Review of potential risk factors for kidney (renal cell) cancer.

Renal cell cancer (RCC) is responsible for a small percentage of total cancer cases and deaths throughout the world, but the incidence rates of RCC have been steadily increasing over the past decade, whereas numerous other cancers have stabilized or even decreased in number. Even in countries that were observed to have a lower incidence of this disease many are now experiencing large increases in the rates of this cancer. Most kidney cancers are RCC, and blacks are currently experiencing RCC rates that are higher than any other race. Older individuals are also at a higher risk compared with young individuals, but this observation may also be changing. The reasons for these potential increases are not understood beyond the partial impact and greater use of newer diagnostic procedures. Other reasons for higher rates of RCC and a better understanding of which individuals may be at the highest risk need to be examined to provide the clinician with possible clues as to who should be tested and what prevention measures should be offered. Most of the past investigations into risk factors have been case-control or retrospective studies, but some generalizations can still be made. Family history and genetics seem to increase risk, but overall are responsible for a small number of the total cases. Smoking, obesity, and even hypertension seem to be risk factors for RCC. Reducing these behaviors and conditions may also reduce the risk of RCC. Healthier eating habits (fruits and vegetables, and a lower caloric intake) and more physical activity may also reduce the risk of RCC. Therefore, it is possible that the increases in RCC may also be due, in part, to unhealthy lifestyle factors that have been on the increase over the past several decades. Recommendations for cardiovascular disease prevention should also be applied to patients or clinicians concerned about RCC risk. Finally, numerous occupations, occupational exposures, reproductive and hormonal changes or manipulations, and a variety of other factors may impact risk, but overall their contribution seems small compared with other more consistent risk factors.