Background and Aims:According to the Chinese Guidelines for the Diagnosis and Treatment of Colorectal Cancer(2023 Edition),patients with early-stage colorectal cancer who present with high-risk factors require additional radical surgery following endoscopic resection.However,due to the relatively low rate of lymph node metastasis in early colorectal cancer,some patients may not benefit from such supplemental surgery.Therefore,accurately identifying patients who are truly likely to benefit and refining the indications for supplemental surgery are pressing clinical challenges.This study was conducted to investigate the risk factors and distribution patterns of lymph node metastasis following additional radical surgery through retrospectively analyzing a large single-center cohort,thereby providing evidence-based support for clinical decision-making.Methods:Clinicopathologic data were retrospectively reviewed for patients with early-stage colorectal cancer who underwent additional radical surgery at Fudan University Shanghai Cancer Center between 2008 and 2023.Binary Logistic regression and multivariate analyses were performed to identify risk factors associated with lymph node metastasis,and the distribution characteristics of metastatic lymph nodes were further examined.Results:A total of 417 patients were included in the study,with lymph node metastasis confirmed in 36 cases(8.63％)postoperatively.Over time,the number of patients undergoing supplemental surgery increased,while the proportion of cases with residual cancer decreased.Among 243 patients included in the risk factor analysis,univariate analysis indicated that submucosal invasion depth of SM2 or greater,poor tumor differentiation,positive vascular invasion,and tumor location were high-risk factors for lymph node metastasis.Multivariate analysis identified invasion depth(P=0.039)and tumor location(P=0.014)as independent risk factors.Among the metastatic cases,58.3％involved a single lymph node;63.9％of metastases were limited to the first station,and 36.1％extended to the second station,with no metastasis found at the third station.Only four patients had preoperative imaging suggestive of lymph node enlargement.Conclusion:Although the number of supplemental surgeries following endoscopic resection of early-stage colorectal cancer has increased significantly,the actual rate of lymph node metastasis remains low,suggesting a potential risk of overtreatment.Submucosal invasion depth ≥SM2 and tumor location are independent risk factors for metastasis.D2 lymph node dissection is deemed necessary,while the diagnostic value of imaging remains limited.Clinical decisions should prioritize precision and individualized treatment planning.

In recent years,the surgical treatment model for rectal cancer has undergone profound changes.The therapeutic goal has gradually shifted from single tumor radical resection to balancing functional preservation,and the therapeutic concept has transformed from merely emphasizing surgical techniques to attaching importance to comprehensive treatment.Especially in the treatment of low rectal cancer,the neoadjuvant therapy model has been continuously optimized.For patients with good tumor regression after neoadjuvant therapy,"watch and wait"and transanal local excision have become important optional strategies.This not only avoids some severe surgery-related complications but also maximizes the preservation of patients'organ functions,bringing a qualitative leap in their quality of life.This treatment strategy is gradually expanding from locally advanced low rectal cancer to relatively early-stage low rectal cancer.In terms of surgical techniques,based on the traditional intermediate approach of"first plane,then vessels",the concept of a"vessel-centered"approach is proposed.By managing vessels first and then expanding the plane,it enables thorough dissection of lymph nodes at the root of the inferior mesenteric artery while preserving the left colic artery.With the aid of dual-fluorescence intraoperative navigation technology[indocyanine green(ICG)fluorescence and intraoperative real-time imaging system(IRIS)ureter fluorescence imaging],real-time visualization of lymph nodes and ureters is achieved,ensuring the completeness of lymph node dissection and helping to reduce the risk of ureteral injury.The angulation-free double anastomosis technique used during surgery effectively reduces the incidence of anastomotic leakage and improves surgical safety.For patients with high-risk factors for anastomotic leakage,intestinal stent bypass is expected to replace the traditional prophylactic end ileostomy,thus avoiding complications associated with prophylactic end ileostomy and the trauma caused by secondary stoma closure.In general,the development trend of surgical treatment for rectal cancer is to minimize patient trauma,preserve organ functions,and improve quality of life under the premise of ensuring oncological efficacy,promoting the development of surgical techniques towards standardization and precision to maximize patients'perioperative safety.

