Gastric Mucosal Atrophy and Serum Biomarker Alterations in Women with Endometriosis: A Case-Control Study.

Endometriosis is a chronic oestrogen-dependent inflammatory disorder that affects approximately 10% of women of reproductive age and is frequently accompanied by gastrointestinal (GI) symptoms. Despite this overlap, gastric mucosal histopathology in this population has not been systematically investigated. In this retrospective case–control study conducted between June 2022 and December 2023, 28 women with laparoscopically or radiologically confirmed endometriosis and 41 controls with similar GI symptoms underwent upper GI endoscopy with biopsy. Demographic data, laboratory results (CRP and tumour markers), and histopathological findings were assessed. Statistical analyses included t-test, Mann–Whitney U, chi-square, and correlation analyses. Women with endometriosis had significantly higher CRP (4.79 vs. 1.98 mg/L, p = 0.022) and CA19-9 [median (IQR): 11.35 (8.75–17.14) vs. 6.77 (4.34–9.25) U/mL, p = 0.033] levels compared with controls. Gastric mucosal atrophy was more prevalent in the endometriosis group (25.0% vs. 2.4%, p = 0.013), while Helicobacter pylori infection and intestinal metaplasia did not differ. Endometriosis correlated positively with CA19-9 and gastric atrophy. Endometriosis is associated with systemic inflammatory alterations and an increased prevalence of gastric mucosal atrophy. These findings suggest extra-pelvic GI involvement and support multidisciplinary management of affected women. In practice, women with endometriosis and persistent upper gastrointestinal symptoms may benefit from coordinated gynecology–gastroenterology evaluation, with endoscopic assessment considered when alarm features or unexplained laboratory abnormalities are present.