Synchronous bilateral breast cancer: A case report of heterogeneous estrogen receptor status

INTRODUCTION: Tumour heterogeneity is important in the management of breast cancer. Hormone receptors are established biomarkers for treatment and prognosis of patients with breast cancer. There are three immunohistochemical biomarkers: estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor 2 (HER2). We explore whether heterogeneity in hormone receptor status in synchronous bilateral breast alters therapeutic management. CASE PRESENTATION: This case details a 54 year old woman who was referred to our clinic by her general practitioner for investigation of bilateral breast pain that she had for 6 months. On clinical examination pathological nodes were palpated in bilateral axilla. There was left sided nipple inversion with a palpable mass in the upper outer quadrant of approximately 3 cm diameter. On examination of the right breast there was skin tethering of the nipple and 3 masses were palpated, the largest being in the upper inner quadrant at 5 cm diameter. Ultrasound and mammography of bilateral breasts demonstrated advanced bilateral breast cancer with axillary node metastases. Core biopsies demonstrated invasive carcinoma. The right breast lesion was ER negative whilst the left breast lesion was ER positive. DISCUSSION: In patients with synchronous bilateral breast cancer ER discordance in patients have been associated with higher mortality than ER concordant positive patients and lower mortality than ER concordant negative patients within the first 5 years of surveillance [1]. CONCLUSION: Heterogeneity in hormone receptor status alters the therapeutic management of patients with synchronous bilateral breast cancer. Both hormone therapy and chemotherapy should be considered in these patients. It is of utmost importance to evaluate the tumor receptor status in cases of synchronous bilateral breast tumour and to assess for change in relation to tumour progression or treatment. Further study in the status change of receptors could open up new treatment modalities.