Better survival of renal cell carcinoma in patients with inflammatory bowel disease

BACKGROUND Immunosuppressive therapy may impact cancer risk in inflammatory bowel disease (IBD). Cancer specific data regarding risk and outcome are scarce and data for renal cell carcinoma (RCC) are lacking. We aimed(1) to identify risk factors for RCC development in IBD patients (2) to compare RCC characteristics, outcome and survival between IBD patients and the general population. METHODS A PALGA (Dutch Pathology Registry) search was performed to establish a case group consisting of all IBD patients with incident RCC in The Netherlands (1991-2013). Cases were compared with two separate control groups: (A) with a population-based IBD cohort for identification of risk factors (B) with a RCC cohort from the general population to compare RCC characteristics and outcomes. RESULTS 180 IBD patients with RCC were identified. Pancolitis (OR 1.8-2.5), penetrating Crohn's disease (OR 2.8), IBD related surgery (OR 3.7-4.5), male gender (OR 3.2-5.0) and older age at IBD onset (OR 1.0-1.1) were identified as independent risk factors for RCC development. IBD patients had a significantly lower age at RCC diagnosis (p < 0.001), lower N-stage (p = 0.025), lower M-stage (p = 0.020) and underwent more frequently surgical treatment for RCC (p < 0.001) compared to the general population. This translated into a better survival (p = 0.026; HR 0.7) independent of immunosuppression. CONCLUSIONS IBD patients with a complex phenotype are at increased risk to develop RCC. They are diagnosed with RCC at a younger age and at an earlier disease stage compared to the general population. This translates into a better survival independent of immunosuppressive or anti-TNFα therapy.