Immunohistochemical Profile of Breast Cancer Patients at a Tertiary Care Hospital in New Delhi, India

Background: To assess the immunohistochemical expression of estrogen receptor (ER), progesterone receptor(PgR) and human epidermal growth factor receptor-2 (HER2) neu receptor in breast cancer and their associationswith various clinicopathological characteristics. Materials and
Methods: This is a retrospective analysis of womenwho presented with primary, unilateral breast cancer in the Department of Medical Oncology at Rajiv GandhiCancer Institute and Research Centre, Delhi, India during the period from January 2008 to December 2011. Datawere retrieved from the medical records of the hospital including both early and locally advanced cancer cases.ER, PgR and HER2neu expression in these patients was assessed and triple negative patients were identified.Associations of triple negative and non-triple negative groups with clinicopathological characteristics were alsoevaluated.
Results: A total of 1,284 women (mean age 52.1 years, 41.9% premenopausal) were included in theanalysis. Hormone receptor positivity (ER and/or PgR) was seen in 63.4% patients, while 23.8% of tumors weretriple negative. Only 23.0% were HER2 positive. Around 10.0% of tumors were both ER and HER2 positive.ER and PgR positivity was significantly associated with negative HER2 status (p-value <0.0001). Younger age,premenopausal status, higher tumor grade, lymph node negativity, advanced cancer stage, and type of tumorwere strongly associated with triple negativity. Significantly, a smaller proportion of women had ductal carcinomain situ in the triple negative group compared with the non-triple negative group (35.6% versus 60.8%, p-value<0.01).
Conclusions: The present analysis is one of the largest studies from India. The majority of the Indianbreast cancer patients seen in our hospital present with ER and PgR positive tumors. The triple negative patientstended to be younger, premenopausal, and were associated with higher tumor grades, negative lymph nodesstatus and lower frequency of ductal carcinoma in situ.