WASHINGTON — Continuous and cyclic administration of oral contraceptives appeared equally effective in preventing recurrent pain in women following laparoscopic endometrioma excision, but continuous administration was associated with significantly higher rates of side effects leading to treatment discontinuation in a prospective, randomized trial.
Evidence from the literature suggests that medical treatment following laparoscopic endometrioma excision can delay, though probably not prevent, recurrence of endometriosis. Although GnRH analogues can be given for 6 months, longer treatment is associated with high cost and significant side effects. Combination oral contraceptives represent a valid cost-effective alternative to GnRH analogues, but the question of whether they should be administered continuously or in a cyclic fashion has not been tested previously in a prospective randomized trial, said Dr. Ludovico Muzii, who presented data from such a trial at the annual meeting of the AAGL.
A total of 57 women who underwent laparoscopic excision of endometriomas by “stripping” were randomized to a 6-month cyclic regimen of monophasic combined ethinyl estradiol 0.020 mg and desogestrel 0.150 mg daily for 21 days followed by a 7-day interval (28 patients) or to a continuous regimen of the same monophasic oral contraceptive combination daily without the interval for 6 months (29), reported Dr. Muzii of Campus Bio-Medico University, Rome.
The two groups were comparable in age (30.3 years for cyclic, 30.6 for continuous), revised American Fertility Society (r-AFS) endometriosis classification (40.4 vs. 42.1), endometriotic cyst diameter (5.0 vs. 5.1 cm), and the proportion of patients with associated superficial implants (23 of 28 cyclic, 24 of 29 continuous). Twelve of the patients randomized to the continuous regimen did not complete the 6-month treatment because of moderate to severe side effects attributable to the OCs, compared with just four patients allocated to the cyclic treatment. The difference in discontinuation rates, 41% vs. 14%, was statistically significant, Dr. Muzzi said.
In a subsequent “intention to treat” analysis at a minimum of 12 months that included all 57 patients, endometriomas recurred in one cyclic (4%) vs. no continuous patients (0%), pain recurred in nine (32%) cyclic vs. five (17%) continuous; and mean time to recurrence was 12 months for cyclic compared with 16 months for continuous. Although none of these differences were statistically significant, they did represent trends that might have reached significance with a larger sample size, Dr. Muzii noted.
Both groups reported significant improvements in quality of life compared with baseline, despite the high dropout rate in the continuous group. This is probably due to a combination of factors: First, it is possible that patients who receive continuous treatment do experience less pain and recurrence—although not significantly—which might counterbalance the negative impact of the side effects, Dr. Muzzi explained in an interview. Also, most of the women who dropped the continuous regimen actually switched to the cyclic regimen, and therefore would still have been evaluated in the intent-to-treat analysis as having “continuous” treatment.