Colorectal cancer is one of the most common malignant tumors in China， ranking second in morbidity and fourth in mortality. Metastasis and recurrence are the leading causes of patient death， and the peritoneum is a frequent site of metastasis in colorectal cancer， second only to liver and lung metastases. However， the prognosis of peritoneal metastasis is much worse than hepatic and pulmonary metastasis. Colorectal cancer peritoneal metastasis is characterized by difficult early diagnosis， severe symptoms and poor prognosis. Its standardized diagnosis and treatment are crucial for improving the prognosis of patients and enhancing their quality of life. The Colorectal Cancer Professional Committee of the Chinese Medical Doctor Association organized authoritative experts in the field of colorectal cancer in China to compile the “Chinese Expert Consensus on the Diagnosis and Treatment of Colorectal Cancer Peritoneal Metastasis （2017 Edition）” as early as 2017， and revised it in 2022. In view of the research progress of colorectal cancer peritoneal metastasis， the Colorectal Cancer Professional Committee of the Chinese Medical Doctor Association organized domestic multidisciplinary experts to revise and update the “Chinese Expert Consensus on the Diagnosis and Treatment of Colorectal Cancer Peritoneal Metastasis （2017 Edition）” and the 2022 revision based on the latest research results and evidence-based medical evidence after repeated discussions. The “Expert Consensus on the Diagnosis and Treatment of Peritoneal Metastasis of Colorectal Cancer （2025 Edition）” was compiled， reaching a preliminary consensus on the definition， diagnosis，treatment and prevention of colorectal cancer peritoneal metastasis， with the aim of guiding and standardizing the diagnosis and treatment of colorectal cancer peritoneal metastasis， developing reasonable and effective comprehensive treatment plans， prolonging survival time and improving quality of life for colorectal cancer peritoneal metastasis patients， thereby raising the overall level of diagnosis and treatment for colorectal cancer in China.

Robotic Natural Orifice Specimen Extraction Surgery （NOSES） is a vital component in the surgical management of colorectal tumors. By combining the strengths of the robotic platform and colorectal tumor NOSES， this technique has become a surgical approach that is attracting widespread attention among colorectal surgeons. In 2022， The Group of NOSES， Colorectal Cancer Professional Committee of the Chinese Medical Doctor Association， The Group of Robotic Surgery， Colorectal Cancer Professional Committee of the Chinese Medical Doctor Association developed the first “Expert Consensus on Robotic Natural Orifice Specimen Extraction Surgery for Colorectal neoplasm”， which has played a positive role in promoting standardized robotic colorectal tumor NOSES procedures. After three years of practice and summarization， a large number of colorectal surgeons have revised the consensus based on new developments and clinical evidence. The main revisions include: adjusted surgical positioning for R-CRC-NOSES Ⅵ/Ⅶ；new methodologies （B/C） for R-CRC-NOSES Ⅷ； optimized digestive tract reconstruction in R-CRC-NOSESⅨ/Ⅹ； and the addition of “poor blood supply to the colorectal stump” as a defined complication. This update aims to enhance scientific rigor and standardization in robotic NOSES， fostering its sustainable development in China's surgical landscape.

The incidence of low rectal cancer continues to rise annually， the research on low rectal cancer and the innovation of technology are constantly advancing and deepening. The new neoadjuvant treatment strategies and anus-preserving surgical plans formulated based on the multidisciplinary team （MDT）scheme closely affect the perioperative management， functional preservation effect， and long-term quality of life of patients. This consensus document establishes standardized multidisciplinary integrated care pathways for preoperative management， aiming to systematize clinical decision-making processes and promote standardized implementation across clinical practice.

Objective

To compare the clinical characteristics， pathologic features and survival outcomes of early-onset and late-onset locally advanced rectal cancer.

Methods

Clinical data of locally advanced rectal cancer patients admitted in our hospital from January 2019 to January 2022 were retrospectively analyzed. According to the age of onset， the patients were divided into early-onset（＜50 years） and late-onset （≥50 years） groups. The primary outcomes were 3-year disease-free survival（3y-DFS） and overall survival （3y-OS）.

Results

A total of 464 locally advanced rectal cancer patients were included， including 92 （19.8%） in early-onset group and 372 （80.2%） in late-onset group. Early-onset patients was more common in women （40.2% vs. 29.3%， P=0.043）， and the proportion of ASA grade I was higher（83.7% vs. 50.0%， P＜0.001）. The pathological complete response rate （33.7% vs. 23.4%， P=0.042） and the proportion of CAP 0-1 grade （62.0% vs. 50.3%， P=0.044） in early-onset group were significantly higher than that in late-onset group. The median follow-up time was 39 （25～52） months with the follow-up rate of 99.8%.Approximately 60 patients had distant metastasis （13 patients in early-onset and 47 patients in late-onset） and 8 patients had tumor relapse （5 patients in early-onset and 3 patients in late-onset）. The distant metastasis rate and local recurrence rate were 12.9% and 1.7%， respectively， and there was no significant difference between the two groups （all P＞0.05）. There was no significant difference in 3y-DFS （81.9% vs. 86.3%， P=0.531） and 3y-OS （92.6% vs. 94.2%， P=0.708） between patients with early-onset rectal cancer and those with late-onset rectal cancer.

