What matters most in FIGO IIIA endometrial cancer: Involvement of serosa, adnexa, or both? (542)

Abstract

Objectives: To compare the clinical-pathologic features and survival outcomes for patients with FIGO Stage IIIA endometrial cancer with uterine serosa or adnexal involvement. Methods: This was an international, multi-institutional, IRB- approved retrospective research collaboration spanning 2000 to 2019. Patients (pts) with surgically staged (FIGO 2009) IIIA endometrial cancer were included for analysis (tumor involving the uterine serosa or adnexa). Patients with sarcoma or concurrent endometrial/ ovarian malignancy, neoadjuvant treatment, positive lymph nodes, or peritoneal disease were excluded. Appropriate statistical tests were performed. Results: A total of 184 pts met inclusion criteria: 138 adnexa only (AO), 40 serosa only (SO), and six with combined adnexal and serosal involvement (AS). Median age at diagnosis for the cohort was 60 years (range: 23-89 years). Compared with AO, 50% SO had endometrioid FIGO Grade 3 (vs 19%, p<0.01), and 58% had lymphovascular invasion (vs 33%, p<0.01). Five pts with AS had non-endometrioid histology (83%). The distribution of surgical approach, cervical stromal involvement, pelvic cytology, or receipt of adjuvant treatment (chemotherapy +/- radiation, radiation, or none) were independent of each other within the three groups. Median follow-up was 77 months (0.6-254 months). Five-year progression-free survival (PFS) for pts with AO was 79% (SE 3.8), SO 61% (SE 8.3), and AS 33% (SE 19.2) (p<0.01). Five- year overall survival for pts with AO was 85% (SE 3.7), SO 70% (SE 7.8), and AS 60% (SE 21.9) (p=0.09). Unadjusted hazard ratios for all FIGO stage IIIA groupings (AO, SO and AS), histology, and lymphovascular invasion (LVSI) were significantly associated with PFS. Stage IIIA tumors with serosal involvement had a negative impact on PFS when adjusted for histologic subtype, receipt of adjuvant treatment, and LVSI (for SO: HR: 2.2, 95% CI 1.1-4.5; for AS: HR: 2.4, 95% CI 0.7-8.4; p=0.04). Conclusions: FIGO Stage IIIA endometrial cancers have distinct survival outcomes depending upon serosa only, adnexa only, or combined involvement. Progression-free survival was poorest for serosa-involved pts (SO and AS) when adjusting for histology, adjuvant treatment, and LVSI. These data suggest that endometrial cancers with serosa involvement should be considered a higher risk group within the Stage IIIA diagnosis. Objectives: To compare the clinical-pathologic features and survival outcomes for patients with FIGO Stage IIIA endometrial cancer with uterine serosa or adnexal involvement. Methods: This was an international, multi-institutional, IRB- approved retrospective research collaboration spanning 2000 to 2019. Patients (pts) with surgically staged (FIGO 2009) IIIA endometrial cancer were included for analysis (tumor involving the uterine serosa or adnexa). Patients with sarcoma or concurrent endometrial/ ovarian malignancy, neoadjuvant treatment, positive lymph nodes, or peritoneal disease were excluded. Appropriate statistical tests were performed. Results: A total of 184 pts met inclusion criteria: 138 adnexa only (AO), 40 serosa only (SO), and six with combined adnexal and serosal involvement (AS). Median age at diagnosis for the cohort was 60 years (range: 23-89 years). Compared with AO, 50% SO had endometrioid FIGO Grade 3 (vs 19%, p<0.01), and 58% had lymphovascular invasion (vs 33%, p<0.01). Five pts with AS had non-endometrioid histology (83%). The distribution of surgical approach, cervical stromal involvement, pelvic cytology, or receipt of adjuvant treatment (chemotherapy +/- radiation, radiation, or none) were independent of each other within the three groups. Median follow-up was 77 months (0.6-254 months). Five-year progression-free survival (PFS) for pts with AO was 79% (SE 3.8), SO 61% (SE 8.3), and AS 33% (SE 19.2) (p<0.01). Five- year overall survival for pts with AO was 85% (SE 3.7), SO 70% (SE 7.8), and AS 60% (SE 21.9) (p=0.09). Unadjusted hazard ratios for all FIGO stage IIIA groupings (AO, SO and AS), histology, and lymphovascular invasion (LVSI) were significantly associated with PFS. Stage IIIA tumors with serosal involvement had a negative impact on PFS when adjusted for histologic subtype, receipt of adjuvant treatment, and LVSI (for SO: HR: 2.2, 95% CI 1.1-4.5; for AS: HR: 2.4, 95% CI 0.7-8.4; p=0.04). Conclusions: FIGO Stage IIIA endometrial cancers have distinct survival outcomes depending upon serosa only, adnexa only, or combined involvement. Progression-free survival was poorest for serosa-involved pts (SO and AS) when adjusting for histology, adjuvant treatment, and LVSI. These data suggest that endometrial cancers with serosa involvement should be considered a higher risk group within the Stage IIIA diagnosis.