Hormone therapy and estrogen receptor expression in breast cancer

Abstract

Postmenopausal hormone therapy (HT) may increase breast cancer risk and influence tumor characteristics. We investigated 321 postmenopausal women aged 50–65 years, with breast cancer, diagnosed and treated at Radiumhemmet, Karolinska Hospital, during 1993–1997. In women using HT (n =90) estrogen receptor concentration (ER) at diagnosis were lower than in non-users (n =135) (1.17 vs 1.70 fmol/µg; p <0.05). HT users also had a tendency to less multifocal (5 vs 12%) (p <0.05) and metastatic disease (5% vs 2%) however this was not statistically significant. The estrogen receptor expression is always considered in the judgement on hormone dependency and the clinical decision on adjuvant endocrine therapy. A suppression of ER during HT could tentatively influence the treatment decisions in breast cancer patients and maybe disregard patients from endocrine treatment.