Neoadjuvant chemoradiation therapy combined with immunotherapy for microsatellite stable ultra-low rectal cancer (CHOICE II): study protocol of a multicentre prospective randomised clinical trial.

INTRODUCTION: Neoadjuvant chemoradiotherapy (nCRT) could bring tumour shrinking and downstaging and increase the probability of organ preservation for patients with low rectal cancer. But for ultra-low rectal cancer, there is little possibility for organ preservation. Immunotherapy has been shown to have significant survival benefits in microsatellite instability-high patients but poor response in microsatellite stable (MSS) patients. Studies have demonstrated that radiotherapy and immunotherapy have synergistic effects in cancer treatment. There is no existing evidence about the clinical efficacy of immunotherapy combined with nCRT for patients with MSS ultra-low rectal cancer. METHOD AND ANALYSIS: This trial is an open-labelled multicentre prospective randomised controlled trial (NCT05215379) with two parallel groups and allocation ratio 1:1 (nCRT+immunotherapy vs nCRT group). Eligible participants will be aged 18-75 years, with a desire for anus preservation, confirmed cT1-3aN0-1M0 rectal adenocarcinoma, confirmed MSS type, inferior margin of ≤5 cm from the anal verge. The primary endpoint of this trial is complete clinical response (cCR) rate. Immunotherapy is added after 1 week of chemoradiotherapy for two cycles, and then the patients will be administered two cycles of immunotherapy and CAPOX. The evaluations will be carried out after the completion of the whole neoadjuvant therapy. We expect the programme to improve the cCR rate and the quality of life for patients with ultra-low rectal cancer. ETHICS AND DISSEMINATION: This trial was approved by the Ethics committee of Changhai Hospital and other medical centres (Grant number:CHEC2022-118). The results of this study will provide further insight into the clinical efficacy of immunotherapy in combination with nCRT in patients with MSS ultra-low rectal cancer. TRIAL REGISTRATION NUMBER: NCT05215379.

The Classification and Surgical Treatments in Adult Hirschsprung's Disease: A Retrospective Study.

Purpose: To explore the treatments and short-term effects of different types of adult Hirschsprung's disease. Methods: 89 patients treated in Shanghai Changhai Hospital were retrospectively analyzed. According to the patient's medical history, clinical manifestations, auxiliary examination and postoperative pathological results, the patients were divided into adult congenital megacolon, adult idiopathic megacolon, ganglion cell deficiency (types I and II), toxic megacolon and iatrogenic megacolon, The Treatment methods and short-term prognosis of patients in each group were summarized. Results: 41 cases of Hirschsprung's disease in adults and low anterior resection or pull-out low anterior resection was performed, and 35 patients with idiopathic Megacolon were treated with one-stage subtotal colon resection under the condition of adequate preoperative preparation. Some patients admitted for emergency intestinal obstruction received conservative treatment first or underwent elective surgery after colonoscopic decompression was improved; two patients with ganglion cell deficiency subtotal colectomy were performed to remove the dilated proximal bowel segment and the narrow distal bowel segment; three patients with toxic Hirschsprung's disease underwent colostomy in mild cases, while subtotal colorectal resection was required in severe cases; Iatrogenic megacolon was diagnosed in eight cases and the optimum operation should be selected according to the specific conditions of patients. Conclusion: Adult Hirschsprung's diseases were divided into adult congenital hirschsprung's disease, idiopathic Hirschsprung's disease, ganglion cell deficiency, toxic hirschsprung's disease, and iatrogenic Hirschsprung's disease. Different types of surgical treatments for Hirschsprung's disease in adults should be selected according to the specific diagnosis. All patients with adult Hirschsprung's diseases have good short-term outcomes after surgical treatment.