Occupation and the risk of prostate cancer in Northeastern Ontario

Transcription

1 Occupation and the risk of prostate cancer in Northeastern Ontario Jeavana Sritharan,Paul A. Demers, Shelley A. Harris, Donald C. Cole, Nancy Kreiger, Andrea Sass Kortsak, Nancy Lightfoot Occupational Cancer Research Centre, Cancer Care Ontario, University of Toronto, Laurentian University CSEB June 1 4 th, 2015

2 Prostate Cancer Second most common cancer worldwide Most commonly diagnosed cancer in 84 nations including Canada

3 Prostate Cancer Risk Factors Well established risk factors Age, family history, ethnicity Poor understanding of etiology No established occupational risk factors

4 Prostate Cancer & Occupation Nearly 60 occupational exposures have been classified as definite or probable cancer causing agents A number of occupational risk factors for prostate cancer have been studied with mixed results Slight elevated risks in farmers/farm workers associated with pesticide exposures Inconsistent findings for workers in mining, logging/forestry, mechanics Inconsistent findings for workers exposed to metals, PAHs, and PCBs

5 Objective This study investigates the risk of prostate cancer among Canadian workers in agriculture, logging and forestry, and mining industries Outcome: prostate cancer diagnosis Exposures: occupation or industry group

6 Northeastern Ontario

7 Methods Cases (n=760) Men aged years Diagnosed between Jan 1995 and Dec 1998 Primary histologically confirmed prostate cancer Identified in the Ontario Cancer Registry Resident of Northeastern Ontario Consent from physician first then telephone contact Controls (n=1632) Randomly selected from Northeastern Ontario via telephone listings 2:1 frequency matched to cases based on five year age groups

8 Methods Cases and controls completed a 25 page questionnaire Diet Cigarette smoking Recreational physical activity Socio demographic information Family history of cancer Occupational history

9 Methods Odds ratios (OR) and 95% Confidence Intervals were estimated for those ever employed based on: 1991 Canadian Standard Occupational Classification (SOC) 1980 Canadian Standard Industrial Classification (SIC) Adjustments made for age and family history of prostate cancer No adjustment made for ethnicity as over 97% of the study population were Caucasian

10 Results: Demographics Cases more frequently reported a family history of prostate cancer (OR 2.88, 95% CI )

11 Table 1. Odds Ratio Estimates and 95% CI for Agriculture Workers (Ever Exposed) # Cases # Controls OR (95% CI) * Agriculture Industries ( ) Livestock, Field Crop and Horticultural Combination Farms ( ) Dairy Farms ( ) Cattle Farms ( ) Agriculture Occupations Results: Agriculture General Farm Workers ( ) Farmers and Farm Managers ( ) *adjusted for age and family history of prostate cancer

12 Results: Logging and Forestry Table 2. Odds Ratio Estimates and 95% CI for Logging and Forestry Workers (Ever Exposed) # Cases # Controls OR (95% CI) * Logging Industry ( ) Logging Industry (Except Contract Logging) ( ) Logging and Forestry Occupations Chain saw and Skidder Operators ( ) Silviculture and Forestry Workers ( ) Logging and Forestry Labourers ( ) Supervisors, Forest Products Processing ( ) *adjusted for age and family history of prostate cancer

13 Results: Wood and Paper Table 3. Odds Ratio Estimates and 95% CI for Wood and Paper Workers (Ever Exposed) # Cases # Controls OR (95% CI) * Wood and Paper Industries ( ) Sawmill and Planing Mill Products Industry (Except Shingles and Shakes) ( ) Newsprint Industry ( ) Pulp Industry ( ) Wood and Paper Occupations Sawmill Machine Operators ( ) Labourers in Wood, Pulp and Paper Processing ( ) Papermaking and Finishing Machine Operators ( ) *adjusted for age and family history of prostate cancer

14 Results: Mining Table 4. Odds Ratio Estimates and 95% CI for Mining Workers (Ever Exposed) # Cases # Controls OR (95% CI) * Mining Industries ( ) Nickel Copper Mines ( ) Gold Mines ( ) Uranium Mines ( ) Iron Mines ( ) Copper and Copper Zinc Mines ( ) Mining Occupations Underground Production and Development Miners ( ) Underground Mine Service and Support Workers ( ) Mine Labourers ( ) Supervisors, Mining and Quarrying ( ) Drillers and Blasters Surface Mining, Quarrying and Construction ( ) *adjusted for age and family history of prostate cancer

15 Discussion Limitations Response bias, self reported Small population sample Limited to the Northeastern Ontario region Strengths Population study Multiple variables available Lifetime occupational history

16 Future Directions Analysis of other factors for occupation physical activity and smoking Currently grouping occupations and industries based on exposure and type of job Analysis of expert assessed exposure estimates Comparison of findings to other Canadian population studies

17 Acknowledgements Thank you to the OCRC Staff and our funding source, the Canadian Cancer Society