Fluid intake and incidence of renal cell carcinoma in UK women.
Allen NE., Balkwill A., Beral V., Green J., Reeves G.
It has been suggested that the apparent protective effect of alcohol intake on renal cell carcinoma may be due to the diluting effect of carcinogens by a high total fluid intake. We assessed the association between intakes of total fluids and of specific beverages on the risk of renal cell carcinoma in a large prospective cohort of UK women.Information on beverage consumption was obtained from a questionnaire sent ∼3 years after recruitment into the Million Women Study. Cox proportional hazards models were used to estimate relative risks (RRs) and 95% confidence intervals (CIs) for renal cell carcinoma associated with beverage consumption adjusted for age, region of residence, socioeconomic status, smoking, and body mass index.After an average of 5.2 years of follow-up, 588 cases of renal cell carcinoma were identified among 779,369 women. While alcohol intake was associated with a reduced risk of renal cell carcinoma (RR for ≥ 2 vs <1 drink per day: 0.76; 95% CI: 0.61-0.96; P for trend=0.02), there was no association with total fluid intake (RR for ≥ 12 vs <7 drinks per day: 1.15; 95% CI: 0.91-1.45; P for trend=0.3) or with intakes of specific beverages.The apparent protective effect of alcohol on the risk of renal cell carcinoma is unlikely to be related to a high fluid intake.