Kidney stones and the risk of renal cell carcinoma and upper tract urothelial carcinoma: the Netherlands Cohort Study

BACKGROUND: We examined the association between kidney stones and renal cell carcinoma (RCC) and upper tract urothelial carcinoma (UTUC) risk in the Netherlands Cohort Study on diet and cancer. METHODS: In total, 120,852 participants aged 55-69 completed a self-administered questionnaire on diet, medical conditions and other risk factors for cancer at baseline (1986). After 20.3 years of cancer follow-up 4352 subcohort members, 544 RCC cases and 140 UTUC cases were eligible for case-cohort analysis. Hazard ratios (HR) and 95% confidence intervals (CIs) were estimated by multivariable-adjusted proportional hazards models. RESULTS: Kidney stones were associated with an increased RCC risk (HR: 1.39, 95% CI 1.05-1.84), vs. no kidney stones. Kidney stones were associated with an increased risk of papillary RCC (HR: 3.08, 95% CI 1.55-6.11), but not clear-cell RCC (HR: 1.14, 95% CI 0.79-1.65). UTUC risk was increased for participants with kidney stones (HR: 1.66, 95% CI 1.03-2.68). No heterogeneity of associations was found for UTUC in the ureter and renal pelvis. An early kidney stone diagnosis (<= 40 years) was associated with an increased RCC and UTUC risk, compared to later diagnosis. CONCLUSION: Kidney stones were associated with increased papillary RCC risk, but not clear-cell RCC risk. No heterogeneity was found for UTUC subtypes.