Endometrioma patients are under-treated with endocrine endometriosis therapy.

Study question: Is there a difference in the use of endocrine endometriosis therapy in endometriosis patients with and without endometrioma?

Summary answer: Patients with endometriomas received significantly less endocrine endometriosis treatment (present intake in 42.5%) compared to patients with other forms of endometriosis and without endometriomas (present intake in 52.1%).

What is known already: Endocrine endometriosis therapy in patients with endometriomas reduces the risk of recurrence and therefore the risk of further surgery and subsequent irreversible damage to ovaries which results into reduced antral follicle counts (AFC), anti-Mullerian hormone levels (AMH), and early menopause. However, there is evidence of increasing rejection of endocrine endometriosis treatment in this population.

Study design, size, duration: A total of 838 premenopausal woman with dysmenorrhea and/or endometriosis (mean age 30.7 ± 6.9 years, range 15-54 years) were included in this observational cross-sectional multicenter study. Data including the extent of dysmenorrhea, prevalence of other comorbidities like migraine with aura and migraine never with aura, diagnosis of endometriosis, history of endometriosis surgery, and hormone therapy, were collected in a retrospective online survey from May to November 2023.

Participants/materials, setting, methods: Patients visiting two university hospital endometriosis centers between January 2017 and March 2023, and with available email address, were invited for study participation by email in May 2023. Further recruitment of participants was achieved through the website and social medial channels of the German Endometriosis Association. Participation in the online survey was open between May and November 2023.

Main results and the role of chance: In the subgroup of women (with dysmenorrhea) without surgically confirmed endometriosis (SCE) (n = 277), 95 (34.3%) were currently undergoing endocrine treatment for dysmenorrhea and contraceptional purposes. On the contrary, in the subgroup of patients with SCE (n = 561), 275 (49.0%) were currently undergoing hormonal treatment. Subjects with SCE therefore significantly more commonly took endocrine treatment (F = 16.587, P < 0.001) compared to those without SCE. Endometriomas were present in 254 patients (45.2% of all SCE patients), and these patients were significantly less likely to have used hormonal treatment (i) in the present and (ii) in the past (i. n = 113 42.5%, ii. n = 187, 73.9%) compared to patients with other forms of endometriosis (n = 261) (i. n = 139, 52.1%, ii. n = 220, 84.3%) (i. F = 3.976, P = 0.047, ii. F = 8.297, P = 0.004). Various reasons for rejection of endocrine endometriosis treatment were analyzed, when comparing endometrioma subjects to patients with other types of endometriosis, but no statistical differences were found.

Limitations, reasons for caution: This study is limited by its retrospective design and an online questionnaire with patient-reported outcomes. A selection bias due to the voluntary nature of the study and the online recruitment is also possible.

Wider implications of the findings: The results show that patients often refuse endocrine endometriosis treatments without a rational medical reason. According to the literature, this unnecessarily exposes these patients to a higher risk for endometrioma recurrence and subsequently a higher risk of repeat surgery and permanent damage to ovarian function.

Study funding/competing interest(s): This study was funded by the University of Luebeck (budget for university teaching and research). A.C. was supported by DFG (CRC/TR 296 'Local control of TH action', LocoTact, P07) and by funds of University of Luebeck, medical section (LACS01-2024). N.B. was supported by the DFG (BR4328.2-1, GRK1957), the Michael J Fox Foundation, the Collaborative Center for X-linked Dystonia-Parkinsonism and the EU Joint Programme-Neurodegenerative Disease Research (JPND). C.C., H.G., C.G., I.A., A.K., A.R. received no funding for this study. There were no competing interests.

Trial registration number: N/A.