The association of endosalpingiosis with gynecologic malignancy

Endosalpingiosis is a poorly understood condition of ectopic epithelium resembling the fallopian tubes. It has been described as an incidental pathology finding, a disease similar to endometriosis, and in association with malignancy. The objective of this study is to determine if endosalpingiosis (ES) has an increased association with gynecologic malignancy when compared to endometriosis (EM).

This is a retrospective case-control analysis of patients with a histologic diagnosis of endosalpingiosis or endometriosis at three affiliated academic hospitals between 2000 and 2020. All ES patients were included, and 1:1 matching was attempted to obtain a comparable cohort of EM patients. Demographic and clinical data were obtained, and statistical analysis was performed.

A total of 967 patients (515 ES and 452 EM) were included. ES patients were significantly older than EM patients (median age 52 vs 48 years, p < 0.001). The ES group had significantly more cancer diagnoses at surgery than the EM group (40.1% vs 18.1%, p < 0.001); this difference persisted in a sub-analysis excluding patients with known or suspected malignancy (20.9% vs 5.6%, p < 0.001). ES patients had lower overall survival (10-year freedom from death: 77.0% vs 90.5%, p < 0.001). After adjusting for confounders, multivariable analysis showed that ES patients had increased cancer diagnosed at surgery (OR = 2.48, p < 0.001) and greater risk of death (OR = 1.69, p = 0.017).

Endosalpingiosis was found concurrently with malignancy in 40% of cases, and this effect was preserved in multi-variable and sub-group analyses. Further research consisting of longer follow-up and exploration of molecular relationships between ES and cancer are forthcoming.