PROSTATE-SPECIFIC ANTIGEN EXPRESSION IN A CASE OF INTRACYSTIC CARCINOMA OF THE BREAST - CHARACTERIZATION OF IMMUNOREACTIVE PROTEIN AND LITERATURE SURVEYS

A case is presented of female breast intracystic carcinoma with prosta te-specific antigen (PSA) expressed in high amounts in aspirated cysti c fluid (55 mu g/L). Tumor extract analysis revealed the presence of b oth estrogen and progesterone receptors (0.38 and 1.87 nmol/L, respect ively) and high quantities of PSA too (19.52 mu g/L). Chromatographic analysis of cystic fluid revealed two peaks of PSA, at the expected po sitions for free and bound serine protease. A major proportion of 33-k Da free form was also confirmed by Western blotting analysis. Free PSA was heat-stable at 56 degrees C and displayed no change after freezin g-thawing, These findings are discussed in the context of a detailed l iterature survey, Our data support the contention that PSA immunoreact ivity in intracystic fluid of breast carcinoma is partly the result of secretory activity by the neoplastic cells and that the steroid recep tors can also modulate its expression.