Upregulation of tumor PD-L1 by neoadjuvant chemoradiotherapy (neoCRT) confers improved survival in patients with lymph node metastasis of locally advanced rectal cancers

In this study, we examined the roles of tumor PD-L1 and IFN-γ before and after neoCRT in locally advanced rectal cancer (LARC) patients. Our results demonstrate that patients with high PD-L1 expression in post-neoCRT tissues exhibit improved 5-year disease-free survival (DFS) and overall survival (OS) compared with those with low PD-L1 e xpression (p <  0.001). Furthermore, in the pN+ population, patients with high PD-L1 expression in post-neoCRT tissues exhibit improved 5-year DFS and OS. PD-L1 and IFN-γ upregulation increased in tumor tissues after neoCRT, and patients with high PD-L1 and high IFN-γ exhibit improved 5-year DFS and OS (p = 0.04 andp = 0.001, respectively). To the best of our knowledge, this study is the first to demonstrate that PD-L1 upregulation in a pN+ cohort correlates with improved prognosis, which is similar to that in patients without nodal metastasis. Moreover, this study verified that PD-L1 and IFN-γ were upre gulated by neoCRT treatment in LARC patients and demonstrated that neoCRT may be useful not only for immune checkpoint inhibitor treatment but also for reinvigorating preexisting anti-cancer immunity.
Source: Cancer Immunology, Immunotherapy - Category: Cancer & Oncology Source Type: research