Tumor-infiltrating lymphocytes in patients undergoing esophagectomy following neoadjuvant DCF therapy.

BACKGROUND: Accumulating evidence suggests that expression levels of tumor-infiltrating (TI) cells may play a prognostic role in patients with esophageal cancer who have undergone esophagectomy. However, its effect on patients undergoing neoadjuvant docetaxel, cisplatin, and 5-fluorouracil (DCF) therapy followed by esophagectomy for esophageal squamous cell carcinoma (ESCC) remains unclear. Therefore, this study aimed to elucidate the prognostic impact of TI cells in patients who underwent esophagectomy following neoadjuvant DCF therapy. METHODS: Overall, 81 patients with ESCC who underwent curative esophagectomy following neoadjuvant DCF therapy were included. The number of TI CD8+ cells was determined using light microscopy at ×400 in tumor invasive margins. Receiver operative characteristic curve was used to determine the cutoff values for mortality for continuous variables; the patients were separated into high and low TI CD8+ cell groups and their backgrounds and clinical outcomes were compared. RESULTS: Overall and relapse-free survival were significantly worse in the TI CD8+-low group than that in the TI CD8+-high group (p < 0.01). Multivariate analysis revealed that positive ypN (hazard ratio [HR], 3.12; 95% confidence interval [CI], 1.08-9.02) and low TI CD8+ cell levels (HR, 2.77; 95% CI, 1.31-5.85) were independent prognostic factors for overall survival. Furthermore, positive venous invasion (HR, 2.63; 95% CI, 1.29-5.35) and low TI CD8+ cell levels (HR, 2.77; 95% CI, 1.70-5.46) were significant prognostic factors for relapse-free survival. CONCLUSIONS: Low TI CD8+ cell level was a prominent prognostic factor for patients with ESCC undergoing neoadjuvant DCF therapy followed by esophagectomy.