Resection Of Colon Cancer Research Articles

Clinical Calculator for Predicting Freedom From Recurrence After Resection of Stage I-III Colon Cancer in Patients With Microsatellite Instability.

Outcome for patients with nonmetastatic, microsatellite instability (MSI) colon cancer is favorable: however, high-risk cohorts exist. This study was aimed at developing and validating a nomogram model to predict freedom from recurrence (FFR) for patients with resected MSI colon cancer. Data from patients who underwent curative resection of stage I, II, or III MSI colon cancer in 2014-2021 (model training cohort, 384 patients, 33 events; median follow-up, 38.8 months) were retrospectively collected from institutional databases. Variables associated with recurrence in multivariable analysis were selected for inclusion in the clinical calculator. The calculator's predictive accuracy was measured with the concordance index and validated using data from patients who underwent treatment for MSI colon cancer in 2007-2013 (validation cohort, 164 patients, eight events; median follow-up, 84.8 months). T category and number of positive lymph nodes were significantly associated with recurrence in multivariable analysis and were selected for inclusion in the clinical calculator. The calculator's concordance index for FFR in the model training cohort was 0.812 (95% CI, 0.742 to 0.873), compared with 0.759 (95% CI, 0.683 to 0.840) for the staging schema of the eighth edition of the American Joint Committee on Cancer Staging Manual. The concordance index for the validation cohort was 0.744 (95% CI, 0.666 to 0.822), confirming robust predictive accuracy. Although in general patients with nonmetastatic MSI colon cancer had favorable outcome, patients with advanced T category and multiple metastatic lymph nodes had higher risk of recurrence. The clinical calculator identified patients with MSI colon cancer at high risk for recurrence, and this could inform surveillance strategies. In addition, the model could be used in trial design to identify patients suitable for novel adjuvant therapy.

Comparison of robotic and laparoscopic surgery for sigmoid colon and rectal cancer: a single-center retrospective study on surgical outcomes and long-term survival.

Although the safety and short-term outcomes of robotic surgery for sigmoid colon and rectal cancer patients are well-documented, there is limited research on the long-term survival outcomes of robotic colorectal surgery. This is a retrospective study that includes 502 patients who underwent either laparoscopic or robotic anterior resection and abdominoperineal resection for rectal or sigmoid colon cancer between August 2016 and September 2021. All patients were diagnosed with rectal or sigmoid colon adenocarcinoma. Propensity score matching (PSM) was implemented to minimize selection bias. Perioperative outcomes, complication rates, and pathological data were evaluated and compared. The 5-year overall survival rate and disease-free survival rate were calculated and compared. Before matching, patients in the robotic group had earlier pathological T and N stages and were more likely to have received neoadjuvant chemoradiotherapy compared to the laparoscopic group. After matching, most clinicopathological outcomes were similar between the two groups, but the robotic group had longer operative times and a lower conversion rate to open surgery compared with laparoscopic group. After matching for clinical factors, the 5-year DFS rates were 88.19% for the robotic group and 82.46% for the laparoscopic group (P = 0.122), and the OS rates were 90.5% and 79.5% (P = 0.342), showing no significant differences. In the stratified analysis, patients in the robotic surgery group had significantly higher 5-year DFS rates in the following subgroups: age < 65years, TNM stage I-II, received neoadjuvant therapy, and primary tumor located in the rectum. The safety and efficacy of robotic surgery for sigmoid colon and rectal cancer were validated compared to laparoscopic surgery, with both groups of patients exhibiting comparable long-term prognoses.

Novel Artificial Intelligence Combining Convolutional Neural Network and Support Vector Machine to Predict Colorectal Cancer Prognosis and Mutational Signatures From Hematoxylin and Eosin Images

Reducing recurrence following radical resection of colon cancer without overtreatment or undertreatment remains a challenge. Postoperative adjuvant chemotherapy (Adj) is currently administered based solely on pathologic TNM stage. However, prognosis can vary significantly among patients with the same disease stage. Therefore, novel classification systems in addition to the TNM are necessary to inform decision-making regarding postoperative treatment strategies, especially stage II and III disease, and minimize overtreatment and undertreatment with Adj. We developed a prognostic prediction system for colorectal cancer using a combined convolutional neural network and support vector machine approach to extract features from hematoxylin and eosin staining images. We combined the TNM and our artificial intelligence (AI)–based classification system into a modified TNM-AI classification system with high discriminative power for recurrence-free survival. Furthermore, the cancer cell population recognized by this system as low risk of recurrence exhibited the mutational signature SBS87 as a genetic phenotype. The novel AI-based classification system developed here is expected to play an important role in prognostic prediction and personalized treatment selection in oncology.

