Stage of diagnosis of prostate, breast and colorectal cancer in farm residents compared with other rural and urban residents in New South Wales

Objective To determine if stage at diagnosis of prostate, breast and colorectal cancers differs between farm, rural non-farm and urban residents. Design Data linkage of baseline survey information from a large cohort study, with state cancer registry records from 2006 to 2009. Setting New South Wales, Australia. Participants New South Wales residents enrolled in the 45 and Up Study cohort. Main outcome measures Adjusted odds ratio of non-localised cancer stage was modelled using binary logistic regression, controlling for commonly known cancer risk factors. Results Overall differences in the odds ratios for later stage prostate, breast and colorectal cancer diagnosis in farm men and women compared with rural non-farm and urban counterparts were not statistically significant, although farm men had twice the odds of either group of being diagnosed at later stage colorectal cancer. The odds of later stage prostate cancer for farm and urban men were similar, but rural non-farm men were significantly less likely than urban men to be diagnosed at later stage. Higher household income was associated with later stage breast and prostate cancer; and private health insurance with extras was negatively associated with later stage prostate cancer. Conclusions Differences in stage of cancer diagnosis, particularly between farm and rural non-farm men, remain unexplained but were not statistically significant. Farm men may be at higher risk of later stage colorectal cancer diagnosis, which if confirmed has implications for research on possible reasons, and for the delivery of appropriate cancer diagnostic services in rural areas.