WORKPLACE SAFETY AND INSURANCE APPEALS TRIBUNAL DECISION NO. 403/12R2

Transcription

1 WORKPLACE SAFETY AND INSURANCE APPEALS TRIBUNAL DECISION NO. 403/12R2 BEFORE: G. Dee: Vice-Chair HEARING: January 12, 2015 Written Post-Hearing activity completed on April 19, 2016 DATE OF DECISION: June 16, 2016 NEUTRAL CITATION: 2016 ONWSIAT 1598 DECISION(S) UNDER APPEAL: WSIB Appeals Resolution Officer decision dated October 15, 2009 APPEARANCES: For the worker: For the employer: Interpreter: D. Wilken, Lawyer Not participating N/A Workplace Safety and Insurance Appeals Tribunal Tribunal d appel de la sécurité professionnelle et de l assurance contre les accidents du travail 505 University Avenue 7 th Floor 505, avenue University, 7 e étage Toronto ON M5G 2P2 Toronto ON M5G 2P2

2 Decision No. 403/12R2 REASONS (i) Issues [1] The worker seeks entitlement for multiple myeloma as a result of his work as a roofer. (ii) Background [2] Findings of fact in this appeal were made in interim Decision No. 403/12I. [3] Following referral to a medical assessor the original Panel in this matter issued Decision No. 403/12 that denied the worker s appeal. This decision was set aside in Decision No. 403/12R and a second referral to a medical assessor was conducted. [4] The second medical assessor who reviewed the circumstances of the worker s appeal was Dr. Mark Minden of the Princess Margaret Cancer Centre who amongst his many other qualifications is Chair in Leukemia Research at the Princess Margaret Hospital and an ad hoc reviewer for the National Cancer Institute of the United States. [5] When the referral was made to Dr. Minden the facts as established in Decision No. 403/12I were accepted by me for the purpose of the referral. The information provided to Dr. Minden did not include the first medical assessor s opinion given the findings made in Decision No. 403/12R. [6] After the start of the reconsideration process the worker died. The worker s appeal was continued by his estate. [7] An opinion was received from Dr. Minden and the representative of the worker s estate was provided with the opportunity to make submissions with respect to that opinion. [8] The opinion of Dr. Minden is supportive of a conclusion that the worker s multiple myeloma resulted from his workplace exposures. (iii) Analysis [9] I have no reason not to accept the opinion that has been provided by the very highly qualified Dr. Minden. I therefore accept the opinion and allow the appeal. [10] The doctor s opinion is reproduced below. (iv) Dr. Minden s report [11] Dr. Minden s report states as follows: Questions posed: 1. Dose (sic) Benzene exposure cause or contribute to the development of multiple myeloma? Based upon my reading of the current literature I would conclude that benzene in a time and dose dependent manner can increase the risk of developing multiple myeloma. Was the exposure described by the Panel sufficient in intensity and duration to cause the worker's multiple myeloma? I believe that the 40 year exposure that this gentleman had to workplace benzene, petroleum products and fumes was sufficient to cause multiple myeloma. There is clearly a time and dose dependent effect from the reported studies. For lymphoid diseases such

