Resection For Colorectal Cancer Research Articles

Outcomes of medial to lateral vs. lateral to medial approaches in laparoscopic colorectal cancer resections.

Bowel cancer is a significant global health concern, ranking as the third most prevalent cancer worldwide. Laparoscopic resections have become a standard treatment modality for resectable colorectal cancer. This study aimed to compare the clinical and oncological outcomes of medial to lateral (ML) vs lateral to medial (LM) approaches in laparoscopic colorectal cancer resections. A retrospective cohort study was conducted at a UK district general hospital from 2015 to 2019, including 402 patients meeting specific criteria. Demographic, clinical, operative, postoperative, and oncological data were collected. Participants were categorised into LM and ML groups. The primary outcome was 30-day complications, and secondary outcomes included operative duration, length of stay, lymph node harvest, and 3-year survival. A total of 402 patients (55.7% males) were included: 102 (51.6% females) in the lateral mobilisation (LM) group and 280 (58.9% males) in the medial mobilisation (ML) group. Right hemicolectomy (n=157, 39.1%) and anterior resection (n=150, 37.3%) were the most performed procedures. The LM group had a shorter operative time for right hemicolectomy (median 165 vs. 225min, P<0.001) and anterior resection (median 230 vs. 300min, P<0.001). There was no significant difference between the two groups in terms of wound infection (P=0.443), anastomotic leak (P=0.981), postoperative ileus (P=0.596), length of stay (P=0.446), lymph node yield (P=0.848) or 3-year overall survival rate (Log-rank 0.759). The study contributes to the limited evidence on ML vs LM approaches. A shorter operative time in the LM group was noted in this study, contrary to some literature. Postoperative outcomes were comparable, with a non-significant increase in postoperative ileus in the LM group. The study emphasises the safety and feasibility of both approaches.

Right vs. Left colorectal cancer – Where do we draw the line?

PurposeNo consensus on the definition of right and left colorectal cancer (CRC) exists, nor studies offering histological or molecular basis for such categorisation. This study investigated the regional variations in the histological and molecular characteristics of CRCs, with the objective of determining an optimal division point between right and left CRCs. Materials and methodsAn observational study of consecutive patients who underwent CRC resection (1995–2022) at Concord Hospital, Sydney was performed. Clinicopathological data were extracted from a prospective database and seven permutations of right-left divisions considered. Logistic regression tested association between the right-left divisions and pathological characteristics. Receiver operating characteristic and area under the curve (AUC) analyses determined the discriminative ability of each division to predict 18 pathology characteristics. Results3753 patients underwent a CRC resection (2120 male; mean 69.5yrs [SD12.6]). There was regional variation in tumours with respect to tumour infiltrating lymphocytes (TILs), mismatch repair deficiency (dMMR), and mutant BRAF (mBRAF). Left-sided tumours were less likely to demonstrate TILs (P < 0.001), be dMMR (P < 0.001), and express mBRAF (P < 0.001). Division at the descending-sigmoid junction yielded highest discriminative abilities: TILs – AUC 0.66, dMMR – AUC 0.76, and mBRAF – AUC 0.73. ConclusionThis is the first study to provide a pathological basis on which right- and left-sided cancers may be defined, and found the optimal division point between the right and left colorectum to be at the descending-sigmoid junction. Further research is needed to determine whether this can facilitate individualised patient management.

Preoperative Vertebral Fracture: A Prognostic Factor in Stage I-III Colorectal Cancer.

This study evaluated the prognostic impact of vertebral fractures (VFs) on the survival of patients with colorectal cancer (CRC). We included 299 patients with stage I-III CRC who had undergone elective surgery. The patients were divided into the VF group (n=94) and non-VF group (n=205). VFs were assessed using sagittal computed tomography image reconstruction (Th11-L5) performed preoperatively. Disease-free survival (DFS) and overall survival (OS) rates were analyzed. The VF group had lower 5-year DFS and OS rates compared to the non-VF group (both, p<0.001). The independent predictors of DFS were carbohydrate antigen 19-9 (CA19-9) ≥37.0 ng/ml, T3/T4 disease, stage III CRC, osteopenia, and VF; for OS, CA19-9 ≥37.0 ng/ml, stage III, osteopenia, and VF. VF, compared with osteopenia, was a more significant prognostic factor for DFS and OS in patients with stage I+ II CRC (both, p<0.001). Preoperative VF was associated with worse DFS and OS following CRC resection.

