Increased cyclooxygenase-2 expression is associated with better clinical outcome in patients submitted to complete ablation for severe endometriosis.

BACKGROUND Recent studies have demonstrated the overexpression of cyclooxygenase-2 (COX-2) in endometriosis. The aim of this study was to investigate the correlation between COX-2 expression and the clinical outcome rate in a homogeneous series of patients undergoing fertility-sparing complete laparoscopic ablation for severe endometriosis. METHODS COX-2 expression was analysed by immunohistochemistry in 103 samples, 71 endometriomas (group 1) and 32 peritoneal implants and or recto-vaginal nodules (group 2) of endometriotic tissue from 85 patients submitted to complete laparoscopic ablation of severe endometriosis. RESULTS At median follow-up of 54 months, a recurrence rate of 24.7% (n = 21) was observed. Patients with COX-2-positive endometriotic cysts showed a lower relapse rate than COX-2-negative cases (16.7 versus 41.2%; P = 0.036). Patients with COX-2-positive peritoneal implant and or recto-vaginal nodule showed a similar trend. Taking the two groups of patients together, we found a significantly lower relapse rate in COX-2-positive patients in comparison to COX-2-negative patients (16.4 versus 40%; P = 0.0152). Moreover, COX-2-positive patients showed a longer relapse-free survival in comparison to COX-2-negative patients (P = 0.016). CONCLUSIONS In patients with severe endometriosis who underwent fertility-sparing complete ablation, COX-2 overexpression characterizes a subgroup of patients with lower risk of relapse and longer relapse-free survival.