Predictive Value of Endoscopic Observations and Biopsy After Neoadjuvant Chemoradiotherapy in Assessing the Pathologic Complete Response of Patients With Esophageal Squamous Cell Carcinoma

Liquid Biopsy and Multidisciplinary Treatment for Esophageal Cancer

Esophageal cancer (EC) is one of the leading causes of cancer-related deaths globally. Surgery is the standard treatment for resectable EC after preoperative chemoradiotherapy or chemotherapy, followed by postoperative adjuvant chemotherapy in certain cases. Upper gastrointestinal endoscopy and computed tomography (CT) are predominantly performed to evaluate the efficacy of these treatments, but their sensitivity and accuracy for evaluating minimal residual disease remain unsatisfactory, thereby requiring the development of alternative methods. In recent years, interest has been increasing in using liquid biopsy to assess treatment responses. Liquid biopsy is a noninvasive technology for detecting cell components in the blood and other body fluids. It involves collecting a small sample of body fluid, which is then analyzed for the presence of components, including circulating tumor DNA (ctDNA), microRNA (miRNA), or circulating tumor cells (CTCs). Further, ctDNA and miRNA are analyzed with various techniques, including digital polymerase chain reaction (dPCR) and next-generation sequencing (NGS). CTCs are isolated by determining surface antigens using immunomagnetic techniques or by filtering the blood according to cell size and rigidity. Several studies indicate that investigating these materials helps predict EC prognosis and recurrence and possibly stratifies high-risk groups. Liquid biopsy may also apply to the selection of cases that have achieved a complete response through preoperative treatment to prevent surgery and preserve the esophagus, as well as identifying the suitability of postoperative chemotherapy and the timing of conversion surgery for unresectable EC. The potential of liquid biopsy to enhance treatment decisions will further advance EC treatment.

A novel CT-based radiomics model for predicting response and prognosis of chemoradiotherapy in esophageal squamous cell carcinoma

No clinically relevant biomarker has been identified for predicting the response of esophageal squamous cell carcinoma (ESCC) to chemoradiotherapy (CRT). Herein, we established a CT-based radiomics model with artificial intelligence (AI) to predict the response and prognosis of CRT in ESCC. A total of 44 ESCC patients (stage I-IV) were enrolled in this study; training (n = 27) and validation (n = 17) cohorts. First, we extracted a total of 476 radiomics features from three-dimensional CT images of cancer lesions in training cohort, selected 110 features associated with the CRT response by ROC analysis (AUC ≥ 0.7) and identified 12 independent features, excluding correlated features by Pearson's correlation analysis (r ≥ 0.7). Based on the 12 features, we constructed 5 prediction models of different machine learning algorithms (Random Forest (RF), Ridge Regression, Naive Bayes, Support Vector Machine, and Artificial Neural Network models). Among those, the RF model showed the highest AUC in the training cohort (0.99 [95%CI 0.86-1.00]) as well as in the validation cohort (0.92 [95%CI 0.71-0.99]) to predict the CRT response. Additionally, Kaplan-Meyer analysis of the validation cohort and all the patient data showed significantly longer progression-free and overall survival in the high-prediction score group compared with the low-prediction score group in the RF model. Univariate and multivariate analyses revealed that the radiomics prediction score and lymph node metastasis were independent prognostic biomarkers for CRT of ESCC. In conclusion, we have developed a CT-based radiomics model using AI, which may have the potential to predict the CRT response as well as the prognosis for ESCC patients with non-invasiveness and cost-effectiveness.

The Use of Trimodality Treatment in Patients With Locally Advanced Oesophageal Squamous Cell Carcinoma: An Experience From a Large Cancer Centre in Pakistan

Introduction Esophageal cancer is one of the most common cancers worldwide. Neoadjuvant chemoradiotherapy followed by surgery is the standard treatment for locally advanced squamous cell carcinoma (SCC). Pathological complete response (pCR) after surgery is associated with better outcomes in terms of overall survival and disease-free survival. We aim to determine the effectiveness of neoadjuvant chemoradiotherapy in patients with locally advanced SCC at our institute, the largest purpose-built cancer center in Pakistan. We also aim to identify various factors influencing pCR, such as chemotherapy regimen, total radiation dose, clinical stage at presentation, and gender. Materials and methods This is a retrospective review of all patients with esophageal SCC presented between January 2019 and 2021 to the institute for treatment. Patients received neoadjuvant chemoradiotherapy (nCRT) as per the CROSS trial protocol, followed by surgery. We assessed the pCR rate. Statistical analyses were performed using IBM SPSS Statistics for Windows, Version 22 (Released 2013; IBM Corp., Armonk, New York). pCR was studied alongside associated factors such as age, gender, stage of disease, chemotherapy regimen, and total dose of radiotherapy. A p-value of <0.05 was considered statistically significant. The chi-square test was used to compare categorical variables. Univariate and multivariate logistic regression was employed to evaluate factors affecting pCR. Results A total of 218 patients were included in the study. pCR was achieved in 64.2% of the patients. The female gender was associated with better outcomes, as 70.4% (n=81) of female patients achieved a complete pathological response, compared to 57.3% (n=59) of males, with a p-value of 0.03. On univariate analysis, the complete pathological response was 69.6% (n=94) in the age group of 45 years and below, whereas it was 55.4% (n=46) in the age group above 45 years, with a p-value of 0.024. Though statistically insignificant, outcomes were slightly better for those with node-negative disease, as 67.2% (n=41) achieved complete pathological response compared to those with node-positive disease at 63.1% (n=99). Univariate logistic regression analysis identified gender (p=0.044, OR=1.77, 95% CI: 1.016-3.108) and age group (p=0.034, OR=1.844, 95% CI: 1.046-3.252) as significantly associated with pCR. Female patients were 77% more likely to achieve pCR compared to male patients (OR=1.77, 95% CI: 1.016-3.108). Younger patients (≤45 years) were 84.4% more likely to achieve pCR compared to the older age group (OR=1.844, 95% CI: 1.046-3.252). However, these did not maintain significance in multivariate logistic regression analysis. Conclusion Our study indicated a high rate of pCR with nCRT in patients with esophageal SCC compared to other studies. The achievement of pCR was higher among females and younger patients, which was statistically significant on univariate logistic regression analysis. Our study also concluded that a higher dose of RT (50Gy/25#) is not superior to a lower dose (45Gy/25#) in terms of pCR achievement but was statistically insignificant. Similarly, CARBO/PAC was not superior to CIS/CAP in terms of pCR achievement and was also statistically insignificant.