ACBC Study Protocol – Acute Colon Resection Versus Bridge to Colon Surgery with Stent Placement or Stoma Diversion: A Prospective Cohort Study

Abstract Background: Approximately 70% of all colon cancer emergencies result from colonic obstruction. Data from the Swedish Colorectal Cancer Registry indicate that patients undergoing emergency surgical resections for colon cancer face higher overall 30-day morbidity and increased mortality rates—5.8% at 30 days and 11.2% at 90 days—compared to those undergoing elective procedures, which have mortality rates of 1.1% and 2.0%, respectively. Other concerns about acute colon cancer resections are oncological outcomes. Long-term outcomes are significantly worse, with higher rates of recurrence and cancer-related death, regardless of the cancer stage or the use of adjuvant chemotherapy. Objectives: To evaluate the short- and long-term outcomes of primary resection for malignant colonic obstruction compared to only decompression using a self-expandable endoscopic metallic stent or diverting stomas as the first intervention (bridge to surgery) followed by later oncological resection. Design: This is a prospective observational study with data collected through the Swedish Colorectal Cancer Registry with an additional electronic case report form. Settings: Swedish multicenter study at both university and regional hospitals. Patients and Methods: Patients with suspected acute malignant large bowel obstruction due to colonic adenocarcinoma will be identified and followed. Analysis will be performed on an intention-to-treat basis. Descriptive statistics of the study cohort will be presented. Primary endpoints will be subjected to multivariate analyses adjusted for confounders. Main Outcome Measures: 30-day severe morbidity (Clavien–Dindo &gt; 3a), 30- and 90-day mortality rates, and overall survival after three and five years. Sample Size: We aim to include 1000 patients, with an interim analysis after the recruitment of 500 patients. Results: The study is ongoing. Conclusions: Acute colon obstruction is associated with substantial morbidity and mortality. We hypothesize that patients with malignant obstruction benefit from avoidance of emergency cancer resection and that bridge to surgery leads to decreased short-term morbidity and mortality and improved long-term oncological outcomes. Limitations: The main limitation is the risk of selection bias when the study is not a randomized controlled trial, which would be a standard process. A prospective observational study is, nevertheless, considered a pragmatic compromise between feasibility and ability to answer the research question. Conflicts of Interest: None.

Advanced Preoperative Clinical Stage Is Associated With More Lymph Node Harvest in Patients With Right Colon Cancer.

The adequacy of lymph node (LN) harvest is important in oncological colon cancer resections. While several studies have suggested factors influencing LN yield in colon cancer, limited data are available only regarding right hemicolectomies with complete mesocolic excision (CME) and central vessel ligation (CVL). A retrospective analysis was conducted on 169 patients who underwent right hemicolectomies with CME and CVL for right-sided colon cancer between February 2019 and March 2023. The patients were divided into 2 groups: groups with ≤24 LN yield and >24 LN yield, and the patient, surgical, and pathologic factors, which could potentially influence the LN yield, were analyzed. Younger age, lower American Society of Anesthesiologists (ASA) classification, and advanced clinical TNM (cTNM) stage among patient factors, the presence of obstructions regarding the surgical factors, and the presence of desmoplastic tumor reaction in the pathologic factors were more likely to harvest >24 LNs. In a multivariate analysis, younger age, lower ASA classification, advanced cTNM stage, and an ileocolic artery (ICA) crossing pattern posterior to the superior mesenteric vein (SMV) were independently associated with a >24 LN harvest. Patients with cTNM 3,4 showed the tendency of > 24 LN yield consistently within each subgroup, irrespective of the age, ASA classification, and ileocolic artery crossing pattern. Our investigation revealed a significant correlation between the advanced preoperative clinical stage and an increased number of harvested lymph nodes (LNs) in patients undergoing right hemicolectomies with CME a CVL. The observed association is potentially influenced by tumor aggressiveness and the extent of surgical resection performed by the surgeon. To elucidate the intricate relationship between surgical outcomes and the quantity of LN harvest in patients subjected to standardized CME and CVL for right-sided colon cancer, further dedicated research is warranted.

Improved Survival With Adjuvant Cyclooxygenase 2 Inhibition in PIK3CA-Activated Stage III Colon Cancer: CALGB/SWOG 80702 (Alliance).

