Associations Between Intraluminal Tumor Cell Involvement in Serially Examined Fallopian Tubes and Endometrial Carcinoma Characteristics and Outcomes

Approximately 12% of routinely examined fallopian tubes of endometrial carcinoma (EC) cases have intraluminal tumor cells (ILTCs). ILTC associations with EC characteristics and outcomes are understudied, and unknown in serially examined and embedded tubal fimbriae. Glass slides of serially examined and embedded tubal fimbriae for 371 EC cases were independently reviewed by 2 pathologists who recorded ILTC presence and characterized them as mucosal if involved and floating if not. Disagreements were reviewed by a third pathologist, and agreement between any 2 determined final ILTC status. Clinico-pathologic associations and ILTC presence were tested for significance (P<0.05) by univariable analysis, and stage and histotype determinants were included in a multivariable analysis. The Kaplan-Meier estimates and log-rank tests compared overall and EC-specific survival, and Cox proportional regression estimated hazard ratios. ILTCs were present in 56 (15.1%) cases: 30 mucosal and 26 floating. FIGO stage 3/4, lymph-vascular space invasion, deep myometrial invasion, nonendometrioid histotype, and adjunctive chemotherapy were significantly associated with ILTC presence, and only stage was significant in the multivariable analysis. Overall, 61 women died: 30 of whom died of EC. ILTCs were nonsignificantly associated with higher overall and EC-specific mortality and mucosal ILTCs had the highest hazard ratios (1.64 and 1.89, respectively). Serially examined and embedded tubal fimbriae have a higher prevalence of ILTCs than routinely examined tubes, and high FIGO stage is an independent determinant. A prognostic effect was not found, but the higher trending hazard ratios suggest additional study is needed to determine whether ILTCs and in particular mucosal ILTCs adversely affect prognosis.