PURPOSEThe neoadjuvant chemoradiotherapy (nCRT) might accentuate surgical complications and toxicity in the treatment of locally advanced rectal cancer (LARC) while neoadjuvant chemotherapy (nCT) alone shows promise as an alternative treatment. However, which patients deserve most from the nCT need further clarify. This trial aimed to assess the non-inferiority of nCT with capecitabine plus oxaliplatin (CAPOX) versus nCRT with capecitabine in LARC with uninvolved mesorectal fascia (MRF).METHODSPatients with LARC within 12 cm from the anal verge and uninvolved MRF were randomly assigned to receive 4 cycles of CAPOX chemotherapy alone (nCT group) or CRT with concurrent Capecitabine (nCRT group). The primary end point is 3-year locoregional recurrence-free survival (LRRFS). Secondary end points, such as 3-year disease-free survival (DFS), 3-year overall survival (OS), and adverse events (AEs), were also reported.RESULTSA total of 663 patients were enrolled and 589 patients received the allocated treatment (nCT, n = 300; nCRT, n = 289). LRRFS was analyzed with a median follow-up of 48 months. 3-year LRRFS was 97.4% (95% CI, 95.5 to 99.3) in the nCRT group and 96.3% (95% CI, 94.0 to 98.6) in the nCT group, resulting in a hazard ratio (HR) of 1.40 (95% CI, 0.53 to 3.68). The nCT and nCRT achieved similar 3-year DFS (89.2% v 87.9%; HR, 0.88 [95% CI, 0.54 to 1.44]) and 3-year OS (95.0% v 94.1%; HR, 0.86 [95% CI, 0.42 to 1.76]). The nCT group showed a lower incidence of grade 2 to 4 long-term AEs (16.0% v 26.3%, P = 0.002) and proctitis (33.6% v 41.7%, P = 0.049) compared with nCRT group.CONCLUSIONSThe non-inferiority of nCT was not confirmed with a very low incidence of local recurrence in both group. But nCT offers comparable DFS and OS while mitigating the burden of toxicity as compared to nCRT. These insights shed light on a potential paradigm shift in the treatment for LARC with uninvolved MRF.

Sphincter preservation (SP) during laparoscopic total mesorectal excision (LaTME) for low rectal cancer is challenged by a deep, narrow pelvis. Robust, MRI-based predictors for both SP success and operative difficulty are lacking. We conducted a retrospective study of 275 consecutive patients undergoing LaTME (development cohort, Jan 2022-Feb 2024). An independent, temporal validation cohort (n = 118; Mar-Dec 2024) from the same institution was used. Eight predefined pelvic MRI parameters were measured. The primary outcome was SP failure (conversion to abdominoperineal resection). Surgical difficulty was defined as operative time ≥ 245 min. Independent predictors from multivariable analysis were used to construct a predictive nomogram. Model performance was evaluated by discrimination (AUC), calibration, and clinical utility (decision curve analysis). Shorter tumor distance from the anal verge (OR, 0.26), greater tumor diameter (OR, 1.45), and narrower intertuberous distance (OR, 0.75) were independent predictors of SP failure. The nomogram showed good discrimination (AUC: 0.85 development, 0.84 validation) and calibration. Among patients with successful SP (n = 278), neoadjuvant radiotherapy (OR, 2.11), shorter tumor distance (OR, 0.65), and larger mesorectal anteroposterior diameter (OR, 1.73) were independently associated with surgical difficulty. We developed and validated an MRI-based nomogram that quantifies the likelihood of SP and identifies factors associated with surgical difficulty in LaTME for low rectal cancer. This tool facilitates preoperative risk stratification and personalized surgical planning.

Background Microsatellite instability (MSI) is an important biomarker in stage II/III colorectal carcinoma (CRC), but pretreatment assessment still relies primarily on tissue-based testing. We evaluated whether contrast-enhanced CT-based radiomics could support non-invasive MSI status prediction before treatment. Methods In this retrospective single-center study, 280 eligible patients with pathologically confirmed stage II/III CRC who underwent preoperative contrast-enhanced abdominal CT were included in the overall cohort. For model development, 261 cases with complete radiomics and retained clinical variables were available and were randomly divided into a training set (n = 195) and a testing set (n = 66). After stability filtering and least absolute shrinkage and selection operator selection, 8 radiomics features were retained from 1,648 extracted features. Four radiomics classifiers were developed, and the best-performing radiomics output was then combined with clinical predictors to construct a clinicoradiomic nomogram. Results The support vector machine (SVM) classifier showed the most favorable balance between training and testing discrimination, with AUCs of 0.75 and 0.74, respectively. A radiomics score derived from the retained features was combined with three clinical predictors to construct a clinicoradiomic nomogram. In the testing set, the combined model achieved an AUC of 0.749, compared with 0.701 for the radscore-only model and 0.633 for the clinical model. Calibration analysis showed acceptable agreement between predicted and observed risk, with a Brier score of 0.2137, and decision-curve analysis suggested potential net benefit across a range of clinically relevant threshold probabilities. Conclusions Contrast-enhanced CT-based radiomics showed feasibility for non-invasive MSI status stratification in stage II/III CRC. The combined clinicoradiomic nomogram performed better than the radiomics-only and clinical-only models in the internal testing set, but external validation remains necessary before clinical application.