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.Observational studies have associated aspirin or cyclooxygenase 2 (COX-2) inhibitor usage either before or after colorectal cancer diagnosis with lower risk of recurrence and suggest that PIK3CA mutational status is predictive of better response to COX-2 inhibition. To prospectively test whether adding the COX-2 inhibitor celecoxib to standard adjuvant chemotherapy reduces the risk of recurrence and improves survival, the National Cancer Institute sponsored the CALGB/SWOG 80702 trial (ClinicalTrials.gov identifier: NCT01150045) for patients with stage III resected colon cancer. Although the primary hypothesis for all patients did not show a statistically significant improvement in disease-free survival (DFS) with celecoxib, subgroup analysis by PIK3CA mutational status was a preplanned study. PIK3CA gain-of-function mutations were detected in 259 of 1,197 tumors with available whole-exome sequencing data. When stratified by PIK3CA status, patients with PIK3CA gain-of-function mutations treated with celecoxib exhibited improved DFS (adjusted hazard ratio [HR], 0.56 [95% CI, 0.33 to 0.96]) compared with PIK3CA wildtype patients (adjusted HR, 0.89 [95% CI, 0.70 to 1.14]), although the interaction test was nonsignificant (Pinteraction = .13). Overall survival was similarly improved for patients with PIK3CA gain-of-function mutations (adjusted HR, 0.44 [95% CI, 0.22 to 0.85]) compared with PIK3CA wildtype patients (adjusted HR, 0.94 [95% CI, 0.68 to 1.30]; Pinteraction = .04). Although the test for heterogeneity in DFS did not reach statistical significance, the results suggest potential utility of PIK3CA to consider selective usage of COX-2 inhibitors in addition to standard treatment for stage III colon cancer.

Extended Pharmacologic Prophylaxis for Venous Thromboembolism After Colon Cancer Surgery Is Associated With Improved Long-term Survival: A Natural Experiment in the Chemotherapeutic Benefit of Heparin Derivatives.

This large database study assessed whether extended pharmacologic prophylaxis for venous thromboembolism after colon cancer resection was associated with improved oncologic survival. Heparin derivatives may confer an antineoplastic effect via a variety of mechanisms (eg, inhibiting angiogenesis in the tumor microenvironment). Studies evaluating the oncologic benefit of heparin and its derivatives have been limited in postsurgical patients. Multiple society guidelines recommend consideration of 30-day treatment with low molecular weight heparin to reduce venous thromboembolism risk after abdominopelvic cancer surgery. However, utilization of extended prophylaxis remains low. Surveillance, Epidemiology, and End Results-Medicare data were used to identify patients (age 65+) undergoing resection for nonmetastatic colon cancer from 2016 to 2017. The primary outcomes were overall and cancer-specific survival. Log-rank testing and multivariable Cox regression compared survival in patients who received extended prophylaxis versus those who did not in an inverse propensity treatment weighted cohort. A total of 20,102 patients were included in propensity-weighting and analyzed. Eight hundred (3.98%) received extended pharmacologic prophylaxis. Overall survival and cancer-specific survival were significantly higher in patients receiving prophylaxis on log-rank tests ( P =0.0017 overall, P =0.0200 cancer-specific). Multivariable Cox regression showed improved overall survival [adjusted hazard ratio 0.66 (0.56-0.78)] and cancer-specific survival [adjusted hazard ratio 0.56 (0.39-0.81)] with prophylaxis after controlling for patient, treatment, and hospital factors. Extended pharmacologic prophylaxis after colon cancer resection was independently associated with improved overall and cancer-specific survival. These results suggest a potential antineoplastic effect from heparin derivatives when used in the context of preventing postsurgical venous thromboembolism.

Close margin of adverse histologic factors with a negative primary tumor margin is not associated with increased locoregional recurrence in colon cancer

PurposeLocoregional recurrence after resection of colon cancer is increased when primary tumor margin is positive (<1 ​mm). Data is limited regarding the risk of locoregional recurrence with close margin (<1 ​mm) of histologic factors, such as intravascular tumor, intranodal tumor, tumor deposits, or extranodal extension. We hypothesized that close margin of these factors doesn't affect locoregional recurrence. MethodsA retrospective review of all colon cancer surgical resections for adenocarcinoma from 2007 to 2020 was performed. Inclusion criteria were specimens with a negative primary tumor margin but a close margin of adverse histologic factors, defined as intravascular tumor, intranodal tumor, tumor deposits, or extranodal extension within 1 ​mm of a mesenteric or circumferential margin. ResultsAmong 4435 pathology reports reviewed, 45 (1 ​%) of cases met inclusion criteria. Average follow-up was 38 months. The adverse histologic factor was identified as intranodal tumor in 24 (53 ​%) cases, intravascular tumor in 8 (17.8 ​%), tumor deposits in 5 (11.1 ​%), and more than one pathologic feature in 6 (13.3 ​%). There were 9 (20 ​%) recurrences; 6 (13 ​%) had distant recurrences only, 2 (4 ​%) patients had locoregional recurrences only, and 1 (2 ​%) patient had both locoregional and distant recurrence. The adverse histologic factor in these three patients was intravascular in two and both intravascular and intranodal in one. ConclusionBased on our results, we do not have evidence that the presence of intravascular tumor, intranodal tumor, tumor deposits, or extranodal extension within 1 ​mm of a mesenteric or circumferential margin is associated with increased risk of locoregional recurrence.

