Endoscopic assessment of rectal cancer response after neoadjuvant chemoradiotherapy: A narrative literature review

Rectal cancer management is currently evolving with the advent of different neoadjuvant treatment strategies and organ preservation strategies. A significant proportion of patients could achieve complete clinical response after neoadjuvant treatment, which often translates to pathologic complete response (pCR) as assessed on surgical specimens after curative intent surgery. Endoscopy plays a significant role in assessing treatment response to neoadjuvant therapies.

To explore the role of endoscopy in predicting subsequent pCR after neoadjuvant treatment in rectal cancer patients.

An extensive literature review was undertaken to identify the criteria used for assessment of endoscopic response and their ability to predict pCR.

Fifteen studies were identified through literature review. The most commonly used endoscopic criteria for evaluation included the presence of a flat white scar and the absence of nodularity or telangiectasia. Information on the timing of endoscopic assessment in relation to neoadjuvant treatment protocols were also extracted from the studies. In most studies, the diagnostic accuracy for predicting pCR exceeded 0.8. The main limitations identified were the retrospective design of included studies included and a moderate risk of bias.

Endoscopy can be a key prognostic factor in predicting pCR to neoadjuvant treatment in rectal cancer despite significant limitations in currently available data.