Studies have demonstrated that the nervous system plays an important role in cancer progression. Nevertheless, the effect of mesenchymal stem cells (MSCs) on cancer has yielded conflicting results. In this study, we discovered that cancer-derived MSCs (CA-MSCs) not only exhibit the properties of neural stem cells (NSCs) but also express a significant amount of neural-related products. These products include neurotrophic factors, neuropeptides, synapse-related products, and axon guidance factors. These identified products exhibit similar or different expression status among human NSCs, cancer and fat-derived MSCs. CA-MSCs expressed more BDNF, GDNF, and NGF than NSCs. Based on these neural-related products expressed by CA-MSCs, expression-prognostic analysis was conducted. It revealed that the expression of MDK and MANF was higher in cancer, and the expression of BDNF, NPTX1, and NGF increased as the tumor stage advanced. For ten neuropeptides, their expression levels were lower in cancer. Thirty synapse-related products displayed their respective expression status between cancer and normal tissues. SYPL1, SYBP2/3, and STX4 had a significant impact on tumor prognosis. Higher levels of syntaxin-4, neugrin, and other axogenesis products were associated with a worse prognosis in cancer. Moreover, immunohistochemistry revealed that NSC-like CA-MSCs were abundant in cancer and exhibited a clear growth-promoting effect on cancer. Briefly, CA-MSCs, which are densely distributed in cancer and have the characteristics of NSCs, express a large number of nerve-related products. These products may have significant effects on tumor progression and prognosis.

Protein Tyrosine Phosphatase Non-Receptor Type 6 (PTPN6) plays a crucial regulatory role in cellular processes and has been implicated in oncogenesis. This pan-cancer analysis aimed to elucidate PTPN6’s involvement across various cancer types, with a particular emphasis on its association with tumor immunity. We analyzed PTPN6 expression data from open access databases using various statistical techniques, including survival analysis, genetic heterogeneity analysis, immune profiling, single-cell analysis, drug sensitivity analysis, and protein interaction analysis. We also conducted in vitro experiments utilizing colorectal cancer cell lines to validate PTPN6’s functional role. PTPN6 exhibited distinct expression patterns across cancers, and its prognostic significance was apparent in several cancer types, particularly in glioblastoma, sarcoma, and melanoma. We observed correlations between PTPN6 and immune genes/cell infiltration in these cancers, suggesting a potential role in modulating the tumor immune microenvironment. Single-cell analysis revealed that PTPN6 is predominantly localized in macrophages, B cells, and dendritic cells within the tumor microenvironment, implying its involvement in regulating immune cell function. Enrichment analysis highlighted PTPN6’s role in immune-related pathways. Drug sensitivity analysis identified specific drugs, including PAC-1, SNX-2112, BELINOSTAT, VORINOSTAT, TPCA-1, and PHA-893,888, whose efficacy may be influenced by PTPN6 expression. Knocking down PTPN6 expression inhibited the proliferation and migration of colorectal cancer cells in vitro, confirming its oncogenic role in this cancer type. This pan-cancer analysis establishes PTPN6’s multifaceted influence on tumor immunity and its potential as a biomarker and therapeutic target.

This multicentre study addresses the genetic spectrum of colorectal polyposis in China. We analyzed 120 patients with over 10 adenomas using a 139-gene next-generation sequencing panel and multiplex ligation-dependent probe amplification. Findings revealed that 89 patients carried pathogenic germline variants, primarily in the APC gene. Notably, one patient had both APC and BRCA2 variants from different parental lines. Our results indicate a higher APC mutation rate compared to prior studies, primarily consisting of nonsense mutations. This research represents the first multicentre clinical investigation in China, highlighting significant differences in mutation profiles compared to the study conducted by the research team from Germany. Since patients were categorized by adenoma count, with none in the 10-19 range diagnosed with hereditary tumors, we recommend delaying genetic testing for those with fewer than 20 adenomas, while emphasizing the need for prompt testing for higher counts.