Genomic analysis of recurrent early stage and de novo metastatic colorectal cancer among veterans.

e15593 Background: The Veterans Health Administration (VHA) diagnoses approximately 4,000 cases of colon cancer each year and conducts Next Generation Sequencing (NGS) on recurrent and metastatic cases. The molecular profile of cancers resected for cure that recur is poorly characterized and holds promise to clarify both the risk and mechanisms of recurrence. We sought to characterize these genetic differences. Methods: A national database from the VHA consisting of colon cancer patients was analyzed for those with recurrent disease who have received NGS testing from 2015-2021. Data was analyzed by stage and presence of DNA mismatch repair (MMR) (MLH1, MSH2, PMS2, MSH6) and DNA damage repair (DDR) abnormalities (BRCA1, BRCA2, ATM, BRIP1, BARD1, CDK12, CHEK1, CHEK2, FANCL, PALB2, RAD51B, RAD51C, RAD51D) in addition to receipt of chemotherapy and overall survival with univariate and multivariate cox proportional hazards analyses and multivariate logistic regression analyses. Chi squared analyses were also performed comparing presence of DNA abnormalities between early recurrent and stage IV cancers. Results: From309,318 cases with colon cancer codes, we identified 2,366 colon cancer patients who had NGS and had recurrent or de novo metastatic disease. 1,072 patients had initial staging annotated (I n = 89, II n = 194, III n = 320 , IV n = 453). The average age was 69.41 years; 70.5% white, 21.5% Black and 7.8% other. Among all patients, DNA MMR abnormalities (n = 117) were associated with better overall survival, after controlling for age and race (HR 0.6, 95% CI 0.42-0.85, p &lt; 0.005). Among recurrent early stage (I-III) and stage IV patients, MMR (n = 55 and n = 21, respectively) is associated with improved survival in multivariable models (HR 0.39, 95% CI 0.33-0.46, p &lt; 0.001) . Among the 4 DNA MMR genes, MSH2 mutations had the strongest association with survival (univariate HR 0.31, 0.15-0.62, p &lt; 0.001). Among patients with MMR abnormalities, those who received either only capecitabine or only fluorouracil (without irinotecan or oxaliplatin) had worse overall survival (HR 2.6, 1.34 -5.04, p &lt; 0.005). This effect was more pronounced in early stage recurrent patients versus patients with de novo metastatic disease (HR 5.1, 1.87 – 13.9, p &lt; 0.001). Finally, we also found that early stage patients with recurrent disease are more likely to have MMR abnormalities compared to de novo metastatic (8.8% vs 4.6%, p &lt; 0.01) and confirmed this finding after controlling for race and age. (OR 2.13, p &lt; 0.005). Conclusions: Among Veteranswith colon cancer, resected recurrent colon cancer is more likely to have DNA MMR abnormalities than de novo metastatic disease. Veterans with recurrent and or metastatic disease with DNA MMR have better outcomes regardless of stage at diagnosis. These findings suggest different pathogenesis for those with recurrent disease after curative resection, and for those with de novo metastatic disease.

Colon adjuvant chemotherapy based on evaluation of residual disease (CIRCULATE-NORTH AMERICA): NRG-GI008.