The association of cognitive coping style with patient preferences in a patient-led follow-up study among colorectal cancer survivors

IntroductionAmidst the rising number of cancer survivors and personnel shortages, optimisation of follow-up strategies is imperative, especially since intensive follow-up does not lead to survival benefits. Understanding patient preferences and identifying the associated patient profiles is crucial. Coping style may be a key determinant in achieving this. Our study aims to evaluate preferences, identify coping styles and their associated factors, and explore the association between coping style and patients’ preferences in colorectal cancer (CRC) follow-up.MethodsIn a prospective multicentre implementation study, patients completed the Threatening Medical Situations Inventory (TMSI) to determine their coping style. Simultaneously patients choose their follow-up preferences for the CRC trajectory regarding frequency of tumour marker determination, location of blood sampling, and manner of contact.ResultsA total of 188 patients completed the TMSI questionnaire after inclusion. A more intensive follow-up was preferred by 71.5% of patients. Of all patients, 52.0% had a coping style classified as ‘blunting’ and 34.0% as ‘monitoring’. Variables such as a younger age, female gender, higher educational level, and lower ASA scores were associated with having higher monitoring scores. However, there were no significant associations between follow-up preferences and patients’ coping styles.ConclusionThis study suggests that none of the provided options in a patient-led follow-up are unsuitable for patients who underwent curative surgery for primary CRC, based on coping style determined at baseline. Low-intensity surveillance after curative resection of CRC may, therefore, be suitable for a wide range of patients independent of coping styles.

Emergency Resection for Colonic Cancer Has an Independent and Unfavorable Effect on Long-Term Oncologic Outcome

BackgroundLong-term outcomes in patients undergoing emergency versus elective resection for colorectal cancer (CRC) remain controversial. This study aims to assess short- and long-term outcomes of emergency versus elective CRC surgery.MethodsIn this single-center retrospective cohort study, patients undergoing emergency or elective colonic resections for CRC from January 2013 to December 2017 were included. Primary outcome was long-term survival. As secondary outcomes, we sought to analyze potential differences on postoperative morbidity and concerning the oncological standard of surgical resection. The Kaplan-Meier curves and Cox proportional hazard model were used to compare survival between the groups.ResultsOverall, 225 CRC patients were included. Of these 192 (85.3%) had an elective and 33 (14.7%) an emergency operation. Emergency indications were due to obstruction, perforation, or bleeding. Patients in the emergency group had higher ASA score (p = 0.023), higher Charlsson comorbidity index (CCI, p = 0.012), and were older than those in the elective group, with median age 70 (IQR 63–79) years and 78 (IQR 68–83) years, for elective and emergency, respectively (p = 0.020). No other preoperative differences were observed. Patients in the emergency group experienced significantly more major complications (12.1% vs. 3.6%, p = 0.037), more anastomotic leakage (12.1% vs. 1.6%, p = 0.001), need for reoperation (12.1% vs. 3.1%, p = 0.021), and postoperative mortality (2 patients vs. 0, p < 0.001). No differences in terms of final pathological stage, nor in accuracy of lymphadenectomy were observed. Overall survival was significantly worse in case of emergency operation, with estimated median 41 months vs. not reached in elective cases (p < 0.001). At the multivariate analysis, emergency operation was confirmed as independent unfavorable determinant of survival (with hazard rate HR = 1.97, p = 0.028), together with age (HR = 1.05, p < 0.001), postoperative major morbidity (HR = 3.18, p = 0.012), advanced stage (HR = 5.85, p < 0.001), and need for transfusion (HR = 2.10, p = 0.049).ConclusionPostoperative morbidity and mortality were increased in emergency versus elective CRC resections. Despite no significant differences in terms of accuracy of resection and pathological stages, overall survival was significantly worse in patients who underwent emergency procedure, and independent of other determinants of survival.