Hesperetin is a naturally occurring flavonoid compound abundantly present in citrus fruit peels and Traditional Chinese Medicinal (TCM). It exhibits diverse pharmacological properties and represents a promising multi-target candidate for anticancer therapy. This study systematically investigated the molecular mechanisms underlying the anti-colorectal cancer (CRC) effects of hesperetin by integrating network pharmacology, molecular docking, and experimental validation. Network pharmacology analysis identified 42 core targets of hesperetin in CRC, with molecular docking confirming strong binding affinities (binding energy <-7 kcal/mol) between hesperetin and key proteins, including Epidermal Growth Factor Receptor (EGFR), Threonine Kinase 1 (AKT1), Protooncogene Tyrosine-protein Kinase Src (SRC), Phosphatidylinositol-4,5-Bisphosphate 3-Kinase Catalytic Subunit Alpha (PIK3CA), and Matrix Metalloproteinase-9 (MMP9). In vitro experiments demonstrated that hesperetin dose-dependently inhibited the proliferation, migration, and invasion of HCT116 and Lovo cells. Mechanistically, hesperetin reversed epithelial-mesenchymal transition (EMT) by upregulating E-cadherin and downregulating Ncadherin, Vimentin, and Snail at both protein and mRNA levels. Western blot analysis revealed that hesperetin suppressed PI3K/AKT pathway activation by reducing phosphorylation of PI3K (Tyr458) and AKT (Ser473). Clinical data further validated the therapeutic relevance of these targets, showing that high expression of EGFR, AKT1, PIK3CA, and MMP9 correlated with poor prognosis in CRC patients. Collectively, these findings establish hesperetin as a promising multi-target nutritional supplement agent against CRC, demonstrating dual modulation of both PI3K/AKT signaling and EMT progression.

Sushi domain-containing protein 4 (SUSD4) is a complement regulatory protein whose primary function is to inhibit the complement system, and it is involved in immune regulation. The role of SUSD4 in cancer progression has largely remained elusive. SUSD4 was studied across a variety of cancer types in this study. According to the results, there is an association between the expression level of SUSD4 and prognosis in multiple types of cancer. Further analysis demonstrated that SUSD4 expression level was related to immune cell infiltration, immune-related genes, tumor heterogeneity, and multiple cancer pathways. Additionally, we validated the function of SUSD4 in colorectal cancer cell lines and found that knockdown of SUSD4 inhibited cell growth and impacted the JAK/STAT pathway. By characterizing drug sensitivity in organoids, we found that the expression of SUSD4 showed a positive correlation trend with IC50 of Selumetinib, YK-4-279, and Piperlongumine. In conclusion, SUSD4 is a valuable prognostic indicator for diverse types of cancer, and it has the potential to be a target for cancer therapy.

The optimal treatment of ypT1 rectal cancer after neoadjuvant chemoradiotherapy (nCRT) remains controversial. This study aimed to determine whether local excision is non-inferior to radical surgery and whether adjuvant chemotherapy (ACT) would improve survival in patients with ypT1 rectal cancer after nCRT. We enrolled 1212 and 91 patients with ypT1 rectal cancer underwent nCRT followed by radical surgery from the SEER database (2004–2018) and the Zhejiang Cancer Hospital (ZJCH) (2010–2022), respectively. Another 62 patients underwent LE were also identified from SEER registries. Propensity score matching was performed to balance baseline characteristics between patients in different treatment groups. Regional nodal metastasis was histopathologically detected in 257 patients (20.7

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).