TPS3641 Background: Currently, there are no biomarkers validated prospectively in randomized studies for resected colon cancer (CC) to determine need for adjuvant chemotherapy (AC). However, circulating tumor DNA (ctDNA) represents a highly specific and sensitive approach (especially with serial monitoring) for identifying minimal/molecular residual disease (MRD) post-surgery in CC patients (pts), and may outperform traditional clinical and pathological features in prognosticating risk for recurrence. CC pts who do not have detectable ctDNA (ctDNA-) are at a much lower risk of recurrence and may be spared the toxicities associated with AC. Furthermore, for CC pts with detectable ctDNA (ctDNA+) who are at a very high risk of recurrence, the optimal AC regimen has not been established. We hypothesize that for pts whose CC has been resected, ctDNA status may be used to risk-stratify for making decisions about AC. Methods: In this prospective phase II/III trial, up to 1,912 pts with resected stage IIB, IIC, and III CC will be enrolled. Based on the post-operative ctDNA status using personalized and tumor-informed assay (Signatera, bespoke assay), those who are ctDNA- (Cohort A) will be randomized to immediate AC with fluoropyrimidine (FP)+oxaliplatin (Ox) for 3-6 mos per established guidelines vserial ctDNA monitoring. Patients who are ctDNA+ post-operatively, or with serial monitoring (Cohort B), will be randomized to FP+Ox v more intensive AC with addition of irinotecan (I) for 6 mos. One cycle of chemotherapy is allowed while awaiting ctDNA testing results for cohort assignment. The primary endpoints for Cohort A are time to ctDNA+ status (phase II) and disease-free survival (DFS) (phase III) in the immediate v delayed AC arms. The primary endpoint for Cohort B is DFS in the FP+Ox v FP+Ox+I arms for both phase II and phase III portions of the trial. Secondary endpoints include prevalence of detectable ctDNA post-operatively, time-to-event outcomes (overall survival and time to recurrence) by ctDNA status, and the assessment of compliance to adjuvant therapy. Biospecimens including archival tumor tissue, as well as post-operative plus serial matched/normal blood samples, will be collected for exploratory correlative research. Active enrollment across the NCTN started in June 2022 with CCTG sites joining in August 2023. Current accrual (as of 02-02-2024) is 240/1,912. NCT05174169. Support: U10-CA-180868, -180822; UG1CA-189867; Natera, Inc. Clinical trial information: NCT05174169 .

158TiP Exploiting circulating tumor DNA (ctDNA) to intensify the adjuvant (adj) or post-adj treatment of stage III and high-risk stage II resected colon cancer patients (pts): The ERASE-CRC project by GONO

158TiP Exploiting circulating tumor DNA (ctDNA) to intensify the adjuvant (adj) or post-adj treatment of stage III and high-risk stage II resected colon cancer patients (pts): The ERASE-CRC project by GONO

Use of circulating tumor DNA (ctDNA) to affect the adjuvant or post-adjuvant treatment of patients with stage III and high-risk stage II resected colon cancer: The ERASE-CRC project by GONO.

TPS3644 Background: Three or 6 months of fluoropyrimidines plus oxaliplatin is the standard adjuvant therapy for stage III and high-risk stage II colon cancer, but 20-25% of patients relapse. CtDNA is a promising biomarker of minimal residual disease (MRD) after primary tumor resection and a potential guide in the adjuvant treatment decision-making process. Indeed, ctDNA-positivity after surgery or at the end of adjuvant therapy is associated with higher risk of recurrence. Intensifying the adjuvant and/or the post-adjuvant treatment could be a valuable strategy in these cases. CtDNA clearance has been suggested as a predictor of long-term clinical outcome. Methods: ERASE-CRC is a prospective, open-label, multicentre study, including three phase 2 trials enrolling ctDNA-positive patients with radically resected stage III or high-risk stage II (one major prognostic factor or at least two minor prognostic factors) adenocarcinoma of the colon or intraperitoneal rectum. CtDNA is centrally assessed through a tissue-informed method, F1Tracker. In the phase II ERASE-CRC Part 1 study, patients that are ctDNA-positive after surgery (2-6 weeks) are randomized 1:1 to 6 months of either FOLFOX or CAPOX at investigators’ choice (standard arm) versus FOLFOXIRI (experimental arm). In the phase II single arm ERASE-HER2 study, ctDNA-positive patients with HER2 amplified and RAS wild-type tumors received FOLFOX plus trastuzumab and tucatinib for 12 cycles. In the phase II ERASE-CRC Part 2 study, ctDNA-positive patients after the end of an oxaliplatin-based adjuvant therapy (either in the context or outside ERASE-CRC Part 1 or ERASE-HER2) are randomized 1:2 to observation (standard arm) or trifluridine/tipiracil for 6 cycles (experimental arm). The primary endpoint is the clearance rate of ctDNA after the adjuvant (ERASE-CRC Part 1 and ERASE-HER2) or the post-adjuvant treatment (ERASE-CRC Part 2). 300 patients will be randomized in ERASE-CRC Part 1 to detect a 15% difference in ctDNA clearance rate between the experimental and the standard arm with expected clearance rates of 65% and 50%, respectively, and 1-sided alpha and beta errors of 0.05 and 0.2, respectively. 18 patients will be enrolled in ERASE-HER2 to observe a ctDNA clearance rate of 80% with the targeted treatment ( versus 50% expected), and ctDNA clearance should be observed in 13 cases to consider the strategy promising. Finally, 159 patients will be randomized in ERASE-CRC Part 2 to detect a 15% difference in ctDNA clearance rate between the experimental and the standard arm with 20% and 5% expected clearance rates respectively, and 1-sided alpha and beta errors of 0.05 and 0.2, respectively. Approximately 40 Italian Oncology Units are participating in the study. Currently, 19 and 8 patients have been randomized in ERASE-CRC Part 1 or 2, respectively. NCT05062889. Clinical trial information: NCT05062889 .

