Prognostic nutritional index as a prognostic marker in metastatic esophageal squamous-cell carcinoma treated with immune checkpoint inhibitor

The prognostic nutritional index (PNI) is an inflammation- and nutrition-based indicator that serves as a prognostic factor for various cancer types. This study aimed to evaluate the association between PNI and survival in patients with esophageal squamous-cell carcinoma (ESCC) receiving immune checkpoint inhibitor (ICI)-based therapies.

This single-center retrospective study included two cohorts: 109 patients treated with nivolumab monotherapy as second-line or later therapy and 92 patients receiving first-line ICI-based treatments (ICI plus chemotherapy or nivolumab plus ipilimumab).

In the nivolumab monotherapy cohort, higher PNI (PNI ≥ 40.5) was linked to longer overall survival (OS) compared with lower PNI (16.2 versus 5.5 months, P = 0.001). In the first-line cohort, 92 patients received ICI plus chemotherapy (n = 60) or nivolumab plus ipilimumab (n = 32). Higher PNI was linked to better OS in both the ICI plus chemotherapy (21.2 versus 7.7 months, P = 0.0008) and the nivolumab plus ipilimumab (not reached versus 10.2 months, P = 0.02) cohorts. Multivariate analysis identified PNI status as an independent prognostic factor in both cohorts. Dynamic changes in PNI (delta PNI ≥ 1.25) 1 month after treatment were linked to better progression-free survival in patients with lower PNI receiving nivolumab monotherapy or nivolumab plus ipilimumab but not in those receiving first-line ICI plus chemotherapy.

PNI and its dynamic changes may serve as useful indicators of prognosis in patients with ESCC receiving ICI-based therapies.