PURPOSE:The aim of this work was to determine whether locally advanced rectal cancer (LARC) with negative mesorectal fascia (MRF) predicted by magnetic resonance imaging (MRI) can be excluded from preoperative radiation therapy treatment. METHODS AND MATERIALS:This multicenter, open-label, non-inferiority, randomized clinical trial enrolled patients with LARC within 6 to 12 cm from the anal verge and with negative MRI-predicted MRF. Participants were randomized to the intervention group (primary surgery, in which the patients with positive pathologic [CRM] circumferential margins were subjected to chemoradiotherapy [CRT] and those with negative CRM underwent adjuvant chemotherapy according to pathologic staging) or the control group (preoperative CRT, in which all patients underwent subsequent surgery and adjuvant chemotherapy). The primary endpoint was 3-year disease-free survival (DFS). RESULTS:A total of 275 patients were randomly assigned to the intervention (n = 140) and control (n = 135) groups, in which 33.57% and 28.15% patients were at clinical T4 stage and 85.92% and 80.45% patients were at "bad" or "ugly" risk in the intervention and control groups, respectively. There were 2 patients (1.52%) and 1 patient (0.77%) with positive CRM in the intervention and control groups, respectively (P > .05). The non-adherence rates for the intervention and control groups were 3.6% and 23.7%, respectively. After a median follow-up of 34.6 months (IQR, 18.2-45.7), 43 patients had positive events (28 patients and 15 patients in the intervention and control groups, respectively). There were 6 patients (4.4%) with local recurrence in the intervention group and none in the control group, which led to the termination of the trial. The 3-year DFS rate was 81.82% in the intervention group (95% CI, 78.18%-85.46%) and 85.37% in the control group (95% CI, 81.75%-88.99%), with a difference of -3.55% (95% CI, -3.71% to -3.39%; hazard ratio, 1.76; 95% CI, 0.94-3.30). In the per-protocol data set, the difference between 3-year DFS rates was -5.44% (95% CI, -5.63% to -5.25%; hazard ratio, 2.02; 95% CI, 1.01-4.06). CONCLUSIONS:Based on the outcomes of this trial, in patients with LARC and MRI-negative MRF, primary surgery could negatively influence their DFS rates. Therefore, primary surgery was an inferior strategy compared with preoperative CRT followed by surgery and cannot be recommended for patients with LARC.

BACKGROUND:The mutation status of rat sarcoma viral oncogene homolog (RAS) has prognostic significance and serves as a key predictive biomarker for the effectiveness of antiepidermal growth factor receptor (EGFR) therapy. However, there remains a lack of effective models for predicting RAS mutation status in colorectal liver metastases (CRLMs). This study aimed to construct and validate a diagnostic model for predicting RAS mutation status among patients undergoing hepatic resection for CRLMs.METHODS:A diagnostic multivariate prediction model was developed and validated in patients with CRLMs who had undergone hepatectomy between 2014 and 2020. Patients from Institution A were assigned to the model development group (i.e., Development Cohort), while patients from Institutions B and C were assigned to the external validation groups (i.e., Validation Cohort_1 and Validation Cohort_2). The presence of CRLMs was determined by examination of surgical specimens. RAS mutation status was determined by genetic testing. The final predictors, identified by a group of oncologists and radiologists, included several key clinical, demographic, and radiographic characteristics derived from magnetic resonance images. Multiple imputation was performed to estimate the values of missing non-outcome data. A penalized logistic regression model using the adaptive least absolute shrinkage and selection operator penalty was implemented to select appropriate variables for the development of the model. A single nomogram was constructed from the model. The performance of the prediction model, discrimination, and calibration were estimated and reported by the area under the receiver operating characteristic curve (AUC) and calibration plots. Internal validation with a bootstrapping procedure and external validation of the nomogram were assessed. Finally, decision curve analyses were used to characterize the clinical outcomes of the Development and Validation Cohorts.RESULTS:A total of 173 patients were enrolled in this study between January 2014 and May 2020. Of the 173 patients, 117 patients from Institution A were assigned to the Model Development group, while 56 patients (33 from Institution B and 23 from Institution C) were assigned to the Model Validation groups. Forty-six (39.3%) patients harbored RAS mutations in the Development Cohort compared to 14 (42.4%) in Validation Cohort_1 and 8 (34.8%) in Validation Cohort_2. The final model contained the following predictor variables: time of occurrence of CRLMs, location of primary lesion, type of intratumoral necrosis, and early enhancement of liver parenchyma. The diagnostic model based on clinical and MRI data demonstrated satisfactory predictive performance in distinguishing between mutated and wild-type RAS, with AUCs of 0.742 (95% confidence interval [CI]: 0.651─0.834), 0.741 (95% CI: 0.649─0.836), 0.703 (95% CI: 0.514─0.892), and 0.708 (95% CI: 0.452─0.964) in the Development Cohort, bootstrapping internal validation, external Validation Cohort_1 and Validation Cohort_2, respectively. The Hosmer-Lemeshow goodness-of-fit values for the Development Cohort, Validation Cohort_1 and Validation Cohort_2 were 2.868 (p = 0.942), 4.616 (p = 0.465), and 6.297 (p = 0.391), respectively.CONCLUSIONS:Integrating clinical, demographic, and radiographic modalities with a magnetic resonance imaging-based approach may accurately predict the RAS mutation status of CRLMs, thereby aiding in triage and possibly reducing the time taken to perform diagnostic and life-saving procedures. Our diagnostic multivariate prediction model may serve as a foundation for prognostic stratification and therapeutic decision-making.

