Urinary tract carcinoma in patients with analgesic nephropathy.

In 19 patients with analgesic nephropathy followed at 6- to 8- month intervals during the past 8 years (average follow-up time 5.1 years), 2 patients developed cancer of the urinary tract. Both patients had heavy consumption of analgesic for more than 25 years, however, they had stopped its use 4 and 8 years ago, respectively. The incidence of bladder tumors in the province of New Brunswick is noted to be 28 per 100,000 population for 5 years. The occurrence of carcinoma in 2 patients in a group of 19 patients with analgesic abuse suggests an association.