological evidence
    offered by [Employer] through Dr. Guidotti would carry the day without the burden
    of proof . . . ever shifting to [Employer] to prove specific causation.” Id.
    We recently applied the analytical framework from Sladek II in Deloatch v.
    Workers’ Compensation Appeal Board (City of Philadelphia), 
    224 A.3d 432
     (Pa.
    Cmwlth.), appeal denied, 
    237 A.3d 973
     (Pa. 2020). The claimant in Deloatch sought
    compensation for lung cancer pursuant to Sections 108(r) and 301(f) of the Act. Just
    as in Sladek II, Dr. Singer testified on behalf of the claimant, and Dr. Guidotti
    testified on behalf of Employer. Additionally, Employer presented the medical
    report of Howard Sandler, M.D., a physician specializing in occupational and
    environmental medicine, who disagreed with Dr. Singer’s conclusion that there is a
    causal link between firefighting and lung cancer. Deloatch, 224 A.3d at 436-37. Dr.
    Sandler admitted, however, that there was sufficient scientific evidence to establish
    a causal link between diesel exhaust (an IARC Group 1 Carcinogen) and lung cancer.
    Id. at 436. The WCJ declined to credit Dr. Singer’s testimony and credited Dr.
    Guidotti and Dr. Sandler’s opinions instead. Based on her decision not to credit Dr.
    Singer’s testimony about a causal connection between firefighting and cancer, the
    19
    As our Supreme Court stated in Grady v. Frito-Lay, Inc., 
    839 A.2d 1038
    , 1043-44 (Pa.
    2003), “[t]he Frye test . . . is part of [Pennsylvania Rule of Evidence] 702[, Pa.R.E. 702]. Under
    Frye, novel scientific evidence is admissible if the methodology that underlies the evidence has
    general acceptance in the relevant scientific community.”
    19
    WCJ concluded that the claimant was not entitled to the presumption in Section
    301(f) of the Act. Id. at 437. The claimant appealed to the Board, which reversed
    and remanded the matter to the WCJ. On remand, the WCJ issued a new decision
    granting the claim petition as directed by the Board, and Employer appealed to the
    Board, which reversed based on its application of Sladek II. The claimant then
    petitioned this Court for review, arguing that the Board’s second decision was in
    error. In reviewing the claimant’s arguments, we observed that, although the WCJ
    found Dr. Singer’s testimony not credible, the WCJ found that the claimant was
    exposed to IARC Group 1 carcinogens, including diesel fumes/exhaust, in the course
    of his work as a firefighter, and expressly credited Dr. Sandler’s opinion that
    independently established that one of those IARC Group 1 carcinogens (diesel
    exhaust) could cause lung cancer. Id. at 441. We also held that Employer failed to
    offer any evidence showing that diesel exhaust does not cause lung cancer. Based
    on the credited evidence, we held that the claimant had met his initial burden of
    showing general causation under Section 108(r) of the Act. Id. Thus, our decision
    in Deloatch confirms that, under Sladek II, the question of whether a claimant meets
    the initial burden of proof on general causation may be resolved solely on a WCJ’s
    credibility determinations.
    Here, Claimant argues that the WCJ and the Board imposed a burden of proof
    greater than Section 108(r) of the Act requires. He insists that he carried his initial
    burden with respect to general causation, thus demonstrating that he suffers from an
    occupational disease.      Claimant maintains that he presented Dr. Singer’s
    uncontradicted testimony as to general causation, including Dr. Singer’s direct
    opinion that certain IARC Group 1 carcinogens can cause prostate cancer. He also
    asserts that the LeMasters Report supported his claim but was ignored by the WCJ.
    20
    We disagree with Claimant’s characterization of his evidence as uncontradicted. Dr.
