ESTROGEN-RECEPTOR EXPRESSION IS A COMMON FEATURE OF OVARIAN BORDERLINE TUMORS

Purpose. The presence of estrogen receptor (ER) and its therapeutic si gnificance in ovarian borderline tumors (OBT) have not been establishe d, We recently observed a response to tamoxifen therapy given empirica lly to a patient with unresectable, recurrent serous borderline tumor (SET). In view of this observation the present study was undertaken to assess ER expression in 51 cases of OBT, Materials and methods. ER ex pression was determined retrospectively, using an immunohistochemical method on formalin-fixed, paraffin-embedded specimens, from 35 cases o f SBTs, 6 cases of mucinous mullerian (MMBT), and 10 cases of mucinous intestinal borderline tumors (MIBT). ER was considered positive if >5 % of tumor epithelial cell nuclei were immunostained, Both SBTs and mu cinous borderline tumors (MBTs) were included to determine the influen ce of histologic type on ER expression. Results. The patients ranged i n age from 25 to 77 years (median 43 years for SBTs, 36 years for MMBT s, and 37 years for MIBTs). The stage distribution for the SBTs was st age I in 27 patients (77%), stage II in 4 patients (11.5%), and stage III in 4 patients (11.5%). All patients with MBTs were stage I, ER exp ression was observed in the majority of cases and correlated with hist ologic type: 94% (33/35) of SBTs and 100% (6/6) of MMBTs were ER posit ive compared to 0% (0/10) of MIBTs (P ( 0.01). In the SET category the presence of ER did not correlate significantly with stage or age. In addition, ER was positive in all four SET implants (including one invo lved lymph node) and two recurrent SBTs analyzed. Conclusion. ER expre ssion is a common feature of SET and MMBT, but not MIBT. The relevance of ER expression in the pathogenesis and treatment of OBTs requires f urther investigation. (C) 1996 Academic Press, Inc.