Risk of Urinary Tract Cancers Following Kidney or Ureter Stones

Abstract

pelvidureter cancer (SIR = 2.5; 95% GI = 1.8-3.3) and bladder cancer (SIR = 1.4; 95% CI = 1.3-1.6) were observed, but the SIRS for women were more than twice those for men. Risks varied little by age or duration of follow-up. Risks of renal pelvidureter cancer and bladder cancer among patients with an associated diagnosis of urinary tract infection were more than double those among patients without such infection, although the risks were significantly elevated in both groups. Conclusions: Individuals hospitalized for kidney or ureter stones are at increased risk of developing renal pelvidureter or bladder cancer, even beyond 10 years of follow-up. Chronic irritation and infection may play a role, since kidney or ureter stones were located on the same side of the body as the tumors in most patients with renal pelvidureter cancer evaluated in our study. Editorial Comment: First, it was vasectomy and its possible association with subsequent coronary artery disease, and now it is urolithiasis leading to urothelial cancer. While the former raised a furor later calmed by additional studies, this most recent finding remains unchallenged. Although squamous cell cancer of the renal pelvis has been related to a history of urolithiasis, this study is possibly the first to link stone disease and transitional cell cancer. The data hold up even if one were to eliminate all patients with tumors discovered during the first year after a stone episode, that is concurrent disease states, or patients with tumors found only at autopsy, that is clinically silent tumors. Notably, there was no increase in renal cell or lung cancer in this patient group, suggesting that the findings cannot be attributed to a generalized renal problem or other confounding problems, such as smoking or job related risks. Also of interest, in 75% of the patients the tumor and stone were located on the same side, again invoking the argument that tumor formation was possibly due to local irritation from the stone. Lastly, the risk of urothelial tumor formation remained as long as 10 years after the initial stone event. The bottom line question is whether radiographic or cystoscopidcytology surveillance is indicated in all patients with stones to detect renal pelvidureteral or bladder tumors in 0.14 and 0.62%, respectively. This article has made me more aware but I am not planning to expand my followup of urolithiasis beyond that of urinalysis and a plain radiograph of the abdomen at routine intervals. Ralph V. Clayman, M.D.