Endometriosis is a common disorder that may not respond to medical therapy. In patients who undergo total abdominal hysterectomy with bilateral salpingo-oophorectomy, there is disagreement about when to initiate estrogen replacement therapy. Some physicians advocate delaying estrogen replacement therapy for up to 18 months after surgery to avoid stimulating any residual implants or microscopic endometriosis tissue that surgery may have missed. Other physicians favor starting estrogen replacement therapy immediately following surgery. Hickman and colleagues conducted a retrospective cohort study to determine if the timing of estrogen replacement therapy following total abdominal hysterectomy with bilateral salpingo-oophorectomy for the treatment of endometriosis increased the incidence of symptom recurrence.

The authors reviewed the medical records of 60 women who began taking estrogen within the immediate postoperative period and 35 women who delayed taking estrogen for at least six weeks after surgery. All of the women reported pain as at least one indication for surgery; 63 percent (60 women) had previous medical therapy, and 78 percent (74 women) reported previous surgical therapy for endometriosis. The two groups were comparable in all respects except the timing of estrogen replacement therapy following surgery. Recurrent pain was reported by four women (7 percent) who began taking estrogen immediately following surgery compared with seven women (20 percent) who delayed taking estrogen for at least six weeks after surgery. This difference was not statistically significant. When factors such as age at time of hysterectomy, degree of endometriosis and adjunctive use of postoperative medroxy-progesterone were considered, the relative risk of pain recurrence following surgery was 5.7 for women who delayed taking estrogen.

The authors conclude that initiating estrogen replacement therapy immediately following total abdominal hysterectomy with bilateral salpingo-oophorectomy for the treatment of endometriosis does not increase the risk of recurrent symptoms.