Surgical Outcomes and Utilization of Laparoscopic Versus Robotic Techniques for Elective Colectomy in Asian American and Native Hawaiian-Pacific Islanders (AAPI) Diagnosed With Colon Cancer

IntroductionAsian American and Native Hawaiian-Pacific Islanders (AAPI) are the fastest growing racial-ethnic group, with 18.9 million people in 2019, and is predicted to rise to 46 million by 2060. Colorectal cancer (CRC) is the most common cancer in AAPI men and the third most common in women. Treatment techniques like laparoscopic colectomy (LC) emerged as the standard of care for CRC resections; however, new robotic technologies can be advantageous. Few studies have compared clinical outcomes across minimally invasive approaches for AAPI patients with CRC. This study compares utilization and clinical outcomes of LC versus robotic colectomies (RCs) in AAPI patients. MethodsWe queried the American College of Surgeons National Surgical Quality Improvement Program database for elective RC and LC in AAPI patients from 2012 to 2020. Outcomes included unplanned conversion to open, operative time, complications, 30-d mortality, and length of stay. Multivariable logistic regression analyses assessed the association between outcomes and the operative approach. ResultsBetween 2012 and 2020, 83,841 patients underwent elective LC or RC. Four thousand six hundred fifty-eight AAPI patients underwent 3817 (82%) LCs and 841 (18%) RCs. In 2012, all procedures were performed laparoscopically; by 2020, 27% were robotic. Mean operative time was shorter in LC (192 versus 249 min, P < 0.001). On multivariable logistic regression, there was no difference in infection (odds ratio [OR] 0.8, 95% confidence interval [CI] 0.59-1.12), anastomotic leak (OR 0.97, 95% CI 0.59-1.61), or death (OR 0.9, 95% CI 0.31-2.61). Length of stay was shorter for RC (−0.44 d, 95% CI −0.71 to −0.18 d). ConclusionsOverall, AAPI postoperative outcomes are similar between LC and RC. Future studies that evaluate costs and resource utilization can assist hospitals in determining whether implementing robotic-assisted technologies in their hospitals and communities will be appropriate.

An internally and externally validated nomogram for predicting cancer-specific survival in octogenarians after radical resection for colorectal cancer

AimsWe aimed to develop an elaborative nomogram that predicts cancer-specific survival (CSS) in American and Chinese octogenarians treated with radical resection for CRC.MethodsThe patient data of newly diagnosed patients aged 80 years or older who underwent radical resection for CRC from 2010 to 2015 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database and then randomly divided into a training cohort and a validation cohort. The patients collected from our hospital were defined as the external validation cohort. Univariate and multivariate Cox regression was used to select independent predictive factors for the construction of a nomogram to predict 1-, 2- and 3-year CSS.ResultsThe multivariate Cox regression model identified age, T stage, N stage, perineural invasion, chemotherapy, tumour deposits, carcinoembryonic antigen level, number of lymph node metastases, and number of solid organ metastases as independent predictors of survival. The C-index of the nomogram for 1-, 2- and 3-year CSS was 0.758, 0.762, and 0.727, respectively, demonstrating significant clinical value and substantial reliability compared to the TNM stage. The calibration curve and area under the curve also indicated considerable predictive accuracy. In addition, decision curve analysis demonstrated desirable net benefits in clinical application.ConclusionWe constructed a nomogram for predicting the CSS of individual octogenarian patients with CRC who underwent radical resection. The nomogram performed better than the TNM staging system in this particular population and could guide clinicians in clinical follow-up and individual therapeutic plan formulation.

