Fassan M, Cavallin F, Guzzardo V, et al. - In this exploratory, retrospective study, researchers examined 88 consecutive patients treated with neoadjuvant chemoradiotherapy (CTRT) for squamous cell carcinoma of the thoracic esophagus to determine immunological predictors of pathological complete response post-neoadjuvant CTRT. According to the Mandard score system, they measured tumor regression following neoadjuvant therapy. Pretreatment biopsies were analyzed for immunohistochemical expression of CD4, Tbet, FoxP3, CD8, CD80, PD-L1, and PD-1. They correlated the immunohistochemical profiles to patients’ outcomes. Findings revealed that pathological complete response following neoadjuvant CTRT was predicted with adequate accuracy by PD-L1 expression and CD8+ and CD4+ lymphocyte rate. A link was found between recurrence/relapse and high level of CD4+ T cell infiltration. Definitive conclusions could not be made due to small sample size.