Progesterone Receptor Status of Epithelial Cells as a Predictive Marker for Postoperative Recurrence of Endometriosis

Context Progesterone resistance including progesterone receptor (PR) deficiency contributes to the pathophysiology of endometriosis; however, whether the PR expression levels in ovarian endometrioma (OE) correlate with the postoperative recurrence of endometriosis remains unclear. Objective This study aimed to investigate the association between PR expression levels in OE and the recurrence of endometriosis. Methods OE specimens were obtained from 132 patients who underwent conservative surgery for endometriosis. The PR expression levels were evaluated using the H score after immunohistochemical staining. Results Of the 132 patients, 36 (27.3%) experienced recurrence and 96 (72.7%) did not. No differences were observed in the patient characteristics between the recurrence and nonrecurrence groups except for follow-up period. PR immunoreactivity in the epithelial cells (ECs) was statistically significantly lower in the recurrent group than in the nonrecurrent group (P < .01); however, this change was not observed in the stromal cells. Moreover, multivariable logistic regression analysis revealed that the H score of PR in ECs was an independent factor and was statistically significantly associated with the recurrence of endometriosis (P = .01). Furthermore, we divided the patients into PR-negative or PR-positive groups. The cumulative recurrence rate in the negative PR group was statistically significantly higher than that in the positive PR group (P = .046). Conclusion Low PR expression levels in OE-ECs may predict the recurrence of endometriosis. The PR status in OE-ECs is associated with the pathophysiology of the recurrence of endometriosis, and optimized postoperative management for endometriosis may be provided by referring to the PR status.