Being overweight and having high blood pressure can independently increase a man's of developing kidney cancer, according to a new study. Combined research carried out at the National Cancer Institute in Bethesda,U.S and Umea University in Sweden reviewed the records of 363,992 Swedish men who had a least one physical exam between 1971 and 1992. These men were followed until death or until the end of 1995. The risk of developing renal cell cancer in men with high blood pressure wasdouble that of men who had a normal reading and the risk increases as the blood pressure level rose. Scientists were not certain why high blood pressure may increase kidney cancer risk but they noted that hypertension may cause kidney damage that makes the organ more susceptible to cancer-causing chemicals. Full findings of the study are published in the November 2 issue of The New England Journal of Medicine.