Purpose: We aimed to investigate the pathological changes, clinicopathological correlation and prognostic factors of neoadjuvant programmed cell death 1 (PD-1) blockade camrelizumab combined with carboplatin and nab-paclitaxel (CCNP) which we have proved its effectiveness in previous research for resectable esophageal squamous cell carcinoma (ESCC).
Methods: 108 patients of resectable ESCC, with a mean follow-up of 13 m (ranging 1-30 m), treated with neoadjuvant CCNP from March 2020 to October 2022 in the First Affiliated Hospital of Sun Yat-sen University were enrolled.
Results: One year overall survival (OS) and disease-free survival (DFS) were 96.4% and 84.7% respectively. Pathological complete response or major pathological response (pCR/MPR) of the primary tumour (T-pCR/T-MPR) and the metastatic lymph node (N-pCR/N-MPR) were 58.3% and 47.5%. Pathological response of both primary tumours (PT) and lymph nodes (LN) metastasis correlated with DFS. LN pathological response was consistent with PT in 70.0% and inconsistent in 30.0% metastatic cases. Higher ratio of CD8+ to FoxP3+ tumour-infiltrating lymphocytes (TILs), earlier ypT stage and PT invasion not beyond circular muscle correlated with better pathological response. Four types of regression patterns of PT and two types of metastatic LN regression were found. A total of 18 (16.7%) out of 108 developed recurrence with a mean time of 6.9 ± 5.3 months. PT pathological response plus ypN and PT invasion beyond circular muscle or not were independent prognostic factors of DFS.
Conclusions: This study suggested that camrelizumab plus chemotherapy had a high rate of T-pCR/T-MPR for resectable ESCC. T-pCR/T-MPR plus ypN0 and tumour invasion not beyond circular muscle predicted better DFS.
Keywords: Esophageal squamous cell carcinoma; Neoadjuvant immunotherapy; PD-1 inhibitor; Pathological response; Recurrence.
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