Perceived susceptibility to developing cancer and screening for colorectal and prostate cancer: A longitudinal analysis of Alberta's Tomorrow Project.

INTRODUCTION To assess the association between perceived susceptibility of developing cancer and being screened via sigmoidoscopy/colonoscopy and prostate-specific antigen, respectively. METHODS Participants aged 35-69, who resided in Alberta, Canada, were enrolled into the study between 2000 and 2008. We used general linear mixed models, adjusted for age, marital status, work status, education, family history and place of residence, to explore the association. RESULTS Perceived susceptibility of developing cancer was associated with both screening tests at baseline and a maximum of 14-year follow-up: (i) colorectal cancer screening - adjusted odds ratios were 1.97 (95% CI = 1.52-2.55) per one-unit increase in participants' personal belief in susceptibility to cancer, and 1.03 (95% CI = 1.00-1.04) per one-percent increase in participants' estimate of their own chance of developing cancer; (ii) prostate cancer screening - adjusted odds ratios were 1.36 times greater (95% CI = 1.07-1.72), and 1.02 times higher (95% CI = 1.01-1.03), for each respective perceived susceptibility measure. CONCLUSION Health promotion can focus on targeting and heightening personal perceived susceptibility of developing cancer in jurisdictions with low screening rates for colorectal or prostate cancer.