Purpose: Familial risks in papillary renal cell carcinoma and association with second primary malignancies were studied using the nationwide Swedish Family Cancer Data Base.
Materials and methods: Cancer data obtained from the Swedish Cancer Registry from 1961 to 1998 included 1,733 cases of papillary renal cell carcinoma. The standardized incidence ratio was used to measure cancer risk.
Results: Only 5 families were identified in which a parent had papillary renal cell carcinoma and an offspring had kidney cancer (nonsignificant SIR 1.51 for offspring). Discordant tumor sites associated with papillary renal cell carcinoma in the 2 generations were the upper aerodigestive tract and bladder (SIR 2.53, 95% CI 1.08 to 4.58 and 2.14, 95% CI 1.02 to 3.68, respectively). There was an overall increase in the risk of second primary malignancies of the lung, prostate and bladder and for non-Hodgkin's lymphoma and leukemia in patients with papillary renal cell carcinoma. The risk for a second primary tumor of the bladder associated with papillary renal cell carcinoma during the followup of 1 to 10 years was about 15 times higher than that associated with adenocarcinoma, which is the most common histological type of kidney cancer. The SIR was significantly higher in females than in males (59.67, 95% CI 40.23 to 82.94 versus 18.76, 95% CI 14.51 to 23.56).
Conclusions: In addition to the familial association of these 2 cancer sites, the high risk of a second primary cancer of the bladder in patients with papillary renal cell carcinoma may reflect a common genetic alteration.