In a case -control study of kidney cancer in four central European countries, with 1097 incident cases and 1476 controls, we found an increased risk for self-reported hypertension and for obesity. Additional unknown risk factors are likely to be responsible for the high rates of kidney cancer in this region. British Journal of Cancer (2008Cancer ( ) 99, 1912Cancer ( -1915 (Murai and Oya, 2004). Smoking is an established risk factor, although the increase in risk is moderate (IARC, 2004). Other possible risk factors are hypertension and obesity, with potentially differing risks for men and women (Shapiro et al, 1999;Bergstrom et al, 2001). To examine the risk factors for kidney cancer in central Europe, we conducted a large multicenter case -control study in Czech Republic, Poland, Russia, and Romania. We present here data on the role of smoking, hypertension, and body mass index (BMI) in this high-risk population.
MATERIALS AND METHODSThis hospital-based case -control study was conducted in seven centres (Moscow (Russia), Bucharest (Romania), Lodz (Poland), and Prague, Olomouc, Ceske Budejovice, and Brno (Czech Republic)). A total of 1097 newly diagnosed, histologically confirmed, renal parenchymal cancers (ICD-O-2 code C64) between 20 and 79 years of age were recruited during August 1999 and January 2003. Trained medical staff reviewed medical records to extract relevant diagnostic information, including date and method of diagnosis, histologic type, tumour location, stage, and grade. Eligible controls (n ¼ 1476) were admitted to the same hospitals as the cases for conditions unrelated to smoking or genitourinary disorders (except for benign prostatic hyperplasia) between August 1998 and March 2003. No single disease made up more than 20% of the control group. Both cases and controls had to be residents of the study areas for at least 1 year. The response rate for cases ranged from 90 to 98.6% and for the controls, 90.3-96.1%.Trained interviewers used standardised questionnaires at all centres to elicit information on demographic background, smoking, alcohol drinking, dietary practices, height, weight, medical history, family history of cancer, residential history, and occupational history.Smoking status (never smoker, former smoker, current smoker) was defined as status 2 years before interview. Packyears were used as a measure of cumulative tobacco smoking and were calculated by the number of cigarettes smoked per day multiplied by years of smoking and divided by 20. History of hypertension was selfreported and a positive history was restricted to patients who reported being treated for hypertension. The weight in kilograms was ascertained for 2 years before the interview. Body mass index was calculated by dividing the weight by the square of the height in metres.Kidney cancer risks were estimated by odds ratios (ORs) and 95% confidence intervals (CIs) using logistic regression analysis, with adjustment for age (5-years interval), smoking (current, former, and never smokers), BMI in five categories (o25, 25...