Morphologic evidence that analgesic-induced kidney pathology contributes to the progression of tumors of the renal pelvis.

BACKGROUND

Whether phenacetin-containing analgesics cause renal pelvic tumors by virtue of the weak mutagenicity of phenacetin, or indirectly through local effects of analgesic-induced renal papillary scarring, is debated. Because phenacetin consumption ceased in New South Wales, Australia in 1975, cases of renal pelvic carcinoma seen 14-15 years later (many of which were associated with long-standing analgesic-induced renal papillary pathology) provided an opportunity to examine the temporal relation between phenacetin exposure and those histologic characteristics of the tumors and adjacent renal tissue that may implicate analgesics in their etiology.

METHODS

The authors conducted a "blinded" histopathologic review of tumors of the renal pelvis and adjacent noncancerous renal tissue from 100 cases for which epidemiologic data regarding risk factor exposure (specifically phenacetin-containing analgesics, tobacco, infection, and kidney stones) had been obtained in a population-based case-control study from New South Wales in 1989 and 1990.

RESULTS

A history of consumption of phenacetin-containing analgesics was associated strongly with the presence and severity of diffuse renal papillary scarring, and less strongly with papillary calcification. The histologic grade of the renal pelvic tumors tended to rise significantly with consumption of phenacetin-containing analgesics in a dose-dependent fashion and with the degree of papillary scarring, but was not related to smoking. In multivariate analysis it was the degree of papillary scarring (to a greater extent than the amount of phenacetin consumption) that was associated significantly and strongly with a higher histologic grade. Only diffuse papillary calcification was associated significantly with squamous change in the renal pelvic tumors.

CONCLUSIONS

Based on the results of the current study, the authors conclude that 1) in phenacetin-related tumors of the renal pelvis, the presence and severity of analgesic-induced renal papillary scarring correlates with tumor progression and 2) papillary calcification is a risk factor for squamous change in renal pelvic urothelioma.