LAS VEGAS — After laparoscopic cystectomy, the long-term use of oral contraceptives can effectively prevent recurrence of ovarian endometrioma, based on results from a single-center study.
In the 2-year study of 217 patients, two groups got either cyclic or continuous oral contraceptives after laparoscopic cystectomy, and one group went untreated.
The recurrence rate for endometriomas was 29% in the untreated group, a rate that was significantly higher than the recurrence rates in the groups who took OCs.
“Oral contraceptive pills can provide a better option in terms of safety, tolerability, and cost” than do other hormones for adjuvant therapy following laparoscopic surgery, Dr. Mohamed Mabrouk said at the annual meeting of the AAGL. “However, data from clinical trials on this topic are few and controversial.”
In one cohort study, long-term exposure to oral contraceptives after conservative surgery for ovarian endometriosis was associated with a major reduction in the risk of endometrioma recurrence, with a gradient effect observed with regard to duration of treatment (Am. J. Obstet. Gynecol. 2008;198:504.e1–5).
Although researchers in an earlier retrospective study found that treatment with oral contraceptives for a mean of 9.5 months after laparoscopic excision did not significantly influence endometrioma recurrence, they did suggest that a longer period of treatment might prevent recurrence (Hum. Reprod. 2006;21:2171–4).
The only published, randomized, controlled trial on the topic dem-onstrated that the postoperative cyclic use of OCs does not significantly influence long-term endometrioma recurrence rates (Am. J. Obstet. Gynecol. 2000;183:588–92).
However, in this trial, OCs were administered for only 6 months after the operation, said Dr. Mabrouk of the minimally invasive gynecologic surgery unit at the University of Bologna (Italy).
“Based on our observational process, we noticed that patients who used oral contraceptives for a longer period of time had lower recurrence rates,” he explained. “So we hypothesized that the length of treatment seems to be an important factor in the long-term efficacy of therapy.”
To test this hypothesis, he and his associates conducted a randomized trial to evaluate the efficacy of long-term cyclic and continuous administration of monophasic, combined low-dose oral contraceptives in preventing endometrioma recurrence in 217 patients (mean age, 29 years) who underwent laparoscopic cystectomy at the university.
Every 6 months for 24 months, the researchers conducted clinical and ultrasonographic studies of all patients, noting the presence of recurrence (defined as the presence of an ovarian endometrioma measuring more than 1.5 cm in diameter), time of recurrence, size of recurrent endometrioma, and increase in mean diameter.
Of the 217 patients, 69 received no therapy, 75 got cyclic oral contraceptives, and 73 received continuous oral contraceptives. The contraceptives contained 0.020 mg ethinylestradiol and 0.075 mg gestodene.
At 2 years' follow-up, 37 endometrioma recurrences were detected in the three groups. Nearly two-thirds of the recurrences (65%) took place between 12 and 18 months after surgery.
The recurrence rate was 29% in the untreated group, a rate that was significantly higher than the recurrence rates in the groups who took OCs (15% for the cyclic therapy group, and 8% for the continuous therapy group).
The mean diameter of recurrent endometrioma in the untreated patients at 2 years' follow-up was 2.73 cm, which was significantly larger than the mean diameter in the treated groups (2.17 cm in the cyclic therapy group and 1.71 cm in the continuous therapy group).
“Our study showed that the mean diameter of recurrent cysts at first observation was significantly smaller in cyclic and continuous users, proving that oral contraceptives can even influence disease expression and reduce its severity,” Dr. Mabrouk said.
He also reported that the mean increase in diameter in the untreated group at every 6 months of follow-up was 0.48 cm, which was significantly larger than that for the treated patients (0.31 cm for the cyclic group vs. 0.25 cm for the continuous group).
No statistically significant differences were observed between the treated groups in terms of the number, size, and growth of recurrent endometriomas.
“However, there was a positive trend in patients receiving continuous therapy regarding size and growth of recurrent endometriomas,” he reported.
Dr. Mabrouk stated that he had no relevant financial disclosures to report.
Oral contraceptive pills 'can provide a better option in terms of safety, tolerability, and cost.' DR. MABROUK