IMMUNORECEPTOR AND KI-67 CHARACTERIZATION OF BREAST CANCER IN A TERTIARY HEALTHCARE FACILITY IN SOUTH EAST NIGERIA

Abstract

Background: Breast cancer is highly complex and heterogeneous with disparities in ethnic and racial histological subtypes and tumour behaviour; is the second most common cancer in the world, and the most common cancer in women. Nigeria maintains the 9th position in breast cancer mortality worldwide.

Aim: The present study assessed the immune receptor and tumour proliferation marker characterization of breast cancers.

Methods: A retrospective cross-sectional study was carried out from 2010 to 2015. Two hundred (200) archived breast cancer tissue samples were retrieved from the histopathology Laboratory of Nnamdi Azikiwe University Teaching Hospital Nnewi. Patients' data were retrieved from the histopathology reports. Tissue blocks were re-embedded in fresh paraffin wax and 4µ thick serial sections were cut and stained accordingly.

Results: Breast tissue samples were the most prevalent sample types (48.9%) while grade 3 tumours were the most pervasive cancer grades; patients' ages at presentation range from 23 to 86 years, with a mean age of 55. Positive immunoreactivity for oestrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and proliferation marker (Ki67) were 89.2%, 69.7%, 24.1% and 98.5% respectively, for invasive ductal carcinoma. Her-2 was the least expressed whereas Ki67 was expressed in almost all the cancer types. ER-positive tumours were the most prevalent with ER/PR co-positivity being the second.

Conclusion: The characterization and hormonal expression pattern of breast cancer maintained the same trend. ER-positive tumours were the most prevalent with ER/PR co-positivity being the second. Her-2 was the least expressed whereas Ki67 was expressed in almost all the cancer types.