Material and Method: A prospective cohort study was conducted in a university hospital. Consecutive premenopausal women with symptomatic endometriosis received hormone therapy following definitive surgery. Before November 2008 conjugated equine estrogen 0.625 mg per day was used in all patients. After that time, all patients received conjugated equine estrogen 0.625 mg plus medroxyprogesterone acetate 2.5 mg per day. Patients came for a follow-up visit every six months to ascertain if they had any recurrent pain.

Results: The cumulative recurrence rates of pain at months 12, 24 and 36 were 0%, 2.9% and 2.9%, respectively in the estrogen plus progestin group (n = 68) and 4.4%, 6.0% and 8.2%, respectively in the estrogen group (n = 93). No significant difference in cumulative recurrence rates of pain between the two groups was observed. It could not be demonstrated that the hormone regimen was an independent risk factor of recurrence of pain.

Conclusion: There was a marginally lower recurrence rate of pain in patients receiving estrogen plus progestin than in those using estrogen. However, no statistically significant difference was demonstrated.

Keywords: Endometriosis, Hormone therapy, Pain, Recurrence, Surgery