Comparison of ER, PR & HER-2/neu (C-erb B 2) reactivity pattern with histologic grade, tumor size and lymph node status in breast cancer

Introduction: Carcinoma of the breast is the most common malignancy of women in Karachi. The current study was conducted with the objective of assessing estrogen receptor (ER), progesterone receptor (PR) and HER-2/neu reactivity patterns of mammary cancers for correlation with histologic grade, tumor size and lymph node metastasis. Materials and methods: One hundred and fifty modified mastectomy specimens received at the section of histopathology, Aga Khan University Hospital, were selected using a non-probability sampling method. Results: Mean age of the patients was 48.3 years (95%CI 46.5, 50.2). The left breast was more commonly involved (57%). Tumor size ranged from 0.3 to 15.0 cm; 12% were ≤2.0 and 35.3% were ≥ 5.0 cm in diameter. The predominant morphology was infiltrating ductal carcinoma (85.3%). The majority of the cases presented as grade II (55.3%) lesions with tumor necrosis (70%) and lymph node involvement (71.3%). ER and PR were positive in 32.7% and 25.3% cases respectively. HER-2/neu was positive (3+) in 24.7%. ER positivity increased and HER-2/neu positivity decreased with rising age. ER and PR expression was significantly lower in HER-2/ neu positive as compared with HER-2/neu negative tumors (ER 83.8% vs 69.8%; PR 91.9% vs 77.8%). In the HER-2/neu positive tumors, ER and PR expression in high grade tumors was significantly decreased compared with intermediate grade tumors (ER 5.6% vs 10.5; PR 0% vs 5.3%). ER expression in the HER-2/neu positive, large sized tumors was also significantly decreased compared with smaller tumors (ER 6.3% vs 11.8). Conclusions: ER and PR expression in breast cancers in the current study was found to be comparable to published international data, but the frequency of HER-2/neu expression was higher, possibly reflecting a young age at diagnosis. Assessment of prognostic markers for the clinical management of breast cancer patients is strongly advocated to provide best therapeutic options.