Laparoscopic assisted colectomy versus laparoscopic complete colectomy: a cost analysis

To compare the short-term outcomes and explore the potential economic benefits of laparoscopic-assisted colectomy with extracorporeal anastomosis (LAC/EA) vs. laparoscopic complete colectomy with intracorporeal anastomosis (LCC/IA) for patients with non-metastatic resectable colon cancer. Data of patients who underwent laparoscopic hemicolectomy from January 2017 to March 2023 were collected and analyzed. Propensity score matching (PSM) analyses was carried out to minimize the selection bias. Before PSM, a total of 113 patients met the inclusion criteria (39 in the LCC/IA vs. 74 in the LAC/EA). Clinicopathologic characteristics were comparable except for the median number of removed lymph nodes (P = 0.023). LCC/IA was associated with longer operative time, less intraoperative blood loss, and shorter incision length. The rate of 30-day postoperative complications was similar, but the time to first flatus and soft diet was shorter in the LCC/IA. No deaths were reported in either group within 30 days after surgery. Costs of surgical instruments (25,945.8 ± 1,918.0 vs. 23,551.9 ± 2,665.5 RMB; P < 0.01) were higher for the LCC/IA but overall costs were similar (LCC/IA, 43,220.0 ± 4,954.0 vs. LAC/EA, 41,269.2 ± 6,685.9 RMB; P = 0.112). After PSM, 38 patients in the LCC/IA and 63 patients in the LAC/EA were compared. LCC/IA was superior in terms of intraoperative blood loss, incision length, and postoperative functional recovery. There was an extra charge of 2385.0 RMB regarding surgical instruments in the LCC/IA but the overall cost did not reach statistical significance. LCC/IA is a feasible, safe, and cost-effective surgical treatment for patients with non-metastatic resectable colon cancer.

Risk of recurrence in high-risk T1 colon cancer following endoscopic and surgical resection: registry-based cohort study.

Endoscopic resection of T1 colon cancer (CC) is currently limited by guidelines related to risk of lymph node metastases. However, clinical outcome following endoscopic and surgical resection is poorly investigated. A retrospective multicentre national cohort study was conducted on prospectively collected data from the Swedish colorectal cancer registry on all non-pedunculated T1 CC patients undergoing surgical and endoscopic resection between 2009 and 2021. Patients were categorized on the basis of deep submucosal invasion (Sm2-3), lymphovascular invasion (LVI), poor tumour differentiation, and R1/Rx into low- and high-risk cases. The primary outcomes of interest were recurrence rates and disease-free interval (DFI, defined as time from treatment to date of recurrence) according to resection methods and risk factors (sex, age at diagnosis, histologic grade, LVI, perineural invasion, mucinous subtype, submucosal invasion, tumour location, resection margin and nodal positivity in the surgical group). In total, 1805 patients undergoing endoscopic (488) and surgical (1317) resection with 60.0 months median follow-up were included. Recurrence occurred in 18 (3.7%) endoscopically and 48 (3.6%) surgically resected patients. Adjuvant treatment was administered in 7.4% and 0.2% of the cases respectively in the surgical and endoscopically treated patients. Five-year DFI was 95.6% after endoscopic and 96.2% after surgical resection, with no significant difference when adjusting for confounding factors (HR 1.03, 95% c.i. 0.56 to 1.91, P = 0.920). There were no statistically significant differences in recurrence comparing endoscopic (1.7%) versus surgical (3.6%) low-risk and endoscopic (5.4%) versus surgical (3.8%) high-risk cases. LVI was the only significant risk factor for recurrence in multivariate Cox regression (HR 3.73, 95% c.i. 1.76 to 7.92, P < 0.001). This study shows no difference in recurrence after endoscopic and surgical resection in high-risk T1 CC. Although it was not possible to match groups according to treatment, the multivariate analysis showed that lymphovascular invasion was the only independent risk factor for recurrence.

