Recurrence and survival in endometrioid endometrial cancer - a population-based cohort study

Abstract

Objective: The aim of this study was to investigate recurrences and survival in endometrioid endometrial cancer (EC) in a complete population-based cohort.

Methods: A regional population-based study including women with endometrioid EC, identified by the Swedish Quality Registry for Gynecological Cancer (SQRGC), where primary surgery was performed between 2010 and 2017. Patient characteristics and outcomes, including recurrences, were retrieved from the SQRGC and completed by records reviews. Overall (OS), net (NS) and disease-free survival (DFS) were calculated using the Kaplan-Meier method. The Fine and Gray proportional subdistribution hazards' regression model was used for risk factors for recurrence.

Results: There were 1630 women included in the study, whereof 136 (8.3%) had a recurrence with a median time to recurrence of 22.5 months (range 3.2-59.3). One site of recurrence was diagnosed in 69.1%, while 27.2% being only vaginal. The total 5-year OS was 88.0%(95% CI:86.4-89.7) and the 5-year NS 98.6%(95% CI:96.5-100.7). If no recurrence occurred, the OS was 91.9%(95% CI:90.4-93.3) and NS 102.8%(95% CI:100.9-104.8). For only vaginal recurrence, 5-year OS was 77.0%(95% CI:64.0-92.6) compared to 36.1%(95% CI:27.5-47.3) for all other recurrences. The total 5-year DFS was 83.9%(95% CI:82.0-85.7). In the multivariable analysis, age, FIGO stage and primary treatment were found independent factors for recurrence with a HR of 1.29(95% CI:1.11-1.51;p = 0.001) for age, 2.78(95% CI:1.80-4.29;p < 0.001) for FIGO stage III and 1.84(95% CI:1.22-2.78;p 0.004) for adjuvant treatment.

Conclusion: There is an overall low recurrence rate for endometrioid ECs with a minor portion being only vaginal, associated with a favorable survival in contrast to other recurrences with a poor prognosis. Age, FIGO stage III and adjuvant treatment were found independent prognostic factors for recurrence.

Keywords: Cohort studies; Endometrial cancer; Lymphadenectomy; Population-based; Recurrence; Registries; Survival.