Continuous versus cyclic oral contraceptives after laparoscopic excision of ovarian endometriomas: a systematic review and meta-analysis

Up to 44% of patients with endometriosis have endometriomas that are usually associated with pelvic pain and infertility. The first-line option for endometriosis-associated pain symptoms is usually medical therapy with oral contraceptives (OCs) and progestins. Because ovarian endometriomas do not respond to medical therapy, standard treatment when they are present is considered to be surgical excision. Medical treatment is often administered after surgical excision of the endometrioma to reduce postoperative pain and cyst recurrence rates, but its effectiveness remains unclear. Several studies and systematic reviews that compared postoperative medical treatment versus placebo or no treatment had conflicting results. One systematic review and meta-analysis suggested that postoperative OC may be effective in reducing recurrence rates, especially when administered in the long term. After excisional surgery for endometriomas, OCs may be administered either with a conventional cyclic regimen or a continuous regimen with no pill-free interval. Few studies have compared these 2 regimens. Results of such studies have been inconsistent as to the efficacy of either regimen on cyst or pain recurrence. There is no consensus in evidence-based guidelines for recommendation of either schedule. The aim of this systematic review and meta-analysis was to compare a continuous versus a cyclic OC regimen administered after surgical excision of ovarian endometriomas. An electronic search was conducted using PubMed, MedLine, and Embase databases through December 2014 to identify relevant articles. The search employed the following combination of terms: endometrioma, endometriosis, OCs, oral estroprogestins, laparoscopy, and surgery. Three investigators independently assessed methodology and extracted data from studies selected. Included studies directly compared a continuous versus a cyclic schedule administered after surgical treatment of endometrioma. The primary outcomes were pain and endometrioma recurrence rates. Pain recurrencewas evaluated separately for dysmenorrhea, noncyclic chronic pelvic pain, and dyspareunia; endometrioma recurrence was evaluated at ultrasonography. Data from each study for dichotomous outcomes were expressed as risk ratio (RR) with a 95% confidence interval (CI). Four studies were included at final analysis: 3 randomized clinical trials and 1 prospective controlled cohort study. A total of 557 patients with endometriosis were evaluated; among these, 343 patients with ovarian endometriomas completed the assigned treatment and scheduled follow-up. Surgical treatment in all the included studies was performed by laparoscopic excision of the cyst wall. Lower recurrence rates for dysmenorrhea were found with a continuous OC regimen (RR, 0.24; 95% CI, 0.06–0.91; P = 0.04). Nonsignificant differences favoring the continuous OC regimen were found for chronic pelvic pain (P = 0.06) and dyspareunia (P = 0.17). With respect to endometrioma recurrence, there was no significant difference between a continuous and a cyclic OC schedule; the RR was 0.54, with a 95% CI of 0.28 to 1.05, P = 0.07. A continuousOC regimen may be suggested after surgery for endometriomas, particularly in patients with dysmenorrhea as the main associated symptom. However, the evidence from the present systematic review is not conclusive due to the small number of included studies and sample sizes. Further randomized trials are needed to confirm these findings. Moreover, important outcomes not addressed in this study such as patient satisfaction and quality of life should also be evaluated.