Survival Outcomes in Patients with Monobloc-Resected Stage IIC (pT4bN0) Colon Cancer: A Retrospective Observational Cohort Study

BackgroundStage II colon cancer (CC) exhibits considerable prognostic heterogeneous. Our objective was to assess survival but also the prognosis impact of microsatellite instability (MSI) in patients with stage IIC (T4bN0M0) CC. Patients and MethodsWe conducted a retrospective observational study including all patients who had primary stage IIC CC resection between 2010 and 2020 in 2 expert centers. The primary endpoint was overall survival (OS) and disease-free survival (DFS) and time-to-relapse (TTR) were secondary endpoints. ResultsSixty-six patients, median age of 74 years [30-95], were included, with 37.9% presenting MSI (n = 25). Organ invasion involved the last ileal loop (n = 17), another colonic segment (n = 15), omentum (n = 13), visceral peritoneum (n = 13), and the bladder (n = 4). Surgical quality criteria showed complete monobloc resection in all patients and 93.9% R0 resection. After a median follow-up of 5 years [3.5-6.6], the entire population showed a 5-year OS of 65.2% [53.0-80.3] and 5-year DFS of 53.5% [41.1-69.6], with 18.9% [6.8-29.4] experiencing relapses at 5 years. The MSI phenotype correlated with improved 5-year OS (75.5% [56.5-100] vs. 59.5% [44.9-79.0], HR 0.41 [0.17-0.99]; P = .04), but DFS and TTR did not differ. Adjuvant chemotherapy was administered to 34.9% of patients. Univariate analysis identified age > 65 years, MSI status, and the number of nodes as factors associated with OS. ConclusionThese data underline, in relation to a low rate of relapse, the lack of consensus regarding the appropriate indication for adjuvant chemotherapy in this high-risk stage II population.

Prognostic value of a nomogram model for postoperative liver metastasis of colon cancer.

Colon cancer is one of the most common malignant tumors of the digestive system. Liver metastasis after colon cancer surgery is the primary cause of death in patients with colon cancer. To construct a novel nomogram model including various factors to predict liver metastasis after colon cancer surgery. We retrospectively analyzed 242 patients with colon cancer who were admitted and underwent radical resection for colon cancer in Zhejiang Provincial People's Hospital from December 2019 to December 2022. Patients were divided into liver metastasis and non-liver metastasis groups. Sex, age, and other general and clinicopathological data (preoperative blood routine and biochemical test indexes) were compared. The risk factors for liver metastasis were analyzed using single-factor and multifactorial logistic regression. A predictive model was then constructed and evaluated for efficacy. Systemic inflammatory index (SII), C-reactive protein/albumin ratio (CAR), red blood cell distribution width (RDW), alanine aminotransferase, preoperative carcinoembryonic antigen level, and lymphatic metastasis were different between groups (P < 0.05). SII, CAR, and RDW were risk factors for liver metastasis after colon cancer surgery (P < 0.05). The area under the curve was 0.93 for the column-line diagram prediction model constructed based on these risk factors to distinguish whether liver metastasis occurred postoperatively. The actual curve of the column-line diagram predicting the risk of postoperative liver metastasis was close to the ideal curve, with good agreement. The prediction model curves in the decision curve analysis showed higher net benefits for a larger threshold range than those in extreme cases, indicating that the model is safer. Liver metastases after colorectal cancer surgery could be well predicted by a nomogram based on the SII, CAR, and RDW.

Outcome of Colorectal Robotic Surgery in Newly Established Robotic Surgery Center: A Case Series

Introduction: The robotic platform compared to laparoscopy has proven to have similar postoperative outcomes; however, its adoption in the Middle East has been slow and there are limited data regarding outcomes with its use in small newly established robotic colorectal programs. Our aim was to report our experience and outcomes of robotic colorectal surgery performed by fellowship-trained robotic colorectal surgeons and compare them to larger, more experienced centers. Methods: This is retrospective review of data collected between November 2021 and March 2023 from a tertiary health care referral center. The series included 51 patients who had elective or urgent robotic colorectal surgery. Patients who had emergency surgery were excluded. The outcomes were overall morbidity, serious morbidity, mortality, conversion to open, length of hospital stay, and quality of oncological specimen. Results: The overall morbidity was 31.4% (n = 16 patients). Only 9.8% (n = 5) had serious morbidity of which three required interventions under general anesthesia. The median length of hospital stay was 6 days (IQR = 4), and there was no mortality. Of 17 rectal cancer resections, 88% had complete mesorectal excision, 15 of them were R0 resections, median lymph node harvested was 14 (IQR = 7) and two cases were converted to open. All the colon cancer resections had R0 resection, median lymph nodes harvested was 21 (IQR = 4) and none were converted to open. Conclusions: The implementation and integration of robotic colorectal surgery at a newly established center in a small country, when led by fellowship-trained robotic colorectal surgeons, is safe and effective in terms of morbidity, mortality, conversion to open and specimen pathological quality.

