Association between HER-2/neu and the progesterone receptor in oestrogen-dependent breast cancer is age-related.
Breast Cancer Res Treat. 2005; 91(1):81-7 (ISSN: 0167-6806)
Huang HJ; Neven P; Drijkoningen M; Paridaens R; Wildiers H; Van Limbergen E; Berteloot P; Amant F; Christiaens MR; Vergote I
Division of Gynaecologic Oncology in Department of Obstetrics and Gynaecology, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
In oestrogen receptor-positive (ER+) breast cancer, HER-2/neu and the progesterone receptor (PR) are inversely associated. This explains a lower response to anti-oestrogens if ER+ breast cancers are HER-2/neu positive. One randomized study however, showed that premenopausal women with an ER+ breast cancer respond to anti-oestrogens independent of HER-2/neu. We therefore hypothesized an age-related association between HER-2/neu and PR in ER+ breast cancers. Receptors for ER, PR and HER-2/neu were analysed by immunohistochemistry (IHC). A uni- and multivariate analyses was carried out to assess this relationship in 1104 women with an ER+ breast cancer. We observed an inverse association between HER-2/neu and PR only after age 45. There were 173 women of age45 years. In multivariate analysis, only tumour grade (p=0.005) but not PR status was associated with HER-2/neu in women age45 years group, both PR status (p=0.001) and tumour grade (p=0.001) were independently associated with HER-2/neu. In ER+ breast cancers from women age>45, PR was positive in 76.9% if HER-2/neu negative but in 53.4% if HER-2/neu positive (p<0.001) and the median quantitative PR levels are 150 and 75 respectively in HER-2/neu negative and HER-2/neu positive tumours (p=0.002). This age effect of HER-2/neu on the PR status was not seen in women age 45 years but not in women age...
(sorry, this was all I could get of the article...)
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