Obesity and renal cell cancer - a quantitative review

Obesity has been associated with an increased risk of renal cell cancer amo ng women, while the evidence for men is considered weaker. We conducted a q uantitative summary analysis to evaluate the existing evidence that obesity increases the risk of renal cell cancer both among men and women. We ident ified all studies examining body weight in relation to kidney cancer, avail able in MEDLINE from 1966 to 1998. The quantitative summary analysis was li mited to studies assessing obesity as body mass index (BMI, kg m(-2)), or e quivalent. The risk estimates and the confidence intervals were extracted f rom the individual studies, and a mixed effect weighted regression model wa s used. We identified 22 unique studies on each sex, and the quantitative a nalysis included 14 studies on men and women, respectively. The summary rel ative risk estimate was 1.07 (95% CI 1.05-1.09) per unit of increase in BMI (corresponding to 3 kg body weight increase for a subject of average heigh t). We found no evidence of effect modification by sex. Our quantitative su mmary shows that increased BMI is equally strongly associated with an incre ased risk of renal cell cancer among men and women. (C) 2001 Cancer Researc h Campaign http://www.bjcancer.com.