Systemic Inflammation Changes Association with Plan Tumor Volume and its Effects on Radiation Therapy Effects in Esophageal Cancer

Abstract

Chemoradiation therapy of inoperable locally advanced esophageal cancer (LAEC), although improving outcomes of patients, still results in 50% of recurrence, which may be facilitated by the recruitment of circulating tumor cells to pro-inflammatory microenvironments in the absence of lymphocytes. Also, radiation can both suppress and stimulate the immune system. This study aimed to investigate the radiation induced-systemic inflammation changes in LAEC for early predicting treatment response to radiotherapy. Subjects consisted of 213 LAEC patients (median age of 66 years) who had received definitive thoracic radiotherapy with a median dose of 60Gy and 30fx, and 76% received concurrent chemotherapy. Peripheral blood was collected pre-RT, at week 2 during RT (mid-RT) and post-RT for each patient and analyzed by using automated flow cytometry. Neutrophil: lymphocyte ratio (NLR), platelet: lymphocyte ratio (PLR) were calculated for each complete blood count. Associations between plan tumor volumes (PTVs) with hematologic parameters pre-RT, mid-RT, post-RT and their changes during RT were assessed with Spearman correlation coefficients. Associations of the hematologic parameters with progression-free survival (PFS) of patients were analyzed by Cox proportional hazards regression analysis. With a median follow-up period of 36.3 months (range 24-44.8 months), median PFS was xx months. For all patients, the median PTV was 405.7±17.2 cc. Smaller PTVs were correlated with lower mid-RT NLR (r = 0.35; p = .000) and lower mid-RT PLR (r = 0.27; p = .000). On univariate analysis, Lower NLR (p = .04) and PLR (p = .01) at mid-RT and more decreasing in NLR (p = .001) and PLR (p = .004) at mid-RT were associated with longer PFS (Table 1). No significant predictive effects were shown in NLR or PLR at pre-RT or post-RT. Lower NLR and PLR during definitive radiotherapy were associated with smaller PTVs and longer PFS in LAEC. It indicated that peripheral inflammation following radiotherapy for LAEC may be a novel prognostic biomarker for radiotherapy response and further studies are needed to develop treatment strategies. Table 1. Univariable and multivariable Cox proportional hazards regression analysis.Abstract 3417; TableUnivariable analysisMultivariable analysisHR95%CIP valueHR95%CIP valueNLRpre-RT1.180.78-1.810.45NLRmid-RT1.591.03-2.440.04*0.640.30-1.370.25NLRpost-RT0.920.60-1.400.68NLRearlychange2.051.33-3.150.001*2.371.12-5.000.02*NLRchange0.860.56-1.330.50PLRpre-RT.760.61-1.430.76PLRmid-RT1.721.12-2.640.01*1.200.68-2.150.53PLRpost-RT1.240.81-1.900.32PLRearlychange1.901.23-2.920.004*1.440.82-2.540.21PLRchange1.310.85-2.000.22* statistically significant. Open table in a new tab