Secretory Component in Breast Cancer: Correlations with Patient AGE and Hormone Receptor Levels in Primary Breast Tumors

Abstract

The present study was undertaken to examine relationships of secretory component (SC) to patient age, estrogen receptors, and progesterone receptors in primary breast tumors. SC was measured in tumor cytosols from 76 patients by a radioimmunoassay which recognizes primarily free SC. Mean SC levels in tumors from premenopausal patients were not significantly lower than levels measured in postmenopausal patients. Significant differences, however, were found when SC levels were correlated with hormone receptor content. Mean SC levels were higher in estrogen- and progesterone-receptor positive tumors than in receptor-negative tumors. The findings from this study, in conjunction with previous data from our laboratory showing that SC is under hormonal control in the uterus, suggest that tumor SC levels may provide valuable information about the hormone responsiveness of tumors.