P-338 Preliminary results of the DINE Study (Dienogest vs. Norethindrone Acetate in Endometriosis Treatment)
Authors: Gurbuz T B , Uncu G , Aslan K , Gadırlı Z , Kasapoglu I 
Published: June 2023

Abstract

Study question
How do the two-progestin type NETA and dienogest affect on pain and recurrence in patients with endometriosis?

Summary answer
NETA and dienogest are progestin derivatives that have similar effects on pain and recurrence in treating endometriosis and canbe safely preferred for treatment.

What is known already
Although surgical treatment significantly improves pain symptoms in endometriosis, it may be associated with significant urinary, intestinal and vascular complications; In addition, postoperative pain and recurrence rates of endometriotic lesions are high. Medical treatment gains importance, and progestins are mainly used in treatment. NETA is one of the most researched progestins for the treatment. It has a good safety profile and efficacy in curing endometriosis-related pain, making NETA a viable medical option among first-line treatments.

Study design, size, duration
The study was designed as a single-center, prospective, randomized study. Patients were randomly assigned to one of the two treatment protocols, with the single digit 'NETA' and double 'dienogest' according to the last digit of their protocol number. Patient recruitment started in February 2022. The patients were evaluated at 6-month visits for one year.

Participants/materials, setting, methods
Seventy patients aged 18-40 years were included. Patients with contraindicated progestins and pelvic inflammatory disease were excluded from the study. Demographic data, medical and surgical treatment histories were recorded. Patients were evaluated with detailed physical examination, ultrasound, and laboratory tests. They were questioned because of their chronic pain symptoms, they were asked to give a score between 1 and 10 with the numerical scoring system and recorded. They were re-evaluated at 6 and 12 months.

Main results and the role of chance
40 dienogest and 30 NETA patients were included in the study. There were eight patients (one headache, one orthostatic hypotension, five metrorrhagia, one pregnancy request) in the NETA group and 11 patients (1 headache, one decreased sexual desire, one surgery, eight metrorrhagia) in the dienogest group. In the final analysis, 48 patients were included in the study. There was no significant difference between the two groups regarding initial laboratory, ultrasonographic and demographic parameters. (p &gt; 0.5) There was no significant difference between the two groups in dropout rates at six months. (p = 0.65)
Dysmenorrhea, dyspareunia, dyschezia, and chronic pelvic pain scores were similar both at the beginning of treatment and at the 6th-month follow-up, and no significant difference was observed in both group. (p &gt; 0.5) Significant improvement was observed in all scores in both groups.(p &lt; 0.001) In the 6th month, the most common side effects in the dienogest group were emotional lability (26%), and metrorrhagia (15%), while the NETA group were metrorrhagia (40%) and weight gain (20%). No significant effect was observed on the lipid profile and bone mineral density at the 6th-month control.

Limitations, reasons for caution
Our study is the first study in the literature to compare NETA and dienogest in the medical treatment of endometriosis. The strongest aspect is that it is a randomized control study. The small number of study population and the high dropout rates are the limitations.

Wider implications of the findings
NETA and dienogest are two progestin derivatives that are effective on pain and recurrence in the medical treatment of endometriosis and can be safely preferred for treatment. An analysis of our long-term data and further studies are needed to evaluate which progestin preparation is more effective and safe in treatment.

Trial registration number
NCT05476172