Epidemiology of renal-cell carcinoma.

Renal-cell cancer is responsible for about 2% of all cancer deaths in developed countries and represents 80-85% of all tumors of the kidney. Its etiology is still largely undefined. Recently the results of a large international population-based case-control study (International Renal-Cell Cancer Study), conducted between 1989 and 1991 in Australia, Denmark, Germany, Sweden and USA, including 1732 cases and 2309 controls, showed an increased risk of renal-cell cancer in relation to tobacco smoking, elevated body mass index, a few medical conditions, the use of beta-blockers, a family history of the disease, high intake of dairy products and low intake of fruit and vegetables and, in women, multiparity. Most other studies agree about a causal role of cigarette smoking in the etiology of renal-cell cancer, although its association is less strong than for several other tobacco-related neoplasms, with a relative risk of about 2 for current smokers. Other established risk factors are elevated body mass index (mainly in women) and a family history of the disease. Occupational exposure to chemicals appears to have little significance, although associations with specific products, such as asbestos fibres, have been reported. Some relationship has been observed between renal-cell cancer and hypertension, use of anti-hypertensives and kidney diseases, although this issue remains open to discussion. Data are inconsistent on the role of nutrition, mainly for fats and proteins, while vegetable and fruit consumption seems to convey some protection on renal-cell cancer risk. The risk of renal-cell cancer was not materially elevated in relation to coffee, tea and alcohol intake and, in women, oral contraceptive use, hormone replacement therapy, and menstrual factors.