Clinicopathological and prognostic characteristics of gastric-type endocervical adenocarcinoma: A single-center retrospective study.

5525 Background: Gastric-type endocervical adenocarcinoma (G-EAC) is a rare and highly aggressive subtype of cervical cancer. Limited screening methods often lead to late-stage diagnosis, contributing to its poor prognosis. This study reviews cases of G-EAC managed at a tertiary gynecological oncology center over the past six years, focusing on prognostic characteristics and responses to adjuvant therapies. Methods: We reviewed demographic, pathological, clinical, and prognostic data from patients diagnosed with cervical adenocarcinoma and treated surgically at Obstetrics and Gynecology Hospital Fudan University from January 1, 2018, to December 31, 2023. G-EAC patients were assigned to the study group, while those with usual endocervical adenocarcinoma (UEA) served as the control. The groups were matched 1:1 using propensity score matching to compare prognosis. Primary endpoints were 3-year progression-free survival (PFS) and overall survival (OS). Kaplan-Meier and Cox regression analyses were used to assess survival, and univariate and multivariate analyses were conducted to identify risk factors for G-EAC. Results: A total of 960 patients were included in this study, comprising 195 cases of G-EAC and 765 cases of UEA. After matching, the G-EAC group exhibited significantly lower 3-year OS and PFS compared to the UEA group (OS: 74.9% vs. 84.6%, PFS: 66.1% vs. 79.8%, χ² = 4.59/6.04, p = 0.032/0.014). Parametrial involvement (OS/PFS: HR = 3.19/2.54, p = 0.003/0.009) and pelvic lymph node metastasis (OS/PFS: HR = 2.64/2.26, p = 0.012/0.013) as independent risk factors for death and recurrence in G-EAC patients. G-EAC patients treated with combined radiotherapy and chemotherapy had significantly better 3-year OS and PFS than those receiving either modality alone (OS: 74.3% vs. 54.5%, PFS: 65.2% vs. 43.6%, χ² = 4.86/4.23, p = 0.028/0.039). Cox regression analysis showed that G-EAC patients receiving radiotherapy or chemotherapy alone had significantly higher risks of death and recurrence compared to UEA patients (OS/PFS HR: 5.88/8.37, p = 0.037/0.009). Similarly, G-EAC patients treated with combined radiotherapy and chemotherapy exhibited slightly higher risks of death and recurrence than UEA patients (OS HR: 2.61 vs. 1.63, PFS HR: 3.91 vs. 2.66). Conclusions: G-EAC is a rare pathological subtype of cervical cancer with an exceptionally poor prognosis, significantly worse than that of UEA. Parametrial involvement and pelvic lymph node metastasis are independent risk factors for recurrence and death in G-EAC patients. Postoperative combined radiotherapy and chemotherapy reduce the risks of recurrence and death compared to single-modality treatments. However, G-EAC remains less responsive to adjuvant chemoradiotherapy than UEA. Further research to develop more effective therapeutic strategies for this rare and aggressive subtype.