TPS225 Background: Most patients (pts) with early-stage colorectal cancer (CRC) have a good prognosis, but some still relapse shortly after surgery. Effective methods to assess the risk of recurrence in these pts and guide adjuvant chemotherapy (ACT) decision-making are lacking. Increasing studies have shown that circulating tumor DNA (ctDNA) can detect minimal residual disease (MRD) and identify pts with a high risk of recurrence. ACT could improve survival of MRD-positive pts with stage Ⅱ CRC suggested by recent studies, whether it is appropriate for those with stage Ⅰ or clinically low-risk stage Ⅱ CRC remains unknown. Methods: CAREME is a multicenter randomized controlled clinical trial aimed at investigating the benefit of chemotherapy for MRD-positive pts with early-stage CRC. Pts with resected stage Ⅰ or Ⅱ CRC will be evaluated by oncologists. Those who did not receive neoadjuvant therapy and are deemed suitable for active surveillance (i.e., ACT is not needed) will undergo a postoperative ctDNA test using MinerVa MRD assay (a tumor-informed assay covering 769 cancer-related genes). Pts with mismatch repair-deficient tumors will be excluded and stage Ⅱ pts should have no traditional high-risk features according to clinical practice guidelines. Pts with positive ctDNA (N = 38) will be equally randomized into two groups: treatment group (Arm A) or surveillance group (Arm B). Arm A will receive 8 cycles of CAPEOX therapy while pts in Arm B will not receive any ACT; both groups will undergo ctDNA tests at 6 months after randomization and be followed up every 3 months. The primary endpoint is 18-month recurrence-free survival, and a key secondary endpoint is ctDNA clearance at 6 months after randomization. Tumor samples from the pts will be collected for MRD assay and exploratory research. Accrual started in February 2023. Support: Genecast Biotechnology Company. Clinical trial information: NCT05699746 .

Supplementary Table 1 Instrument used for the evaluation of the risk of bias and applicability concerns of the included prognostic studies (adapted from QUADAS-2). Supplementary Table 2 Characteristics of studies included in the diagnostic meta-analysis. Supplementary Table 3 Characteristics of studies included in the prognostic meta-analysis. Supplementary Table 4 Quality assessment of the included diagnostic studies according to QUADAS-2. Supplementary Table 5 Risk of bias and applicability concerns of included prognostic studies. Supplementary Table 6 Methodological quality of included prognostic studies according to STROBE criteria. Supplementary Figure 1 Receiver operating characteristic curves of plasma miR-21 for discrimination CRC patients from controls. Supplementary Figure 2 Kaplan–Meier curve of tissue miR-21 expression in relation to the survival of CRC patients in the original study. Supplementary Figure 3 Funnel plots of the meta-analyses (A) Funnel plot of tissue miR-21 and CRC OS (B) Funnel plot of tissue miR-21 and CRC DFS (3) Funnel plot of circulating miR-21 and CRC diagnosis. PRISMA Checklist.

