Peri-treatment peripheral blood cell score predicts long-term locoregional progression hazard in oesophageal squamous cell carcinoma after definitive chemoradiotherapy

Abstract

Background Prediction of response to chemoradiotherapy is critical for the optimal management of oesophageal cancer, yet it is still an unmet clinical need. This study aims to evaluate the predictive potential of peri-treatment peripheral blood cells (PBC) in disease progression hazard in oesophageal cancer following chemoradiotherapy.Methods 87 patients with primary oesophageal squamous cell carcinoma were subjected to definitive concurrent chemoradiotherapy in a phase II trial. PBC parameters (haemoglobin, neutrophils, platelets, lymphocytes and monocytes) were collected at 7 time points through the course of radiotherapy. The values of peri-treatment PBC parameters in predicting 3-year cumulative hazard of tumour progression were evaluated.Results Patients with disease progression displayed distinct distribution patterns of peri-treatment PBC compared to patients without. Greater prediction capabilities for risk of locoregional disease progression were found in PBC collected after the start of radiotherapy compared to their pretreatment counterparts, and in individual parameters rather than cell-to-cell ratios. The most predictive PBC parameters were integrated by summation and designated as a PBC score (PBCS), which further augmented their predictive power. Patients divided according to their PBCS (high vs medium vs low) had significantly different 3-year cumulative hazards of locoregional progression (58% vs 29% vs 7%, P = 0.0017). Multivariate analysis confirmed that PBCS high (HR 12.2, 95%CI 2.0-76.3, P = 0.007) and medium (HR 5.8, 95%CI 1.2-27.7, P = 0.028) are independent indicators of locoregional progression.Conclusion Peri-treatment PBCS can predict the long-term hazard of locoregional progression after definitive chemoradiotherapy in patients with oesophageal squamous cell carcinoma.