Treatment of obstructive colorectal cancer / 中华胃肠外科杂志

Obstructive colorectal cancer is a common malignant bowel obstruction. Colostomy or colostomy following tumor resection may be the first choice for emergency surgery. The intestinal and systemic conditions of patients undergoing emergency surgery are often poor, and patients need to undergo multiple operations, which increase the surgical risk and economic burden and reduce the quality of life of patients. Poor intraoperative visualization may also affect the radical operation of emergency surgery. Transanal decompression tube (TDT) can rapidly decompress and drain the obstructed bowel, effectively relieve obstruction symptoms, and improve the success rate of primary radical resection. The TDT squeeze the tumor lightly, causing no spread of tumor cells, and is cheap, but the cavity of transanal decompression tube is small and easily blocked, and requires tedious flushing or regular replacement. Self-expanding metallic stents (SEMS) can relieve intestinal obstruction effectively, provide sufficient preparation time for preoperative examination and improvement of nutritional status. By improving patient's tolerance to radical surgery, SEMS might be used as an important treatment strategy choice for obstructive colorectal cancer. However, SEMS may squeeze the tumor, leading to the spread of tumor cells, increase the recurrence rate and metastasis rate, and reduce the survival rate. Moreover, intestinal wall edema still existed during the operation following SEMS, and the rate of ostomy after anastomosis was as high as 34%. We hypothesized that prolonging the interval between stent insertion and surgery to 2 months, with neoadjuvant chemotherapy administered during this interval (SEMS-neoadjuvant chemotherapy strategy), would help improve outcomes. The SEMS-neoadjuvant chemotherapy strategy is a safe, effective, and well tolerated treatment approach with a high laparoscopic resection rate, low stoma formation rate and improvement in the overall survival for patients with left-sided colon cancer obstruction. The patient physical status is improved, the primary tumor is downstaged, and intestinal wall edema is relieved during the relatively longer interval between SEMS placement and surgery. The SEMS-neoadjuvant chemotherapy strategy may be a preferred therapeutic strategy for obstructive left colon cancer.

Evaluation strategy of complete response after neoadjuvant therapy for rectal cancer / 中华外科杂志

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.