Objective: To investigate the impact of relative locations of multiple foci and microsatellite status of sporadic, synchronous, multiple, primary, colorectal carcinomas on clinicopathological features and prognosis. Methods: The clinicopathologic and prognostic data of 278 patients with sporadic, synchronous, multiple, primary, colorectal carcinomas who had been admitted to the Department of Colorectal Surgery at Zhejiang Cancer Hospital from January 2008 to July 2022 were retrospectively collected. The patients were categorized into three groups based on the relative locations of their multiple cancer foci: (1) a right-sided group that comprised patients with multiple cancer foci in the cecum, ascending colon, hepatic flexure of the colon, and transverse colon; (2) a left-sided group that comprised patients with multiple cancer foci in the splenic flexure of the colon, descending colon, sigmoid colon, and rectum; and (3) a left- and right-sided group that comprised patients with multiple cancer foci in the right half of the colon and left half of the colon/rectum. Additionally, the patients were further divided into two groups based on microsatellite status: a high microsatellite instability (MSI-H) and a low MSI/stable MSI (MSI/L&MSS) group. We compared differences in clinical characteristics and prognostic indicators between these groups. The χ2 test was utilized to compare selected clinical characteristics, whereas Kaplan-Meier survival analyses and log-rank tests were performed to compare their effects on prognosis. Result: Among 278 patients with SSCRC, 256 (92.1%) presented with two cancer foci and 22 (7.9%) with more than two foci. Additionally, 255 patients (91.7%) had adenocarcinomas, whereas the remaining 23 (8.3%) had mucinous adenocarcinomas. Lymph node metastases were identified in 136 patients (48.9%); the cancer foci had infiltrated beyond the muscular layer in 238 (85.6%); and 147 patients (52.9%) were diagnosed with TNM Stage III-IV disease. There were 155 patients (55.8%) in the left-sided group, 55 (19.8%) in the right-sided group, and 68 (24.5%) in the left- and right-sided group. Immunohistochemical examination of all four mismatch repair proteins were performed in 199 cases, revealing that 166 of these patients had MSI/L&MSS and 33 MSI-H disease. In the left-sided, left- and right-sided, and right-sided groups, the proportion of women was 16.8% (26/155), 26.5% (18/68), and 49.1% (27/55), respectively; these differences are statistically significant (χ2=22.335, P<0.001). The proportions of patients with more than three cancer foci were 5.2% (8/155), 16.2% (11/68), and 5.5% (3/55), respectively; these differences are statistically significant (χ2=8.438, P=0.015). The proportions of mucinous adenocarcinomas were 4.5% (7/155), 8.8% (6/68), and 18.2% (10/55), respectively; these differences are statistically significant (χ2=10.026, P=0.007). The proportions of patients with lymph node metastases were 55.5% (86/155), 48.5% (33/68), and 30.9% (17/55); these differences are statistically significant (χ2=9.817, P=0.007). The proportions of patients with Stage T3 & T4 disease in each group according to location were 81.3% (126/155), 88.2% (60/68), and 94.5% (52/55), respectively; these differences are statistically significant (χ2=6.293,P=0.043). The proportions of TNM Stage III-IV tumors were 59.4% (92/155), 54.4% (37/68), and 32.7% (18/55), respectively; these differences are statistically significant (χ2=11.637, P=0.003). Age, size of cancer foci, presence of distant metastasis, adenoma, nerve invasion, and vascular invasion did not differ significantly between the three groups (all P>0.05). Compared with those with MSI-H, patients with MSI/L&MSS disease were more likely to be aged >65 years and male (50.6% [84/166] vs. 15.2% [5/33], χ2=13.994,P<0.001; 80.7% [134/166] vs. 54.5% [18/33], χ2=10.457,P=0.001), more likely to be in the left-sided group (63.3% [105/166] vs. 24.2% [8/33], χ2=18.232, P<0.001), had a higher proportion of cancer foci of diameter <4 cm (54.8% [91/166] vs. 33.3% [11/33], χ2=5.086,P=0.024), and a lower proportion of mucinous adenocarcinomas (4.2% [7/166] vs. 27.3% [9/33], χ2=19.791,P<0.001), more likely to develop distant metastases (22.3% [37/166] vs. 6.1% [2/33], χ2=4.601,P=0.032), more likely to have lymph node metastases (57.2% [95/166) vs. 24.2% [8/33], χ2=11.996,P<0.001) and nerve invasion (28.9% [48/166] vs. 6.1% [2/33], χ2=7.643, P=0.006), had a higher proportion of TNM Stage III-IV disease (60.2% [100/166] vs. 24.2% [8/33], χ2=14.374, P<0.001), and a smaller proportion of family history of tumors (28.9% [48/166] vs. 60.6% [20/33], χ2=12.228, P<0.001). All the above-listed differences are statistically significant (all P<0.05). The differences in number of cancer foci, depth of infiltration, presence or absence of adenomas, and vascular invasion were not statistically significant (all P>0.05). In the 33 patients with MSI-H status and mismatch repair protein loss, the highest frequency of deletion was found in PMS-2 (66.7%, 22/33), followed by MLH-1 (57.6%, 19/33), whereas the proportions of MSH-2 (33.3%, 11/33) and MSH-6 (24.2%, 8/33) deletions were relatively low. There were statistically significant differences in the 3-year overall survival rates among the groups according to relative locations of cancer foci. The 3-year overall survival rates were 96.8%, 79.6%, and 88.5% in the right-sided, left- and right-sided, and left-sided groups, respectively (P=0.021). As to microsatellite status, the 3-year overall survival rate of patients with MSI-H disease was 93.8%, which is significantly better than the 78.4% for those with MSI/L & MSS (P=0.026). Conclusions: Among sporadic, synchronous, multiple, primary, colorectal carcinomas, those with right-sided disease had the deepest local infiltration, whereas those with left-sided disease had the greatest number of lymph node metastases, most advanced clinical TNM stage, lowest percentage of MSI-H disease, and the poorest prognosis.

