Clinical Efficacy of Taxol Plus Platinum (TP) Chemotherapy Combined with Delayed Administration of PD-1 Inhibitors in Patients with Locally Advanced, Recurrent or Metastatic Esophageal Squamous Cell Carcinoma: A Retrospective Study

Purpose: Immune checkpoint inhibitors (ICIs) combined with chemotherapy have become the first-line standard treatment for locally advanced or metastatic esophageal squamous cell carcinoma (ESCC). The evidence also demonstrates improved synergistic effects of chemotherapy when combined with delayed administration of ICIs. In this study, we conducted a retrospective investigation into the treatment efficacy of taxol plus platinum (TP) chemotherapy combined with delayed administration of PD-1 inhibitors for ESCC patients.
Patients and Methods: Clinical data of ESCC patients who received PD-1 inhibitors 3– 5 days after TP chemotherapy as first-line treatment was retrospectively reviewed between January 2019 and April 2023. Clinical outcomes and treatment safety were analyzed. The potential roles of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), and pan-immune-inflammation value (PIV) were investigated.
Results: A total of 34 locally advanced, recurrent or metastatic ESCC patients received PD-1 inhibitors 3– 5 days following TP chemotherapy were included. The objective response rate (ORR) and disease control rate (DCR) were 85.3% and 97.1% respectively. The median progression-free survival (PFS) and overall survival (OS) were 13.2 and 19.1 month respectively. Seven patients received radical surgery, 1 patient achieved pathologic complete response (pCR) and 3 patients achieved major pathologic response (MPR). Among the 27 patients without surgery, the median PFS and OS were 9.7 and 19.1 month respectively. A more favorable prognosis was correlated with NLR less than 3 at the 3rd and 4th cycle of immunochemotherapy. No significant correlations between other parameters (PLR, MLR and PIV) and prognosis were observed. A total of 22 patients developed grade 3– 4 toxicity events.
Conclusion: The optimized sequence of PD-1 inhibitors administered 3– 5 days after TP chemotherapy as the first-line treatment of ESCC demonstrated favorable treatment efficacy. Pretreatment NLR of less than 3 at the 3rd and 4th cycle of immunochemotherapy is associated with a better prognosis.

Keywords: immune checkpoint inhibitors, chemotherapy, rational sequence, esophageal squamous cell carcinoma, peripheral blood parameters