Case-control study of occupation and cancer of the prostate in New Zealand.

A New Zealand Cancer Registry based case-control study involved 617 male patients with prostate cancer registered during 1979 and aged 20 years or more at the time of registration. Controls were also males chosen from the Cancer Registry with two controls per case, matched on age and year of registration. There was an elevated risk in the upper social class groupings. The data did not support the findings, from other countries, of elevated risks in agricultural workers (odds ratio = 1.08, 90% confidence limits 0.86-1.36). The only occupational groups showing elevated risks were sales and service workers (odds ratio = 1.29, 90% confidence limits 0.99-1.69) and teachers (odds ratio = 2.44, 90% confidence limits 1.05-5.70). The New Zealand data do not in general suggest that occupational factors--or lifestyle factors associated with occupation--are of major direct importance in the aetiology of prostate cancer.