Impact of surgical proximal and distal margins on the recurrence of resectable colon cancer: a single-center observational cohort study.

Few studies have investigated the impact of the surgical proximal and distal margins on colon cancer recurrence. We conducted this study to investigate the effect of resection margins on the prognosis of resectable colon cancer. We analyzed data on 1458 patients who underwent colorectal resection in our institute between January, 2004 and March, 2020, including 579 patients with resectable colon cancer. The association between the resection margin and recurrence for each oncological status was assessed and the value of the resection length that influenced recurrence was analyzed. Patients who had pT4 colon cancer with margins of more than 7cm had a trend of fewer recurrences and longer relapse-free survival (RFS) than those with colon cancer of other stages (P = 0.033; hazard ratio [HR], 0.42; 95% confidence interval [CI], 0.20-0.89). Multivariate analysis identified a margin of < 7cm as an independent risk factor for RFS in patients with pT4 colon cancer (P = 0.023; HR, 2.65; 95% CI 1.013-6.17). No correlation was found between resection margins and recurrence, depending on the extent of lymph node metastasis and tumor location. A resection margin of at least 7cm should be maintained for patients with pT4 colon cancer.

It Is What the Surgeon Does Not See That Kills the Patient.

Patients with colon cancer may present at multiple different stages of the disease process. Many patients can be cured of colon cancer as a result of a simple surgical procedure usually performed by minimally invasive techniques. However, there are a variable number of patients, estimated at approximately 10%, who have a more advanced disease. If these patients are treated by the current conventional standard of care, the likelihood for treatment failure is extremely high. These are not patients with known disseminated disease but patients who are at high risk of recurrent disease unless special treatments are initiated preoperatively and intraoperatively. The identification of these patients is by (1) a high-quality CT scan, (2) tumor markers found preoperatively, (3) colonoscopic findings, and (4) symptoms. Patients identified as being at high risk require special preoperative treatments which include neoadjuvant chemotherapy. Intraoperative chemotherapy with HIPEC should occur as part of the treatment if peritoneal metastases are documented by biopsy. In the operating room, a thorough exploration of all possible occult peritoneal spaces for metastatic disease needs to be performed. A modified cytoreductive surgical procedure along with a colon resection is performed in order to minimize sites of occult peritoneal metastases. This includes the greater omentum, ovaries, and tubes in postmenopausal women. Peritonectomy is used to create a shroud around the tumor so that all peritoneum that has been in direct contact with the tumor surface is resected and is used as a barrier against tumor cell dissemination in the process of colon cancer resection. If peritoneal metastases are visualized at any site, HIPEC should be included as part of the treatment package. I am convinced that patients at high risk of recurrence will have an improved outcome with proper preoperative evaluation, preoperative neoadjuvant chemotherapy, and a revised intraoperative management strategy.

Two Cases of Bleeding from the Ileal Conduit Due to Ectopic Varices

Case 1 : A 75-year-old man was emergently admitted to our hospital with a complaint of continuous bleeding from the ileal conduit. The conduit was constructed by a total pelvic resection for sigmoid colon cancer that invaded the urinary bladder 24 years ago. Swollen cutaneous mucosa was seen around the ileal conduit, but no obvious bleeding spot was observed. The contrast-enhanced computed tomographic (CT) scan and 3D visualization revealed varices extending to the abdominal wall. Percutaneous transhepatic embolization successfully stopped the bleeding, but it was needed again after two years. Case 2 : A 72-yearold man with a history of open cystectomy and ileal conduit for bladder cancer came to our hospital two years after the surgery, complaining of continuous bleeding from the conduit. The skin around the stoma site was discolored purple, but no obvious bleeding site or bloody urine was observed. The CT scan similar to Case 1 revealed varices in the ileal conduit, and percutaneous transhepatic embolization successfully stopped the bleeding, but it was needed again after five months. After that, three months passed without recurrence.