Immunohistochemical expression of hormone receptors in invasive breast carcinoma: Correlation of results of H-score with pathological parameters

The results of H-scores of oestrogen and progesterone receptor (ER and PR) expression in 150 invasive breast cancers were correlated with conventional pathological prognostic parameters: tumour size, histological grade and subtype, lymph node status, lymphovascular invasion, Nottingham Prognostic Index (NPI) and pathological stage. ER and PR status was determined by immunohistochemical staining of sections cut from archival paraffin-embedded tissue blocks. We defined positive receptor expression as a H-score of 50 and above. Our findings revealed ER and PR positivity in 98 (65%) and 52 (35%) cases, respectively. Fifty-one (34%) ER-positive cases also showed PR expression, while 51 (34%) tumours were negative for both ER and PR. Positive expression for ER and PR was significantly correlated with histological grade (P < 0.0005), mitotic score (P < 0.05) and nuclear pleomorphism (P < 0.05). When we used the relatively simpler method of a cut off of at least 10% tumour cell nuclear staining of moderate or greater intensity as positive receptor status, we found that it agreed well with results of the H-score, a more quantitative method of assessment.