Background:Frailty and systemic inflammation are parameters, which are easy to evaluate, can be used to predict disease outcomes, and are potentially modifiable. The combination of frailty and inflammation-based data may help identify elderly cancer patients predisposed to adverse clinical outcomes. The aim of this study was to examine the association of systemic inflammation and frailty at admission, and to determine whether these risk factors interact and may predict the survival of elderly cancer patients. Methods:A prospective Investigation on Nutrition Status and Clinical Outcome of Common Cancers (INSCOC) with 5,106 elderly cancer patients admitted from 2013 through 2020 was included in this study. The primary marker of inflammation was the neutrophil-to-lymphocyte ratio (NLR), with the reference group having NLR<3, which indicated no inflammation. Frailty was assessed using the FRAIL scale, and patients with≥3 positives out of a total of five components were assumed to be frail. The primary outcome was all-cause mortality. We classified participants according to the presence (or absence) of frailty and high inflammation and assessed their association with overall survival using the Cox proportional hazards models adjusted for demographic, tumor, and treatment factors. Results:Among the 5,106 patients enrolled in the study, 3396 individuals (66.51%) were male and the mean( ± SD) age at diagnosis was 70.92( ± 5.34). Over a median of 33.5 months follow-up, we observed 2,315 deaths. Increasing NLR was associated with frailty (compared with NLR<3, odds ratio=1.23, 95%CI=1.08-1.41 for NLR≥3). An NLR≥3 and frailty independently predicted the overall survival [hazard ratio(HR)=1.35, 95%CI=1.24-1.47 and HR=1.38, 95%CI=1.25-1.52, respectively). Patients with both frailty and NLR≥3 had the lowest overall survival(HR=1.83, 95%CI=1.59-2.04) than patients with no risk factors. The mortality rate increased with the presence of the frailty components. Conclusions:Systemic inflammation was positively associated with frailty. Frail elderly cancer patients with elevated systemic inflammation had low survival rate.

Purpose Colorectal cancer is a common malignant tumor worldwide. In China, the ratio of rectal cancer to colon cancer in terms of incidence is close to 1: 1. Low rectal cancer accounts for more than half of all cases of rectal cancer. In recent years, the proportion of rectal cancer has trended downward, however the incidence of rectal cancer in younger adults is increasing. The CACA Guidelines for Holistic Integrative Management of Rectal Cancer were edited to help improve the diagnosis and comprehensive treatment in China. Methods This guideline has been prepared by consensuses reached by the CACA Committee of Colorectal Cancer Society, based on a careful review of the latest evidence including China’s studies, and referred to domestic and international relative guidelines, also considered China’s specific national conditions and clinical practice. Results The CACA Guidelines for Holistic Integrative Management of Rectal Cancer include the epidemiology of rectal cancer, prevention and screening, diagnosis, treatment of nonmetastatic and metastatic rectal cancer, follow-up, and whole-course rehabilitation management. Conclusion Committee of Colorectal Cancer Society, Chinese Anti-Cancer Association, standardizes the diagnosis and treatment of rectal cancer in China through the formulation of the CACA Guidelines.

Background:Natural orifice specimen extraction surgeries (NOSES) have been applied to colorectal cancer (CRC). Different types of NOSES have been proposed. Traditional laparoscopic CRC surgeries (non-NOSES) have been widely adopted in clinical practice. Therefore, the safety and feasibility of NOSES could be clarified by comparing with non-NOSES.Methods:Consecutive cases who underwent NOSE or non-NOSE rectal surgeries were retrospectively collected at the Second Affiliated Hospital of Harbin Medical University between 1 January 2013 and 31 December 2018. Other inclusion criteria included patients with adenocarcinoma of the rectum within 15 cm of the anal verge, over the age of 18 and undergoing primary laparoscopic rectal resection. Patients who were lost to follow-up or had incomplete information were excluded. Basic characteristics including gender, tumor location, age, staging, treatment, and Body Mass Index (BMI) were analyzed. Short-term outcomes including comorbidities, intra-operative blood loss, hospital stay, gas exhaust time were compared between different NOSES and non-NOSES groups. Long-term outcomes including overall survival (OS) and disease-free survival (DFS) were also analyzed. Patients were followed-up during the inpatient period, at an outpatient clinic, or by phone call.Results:A total of 196 NOSES cases and 243 non-NOSES cases were included. There was a sex difference between the two groups and other factors were comparable. Cases were divided into NOSES groups [including extra-abdominal resection (EVER), specimen extraction and extra-abdominal resection (EXER), and intra-abdominal resection and specimen extraction (IREX)] and non-NOSES groups. Differences in sex (P=0.016), BMI (with mean of 22.08, 22.00, 22.53, and 23.26 kg/m2, P=0.003), and staging (P=0.008) were observed between the four groups. There was a difference in the intra-operative blood loss between NOSES and non-NOSES groups (57.05±62.78, 52.65±68.19, 36.52±43.99 vs. 76.12±90.11 mL, P=0.002), in which NOSES groups had less blood loss. Furthermore, NOSES groups showed a better post-operative gas exhaust time (54.68±37.80, 45.06±24.69, 47.91±28.93 vs. 56.94±27.69 hours, P=0.012). NOSES groups also had fewer ileostomies (17 vs. 37, P=0.003). There was no difference in the long-term DFS and OS between the two groups.Conclusions:NOSES in rectal cancer showed better short-term outcomes and had comparable long-term outcomes compared with non-NOSE surgeries.

