Incidence of Cancer in Finnish Families with Clinically Aggressive and Nonaggressive Prostate Cancer

Background: Clinical features of familial prostate cancer (PCa) and other malignancies associated with PCa are poorly described. Using a large family-based data registry of histologically confirmed cancers with a 40-year follow-up, we sought to determine incidence of cancer in Finnish PCa families, separately for clinically aggressive and clinically nonaggressive PCa. Methods: We calculated standardized incidence ratios (SIR) for 5,523 members of 202 families by dividing the number of observed cancers (altogether 497 cases) by the number of expected cancers. The number of expected cancers is based on the national cancer incidence rates. Results: SIR for overall cancer risk, excluding PCa, for male relatives in clinically nonaggressive families was 0.7 [95% confidence interval (95% CI), 0.6-0.8] and in clinically aggressive families 0.8 (95% CI, 0.6-1.0). The respective SIRs for women were 1.0 (95% CI, 0.8-1.1) and 1.1 (95% CI, 0.8-1.3). The incidence of lung cancer among men was significantly lower than in the general population. The SIR for gastric cancer among women was 1.9 in both clinically nonaggressive and clinically aggressive families. In clinically aggressive families, there was borderline significant excess of cancer of the gallbladder in men and liver cancer in women. Conclusions: The incidence of non-PCa cancers is not increased in clinically aggressive or clinically nonaggressive PCa families except for stomach cancer among women. (Cancer Epidemiol Biomarkers Prev 2009;18(11):3049–56)