In recent years,the surgical treatment model for rectal cancer has undergone profound changes.The therapeutic goal has gradually shifted from single tumor radical resection to balancing functional preservation,and the therapeutic concept has transformed from merely emphasizing surgical techniques to attaching importance to comprehensive treatment.Especially in the treatment of low rectal cancer,the neoadjuvant therapy model has been continuously optimized.For patients with good tumor regression after neoadjuvant therapy,"watch and wait"and transanal local excision have become important optional strategies.This not only avoids some severe surgery-related complications but also maximizes the preservation of patients'organ functions,bringing a qualitative leap in their quality of life.This treatment strategy is gradually expanding from locally advanced low rectal cancer to relatively early-stage low rectal cancer.In terms of surgical techniques,based on the traditional intermediate approach of"first plane,then vessels",the concept of a"vessel-centered"approach is proposed.By managing vessels first and then expanding the plane,it enables thorough dissection of lymph nodes at the root of the inferior mesenteric artery while preserving the left colic artery.With the aid of dual-fluorescence intraoperative navigation technology[indocyanine green(ICG)fluorescence and intraoperative real-time imaging system(IRIS)ureter fluorescence imaging],real-time visualization of lymph nodes and ureters is achieved,ensuring the completeness of lymph node dissection and helping to reduce the risk of ureteral injury.The angulation-free double anastomosis technique used during surgery effectively reduces the incidence of anastomotic leakage and improves surgical safety.For patients with high-risk factors for anastomotic leakage,intestinal stent bypass is expected to replace the traditional prophylactic end ileostomy,thus avoiding complications associated with prophylactic end ileostomy and the trauma caused by secondary stoma closure.In general,the development trend of surgical treatment for rectal cancer is to minimize patient trauma,preserve organ functions,and improve quality of life under the premise of ensuring oncological efficacy,promoting the development of surgical techniques towards standardization and precision to maximize patients'perioperative safety.

Background and Aims:According to the Chinese Guidelines for the Diagnosis and Treatment of Colorectal Cancer(2023 Edition),patients with early-stage colorectal cancer who present with high-risk factors require additional radical surgery following endoscopic resection.However,due to the relatively low rate of lymph node metastasis in early colorectal cancer,some patients may not benefit from such supplemental surgery.Therefore,accurately identifying patients who are truly likely to benefit and refining the indications for supplemental surgery are pressing clinical challenges.This study was conducted to investigate the risk factors and distribution patterns of lymph node metastasis following additional radical surgery through retrospectively analyzing a large single-center cohort,thereby providing evidence-based support for clinical decision-making.Methods:Clinicopathologic data were retrospectively reviewed for patients with early-stage colorectal cancer who underwent additional radical surgery at Fudan University Shanghai Cancer Center between 2008 and 2023.Binary Logistic regression and multivariate analyses were performed to identify risk factors associated with lymph node metastasis,and the distribution characteristics of metastatic lymph nodes were further examined.Results:A total of 417 patients were included in the study,with lymph node metastasis confirmed in 36 cases(8.63％)postoperatively.Over time,the number of patients undergoing supplemental surgery increased,while the proportion of cases with residual cancer decreased.Among 243 patients included in the risk factor analysis,univariate analysis indicated that submucosal invasion depth of SM2 or greater,poor tumor differentiation,positive vascular invasion,and tumor location were high-risk factors for lymph node metastasis.Multivariate analysis identified invasion depth(P=0.039)and tumor location(P=0.014)as independent risk factors.Among the metastatic cases,58.3％involved a single lymph node;63.9％of metastases were limited to the first station,and 36.1％extended to the second station,with no metastasis found at the third station.Only four patients had preoperative imaging suggestive of lymph node enlargement.Conclusion:Although the number of supplemental surgeries following endoscopic resection of early-stage colorectal cancer has increased significantly,the actual rate of lymph node metastasis remains low,suggesting a potential risk of overtreatment.Submucosal invasion depth ≥SM2 and tumor location are independent risk factors for metastasis.D2 lymph node dissection is deemed necessary,while the diagnostic value of imaging remains limited.Clinical decisions should prioritize precision and individualized treatment planning.