    Guidotti directly testified that Dr. Singer’s method for reviewing the various
    epidemiologic studies Dr. Singer cited was not a sufficient method for determining
    general causation, thereby challenging Dr. Singer’s general causation opinion. (R.R.
    at 1084-85.) More critically, the WCJ, in her discretion, did not credit Dr. Singer’s
    testimony, which was based, in part, on the LeMasters Report, and this is not subject
    to this Court’s review. See Rife, 
    812 A.2d at 755
     (“The WCJ is the ultimate fact
    finder and has complete authority for making all credibility determinations.”).
    Instead, the WCJ credited Employer’s witnesses, Dr. Guidotti and Dr. Stanford, both
    of whom disputed Dr. Singer’s general causation opinion, and Dr. Stanford’s opinion
    contradicted the LeMasters Report. (Mar. 2, 2018 WCJ Decision, FOF ¶¶ 9-10.)
    We may not disturb a WCJ’s factual findings so long as they are supported by
    substantial evidence.20 Here, Claimant does not challenge any of the findings on the
    basis they lack substantial evidence. Regardless, the WCJ’s findings are supported
    by substantial evidence.
    Moreover, the WCJ provided a reasoned explanation for her decision not to
    credit Dr. Singer’s testimony. She explained that her decision was based on Dr.
    Singer’s lack of training in epidemiology, the vagueness of his testimony, and his
    failure to identify an accepted methodology for demonstrating general, as opposed
    20
    Substantial evidence is defined as “relevant evidence that a ‘reasonable person might
    accept as adequate to support a conclusion.’” Pocono Mountain Sch. Dist. v. Workers’ Comp.
    Appeal Bd. (Easterling), 
    113 A.3d 909
    , 918 (Pa. Cmwlth. 2015) (quoting Wieczorkowski v.
    Workers’ Comp. Appeal Bd. (LTV Steel), 
    871 A.2d 884
    , 890 (Pa. Cmwlth. 2005)). When
    reviewing a WCJ decision for substantial evidence, we “must view the evidence in the light most
    favorable to the” prevailing party and draw all reasonable inferences in the prevailing party’s favor.
    
    Id.
     It is important to note that “it is irrelevant whether the record contains evidence to support
    findings other than those made by the WCJ; the critical inquiry is whether there is evidence to
    support the findings actually made.” Lahr Mech. v. Workers’ Comp. Appeal Bd. (Floyd), 
    933 A.2d 1095
    , 1101 (Pa. Cmwlth. 2007) (citation omitted).
    21
    to specific, causation. (FOF ¶ 9.) The requirement for a reasoned decision “does
    not permit a party to challenge or second-guess” a WCJ’s credibility determinations
    because “determining the credibility of witnesses remains the quintessential function
    of the WCJ as the finder of fact.” Reed v. Workers’ Comp. Appeal Bd. (Allied Signal,
    Inc.), 
    114 A.3d 464
    , 470 (Pa. Cmwlth. 2015).
    Here, unlike in Sladek II and Deloatch, none of the testimony credited by the
    WCJ, i.e., the testimony of Claimant, Dr. Weaver, Dr. Guidotti, or Dr. Stanford,
    established that any IARC Group 1 carcinogen can cause prostate cancer. As we
    have discussed, the WCJ’s decision not to credit Dr. Singer’s testimony was an
    exercise of discretion accompanied by a reasoned explanation, and it must, therefore,
    stand. We conclude that Claimant has not met his initial burden of demonstrating
    general causation under Section 108(r) of the Act, and he has not established that his
    cancer is an occupational disease under that section. Because Claimant did not meet
    this initial burden, his demonstration of the other factors under Section 301(f) of the
    Act does not entitle him to the presumption found in that section, and the Board did
    not err in declining to apply that presumption. See Sladek II, 195 A.3d at 207;
    Deloatch, 224 A.3d at 440. Accordingly, the burden never shifted to Employer to
    rebut the presumption that Claimant’s cancer was caused by his work. Sladek II,
    195 A.3d at 210.21
    21
    Because Claimant did not show that he suffers from an occupational disease, we do not
    consider his arguments concerning subsequent steps in the analytical framework laid out in Sladek
    II, including demonstration of the factors in Section 301(f) of the Act or Employer’s rebuttal of
    the presumption.