3515 Background: Neoadjuvant radiochemotherapy is the standard treatment for locally advanced rectal cancer. However, radiation therapy can lead to bowel, urinary and sexual dysfunction. The study aims to clarify whether locally advanced rectal cancer with a distance of 6 to 12 cm from the anus with negative circumferential margins (CRM) predicted by MRI can be exempted from preoperative radiotherapy. Methods: PSSR (NCT02121405), a multicentre, randomized, open-label, non-inferiority, phase 3 trial, was done across 10 hospitals in China. Patients aged from 18 to 75 years with locally advanced rectal cancer (including all cT3/4 and/or Nany) with negative MRI-predicted CRM and tumor distance of 6 to 12 cm from anus were randomly assigned (1:1), by central randomization, to intervention group (surgery directly, in which positive CRM was supplemented with chemoradiotherapy, negative CRM received adjuvant chemotherapy according to surgical pathologic staging), or control group (neoadjuvant chemoradiotherapy then underwent surgery and adjuvant chemotherapy). The primary endpoint is the rate of 3-year disease-free survival (DFS). A sample size of 350 was set according to the original non-inferiority margin of 15% for the difference of rates for 3-year DFS, which was changed to 5% under the Data Safety Monitoring Board (DSMB) suggestion after an interim analysis. The efficacy analysis followed the per-protocol (PP) principle. Results: From December 2015 to February 2021, 299 patients were recruited. DSMB stopped this trial due to the difference of 3-year DFS’s rate between two groups more than 5% at the interim analysis in July 2021. A total of 275 were included for the final analysis. Based on the PP dataset, 238 patients followed the original protocol (135 patients in the intervention group and 103 patients in the control group). Patients who had positive CRM were 2(1.5%) and 1(1.0%) in two groups, respectively ( P= 1.00). After a median follow-up of 34.6 (IQR: 18.2-45.7) months, a total of 42 patients had positive events (30 patients in the intervention group and 12 patients in the control group). There were 5 (3.7%) patients with local recurrence in the intervention group ( P= 0.062). Patients with pathological complete response (pCR) and near pCR were 19 (18.4%) and 21 (20.4%) in the control group. The rate of 3-year DFS was 81.1% (77.3%-84.9%) (HR = 2.02, 95%CI: 1.01-4.06, P= 0.048) in the intervention group and 86.6% (82.7%-90.5%) in the control group, with difference of 5.4% (5.3%-5.6%), which did not meet the criteria for non-inferiority. Conclusions: In terms of DFS, initial surgery was inferior to conventional preoperative radiochemotherapy for locally advanced middle rectal cancer with MRI negative circumferential margin. Clinical trial information: NCT02121405.

Death-associated protein kinase 1 (DAPK1), as a calcium/calmodulin (CaM) regulated serine/threonine kinase, functions in apoptotic and autophagy pathways and represents an interesting drug target for inflammatory bowel disease and Alzheimer’s disease. The crystal structure of the DAPK1 catalytic domain and the autoregulatory domain (ARD) in complex with CaM provides an understanding of CaM-dependent regulation of DAPK1 activity. However, the molecular basis of how distinct Trp305 (W305Y and W305D) mutations in the ARD modulate different DAPK1 activities remains unknown. Here, we performed multiple, μs-length molecular dynamics (MD) simulations of the DAPK1–CaM complex in three different (wild-type, W305Y, and W305D) states. MD simulations showed that the overall structural complex did not change significantly in the wild-type and W305Y systems, but underwent obvious conformational alteration in the W305D system. Dynamical cross-correlation and principal component analyses revealed that the W305D mutation enhanced the anti-correlated motions between the DAPK1 and CaM and sampled a broader distribution of conformational space relative to the wild-type and W305Y systems. Structural and energetical analyses further exhibited that CaM binding was unfavored in response to the W305D mutation, resulting in the decreased binding of CaM to the W305D mutant. Furthermore, the hydrogen bonds and salt bridges responsible for the loss of CaM binding on the interface of the DAPK1–CaM complex were identified in the W305D mutant. This result may provide insights into the key role of Trp305 in the regulation of CaM-mediated DAPK1 activity.