Conclusion

Compared to late-onset group， patients in the early-onset group is more common in females， and exhibit a relatively superior response to neoadjuvant chemoradiotherapy， but this kind of better local control of disease did not result in an improved long-term survival outcomes.

Objective

To analyze and explore the risk factors for early stoma complications in patients with colorectal cancer after surgery and to construct a visual prediction model.

Methods

This study retrospectively collected and analyzed the clinicopathological data and related surgical information of colorectal cancer patients who underwent enterostomy in the Department of Gastrointestinal Surgery of the Second Affiliated Hospital of Soochow University from January 2018 to January 2021. The Logistic regression analyses were used to identify independent risk factors for stoma complications. Subsequently，a nomogram was constructed， and the model was validated through 1 000 bootstrap resamples based on the Bootstrap method. A receiver operating characteristic （ROC） curve was plotted， and the accuracy and clinical applicability of the nomogram prediction model were evaluated by calculating the area under the curve （AUC），Hosmer-Lemeshow goodness-of-fit test， calibration curve， and decision curve analysis （DCA）.

Results

A total of 267 stoma patients were ultimately included in the analysis， among which 71 patients observed varying degrees of stoma complications. The multivariate Logistic regression results showed that age （OR=0.040，P=2.509）， BMI （OR=5.119， P＜0.001）， serum albumin （OR=0.168， P＜0.001）， skin folds （OR=9.854， P＜0.001），and history of abdominal surgery （OR=23.331， P＜0.001） were independent predictors of early complications in stoma patients （P＜0.05）. A nomogram model was constructed based on these five independent predictors.The AUCs for the training set and validation set were 0.880 （95%CI: 0.820～0.940） and 0.861 （95%CI:0.770～0.953）， respectively. The Hosmer-Lemeshow test showed good agreement between the prediction model and the actual incidence of stoma complications （P＞0.05）. The DCA curve indicated that the model had a high net benefit.

Conclusion

The predictive model demonstrates good performance， aiding healthcare providers in promptly identifying the risk of early complications in patients with intestinal stomas and facilitating timely interventions.

Objective

Comparative analysis of clinicopathological characteristics and prognostic outcomes between sporadic microsatellite instability （MSI） colorectal cancer and Lynch Syndrome （LS）-associated cases in Chinese patients.

Methods

A total of 338 consecutive postoperative cases of MSI colorectal cancer diagnosed at the Cancer Hospital of the Chinese Academy of Medical Sciences from January 2015 to December 2017 were collected， including 105 cases of LS and 233 cases of sporadic MSI colorectal cancer. The clinicopathological characteristics were retrospectively analyzed， and relevant literature was reviewed.

Results

LS patients were significantly younger at the time of diagnosis compared to sporadic MSI colorectal cancer patients （t=4.179， P＜0.001）， and the type of mismatch repair protein deficiency tended to be more of type 3 （χ²=28.036， P＜0.001） or type 4 （χ²=4.325， P=0.038）. Sporadic MSI patients were more likely to experience promoter methylation （χ²=22.388， P＜0.001） and BRAF mutation （χ²=13.005， P＜0.001）.There was no significant difference in histological morphology between the two groups， and the differences in overall survival （χ²=1.053， P=0.305） and progress-free survival （χ²=0.008， P=0.928） were not statistically significant. High-risk histological components such as micropapillary and signet ring cells were significant independent prognostic factors for progress-free survival in MSI colorectal cancer patients （HR=4.075， P＜0.05）.

Conclusion

LS and sporadic MSI colorectal cancers display differences in clinicopathological characteristics， and the molecular mechanisms behind their varied responses to immunotherapy warrant further investigation.

Objective

To investigate the influencing factors of colorectal polyp recurrence and explore the role of BMI in colorectal polyp recurrence.

Methods

A total of 317 colorectal polyp patients who underwent endoscopic resection at the Department of Gastroenterology， Beijing Haidian Hospital， from November 2018 to August 2022， were included. Based on postoperative polyp recurrence， the patients were divided into a recurrence group （237 patients） and a non-recurrence group （80 patients）. Clinical data of the patients were collected， including demographic， history of diseases， and polyp characteristics， and influencing factors of colorectal polyp recurrence and their difference between different groups by BMI levels were analyzed.

