Beyond mismatch repair deficiency? Pre-treatment neutrophil-to-lymphocyte ratio is associated with improved overall survival in patients with recurrent endometrial cancer treated with immunotherapy

Objective: To determine the association of pre-treatment neutrophil-to-lymphocyte ratio (NLR) with progression-free survival (PFS) and overall survival (OS) for patients with recurrent endometrial cancer (EC) treated with immunotherapy.

Methods: Recurrent EC patients treated with immunotherapy alone or in combination from 2016 to 2021 were included. Demographics, pre-treatment laboratory results, pathologic data, response at first radiographic assessment, and cancer outcomes were obtained from the medical record. Kaplan-Meier curves were generated to compare PFS and OS stratified by NLR.

Results: The 106 patients included in the study were stratified by NLR <6 (n = 77, 72.6%) or NLR ≥6 (n = 29, 27.3%). Most had endometrioid pathology (59%), widely metastatic disease, and 36.8% had received ≥2 treatment lines before initiating immunotherapy. Mismatch repair deficiency (dMMR) was noted in 52 (49.1%) tumors. Most dMMR patients (94.3%) were treated with single-agent pembrolizumab, and most MMR proficient patients (78.7%) were treated with lenvatinb plus pembrolizumab. In the overall cohort, 40.2% (partial response (PR) 29.9%, complete response (CR) 10.4%) of patients with a NLR <6 responded at first radiographic assessment, compared to 31% (PR 27.5%, CR 3.4%) of patients with NLR ≥6 (p 0.691). Kaplan-Meier curves stratified by NLR <6 vs. ≥6 showed no difference in PFS. However, NLR <6 was associated with improved OS (p < 0.05). In the NLR < 6 group, the probability of survival at one year was 69% (95% CI: 58%, 82%), compared to 41% (95% CI: 26%, 67%) for the NLR > 6 group.

Conclusions: Pre-treatment NLR <6 was associated with improved OS for recurrent EC patients treated with immunotherapy. NLR holds promise as a predictive biomarker for survival after immunotherapy treatment for patients with recurrent EC.