Trial Protocol of a Phase II Study of mFOLFOXIRI after Metastasectomy in Patients with Oligometastatic Colorectal Cancer (FANTASTIC Study).

The survival benefit of adjuvant chemotherapy after surgical resection of oligometastases from colorectal cancer (CRC) remains unclear. The prognostic role of circulating-tumor DNA (ctDNA) was reported recently and a risk stratification strategy based on monitoring minimal/molecular residual disease (MRD) has been proposed, however, which drug regimen is most effective for ctDNA-positive patients is unknown. Oligometastatic CRC patients planning to undergo surgery were registered in this study. After metastasectomy, the registered patients were enrolled in the treatment arm, in which 8 courses of modified-FOLFOXIRI (mFOLFOXIRI; irinotecan 150 mg/m2, oxaliplatin 85 mg/m2, l-leucovorin (l-LV) 200 mg/m2, and 46-h continuous infusion of 5-fluorouracil (5-FU) 2400 mg/m2 every 2 weeks) followed by 4 courses of 5-FU/l-LV are administered. The patients who did not meet the eligibility criteria for the treatment arm or did not consent to mFOLFOXIRI enrolled in the observation arm in which standard of care treatment is provided. Prospective blood collections for retrospective ctDNA analysis are scheduled pre-surgery, and at 28 days, 4 and 7 months after surgery. The primary endpoint is treatment compliance at 8 courses of mFOLFOXIRI and the key secondary endpoints are the ctDNA-positivity rate and survival outcomes in ctDNA-positive and -negative groups. A total of 85 patients will be enrolled from 11 institutions. First patient-in was on July 2020. Accrual completed in February 2024. This study will potentially identify a better treatment strategy for patients with resectable oligometastatic CRC having postsurgical ctDNA positivity, compared to the current standard of care approaches.

Reduced Abundance of Phocaeicola in Mucosa-associated Microbiota Is Associated with Distal Colorectal Cancer Metastases Possibly through an Altered Local Immune Environment.

The aim of this study was to identify the microbiota whose decrease in tumor area was associated with the metastatic process of distal colorectal cancer (CRC). Twenty-eight consecutive patients with distal CRC undergoing surgical resection in our hospital were enrolled. Microbiota in 28 specimens from surgically resected colorectal cancers were analyzed using 16S ribosomal ribonucleic acid gene amplicon sequencing and the relative abundance (RA) of microbiota was evaluated. The densities of tumor-infiltrating lymphocytes (TIL) and tumor associated macrophages (TAM) in the colorectal cancers were immunohistochemically evaluated. Phocaeicola was the most abundant microbiota in normal mucosa. The RA of Phocaeicola in tumor tissues tended to be lower than that in normal mucosa although the difference was not significant (p=0.0732). The RA of Phocaeicola at tumor sites did not correlate either with depth of tumor invasion (pT-stage) or tumor size, however they were significantly reduced in patients with nodal metastases (p<0.05) and those with distant metastases (p<0.001). The RA of Phocaeicola at tumor sites showed positive correlation with the densities of CD3(+) or CD8(+) TIL. Since P. vulgatus was the most dominant species (47%) of the Phocaeicola, the RA of P. vulgatus and CRC metastasis and its association with TIL and TAM were also investigated. P. vulgatus showed a similar trend to genus Phocaeicola but was not statistically significant. A relative reduction of Phocaeicola attenuates the local anti-tumor immune response in distal CRC, which may facilitate metastatic spread.

Does computed tomography-derived volumometry and densitometry of psoas muscle really correlate with complications in rectal cancer patients after elective surgery?