3 Page: 2 Decision No. 403/12R2 as myeloma and lymphoma the literature indicates that prolonged exposure is required to produce disease (1). Is this medically likely? I believe this to be medically likely. Benzene exposure has been linked to the development of acute myeloid leukemia (AML), multiple myeloma (MM) and chronic lymphocytic leukemia (CLL)(2). Interestingly no link to diffuse large B-cell lymphoma (DLBCL) has been noted. For AML, MM and CLL a dose and time relationship has been observed. In terms of biology both CLL and MM are diseases of mature B cells (3). The nature of disease causing mutations in AML, CLL and MM are different from those found in DLBCL which may account for the different spectrum of cancers associated with benzene. Please comment on the risk of benzene exposure through cigarette smoking? The level of benzene in cigarette smoke is much less than the worker was exposed to. Furthermore there is no association between smoking and the development of multiple myeloma, Andreotti et al (4, 5). 2. Please review the literature cited in the reports of Dr. Kerin and Dr. Patel and comment on its reliability, validity and relevance to this case? I believe there are more reputable articles than the two provided by Dr. Kerin. As for the Wong paper provided by Dr. Kerin I believe there is a flaw in using cause of death as a means of collecting such data. The reason for this is that death certificates have no review for accuracy or completeness. It is not clear in the Wong and Raabe paper whether myeloma was recorded as primary cause of death or any cause of death. Furthermore, Wong and Raabe worked for Mobil and so have a potential conflict of interest. As for the papers provided by Dr. Patel, overall they support the contention that prolonged benzene exposure causes MM. Certainly the review published by Bergsagel et al should be discounted not only for the obvious conflict of interest of the authors but the lack of rigor applied (6). In table 2 the data would suggest an association, while they claim it does not. Furthermore they comment on small studies where 1 out of 594 individuals and 1 out of 59 individuals exposed to benzene develop MM. They conclude that this does not support on association. This demonstrates lack of scientific thought in a relatively uncommon disease that has an incidence in the 70 year old age group of about 45 in 100,000. Furthermore this paper focused on death due to MM and not cancer registry information and as noted above death certificate information can be inaccurate for a variety of reasons. If there is controversy in the literature please indicate which is the most reflective of the current state of scientific knowledge and why? See 3 below. lf there is inconsistency of views of equal weight please advise on this and explain why? See 3 below. 3. Have there been more recent studies that relate to multiple myeloma and benzene? Included in the most recent brief is a paper by Stenehjem et al that demonstrates a relationship between benzene exposure and MM(2). In addition, and missing from the prior reports and the current package are the World Health Organization IARC (International Agency for Research on Cancer) reports of 2012 and 2014 in which that group linked benzene exposure to the development of MM. Other papers that support the association of benzene with causation of MM are referenced below (7-9). The controversial and moving nature of this field is illustrated by the publication of Iafante in which the IARC in their 2009 monograph did not consider benzene causative for AML, while in latter publications from this group and others, a clear causation is recognized (10). It is my opinion that the difficulty in showing an association of benzene with

4 Page: 3 Decision No. 403/12R2 causation of myeloma relates to the methodology that has been used over time and the inconsistency in classification of disease. Furthermore the long exposure that appears to be required for causing myeloma complicates studies due to poor record keeping, individuals changing jobs, and problems with case identification. 4. Please provide any other medical information that you would think would be helpful? I have included the paper indicating that smoking is not associated with the development of MM. Reference List (1) Sergentanis TN, Zagouri F. Tsilimidos G, Tsagianni A. Tseliou M, Dimopoulos MA. et al. Risk Factors for Multiple Myeloma: A Systematic Review of Meta-Analyses. Clin Lymphoma Myeloma Leuk 2015;l5: (2 ) Stenehjem JS, Kjaerheim K. Bratveit M, Samuelsen SO, Barone-Adesi F, Rothman N, et al. Benzene exposure and risk of lymphohaematopoietic cancers in offshore oil industry workers. Br J Cancer 2015;112: (3) Morton LM, Slager SL, Cerhan JR, Wang SS. Vajdic CM, Skibola CF. et al. Etiologic heterogeneity among non-hodgkin lymphoma subtype: the InterLymph Non-Hodgkin Lymphoma Subtypes Project. J Natl Cancer Inst Monogr 2014;2014: (4) Andreotti G, Birmann BM, Cozen W, De Roos AJ, Chiu BC, Costas L, et al. A pooled analysis of cigarette smoking and risk of multiple myeloma from the international multiple myeloma consortium. Cancer Epidemiol Biomarkers Prev 2015; 24: (5) Psaltopoulou T, Sergentanis TN, Kanellias N, Kanavidis P, Terpos E, Dimopoulos MA. Tobacco smoking and risk of multiple myeloma: a meta-analysis of 40 observational studies. Int J Cancer 2013; 132: (6) Bergsagel DE, Wong 0, Bergsagel PL, Alexanian R, Anderson K, Kyle RA, et al. Benzene and multiple myeloma: appraisal of the scientific evidence. Blood 1999; 94:l (7) Costantini AS, Benvenuti A, Vineis P. Kriebel D, Tumino R, Ramazzotti V. et al. Risk of leukemia and multiple myeloma associated with exposure to benzene and other organic solvents: evidence from the Italian Multicenter Case-control study. Am J Ind Med 2008;51 : (8) Lincz LF, Scorgi FE, Robertson R, Enno A. Genetic variations in benzene metabolism and susceptibility to multiple myeloma. Leuk Res 2007;3l : (9) Infante PF. Benzene exposure and multiple myeloma: a detailed meta-analysis of benzene cohort studies. Ann N Y Acad Sci 2006;1076: (10) Infante PF. The IARC October 2009 evaluation of benzene carcinogenicity was incomplete and needs to be reconsidered. Am J Ind Med 2011;54:

5 Page: 4 Decision No. 403/12R2 DISPOSITION [12] The worker s appeal is allowed. [13] The worker has entitlement for multiple myeloma. DATED: June 16, 2016 SIGNED: G. Dee