Familial risk of urological cancers: data for clinical counseling

Familial risks for cancer are important for clinical counseling and understanding cancer etiology. The nationwide Swedish Family-Cancer Database includes all Swedes born in 1932 and later (0 to 68-year-old offspring) with their parents, totaling over 10.2 million individuals. Urological cancer cases were retrieved from the Swedish Cancer Registry up to year 2000. Standardized incidence ratios (SIR) and 95% confidence limits (CI) were calculated for age-specific familial risk in offspring by an exact proband status. The familial risks for offspring cancer were increased at all urological sites from concordant cancer in the parent and in a sibling proband. The highest SIRs by parent were for testicular and prostate cancer (4.26 and 2.45). When a sibling was affected, even kidney cancer (4.74) showed a high SIR. For kidney cancers, and also for prostate and testicular cancers, the SIRs were higher among siblings than among offspring and parents, which may indicate the involvement of recessive effects. Family members of patients with prostate cancer or von Hippel Lindau disease can expect organized clinical counseling, but family members of patients with other urological cancers are probably not counseled. Guidelines for clinical counseling or action level should be developed for all urological cancers because of the established familial risks. Urological cancers also offer a challenge to molecular geneticists attempting to identify the susceptibility genes underlying the familial clustering.