Although sarcopenia is recognized as one of the risk factors for increased morbidity after resection for colorectal cancer, the question of the most appropriate way to identify and quantify it is still unresolved. This is a retrospective unicentric study following patients undergoing elective resection of the rectum for carcinoma with available staging computed tomography (CT) of the trunk. Psoas muscle density (PMD) and its area relative to patient height psoas muscle index (PMI) at the level of inferior vertebral end plate of third lumbar vertebra (L3) were assessed using an initial staging CT scan of the trunk. Post-operative complications, evaluated according to the Clavien-Dindo classification, and blood samples on post-operative days (POD) 3 and 5 were also recorded in the study population. Patients were divided into groups with complicated and uncomplicated post-operative course, and observed parameters were then statistically compared. The correlation of PMI values with the development of post-operative complications was not confirmed in a data set of 206 patients. PMD values were found to be borderline statistically significant in patients with complicated post-operative course, while in the group of patients with severe complications (Clavien-Dindo III-IV), there was no statistically significant difference in PMI or PMD values. The same results were obtained when comparing patients with anastomotic leak (AL). It was confirmed that operations on the lower rectum are riskier for the development of post-operative complications. The secondary objective of our study regarding serum C-reactive protein (CRP) levels of 3rd and 5th POD gave us the answer in the form of cutoff values of 115.7 mg/L (3rd POD) and 76 mg/L (5th POD). PMD appears to be a promising tool for predicting post-operative morbidity in patients after rectal resection, but a clear consensus on the method of measurement, interpretation of results and cutoff values is needed. Lower rectal resections are burdened with a higher risk of post-operative complications, especially AL. Monitoring of CRP levels remains an important marker in the prediction of AL due to its negative predictive value.

Tissue-Free Liquid Biopsies Combining Genomic and Methylation Signals for Minimal Residual Disease Detection in Patients with Early Colorectal Cancer from the UK TRACC Part B Study.

The absence of postoperative circulating tumor DNA (ctDNA) identifies patients with resected colorectal cancer (CRC) with low recurrence risk for adjuvant chemotherapy (ACT) de-escalation. Our study presents the largest resected CRC cohort to date with tissue-free minimal residual disease (MRD) detection. TRACC (tracking mutations in cell-free tumor DNA to predict relapse in early colorectal cancer) included patients with stage I to III resectable CRC. Prospective longitudinal plasma collection for ctDNA occurred pre- and postsurgery, post-ACT, every 3 months for year 1 and every 6 months in years 2 and 3 with imaging annually. The Guardant Reveal assay evaluated genomic and methylation signals. The primary endpoint was 2-year recurrence-free survival (RFS) by postoperative ctDNA detection (NCT04050345). Between December 2016 and August 2022, 1,203 were patients enrolled. Plasma samples (n = 997) from 214 patients were analyzed. One hundred forty-three patients were evaluable for the primary endpoint; 92 (64.3%) colon, 51 (35.7%) rectal; two (1.4%) stage I, 64 (44.8%) stage II, and 77 (53.8%) stage III. Median follow-up was 30.3 months (95% CI, 29.5-31.3). Two-year RFS was 91.1% in patients with ctDNA not detected postoperatively and 50.4% in those with ctDNA detected [HR, 6.5 (2.96-14.5); P < 0.0001]. Landmark negative predictive value (NPV) was 91.2% (95% CI, 83.9-95.9). Longitudinal sensitivity and specificity were 62.1% (95% CI, 42.2-79.3) and 85.9% (95% CI, 78.9-91.3), respectively. The median lead time from ctDNA detection to radiological recurrence was 7.3 months (IQR, 3.3-12.5; n = 9). Tissue-free MRD detection with longitudinal sampling predicts recurrence in patients with stage I to III CRC without the need for tissue sequencing. The UK TRACC Part C study is currently investigating the potential for ACT de-escalation in patients with undetectable postoperative ctDNA, given the high NPV indicating a low likelihood of residual disease.

T1 colorectal cancer patients' perspective on information provision and therapeutic decision-making after local resection.

