Long-term Adjuvant Therapy for the Prevention of Postoperative Endometrioma Recurrence

The presence of a primary endometrioma and its surgical excision may be detrimental for future fertility. After removal of the primary tumor, recurrence is common: 30% to 50% after 2 to 5 years of follow-up. The likelihood of conception after recurrence and surgical removal of the secondary tumor is almost half than that after a primary procedure. Ovulation appears to play a fundamental role in the pathogenesis of ovarian endometriomas. It has been suggested that postoperative suppression of ovulation can protect against cyst relapse after excision. However, the recommendations of a number of international guidelines on treatment modalities to prevent recurrent endometriosis are conflicting. Although some guidelines consider prolonged ovulation suppression with ovarian contraceptives to prevent recurrence, most do not recommend it. This systematic review and meta-analysis was designed to assess the possible long-term benefit of postoperative medical treatment to reduce the risk of endometrioma recurrence. The recurrence rate in women who received hormonal medical treatment for 12 months or longer after surgical excision of a primary tumor was compared with that in women who underwent postoperative expectant management. A MEDLINE search was performed to identify all relevant articles written in English published between 2000 and February 2012. Of the12 articles initially assessed in detail, 4 met the following criteria for inclusion: surgery of endometriotic cysts, direct comparison of postoperative medical treatment use for 12 or more months versus expectant management, and ultrasonographic and/or histopathologic diagnosis of recurrent endometrioma. The 4 selected studies had data on 965 women: 726 from 3 cohort studies and 239 in 1 randomized controlled trial. Oral contraceptives (OCs) were used as postoperative adjuvant treatment in all 4 studies. The women were categorized into 3 groups based on use of suppression treatment: always users, ever users, and never users. Never users were women undergoing postoperative expectant management, and ever users were those who used the treatment for limited periods. A recurrent endometrioma was found in 8% (33/423) of always users and in 34% (117/341) of never users; the odds ratio (OR) was 0.12, with a 95% confidence interval (CI) of 0.05 to 0.29. To determine the effect of duration of use on study outcome, always users were compared with ever users and ever with never users. Comparing always with ever users, the OR was 0.21 (95% CI, 0.11–0.40), and comparing ever with never users, the OR was 0.39 (95% CI, 0.23–0.66). These findings show that postoperative OC use after surgical excision of a primary ovarian endometrioma markedly decreases the risk of recurrence, especially when used regularly and for prolonged periods.