[Progress in the evaluation of tumor response status after neoadjuvant therapy for rectal cancer]

In recent years,neoadjuvant therapy has become an integral part of the standard treatment for locally advanced rectal cancer.However,only approximately 15%-25% of patients achieve pathological complete response(pCR).With advances in tumor immunotherapy,treatment strategies targeting mismatch repair deficiency(dMMR) or microsatellite instability-high (MSI-H) status have demonstrated remarkable efficacy.Since the introduction of immunotherapy,either as monotherapy or in combination with chemoradiation,the pCR rate in dMMR or MSI-H rectal cancer patients has significantly improved,far surpassing that achieved with conventional neoadjuvant regimens.This enhancement in tumor regression has also facilitated the adoption of watch-and-wait(W&W)strategies.Accurate assessment of tumor response is essential for guiding individualized treatment plans.Consequently,more accurate evaluation methods are reqnired.This article comprehensively reviews recent advances in imaging,molecular biomarkers,endoscopic techniques,and multipoint full-layer puncture biopsy,offering a theoretical foundation and technical support for organ preservation strategies in the era of precision medicine.