Distribution of estrogen and progesterone receptors on primary tumor and lymph nodes in individual patients with breast cancer.

Primary breast cancer tissue and lymph nodes were obtained from 55 patients, Histologically, 34 of these patients had positive and 21 negative lymph nodes. Estrogen receptors (ER) and progesterone receptors (PR) were determined by a dextran-coated charcoal assay. The tumor tissue was ER positive in 58% of the cases and PR positive in 34%. The malignant lymph nodes were ER positive in 56% and PR positive in 24%. ER in 14% and PR in 5% of the benign lymph nodes could be detected. The primary tumor tissue and the corresponding malignant lymph nodes showed an identical ER and PR status, i.e. both tumor sites were receptor positive or both receptor negative, in 68 and 74%, respectively. However, 21% of the patients had receptor-positive tumors but receptor-negative lymph nodes. Receptor-positive lymph nodes in combination with receptor-negative tumors occurred in only 11% for ER and 6% for PR. These data show that receptor-positive malignant lymph nodes mostly display the same receptors status as the corresponding primary tumor, whereas receptor-negative lymph nodes may be combined with receptor-positive tumors.