Clinical decision-making has been perceived as a primary cognitive activity for clinicians in daily practice,which based on the process of choosing between alternatives or options for patients.A single clinical decision might affect one patient's health outcomes,while the sum of clinical decisions made by all clinicians would play a decisive role in the allocation and utilization of health resources.Several dimensions should be taken into consideration when making clinical decisions,such as scientificity,clinical experience,economical status,medical humanities and government administration.In addition,clinical decision-making behavior should be administrated and guided by government,from the following seven aspects,so as to avoid "scientism" or " commercial alienation" phenomenon:national guidelines and standards development,academic standardization,expertise offering,medical training with human factors as well as legal punishment,medical knowledge accessibility,reimbursement restriction,and application of artificial intelligence.

A proportion of patients with locally advanced rectal cancer will achieve clinical complete response (cCR) or pathologic complete response (pCR) after neoadjuvant chemoradiotherapy. With the proposal of the concept of total neoadjuvant therapy (TNT), higher complete response rates will be observed. The management of patients with cCR has long been an issue of controversy and is attractive for clinical trials. A "watch and wait" strategy for patients with cCR has been put forward by some scholars. A non-operative approach can preserve the organfunction and avoid complications after radical surgery. The safety and feasibility of a "watch and wait" strategy have been established in several non-randomized controlled studies. There is no consensus on how to make an optimal decision for patients with cCR. For example, it is only observed in partial patients that cCR is consistent with pCR and the molecular biomarkers for predicting pCR are suboptimal. Besides, cCR is inconsistently defined and surveillance recommendations varies. Furthermore, there are insufficient high-level evidence for the "watch and wait" strategy. For patients with good response after chemoradiotherapy, local excision is an attractive alternative to total mesorectal excision, however with uncertain indications and challenged oncological safety. For patients with cCR, we implement the therapeutic principles of goal-orientation, layered treatment and the whole process management.

A proportion of patients with locally advanced rectal cancer will achieve clinical complete response (cCR) or pathologic complete response (pCR) after neoadjuvant chemoradiotherapy. With the proposal of the concept of total neoadjuvant therapy (TNT), higher complete response rates will be observed. The management of patients with cCR has long been an issue of controversy and is attractive for clinical trials. A "watch and wait" strategy for patients with cCR has been put forward by some scholars. A non?operative approach can preserve the organfunction and avoid complications after radical surgery. The safety and feasibility of a "watch and wait"strategy have been established in several non?randomized controlled studies. There is no consensus on how to make an optimal decision for patients with cCR. For example, it is only observed in partial patients that cCR is consistent with pCR and the molecular biomarkers for predicting pCR are suboptimal. Besides, cCR is inconsistently defined and surveillance recommendations varies. Furthermore, there are insufficient high ? level evidence for the "watch and wait"strategy. For patients with good response after chemoradiotherapy, local excision is an attractive alternative to total mesorectal excision, however with uncertain indications and challenged oncological safety. For patients with cCR, we implement the therapeutic principles of goal?orientation, layered treatment and the whole process management.

A proportion of patients with locally advanced rectal cancer will achieve clinical complete response (cCR) or pathologic complete response (pCR) after neoadjuvant chemoradiotherapy. With the proposal of the concept of total neoadjuvant therapy (TNT), higher complete response rates will be observed. The management of patients with cCR has long been an issue of controversy and is attractive for clinical trials. A "watch and wait" strategy for patients with cCR has been put forward by some scholars. A non?operative approach can preserve the organfunction and avoid complications after radical surgery. The safety and feasibility of a "watch and wait"strategy have been established in several non?randomized controlled studies. There is no consensus on how to make an optimal decision for patients with cCR. For example, it is only observed in partial patients that cCR is consistent with pCR and the molecular biomarkers for predicting pCR are suboptimal. Besides, cCR is inconsistently defined and surveillance recommendations varies. Furthermore, there are insufficient high ? level evidence for the "watch and wait"strategy. For patients with good response after chemoradiotherapy, local excision is an attractive alternative to total mesorectal excision, however with uncertain indications and challenged oncological safety. For patients with cCR, we implement the therapeutic principles of goal?orientation, layered treatment and the whole process management.

OBJECTIVETo examine the association of preoperative carcinoembryonic antigen (CEA) level with the efficacy of neoadjuvant radiochemotherapy and postoperative metastasis and relapse in patients with rectal cancer.

