[Evaluation strategy of complete response after neoadjuvant therapy for rectal cancer].

Currently, the standard of clinical complete response (cCR) after neoadjuvant chemoradiotherapy (nCRT) for local advanced rectal cancer generally lacks pathological examination, the cCR judged by the current standard is still far from the real pathological complete response. After nCRT, due to the presence of tissue edema and fibrosis, MRI is highly uncertain in determining the staging of local lesions. The precision of colonoscopy biopsy is generally low because residual cancer foci exist primarily in the muscular layer, which limits the determination of cCR by colonoscopy biopsy. Local excision through the anus can resect the whole intestinal wall tissue, which is relatively accurate and close to the real state of remission of the lesion, but there are many problems, such as affecting anal function, high rate of complications, and increased difficulty of following radical surgery. Based on the present diagnosis of cCR, the authors put forward the concept of modified cCR (m-cCR) which combined with the pathological standard of transanal multipoint full-layer puncture biopsy. It is possible to improve the accuracy of cCR, and improve the safety of cCR patients who receive wait-and-watch therapy without increasing complications or affecting anal function. The exact conclusion needs to be confirmed by further studies.目前新辅助放化疗后直肠癌临床完全缓解缺乏统一标准，现有标准下判断的临床完全缓解距真正的病理学完全缓解尚有很大距离。由于新辅助放化疗后的组织水肿和纤维化，MRI判断局部病灶分期存在很大不确定性。由于残留癌灶主要存在于肌层，肠镜活检的准确性大大降低。经肛门局部切除能够切除全层肠壁组织，比较准确地获得病灶缓解的真实状态，但存在影响肛门功能、并发症发生率较高、追加手术难度增加等问题。在目前临床完全缓解诊断的基础上，作者提出了结合经肛多点全层穿刺活检病理学标准的改进临床完全缓解的概念，在不增加并发症和不影响肛门功能的前提下，有可能提高临床完全缓解的准确性，提高临床完全缓解患者接受等待观察治疗的安全性，有必要进行深入研究以获得确切的结论。.