Association of Single Nucleotide Polymorphisms in STAT3, ABCB1, and ABCG2 with Stomatitis in Patients with Metastatic Renal Cell Carcinoma Treated with Sunitinib: A Retrospective Analysis in Japanese Patients.

Signal transducer and activator of transcription (STAT) 3 is a key factor in homeostasis of the oral mucosa by regulating the production of inflammatory cytokines. Sunitinib is a substrate of P-glycoprotein (multidrug resistance (MDR)-1/ABCB1) and breast-cancer resistance protein (BCRP/ABCG2). In this retrospective study, we evaluated the association between sunitinib-induced stomatitis and STAT3, ABCB1, and ABCG2 polymorphisms in patients with metastatic renal cell carcinoma (mRCC). Fifty-two Japanese patients with RCC treated with sunitinib were retrospectively genotyped to elucidate a potential association between STAT3, ABCB1, and ABCG2 polymorphisms and stomatitis development. Stomatitis occurred in 22 out of 52 patients. The TT+TC genotypes at STAT3 rs744166 had an odds ratio of 5.00 against CC genotype for the stomatitis development (95% confident interval, 0.97-25.8). In the Kaplan-Meier method for the cumulative incidence of stomatitis, a statistically significant difference was observed between the TT+TC and CC genotypes in STAT3 rs744166 (p=0.037). Both multiple logistic regression analysis and Cox proportional-hazards regression analysis show STAT3 rs744166 TT+TC genotypes and serum creatinine in each patient were significant independent factors for stomatitis development. In conclusion, STAT3 polymorphism may be a novel risk factor for sunitinib-induced stomatitis in patients with mRCC.