Results

The univariate analysis showed that there were significant differences （P＜0.05） between the recurrence group and the non-recurrence group in terms of gender （χ²=7.783， P=0.005）， age （Z=2.541，P=0.011）， history of hypertension （χ²=5.071， P=0.024）， history of diabetes （χ²=9.889， P=0.002）， history of coronary heart disease （χ²=4.746， P=0.029）， smoking history （χ²=8.375， P=0.004）， number of polyps （Z=5.995，P＜0.001）， and the largest polyp location （χ²=16.050， P=0.003）. Multivariate logistic regression analysis indicated that diabetes history ［OR: 2.949， 95%CI: （1.064， 8.171）］， number of polyps ［OR: 1.532， 95%CI:（1.261， 1.861）］， and the growth site of the largest polyp in the transverse colon ［OR: 2.765， 95%CI: （1.046， 7.308）］and rectum ［OR: 3.075， 95%CI: （1.239， 7.634）］were independent factors for colorectal polyp recurrence（P＜0.05）. Further stratified analysis revealed that factors， such as diabetes history， number of polyps and histological pattern， and the growth site of the largest polyp had statistically significant effects on recurrence in the BMI≥24 kg/m² group.

Conclusion

Colorectal polyp recurrence is closely related to factors， such as diabetes history， number of polyps， and the growth site of the largest polyp. The risk factors of recurrence differ in patients with different BMI levels. In patients with normal or lower BMI， the recurrence risk is mainly influenced by number of polyps and smoking， while in overweight or obese patients， the recurrence risk is influenced by multiple factors， including diabetes history， polyp number and histological pattern， and the growth site of the largest polyp.

Objective

The aim of this study was to establish an efficient circulating tumor cells（CTC） sorting system for colorectal cancer and to investigate the feasibility of CTC instead of tumor tissue for gene mutation detection.

Methods

The CTC sorting system modified by EpCAM and Vimentin antibody was established. The sorting efficiency of the CTC sorting system on colorectal cancer cells was detected by cellular experiments， and CTC from 30 colorectal cancer patients were captured and counted. The hotspot mutated genes in patient tumor tissue samples were detected by NGS， and the hotspot mutated genes in blood CTC were detected by Sanger sequencing， and the consistency of hotspot gene mutations between tumor tissues and blood CTC was analyzed.

Results

The CTC sorting system constructed in this study had good dispersion， stability and low cytotoxicity， with a specificity of 90.54% and a sensitivity of 89.07%.The mean number of CTC in the blood of colorectal cancer patients was （10.90±5.11）/7.5 mL. The highfrequency mutated genes （TP53， KRAS， EGFR， BRAF， APC， PIK3CA） detected by CTC were all in high concordance with the tissue assay， and the overall mutation concordance rate for all the genes was （92.89±4.89）%.

Conclusions

The CTC sorting system based on sequential enrichment of Ep-LMB/Vi-LMB is capable of efficiently capturing CTC from peripheral blood of colorectal cancer patients. Using the captured CTC for hotspot mutation detection in the clinic solves the problem of difficult tumor tissue sampling to a certain extent， which is of great clinical significance.

Artificial intelligence（AI） has made significant progress in multiple medical fields， and deep learning， as a main branch of artificial intelligence， shows considerable clinical effects in the recognition and protection of nerves during endoscopic surgeries. In colorectal cancer surgery， damage to the pelvic autonomic nerves （PAN） can lead to complications such as urinary dysfunction and sexual dysfunction. The application of AI technology shows certain potential in assisting the identification of autonomic nerves and reducing complications.

Adult colonic duplication is a rare congenital malformation of the digestive tract whose etiology may be related to abnormal embryonic development. This disease can be divided into four types according to the morphology and structure. The clinical manifestations vary according to the type，location and whether it is connected with the intestinal cavity， including abdominal pain， abdominal mass，gastrointestinal bleeding， intestinal obstruction， infection or perforation， etc. Surgery is the main treatment method at present. A case of colon duplication in adult was reported in this paper in order to improve the understanding of this disease.

Delayed urethral fistula after combined abdominoperineal resection （Miles） of rectal cancer is a rare and serious complication. This paper reports a case of delayed urethral fistula in a cT3N2M0 rectal cancer patient with preoperative neoadjuvant radiotherapy and chemotherapy combined with Miles. The evolution and outcome of delayed urethral fistula after Miles were discussed. The aim is to provide reference for the prevention and treatment of delayed urethral fistula after Miles surgery.

Colorectal cancer is one of the most common malignant tumors in China， and its treatment is mainly based on surgical operation， combined with radiotherapy， chemotherapy and targeted therapy. In recent years， natural orifice specimen extraction surgery（NOSES） has attracted much attention in the field of minimally invasive surgery， and its therapeutic value for colorectal tumors is increasingly significant. This article reports a case of laparoscopic right hemicolectomy with specimen extraction through the anus without abdominal auxiliary incision， and analyzes and discusses the technical concept and key points of this operation.