Estrogen and progesterone receptor status in breast cancer: effect of oral contraceptive pills and hormone replacement therapy

BACKGROUND: Higher incidence of hormone receptor positive breast cancer (BC) in White women compared to Blacks and Asians is attributed to different inherent biology. Many of our patients have estrogen receptor (ER) and progesterone receptor (PR) negative tumors. We tried to explore if this is related to low frequency of oral contraceptive pills (OCP) and hormone replacement therapy (HRT) intake. SETTING: Breast Unit, Department of Surgical Oncology, Tertiary Care Hospital, India. METHODS: Records of female BC patients classified as 'Users' of OCP/HRT for minimum of 1 year and age, stage, histopathology matched 'Non-users' were reviewed retrospectively from January 1990 to October 2006. RESULTS: Analysis of 150 evaluable 'Users' (58/122 premenopausal, 92/178 postmenopausal) and 150 matched 'Non-users' revealed 128 (42.67%) patients had ER and PR-negative, 157 (52.33%) ER and PR-positive, 12(4%) ER-positive/PR-negative, 3(1%) ER-negative/PR-positive tumor. Significantly more ER-positive tumor was found in both premenopausal [62.07% versus 39.06%, p=0.0184, odd's ratio (OR) 2.5527 and 95% confidence interval (CI) 1.2297-5.2993] and postmenopausal (63.04% versus 40.7%, p=0.0046, OR 2.4857 and 95% CI 1.3593-4.5455) 'Users' compared to 'Non-users', respectively. Grade III tumors were significantly less in premenopausal (p=0.0041) and postmenopausal (p=0.0012) 'Users'. CONCLUSIONS: These observations suggest that a low incidence of hormone receptor positivity in our patients could be partly due to low prevalence of OCP/HRT intake.