The risk of kidney cancer in patients with kidney stones: a systematic review and meta-analysis

Background: The objective of this meta-analysis was to evaluate the association between a history of kidney stones and kidney cancer. Methods: A literature search was performed from inception until June 2014. Studies that reported odds ratios or hazard ratios comparing the risk of renal cell carcinoma (RCC) and transitional cell carcinoma (TCC) of the upper urinary tract in patients with the history of kidney stones versus those without the history of kidney stones were included. Pooled risk ratios (RRs) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method. Result: Seven studies were included in our analysis to assess the association between a history of kidney stones and RCC. The pooled RR of RCC in patients with kidney stones was 1.76 (95% CI, 1.24-2.49). The subgroup analysis found that the history of kidney stones was associated with increased RCC risk only in males (RR, 1.41 [95% CI, 1.11-1.80]), but not in females (RR, 1.13 [95% CI, 0.86-1.49]). Five studies were selected to assess the association between a history of kidney stones and TCC. The pooled RR of TCC in patients with kidney stones was 2.14 (95% CI, 1.35-3.40). Conclusion: Our study demonstrates a significant increased risk of RCC and TCC in patients with prior kidney stones. However, the increased risk of RCC was noted only in male patients. This finding suggests that a history of kidney stones is associated with kidney cancer and may impact clinical management and cancer surveillance.