Cyclooxygenase-2 (COX-2) expression is mediated by constitutive nuclear factor (NF)-kappaB. The aim of this study was to investigate the association between the germline alteration of the NF-kappaB binding site of COX-2 and the risk of developing various types of human cancers. Using PCR and DNA sequence analysis, we performed a hospital-based case-control study involving various types of human cancers, namely cervical, breast, lung, and bladder cancer. The COX-2 gene was sequenced in 217 Korean individuals (122 cancer patients; 95 non-cancer patients). We identified 2 novel polymorphisms -1166 C-->G and -1186 T-->G, in the NF-kappaB binding promoter region of COX-2. A polymorphism in nucleotide 1186 was found to be associated with an increased risk of bladder cancer (P=0.038). However, in the case of the other cancers, no significant association was found between polymorphisms in the COX-2 promoter region and the risk of cancer. In conclusion, our results suggest that polymorphisms in nucleotide -1186, which is in the NF-kappaB binding promoter region of the COX-2 gene, may be associated with an increased risk of bladder cancer. Further research is needed to investigate the functional implications of the polymorphisms of the COX-2 promoter gene in human cancer.