Human progesterone receptor gene polymorphism PROGINS and risk for breast cancer in Austrian women.

A germline TaqI restriction fragment length polymorphism in the intron G of the progesterone receptor (PR) gene designated PROGINS was described to be associated with an increased risk for ovarian carcinoma. It was supposed that the PR isoform A protein associated with PROGINS has an increased stability and therefore, a higher transcriptional activity. This may cause an inadequate control of estrogen receptor (ER) and PR B isoform and lead to the increased risk of tumor development. On the other hand, loss of heterozygosity (LOH) of the chromosomal region 11q22-23, where the PR gene is located, was frequently observed in breast cancer, suggesting the presence of a tumor suppressor gene in this region. Recently, it was reported that PROGINS is associated with a decreased risk for breast cancer. In order to examine if PROGINS is associated with an alteration of the risk for breast cancer, we examined PROGINS in 155 sporadic breast cancer patients in Austrian women and in a control group of 106 healthy volunteers. LOH affecting the PR gene was also analyzed in the tumor patients. No statistically significant difference was found for the frequencies of the PROGINS carriers (23.2%) in the Austrian breast cancer patients and in the healthy control group (26.4%), indicating that PROGINS is not associated with either an increased or a decreased risk for breast cancer. Furthermore, no associations between the PROGINS status and the protein levels of ER and PR, clinical data like tumor type, differentiation grade, tumor size, and the nodal status as well as the age of the patients were found. There was also no significant difference in the frequency of LOH affecting the PR gene in the PROGINS carriers and non carriers, demonstrating that LOH at PR gene is not associated with the PROGINS status.