Risk factors for renal cell carcinoma in Denmark: role of medication and medical history.

Background: Several recent studies of risk factors for renal cell carcinoma have indicated that use of diuretics may increase risk of this cancer. It has also been suggested that use of weak analgesics, which are known to increase risk of cancer of the renal pelvis and ureter, may also be associated with an increased risk of renal cell carcinoma--the most frequent type of kidney cancer.
Methods: A population-based case-control study was undertaken to investigate the role of diuretics, other anti-hypertensive drugs, analgesics, and medical history in the aetiology of renal cell carcinoma. The study base was the total Danish population, and 368 histologically verified cases and 396 sex- and age-matched controls who were interviewed from February 1989 to May 1992.
Results: Response rates were 76% among cases and 79% among controls. We found no general increase in risk among users of diuretics or analgesics, although women taking loop diuretics and heavy users of acetyl salicylic acid had slightly increased risks. The use of nondiuretic anti-hypertensive medications was associated with decreased risk in women. We found non-significantly increased risks for history of hypertension and other cardiovascular disorders. We also observed elevated risks for urological disorders in both sexes which may be a result of recall bias.
Conclusion: This study provides only limited support for the suggested association between risk of renal cell carcinoma and use of diuretics and analgesics. The coexistence of renal cell carcinoma and cardiovascular diseases could be caused by risk factors that are common to these conditions.