An analysis of factors affecting the accuracy of endoscopic biopsy after neoadjuvant chemoradiotherapy in patients with esophageal squamous cell carcinoma

Purpose The accuracy of endoscopic esophageal biopsy after neoadjuvant chemoradiotherapy (nCRT) remains suboptimal. We retrospectively examined the factors that may affect the diagnostic accuracy of post-nCRT endoscopic biopsy in patients with esophageal squamous cell carcinoma (ESCC). Materials and methods A total of 213 ESCC patients were enrolled. Biopsy findings were cross-checked against the final pathology outcomes (ypT0 versus non-ypT0) to assess their accuracy. The independent predictors of diagnostic accuracy were identified by multivariate logistic regression analysis. Results Post-nCRT endoscopic biopsy results were diagnostically consistent with the final pathology outcomes in 116 (54.5%) patients. Multivariate logistic regression analysis identified a long time interval between the completion of nCRT and the endoscopic examination as the only factor independently associated with a higher diagnostic accuracy. Receiver operating characteristic curve analysis showed that the optimal cutoff value for the time interval between nCRT completion and endoscopic biopsy was 45 days. The estimated diagnostic accuracies of biopsies performed before and after the optimal cutoff time were 49.1% and 72.9%, respectively. Conclusions Endoscopic biopsies performed ≥45 days after nCRT are associated with a higher diagnostic accuracy. This time cutoff may serve as a reference to inform the choice of the optimal treatment strategy following nCRT, especially among complete responders in whom surgery withholding is being considered.