During 1999-2003, the authors conducted a hospital-based study in Czech Republic, Poland, Romania and Russia, including 1097 cases of RCC and 1476 controls. For cadmium and other followed up metals, the lack of statistical significance of most results, potential confounding and the absence of clear dose-response relations suggest that an association with RCC is unlikely to be causal.
In the case of lead, however, the elevated risk in the category of highest cumulative exposure is noteworthy and justifies further investigation.