Urinary infection, renal lithiasis and bladder cancer in Spain.

A case-control study on bladder cancer was carried out in 12 hospitals located in 4 regions of Spain. The study included 497 cases and 530 population controls, matched by sex, age and residence. The present paper reports the results regarding the risk for bladder cancer in relation to history of infections and lithiasis of the urinary tract. Increased risk was found for infections starting 4 years or less before diagnosis (OR = 15.00; 95% CL: 6.07-51.66) but no statistically significant increase in risk was observed for infections starting 5 or more years before (OR = 1.44; 95% CL: 0.86-2.47). Our data suggest that the association of urinary infections with bladder cancer is probably not causal and is more likely to be a consequence of cancer, although a weak causal association cannot be excluded. A small but not statistically significant increase in risk was found to be associated with a history of renal lithiasis.