Alleviation of neoadjuvant immunochemotherapy for esophageal squamous cell carcinoma and its relationship with expression and changes of PD-L1

The alleviation of neoadjuvant immunochemotherapy (NICT) and neoadjuvant chemoradiotherapy (NCRT) was compared for esophageal squamous cell carcinoma (ESCC), and the correlation between the expression and changes of PD-L1 and the efficacy of NICT was evaluated in this study. Fourteen patients with ESCC who received preoperative NICT were included in group A, and fourteen patients with ESCC who received preoperative NCRT were included in group B. Next, group A was divided into CR (complete response), PR (partial response), and NR (no response) according to the degree of pathological response. Also, the expression and changes of PD-L1 (CPS, TPS, IPS) before and after treatment were compared between the groups. We observed that after the treatment, the expression of PD-L1 in both groups was higher than before treatment. In group B, the expression of PD-L1 was elevated in 92.8% of patients, which was higher than that in group A, which had significantly increased IPS (p<0.05). In group A, 9 (64.2%) patients with CPS <10 achieved partial or complete response. There was no significant difference in pathological response and reduction of tumor thickness between the two groups or significant differences in CPS and TPS among CR, PR, and NR groups before treatment. The IPS was the highest in the CR group; however, the difference was not statistically significant. The differences in IPS change were significant among the three groups (p<0.05). In conclusion, NICT and NCRT could upregulate the expression of PD-L1. NCRT more significantly upregulated the expression of PD-L1, mainly of PD-L1 in immune cells in the tumor microenvironment. NICT was not less effective than NCRT in pathological response and tumor thickness changes. The preoperative CPS and TPS scores of PD-L1 did not effectively predict the degree of pathological response, but the high IPS and high IPS downregulation could be related to the degree of pathological response. Some patients with low preoperative expression of PD-L1 could still achieve a good response by NICT. As NCRT can upregulate the expression of PD-L1, the low preoperative expression of PD-L1 is no contraindication for immunotherapy, which provides a new basis and prognostic indexes for chemoradiotherapy combined with immunotherapy.