Anus preservation in low rectal adenocarcinoma based on MMR/MSI status (APRAM): a study protocol for a randomised, controlled, open-label, multicentre phase III trial.

BACKGROUND: Anus preservation has been a challenge in the treatment of patients with low rectal adenocarcinoma (within 5 cm from the anal verge) because it is difficult to spare the anus with its functioning sphincter complex under the safe margin of tumour resection. Patients with dMMR/MSI-H can achieve a favourable complete response (CR) rate by using a single immune checkpoint inhibitor. For patients with pMMR/MSS/MSI-L, intensified neoadjuvant three-drug chemotherapy may be the preferred option for anal preservation. In addition, the watch and wait (W&W) strategy has been proven safe and feasible for patients with rectal cancer who achieve a clinical complete response (cCR). Therefore, we initiated this clinical trial to explore the optimal neoadjuvant treatment pattern for patients with low locally advanced rectal cancer (LARC) with different MMR/MSI statuses, aiming to achieve a higher cCR rate with the W&W strategy and ultimately provide more patients with a chance of anus preservation. METHODS: This is a randomised, controlled, open-label, multicentre phase III trial. Patients with clinical stage T2-4 and/or N + tumours located within 5 cm from the anal verge are considered eligible. Based on the results of pathological biopsy, the patients are divided into two groups: dMMR/MSI-H and pMMR/MSS. Patients in the dMMR/MSI-H group will be randomly allocated in a 1:1 ratio to either arm A (monoimmunotherapy) or arm B (short-course radiotherapy followed by monoimmunotherapy). Patients in the pMMR/MSS group will be initially treated with long-term pelvic radiation with concurrent capecitabine combined with irinotecan. Two weeks after the completion of chemoradiotherapy (CRT), the patients will be randomly allocated in a 1:1 ratio to arm C (XELIRI six cycle regime) or arm D (FOLFIRINOX nine cycle regime). The irinotecan dose will be adjusted according to the UGT1A1-genotype. After treatment, a comprehensive assessment will be performed to determine whether a cCR has been achieved. If achieved, the W&W strategy will be adopted; otherwise, total mesorectal excision (TME) will be performed. The primary endpoint is cCR with the maintenance of 12 months at least, determined using digital rectal examination, endoscopy, and rectal MRI or PET/CT as a supplementary method. DISCUSSION: APRAM will explore the best anus preservation model for low LARC, combining the strategies of consolidation chemotherapy, immunotherapy, and short-course radiotherapy, and aims to preserve the anus of more patients using W&W. Our study provides an accurate individual treatment mode based on the MMR/MSI status for patients with low LARC, and more patients will receive the opportunity for anus preservation under our therapeutic strategy, which would transform into long-term benefits. TRIAL REGISTRATION: Clinicaltrials.gov NCT05669092 (Registered 28th Nov 2022).

Unraveling Colorectal Cancer and Pan-cancer Immune Heterogeneity and Synthetic Therapy Response Using Cuproptosis and Hypoxia Regulators by Multi-omic Analysis and Experimental Validation.

Cuproptosis, a new type of programmed cell death (PCD), is closely related to cellular tricarboxylic acid cycle and cellular respiration, while hypoxia can modulate PCD. However, their combined contribution to tumor subtyping remains unexplored. Here, we applied a multi-omics approach to classify TCGA_COADREAD based on cuproptosis and hypoxia. The classification was validated in three colorectal cancer (CRC) cohorts and extended to a pan-cancer analysis. The results demonstrated that pan-cancers, including CRC, could be divided into three distinct subgroups (cuproptosis-hypoxia subtypes, CHSs): CHS1 had active metabolism and poor immune infiltration but low fibrosis; CHS3 had contrasting characteristics with CHS1; CHS2 was intermediate. CHS1 may respond well to cuproptosis inducers, and CHS3 may benefit from a combination of immunotherapy and anti-fibrosis/anti-hypoxia therapies. In CRC, the CHSs also showed a significant difference in prognosis and sensitivity to classic drugs. Organoid-based drug sensitivity assays validated the results of transcriptomics. Cell-based assays indicated that masitinib and simvastatin had specific effects on CHS1 and CHS3, respectively. A user-friendly website based on the classifier was developed (https://fan-app.shinyapps.io/chs_classifier/) for accessibility. Overall, the classifier based on cuproptosis and hypoxia was applicable to most pan-cancers and could aid in personalized cancer therapy.