Detection of endometrial cancer cells in the fallopian tube lumen is associated with adverse prognostic factors and reduced survival

Stage is a critical determinant of prognosis and treatment for endometrial cancer (EC) patients. Women who have had a tubal ligation for sterilization have improved EC survival, secondary to lower stage at presentation, suggesting that transtubal spread may represent an important route of metastasis. We evaluated detection of intraluminal tumor cells (ILTCs) in relation to tumor characteristics and survival. One pathologist retrospectively evaluated hematoxylin and eosin sections of routinely collected fallopian tubes for ILTCs from 295 EC patients, masked to outcome. We used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for associations between demographic (age, race) and clinical [FIGO 2009 stage, lymphovascular space invasion (LVSI), histological subtype] characteristics and ILTCs. Cox regression was used to estimate hazard ratios (HRs) and 95% CIs for associations between ILTCs and recurrence-free survival (RFS) and EC-specific survival, overall and stratified by histological subtype or stage. In univariable logistic regression models, age (55–64 vs. ≥65: OR = 3.41, 95% CI = 1.48–7.84), stage (stage IV vs. stage I OR = 14.58, 95% CI = 5.27–40.35), LVSI (OR = 2.93, 95% CI = 1.42–6.04), and histological subtype (serous vs. low-grade endometrioid OR = 3.21, 95% CI = 1.08–9.58), were associated with ILTCs. Only age and stage remained significantly associated with ILTCs in adjusted models. ILTCs were significantly associated with lower EC-specific survival among women with serous EC or stage I disease; however, adjustment for age, stage, and histology attenuated these associations. Our findings suggest that ILTCs are associated with adverse EC prognostic features and reduced survival in cases of early stage or serous histology. •Endometrial cancer stage is an important prognostic factor; however; transtubal spread is not captured in current criteria.•Intraluminal tumor cells (ILTCs) are a putative marker of transtubal spread.•ILTCs were associated with higher stage, serous histology, and lymphovascular space invasion.•ILTCs were significantly associated with lower survival among women with serous or stage I disease.•In our small sample associations were attenuated after adjustment for other prognostic factors.