Estrogen & progesterone receptors measurement in breast cancer with enzyme-immunoassay & correlation with other prognostic factors.

Estrogen and progesterone receptor (ER and PgR) estimation was carried out by an enzyme-immunoassay by a 'sandwich' technique using two different monoclonal antibodies against each receptor on 508 consecutive breast cancer samples. 43.9 per cent of the tumours were ER+ve and 26.6 per cent were PgR+ve; 23.8 per cent were both ER and PgR+ve, 53.3 per cent were both ER and PgR-ve, 20.0 per cent were ER+ve PgR-ve and 2.8 per cent were ER-ve PgR+ve. Both ER and PgR positivity was associated with increasing age, and this was seen within both pre and post-menopausal subgroups. Grades I and II tumours were more often ER and PgR+ve compared with grade III tumours, indicating that receptor positivity is a marker of a more well differentiated tumour phenotype. Receptor positivity was higher in primary tumours compared to that in metastatic tissues. The proportion of tumours that was ER+ve was found to vary among the four major religious communities, viz., Hindu, Muslim, Christian and Parsi, and this variation was significant in the overall analysis (P less than 0.01). The Christians had the highest rate of ER+ve tumours while the Muslims had the lowest rate. No correlation was observed between ER and PgR status and axillary nodal involvement or tumour size, suggesting that ER and PgR are independent prognostic factors in breast cancer. We found the EIA method to be an easy and rapid technique for ER and PgR analysis and which requires a small amount of tissue and does not involve the use of radioisotopes.