VANCOUVER (FRONTLINE MEDICAL NEWS) – Endometriosis, while generally considered a premenopausal condition, can also occur in women following surgical or natural menopause, and can undergo malignant transformation, although this risk is likely very small.

That was the main message from a new meta-analysis presented at the World Congress on Endometriosis. “We wanted to synthesize the case reports out there to show some common factors so physicians can be aware of them,” said Laura Gemmell, a second-year medical student at Case Western Reserve University, Cleveland, who presented the research.

While surgical or natural menopause can resolve endometriosis symptoms, it can bring its own problems, such as hot flashes and mood symptoms. These can be particularly severe in patients who undergo surgical menopause as a treatment for endometriosis. Hormone therapy (HT) may improve quality of life and reduce the risk of osteoporosis, but HT runs the risk of reactivating endometriosis foci and malignant transformation of the endometriosis, Ms. Gemmell said.

The researchers surveyed the literature for studies in postmenopausal women with a confirmed or clinically suspected history of endometriosis, and who discussed the management of their menopausal symptoms. They included 33 case reports and case series (42 patients, 36 surgical menopause, 4 natural, 2 presumed natural with later oophorectomy), as well as 6 observational studies and clinical trials.

In the case reports, patients were on HT for a mean of 7.8 years, and 17 of 42 women experienced a recurrence of endometriosis. Also, 25 women had a malignant transformation and there was some overlap with the recurrence group.

Among 17 patients with recurrence, 6 had “severe” or “extensive” endometriosis, and 14 had surgical menopause, with a mean of 7.1 years between surgical menopause and presentation. Twelve of 17 received unopposed estrogen. Following surgical excision (16 of 17 cases), 10 had symptom regression without relapses.

When the researchers looked at the 25 cases of malignant transformation, they found that 13 women had endometriosis at more than one site, 22 had undergone surgical menopause, 19 were on unopposed estrogen, and the mean duration of HT was 6.7 years. Seven women presented with vaginal bleeding and nine with masses. Three died from the disease. These three women had severe endometriosis complicating factors, including older age and multiple malignancies.

The analysis also included six observational studies and clinical trials that explored recurrence of endometriosis, and whether HT should be given to women with a history of endometriosis, whether it should be given immediately after surgical menopause, and the most appropriate menopause treatments.

Predictably, the evidence could not be summed up neatly, but Ms. Gemmell emphasized the need to individually weigh the risks and benefits of HT in each patient, with consideration of characteristics such as age, previous disease severity, family history, comorbidities, and body mass index.

She also suggested that patients should be active participants in decision making.

Finally, if the decision is to go forward or continue with HT, she suggested that clinicians consider a combined treatment rather than estrogen-only, though she pointed out the increased risk for breast cancer that this presents.

Tommaso Falcone, MD , chairman of obstetrics and gynecology at the Cleveland Clinic, sounded a note of caution about the use of progestins during the question-and-answer session. “The data are not strong that it actually prevents the development of cancer in the residual disease, if there is any. Even if you take the hypothesis that progestins are going to prevent cancer of residual disease, which is a low-level risk, the main worry that women have is breast cancer, and progestin is strongly associated with breast cancer,” Dr. Falcone said in an interview.

Ms. Gemmell and Dr. Falcone reported having no financial disclosures.