Cancer risk in farmers: results from a multi-site case-control study in north-eastern Italy

The relationship between farming and cancer risk was investigated in an integrated series of case-control studies conducted from 1985 to 1991 in the Friuli Venezia Giulia region, north-east Italy. Patients with cancer of the oral cavity and pharynx, larynx, oesophagus, colon and rectum, pancreas, breast, thyroid gland, kidney and urinary tract, bladder, prostate, soft-tissue sarcomas, Hodgkin's diseases, non-Hodgkin's lymphomas and multiple myelomas, and controls admitted to hospital for acute, non-neoplastic conditions, were interviewed. For males, a significantly elevated relative risk was seen for oral cavity and pharynx. Farming, however, was associated with a significant protection against cancer of the colon and rectum and bladder. In females, only one significant association emerged, for multiple myeloma. A few significant interactions between cancer risk and year of birth (i.e., before 1930 or 1930 and after) were observed. The risk of cancer of the larynx was significantly elevated in younger male farmers but not in older ones. Our multi-site case-control study confirms that farmers have, for some cancer sites, a distinctive pattern. Excesses of cancer of the oral cavity and pharynx in farmers are characteristic of the present study area and, possibly, of similar European rural populations who have in common high levels of alcohol consumption and, at least in the past, unbalanced diets.