Arsenic, syphilis, and cancer of the prostate.

A study was conducted to investigate the association of cancer of the prostate with historical records of previous venereal disease and treatment with arsenical drugs. Eighty-three cancer cases were each age matched with two male controls--one with benign prostatic hypertrophy and one other non-cancer patient. Analysis from pooled data showed a statistically significant difference for syphilis infection between cases and controls at p less than 0.05; odds ratio 2.9. Matched pair analysis maintained p less than 0.05 significance for the first control group but odds ratios were 5.5 and 2.75 in respect of control groups 1 and 2. The mean age at which venereal infection was acquired was higher for syphilis than for gonorrhoea, but the mean age at diagnosis of cancer was younger for the syphilis group; there was a statistically significant difference between the mean at cancer diagnosis of those who had syphilis and those who had no record of previous venereal infection (t = 2.18, df 70, p less than 0.05). No association was demonstrated for history of treatment with arsenical drugs.