Breast cancer risk associated with polymorphism in CYP19 in Japanese women.

Screening of the entire coding and major promoter regions of the CYP19 gene identified two novel polymorphisms at codon 39 (Trp to Arg) and codon 408 (silent) in addition to those reported previously at codon 264 (Arg to Cys) and intron 4 [tetranucleotide (TTTA) simple tandem repeat]. A case-control study was conducted in order to see whether or not these polymorphisms were associated with breast cancer risk in Japanese women. Homozygous and heterozygous carriers of the variant allele Arg at codon 39 showed a significantly decreased risk of breast cancer (OR=0.39, 95%C.I.=0. 17-0.89). On the other hand, homozygous carriers of the allele with 10 or more TTTA repeats at intron 4 showed a trend toward an increase (OR=1.80, 95%C.I.=0.97-3.36) in breast cancer risk. Other polymorphisms were found not to be associated with breast cancer risk. These results suggest that the CYP19 polymorphisms at exon 39 and intron 4 would be useful for selecting Japanese women at a high risk of breast cancer. Copyright 2000 Wiley-Liss, Inc.