METHODSBetween January 2011 and January 2014, 325 patients with local advanced rectal cancer underwent preoperative radiochemotherapy and radical operation in Department of Colorectal Cancer Surgery, Beijing University Cancer Hospital, including 194 males and 131 females. According to preoperative MRI, all the patients suffered from clinical T3-4 tumors or positive lymph nodes. Their Zubrod-ECOG-WHO score was 0-1. These patients received preoperative intensity modulated radiotherapy which consisted of 50.6 Gy in 22 fractions (IMRT GTV 50.6 Gy/CTV 41.8 Gy/22 f) with capecitabine(825 mg/m, twice per day) as radiosensitizer. According to the preoperative serum CEA level, patients were divided into high group (125 cases) and normal group (200 cases). In high group, serum CEA level decreased into normal range in 60 patients (high-normal group) after radiochemotherapy, while it was still in high level in other 65 patients (high-high group). The differences in sensitivity to radiochemotherapy and 3-year disease free survival (DFS) of these patients were both evaluated.

RESULTSIn high group and normal group, the complete response rates were 18.4% (23/125) and 17.5% (35/200) (χ=0.319, P=0.660); the percentages of tumor regression grade(TRG) 0-1 patients were 68.0%(85/125) and 67.5%(135/200)(χ=0.009, P=0.925); the T downstage rates were 63.2%(79/125) and 70.0%(140/200)(χ=1.266, P=0.274), respectively, whose differences were all not significant. The 3-year DFS rate in high group was 62.4%, which was significantly lower than 93.5% in normal group (χ=53.147, P=0.000). There were 65 patients in high-high group, accounting for 52% (65/125) of high group. Among these 65 patients, 44(67.7%) presented recurrence and metastasis within 3 years and the 3-year DFS was 32.3%, which was much lower than 95.0% of 60 patients in high-normal group(χ=182.085, P=0.000).

CONCLUSIONSPreoperative serum CEA level may not be used to predict tumor response of rectal cancer patients who receive preoperative radiochemotherapy. However, the prognosis of patients with high CEA level is worse. Recurrence and metastasis are more likely to occur in patients with high CEA level after radiochemotherapy.

Adult ; Aged ; Biomarkers, Tumor ; blood ; Carcinoembryonic Antigen ; blood ; Chemoradiotherapy ; statistics & numerical data ; Digestive System Surgical Procedures ; statistics & numerical data ; Disease-Free Survival ; Female ; Humans ; Male ; Middle Aged ; Neoadjuvant Therapy ; statistics & numerical data ; Neoplasm Metastasis ; prevention & control ; Neoplasm Recurrence, Local ; prevention & control ; Predictive Value of Tests ; Prognosis ; Rectal Neoplasms ; drug therapy ; mortality ; surgery ; Survival Rate

Objective Long-chain triacylglycerol (LCT) by three producers,each mixed with the same medium-chain triacylglycerol (MCT),were compared with the brand MCT/LCT in causing focal necrosis of hepatocytes in beagle dogs (a bioequivalence evaluation).Methods 21 beagle dogs (male,0.7-1.5 years old,10-15 kg) were used in this study.According to the sources of the LCT,the animals were divided into Group A (LCT made in China),Group B (LCT made in Japan),Group C (LCT made in Germany),and the control group (the brand 10％ MCT/LCT).Central venous port was placed via the lumber vein of the animals under general anesthesia.After 2 weeks of rehabilitation,MCT/LCT was administered through this port for 28 days at 9 g/ (kg · d) [while the routine dose used clinically was 1 g/ (kg · d)].The laboratory indexes and the pathomorphism of the liver and kidney were studied single blindly.Results Laboratory tests,including liver and kidney function,blood coagulation function and lipid metabolism,did not identify differences among emulsions with different sources of LCT.Liver biopsy at day 28 showed no focal necrosis in Group C and the control group;there was minor damage in Group B;and Group A had obvious liver necrosis.and the pathological findings of other organs are similar.No significant difference was observed in biopsies of other organs.Conclusions Emulsions with different sources of LCT varied in their damage to the liver.Generics with LCT of higher quality were equivalent to the brand MCT/LCT in terms of safety.