Risk factors for adult renal cell carcinoma: a systematic review and implications for prevention.

RCC accounts for < 3% of cancers in adults and < 85% of all primary malignant kidney tumours. The incidence of RCC has been steadily increasing for several years. In France, the incidence of RCC according to cancer registers was 12 per 100 000 men and 6 per 100 000 women in 1995, and mortality rates were over 7.5 per 100 000 men and 4.0 per 100 000 women, similar to reports from other European countries [1,2]. About half the cases of RCC diagnosed are currently discovered by chance during ultrasonography. This suggests that these tumours could be detected more frequently by simple imaging techniques at earlier stages of the disease, when surgical treatment is curative. The 5year survival rate is 88±100% for localized tumours but only 20% or less for metastatic tumours [3]. As patients with localized RCC survive longer than those with disseminated disease, it is likely that a screening programme for RCC would improve disease prognosis. However, in the absence of known high-risk populations, systematic early detection of RCC may not be cost-effective. Several potential risk factors for RCC have been identi®ed in previous epidemiological studies. Discrepancies between these studies and the weakness of associations between various types of exposure and RCC make it dif®cult to identify unequivocally the true risk factors. We attempted to rank the most consistent associations and to de®ne populations at high-risk of RCC by systematically reviewing published analytical epidemiological studies.