A retrospective cohort study of cancer incidence among New York State Farm Bureau members.

Cancer incidence from 1973 through 1983 in 18,811 New York Farm Bureau members was examined using a retrospective cohort study design. The observed number of cancers for all age groups was 72% of the expected, and the major deficits in incidence occurred for lung (52% of expected), gastrointestinal (67% of expected), and bladder (78% of expected). Similar deficits have been reported by other researchers. Unlike other studies, we did not find a significant excess of cancer of any site. Given the healthy worker effect and the small numbers of incident tumors at some sites, the Standardized Cancer Incidence Ratios that were over 100 in value (i.e., lip, melanoma of the skin, prostate, multiple myeloma) merit further investigation. This study differs from previous research in population, setting, and method. Nonetheless, the general pattern of results is consistent with the findings of other investigations.