Rectal Cancers.

Rectal cancer surgery has become increasingly effective, allowing many patients to avoid permanent colostomy. However, anastomotic leakage remains one of the most serious complications after rectal cancer surgery, especially in patients undergoing low anterior resection. Anastomotic leakage may lead to pelvic infection, prolonged hospitalization, additional treatments, and may affect the recovery of temporary diverting stomas. This investigator-initiated clinical study aims to evaluate the safety and potential effectiveness of local methylene blue injection around the pelvic floor after completion of colorectal anastomosis in patients with high-risk rectal cancer undergoing low anterior resection with a temporary diverting ileostomy. In this study, eligible patients will receive local injection of diluted methylene blue solution into the pelvic floor muscles surrounding the anastomosis after surgery. Participants will be followed for 12 months after surgery. The study will evaluate postoperative outcomes, including the occurrence of anastomotic leakage, complications related to the injection procedure, and whether the temporary stoma can be successfully reversed. The information collected in this study may help determine whether local methylene blue injection is a safe and feasible approach for reducing postoperative complications and improving recovery after rectal cancer surgery.

To explore the efficacy and safety of radiotherapy combined with Adebrelimab and NALIRIFOX in patients with pMMR/MSS locally advanced rectal cancer

This phase II, registry-based cohort-multiple randomized controlled trial (cmRCT) evaluates whether daily online adaptive radiotherapy (ART) enables the safe delivery of hypofractionated, iso-biologically equivalent (EQD2) external beam radiotherapy compared with standard-of-care (SOC) fractionation. Conventional radiotherapy requires generous planning target volume (PTV) margins to account for inter-fraction anatomical variation, which increases radiation exposure to surrounding organs at risk (OARs) and may contribute to toxicity. Modern ART platforms using daily on-table imaging (kV-CBCT or MRI guidance) allow real-time contour adaptation and online plan re-optimization based on same-day anatomy. This approach enables margin reduction while maintaining target coverage and may permit safe hypofractionation. Eligible patients enrolled in an institutional prospective registry will be randomized (1:1) to receive either SOC radiotherapy or hypofractionated ART across multiple pelvic disease strata (post-prostatectomy prostate cancer, intact prostate cancer, endometrial cancer, cervical cancer, and rectal cancer). The primary objective is to demonstrate non-inferiority of hypofractionated ART compared with SOC in terms of cumulative incidence of Grade ≥2 toxicity (CTCAE v5). Secondary outcomes include acute and late toxicity, oncologic outcomes (progression-free survival, locoregional failure, distant metastases, overall survival), patient-reported outcomes, treatment efficiency, and dosimetric parameters. A Bayesian monitoring framework with pre-specified safety and futility stopping rules will be used to ensure patient safety and clinical equipoise throughout the trial.

This multicenter prospective interventional study will evaluate stool and saliva microRNA expression and microbiome composition in patients with histologically confirmed colon or rectal cancer during key phases of the diagnostic and therapeutic pathway. The study aims to confirm and refine molecular signatures associated with colorectal cancer, assess the diagnostic and prognostic potential of salivary biomarkers, and characterize dynamic molecular changes during treatment and follow-up