Impact of histology and surgical approach on survival among women with early-stage, high-grade uterine cancer: An NRG Oncology/Gynecologic Oncology Group ancillary analysis.

Objectives: We sought to analyze the clinicopathologic features, recurrence patterns and survival outcomes of women with high-grade uterine cancer (UC) enrolled on The Gynecologic Oncology Group (GOG) LAP2 trial.

Methods: This is a post-hoc analysis of LAP-2 patients with grade 3 endometrioid adenocarcinoma (ENDO), uterine serous (USC), clear cell (CC) and carcinosarcoma (CS). Demographics, clinicopathologic features, and recurrence patterns, were compared by histology and surgical approach. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method.

Results: Of the 2600 patients enrolled in LAP-2, 753 patients had high-grade UC: 350 had ENDO, 289 had USC, 42 had CC and 72 had CS. Compared with the ENDO cohort, those with other high-grade subtypes were older (p<0.001) and were more likely to have positive peritoneal cytology (p<0.001), positive lymph nodes (p=0.05) and higher disease stage on final pathology (p<0.001). With a median follow-up time of 60months, compared to patients with ENDO, those with USC, CCC and CS subtypes had higher recurrence rates (p<0.001), extra-pelvic recurrences (p<0.001) and poorer PFS (p<0.001) and OS (p<0.001). Those diagnosed with USC and CS experienced the worst survival outcomes (p=0.003). Patterns of recurrence and survival were not different in those staged with LSC vs LAP. On multivariable analysis, age, stage, pelvic washings and Type II histology were independently and adversely associated with survival.

Conclusions: Women with apparent early-stage, USC and CS histologies have poorer outcomes than women with grade 3 endometrioid adenocarcinoma. Patterns of recurrence and survival were not impacted by surgical approach.