Abstract
BACKGROUND: The impact of radiation-related lymphocyte recovery on prognosis in locally advanced esophageal squamous cell carcinoma (LA-ESCC) remains unclear. METHODS: Patients with stage II-IVa ESCC who received definitive RT were screened. Collect absolute lymphocyte counts (ALCs) before, during, and after RT. The recovery status of lymphocytes was observed at one-month post-RT (P1) and three months post-RT (P3). Patients with relatively lower lymphocyte recovery levels at P1 were divided into Group a and those with higher levels were divided into Group b. Patients with relatively lower lymphocyte recovery levels at P3 were divided into Group A and those higher were divided into Group B. Kaplan-Merier's analysis and Cox analysis were conducted to compare survival outcomes. Binary logistic regression analyses was employed to ascertain factors associated with lymphocyte recovery. RESULTS: 116 patients were enrolled. During RT, ALCs reached the bottom 5 weeks after RT started and 70.7% of patients experienced G3 lymphopenia. The median OS for Group a and Group b were 38.1 months and 14.4 months, p = 0.097. The median PFS for Group a and Group b were 14.2 months and 10.0 months, p = 0.037. Whereas, the median OS for Group A and Group B was 14.5 months and 22.2 months, p = 0.019. The median PFS for Group A and Group B were 8.4 months and 12.4 months, p = 0.021. Cox multivariable analysis revealed that higher lymphocyte recovery level at P3 was significantly associated with superior OS (p = 0.040, HR0.636) and PFS (p = 0.028, HR0.627). The logistic analysis identified a positive association between G4 lymphopenia during RT (p = 0.012, OR 7.742) and PTV dose < 60 Gy (p = 0.014, OR 2.655) with lymphocyte recovery. CONCLUSIONS: The prognostic value of lymphocyte recovery status at P3 appears to be greater than that of lymphocyte recovery status at P1 for locally advanced ESCC patients. Radiation-related lymphocyte recovery might serve as a valuable prognostic factor in LA-ESCC.