    22
    B. Section 108(n) of the Act
    Our analysis does not end here because “the inability of the firefighter to prove
    that his cancer is an occupational disease under Section 108(r) of the Act does not
    mean that he cannot pursue a claim for compensation.” Demchenko v. Workers’
    Comp. Appeal Bd. (City of Phila.), 
    149 A.3d 406
    , 419 (Pa. Cmwlth. 2016), appeal
    denied, 
    200 A.3d 940
     (Pa. 2019). Section 108(n) of the Act includes in the definition
    of occupational disease “[a]ll other diseases (1) to which the claimant is exposed by
    reason of his employment, and (2) which are causally related to the industry or
    occupation, and (3) the incidence of which is substantially greater in that industry or
    occupation than in the general population.” 77 P.S. § 27.1(n). This “catch-all
    provision” allows claimants in cancer cases to claim the general evidentiary
    presumption as to causation even if they cannot do so under Section 108(r) of the
    Act. Demchenko, 149 A.3d at 417 n.20. The presumption triggered by application
    of Section 108(n) of the Act is the general evidentiary presumption in Section 301(e)
    of the Act, which applies to all occupational diseases and to claimants in all types of
    work. Id. at 416-17, 419-20. When proceeding under Section 108(n), the claimant
    is required to prove, inter alia, that the type of cancer from which he suffers is
    “causally related to [his] industry or occupation.” 77 P.S. § 27.1(n). This is a general
    causation inquiry, which, once the elements in Section 108(n) are shown, results in
    application of the presumption in Section 301(e). See Demchenko, 149 A.3d at 419-
    20 (noting that the burden under Section 108(n) relies on “‘general causation’
    principles”).
    Claimant argues that he established that his cancer fell within this catch-all
    provision. However, Claimant’s argument under Section 108(n) of the Act lacks
    merit. We have repeatedly considered matters in which the claimant failed to obtain
    23
    the special presumption under Section 108(r) of the Act and sought relief in the
    alternative under Section 108(n). See Capaldi v. Workers’ Comp. Appeal Bd. (City
    of Phila.), 
    152 A.3d 1107
    , 1117 (Pa. Cmwlth. 2017); Demchenko, 149 A.3d at 419.
    In both of those cases, the claimant offered Dr. Singer’s testimony to show a general
    causal connection between firefighting and the type of cancer the claimant suffered,
    and the WCJ specifically rejected Dr. Singer’s testimony as to causation. Capaldi,
    152 A.3d at 1109, 1112-13; Demchenko, 149 A.3d at 409-10, 414. In both cases,
    we concluded that, because the WCJ rejected the medical evidence on which the
    claimant must rely to make a showing under Section 108(n), the claimant could not
    prevail under that section. Capaldi, 152 A.3d at 1117; Demchenko, 149 A.3d at 420.
    The same applies here, where the WCJ rejected Dr. Singer’s causation testimony.
    Accordingly, Claimant cannot demonstrate his entitlement to benefits under Section
    108(n).
    IV. CONCLUSION
    For the foregoing reasons, Claimant did not satisfy his initial burden of
    demonstrating that his cancer is an occupational disease under the Act or that his
    cancer was caused by his work and, therefore, the Board did not err in affirming the
    WCJ’s denial of the Claim Petition.
    Accordingly, we affirm the Board’s Order.
    _____________________________________
    RENÉE COHN JUBELIRER, Judge
    24
    IN THE COMMONWEALTH COURT OF PENNSYLVANIA
    Michael Malone,                         :
    Petitioner       :
    :
    v.                    :   No. 22 C.D. 2020
    :
    Workers’ Compensation Appeal            :
    Board (City of Philadelphia),           :
    Respondent     :
    ORDER
    NOW, January 6, 2021, the Order of the Workers’ Compensation Appeal
    Board, entered in the above-captioned matter, is AFFIRMED.
    _____________________________________
    RENÉE COHN JUBELIRER, Judge