Japanese researchers have found that given dienogest — a synthetic progestogen hormone — to women who have had keyhole surgery for deep infiltrating endometriosis lowers the recurrence rates of both pain and endometriomas, or cysts formed by endometriosis tissue.
Teams from Japan’s Kurashiki Medical Center and Shiga University of Medical Science that analyzed the medical records of more than 100 patients who had such surgery say the difference is rather substantial — and that prospective clinical trials are needed to confirm these findings.
Their study, “Effect of dienogest on pain and ovarian endometrioma occurrence after laparoscopic resection of uterosacral ligaments with deep infiltrating endometriosis,” appeared in the European Journal of Obstetrics & Gynecology and Reproductive Biology.
Uterosacral ligaments are the most common location of deep infiltrating endometriosis. These ligaments connect the uterus to the lowest part of the spine, called the sacrum. The team analyzed records of women who had surgery for deep infiltrating endometriosis involving uterosacral ligaments.
These patients were assessed every six months after their surgery, for an average 32 months. Among them, 59 were treated with dienogest after surgery, while 67 received no medication.
By the end of the study, 31.3 percent of patients who had not been treated had a recurrence of endometriomas, confirmed by magnetic resonance imaging (MRI) transvaginal ultrasound exams. In addition, 11.9 percent of non-medicated women developed pain that was as severe as before the surgery.
Among women treated with dienogest, only 5 percent had a recurrence of disease, and none experienced the return of pain. The differences persisted, so that five years after surgery, untreated patients were still much more likely to have recurrences of lesions or pain.
In addition, the rates of other endometriosis-related symptoms were lower among women treated with dienogest throughout the study period.
Although clinical trials have indicated that dienogest lowers endometriosis pain and prevents endometriomas in women who have had them removed, the new study showed that the drug also prevents cyst formation in women who have surgery for deep infiltrating endometriosis.
But as the study was retrospective, the evidence for dienogest’s effectiveness is limited, and randomized clinical trials must confirm the findings, researchers said.