Risk of subsequent cancers in renal cell carcinoma survivors with a family history

Background: This study aimed at elucidating the effect of family history on the development of subsequent cancers in renal cell carcinoma (RCC) survivors and aimed at assessing whether the interactions between risks of subsequent cancers in RCC survivors and familial risk of subsequent cancer are additive or multiplicative interactions. Methods: A population-based cohort (Swedish Family-Cancer Database) of 14,267 RCC patients diagnosed in 1990-2010 was followed for cancer incidence. Standardised incidence ratios (SIRs) were calculated for subsequent cancers in RCC survivors and in RCC survivors with a family history of subsequent cancer. Familial risk of subsequent cancer was calculated for individuals with family history of specific cancer, compared to those without. Results: For subsequent hemangioblastoma (HB) in RCC survivors, drastically elevated risk was observed for the effect of family history of HB [SIR = 777 (95% confidence interval (CI): 160-2270)] and of family history of RCC [378 (46-1367)]. Colorectal, lung, prostate and RCCs favoured additive interactions between risk of subsequent cancers in RCC survivors and familial risk, while endocrine glands, nervous system and urinary bladder cancers favoured multiplicative interactions. Conclusions: Risks of subsequent HB in RCC survivors were tremendously modified by family history of RCC or HB, which may resemble characteristics of von Hippel Lindau syndrome and show the power of present approach to detect heritable cancer clusters. Additive or multiplicative interactions found for colorectal, lung, prostate, endocrine glands, nervous system, urinary bladder and RCCs might raise awareness among clinicians and RCC survivors with a family history of seven cancers about elevated risks of subsequent those cancers. (C) 2014 Elsevier Ltd. All rights reserved.