MedWire News: The combination of letrozole with norethisterone acetate (NET) reduces endometriosis pain intensity to a greater extent than NET alone, but is associated with more side-effects and has a similar effect on recurrence of pain, show study results.

Simone Ferrero (University of Genoa, Italy) and colleagues performed a prospective study of 82 women with endometriosis pain after laparoscopy who did not want to undergo further surgery. Over a 6-month period, half of the patients received a combination of letrozole and NET (group L) and the remainder were treated with NET alone (group N).

Both treatments significantly reduced pain intensity but, at both the 3- and 6-month assessment, pain intensity was significantly lower in group L than in group N, with corresponding values of 1.9 and 1.5 versus 3.4 and 2.8 for chronic pelvic pain, and 2.2 and 1.7 versus 3.8 and 3.1 for deep dyspareunia using a 10-cm visual analogue scale.

After treatment cessation, symptoms recurred at the 6- and 12-month follow-up, with no significant difference in pain symptom intensity seen between the two groups.

Significantly more patients in group L than group N experienced at least one side effect (43.2 vs 18.4 percent). Furthermore, some of these side effects, such as joint pain and myalgia, were not experienced during treatment with NET alone.

“On the basis of these findings and considering the higher cost of the double-drug regimen, we believe that aromatase inhibitors should be administered only to patients who previously failed to respond to established therapies and refuse surgery,” conclude the authors.

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