['The objective of the present study was to investigate the relationship between colorectal and prostate cancer.', 'All Victorian men who developed metachronous colorectal and prostate cancer with the first primary diagnosed between 1982 and 1993 were identified retrospectively from the Victorian Cancer Registry and were followed up to the end of 1995. Analyses were stratified by age group and years of follow up. The cause of death in those men who had prostate cancer following colorectal cancer was determined. The stage of colorectal cancer was compared between men with and without second primary prostate cancer and the grade of prostate cancer was compared with men who did not have a prior colorectal cancer.', 'Men who develop colorectal cancer are at increased risk of prostate cancer, with the greatest risk in men under the age of 65 (Relative risk approximately 2). Men with first primary colorectal cancer are more likely to develop prostate cancer than colorectal second primaries, and men who develop second primary prostate cancer are more likely to die of prostate cancer than colorectal cancer.'] Are men with colorectal cancer predisposed to prostate cancer?