Dynamic radiological features predict pathological response after neoadjuvant immunochemotherapy in esophageal squamous cell carcinoma

Abstract

Background: Neoadjuvant immunochemotherapy (NICT) plus esophagectomy has emerged as a promising treatment option for locally advanced esophageal squamous cell carcinoma (LA-ESCC). Pathologic complete response (pCR) is a key indicator associated with great efficacy and overall survival (OS). However, there are insufficient indicators for the reliable assessment of pCR.

Methods: 192 patients with LA-ESCC treated with NICT from December 2019 to October 2023 were recruited. According to pCR status, patients were categorized into pCR group (22.92%) and non-pCR group (77.08%). Radiological features of pretreatment and preoperative CT images were extracted. Logistic and COX regressions were trained to predict pathological response and prognosis, respectively.

Results: Four of the selected radiological features were combined to construct an ESCC preoperative imaging score (ECPI-Score). Logistic models revealed independent associations of ECPI-Score and vascular sign with pCR, with AUC of 0.918 in the training set and 0.862 in the validation set, respectively. After grouping by ECPI-Score, a higher proportion of pCR was observed among the high-ECPI group and negative vascular sign. Kaplan Meier analysis demonstrated that recurrence-free survival (RFS) with negative vascular sign was significantly better than those with positive (P = 0.038), but not for OS (P = 0.310).

Conclusions: This study demonstrates dynamic radiological features are independent predictors of pCR for LA-ESCC treated with NICT. It will guide clinicians to make accurate treatment plans.

Trial registration: ClinicalTrials.gov NCC201908A03.

Keywords: Computed tomography; Esophageal cancer; Neoadjuvant PD-1 blockade; Pathological complete response.

Fig. 1

The flow diagram of selection esophageal squamous cell carcinoma patients. A Enrollment of patients; B selection of factors; C data validation. CT computed tomography, ESCC esophageal squamous cell carcinoma

Fig. 2

Radiological features before and after treatment for esophageal cancer. A Vascular sign; B tumor length; C tumor thickness; D tumor area

Fig. 3

Construction and validation of a scoring system for LA-ESCC. A Radiographic scoring system; B ROC curve for scoring system; C correlation heatmap of individual metrics and pCR in LA-ESCC

Fig. 4

The representative cases of vascular sign and radiological features and pathological tissue in two patients

Fig. 5

The proportion of each indicator in radiological features A pCR vs. non-pCR; B nerve invasion vs. vascular invasion; C ypT stages vs. ypN stages

Fig. 6

Survival analysis based on different indicators in LA-ESCC patients. A RFS: pCR vs. non-pCR; B OS: pCR vs. non-pCR; C RFS: score < 2 vs. score ≥ 2; D OS: score < 2 vs. score ≥ 2; E RFS: vascular sign (−) vs. vascular sign (+); F OS: vascular sign (−) vs. vascular sign (+)