Decision-making after local resection of T1 colorectal cancer (T1CRC) is often complex and calls for optimal information provision as well as active patient involvement. The aim was to evaluate the perceptions of patients with T1CRC on information provision and therapeutic decision-making. This multicenter cross-sectional study included patients who underwent endoscopic or local surgical resection as initial treatment. Information provision was assessed using the EORTC QLQ-INFO25 questionnaire. In patients with high-risk T1CRC, we evaluated decisional involvement and satisfaction regarding the choice as to whether to undergo additional treatment after local resection, and the level of decisional conflict using the Decisional Conflict Scale. Ninety-eight patients with T1CRC were included (72% response rate; 79/98 endoscopic and 19/98 local surgical resection; 45/98 high-risk T1CRC). Median time since local resection was 28months (IQR 18); none had developed recurrence. Unmet information needs were reported by 29 patients (30%; 18 low-risk, 11 high-risk), mostly on post-treatment related topics (follow-up visits, recovery time, recurrence prevention). After local resection, 24 of the 45 high-risk patients (53%) underwent additional treatment, while others were subjected to surveillance. Higher-educated patients were more often actively involved in decision-making (93% vs. 43%, p=0.002) and more frequently underwent additional treatment (79% vs. 40%, p=0.02). Decisional conflict (p=0.19) and satisfaction (p=0.78) were comparable between higher- and lower-educated high-risk patients. Greater attention should be given to the post-treatment course during consultations following local T1CRC resection. The differences in decisional involvement and selected management strategies between higher- and lower-educated high-risk patients warrant further investigation.

A combined nutritional risk index and carcinoembryonic antigen score predicts the outcome in radically resected colorectal cancer.

Nutritional risk index (NRI) and carcinoembryonic antigen (CEA) are useful prognostic markers in colorectal cancer (CRC); however, the prognostic value of a combination of the NRI and CEA, namely, the NRI and CEA score (NCS), needs further investigation. Stage I-III CRC patients were collected and then divided into three subgroups by counting the NCS: NCS 1: high NRI with normal CEA; NCS 2: high NRI with elevated CEA or low NRI with normal CEA; and NCS 3: low NRI with elevated CEA. The differences in outcome, counted as disease-free survival (DFS) and overall survival (OS), were tested among the subgroups. A total of 285 patients were enrolled, with 108 in NCS 1, 118 in NCS 2 and 59 in NCS 3. Patient features, including age, tumour deposit, T stage, N stage and TNM stage, were significantly different in the NCS subgroups. Both the DFS (log-rank = 26.06, P<0.001) and OS (log-rank = 39.10, P<0.001) were significant in different NCS subgroups, even in maximum tumour diameter ≤4 cm cases (DFS: log-rank = 21.42, P<0.001; OS: log-rank = 30.95, P<0.001), and NCS 1 patients displayed the best outcome compared with the rest of the subgroups. NCS was also found to be an independent risk factor for both DFS and OS. NCS was a useful prognostic indicator in stages I-III CRC patients.

Construction and validation of a risk prediction model for postoperative ICU admission in patients with colorectal cancer: clinical prediction model study

BackgroundTransfer to the ICU is common following non-cardiac surgeries, including radical colorectal cancer (CRC) resection. Understanding the judicious utilization of costly ICU medical resources and supportive postoperative care is crucial. This study aimed to construct and validate a nomogram for predicting the need for mandatory ICU admission immediately following radical CRC resection.MethodsRetrospective analysis was conducted on data from 1003 patients who underwent radical or palliative surgery for CRC at Ningxia Medical University General Hospital from August 2020 to April 2022. Patients were randomly assigned to training and validation cohorts in a 7:3 ratio. Independent predictors were identified using the least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression in the training cohort to construct the nomogram. An online prediction tool was developed for clinical use. The nomogram's calibration and discriminative performance were assessed in both cohorts, and its clinical utility was evaluated through decision curve analysis (DCA).ResultsThe final predictive model comprised age (P = 0.003, odds ratio [OR] 3.623, 95% confidence interval [CI] 1.535–8.551); nutritional risk screening 2002 (NRS2002) (P = 0.000, OR 6.129, 95% CI 2.920–12.863); serum albumin (ALB) (P = 0.013, OR 0.921, 95% CI 0.863–0.982); atrial fibrillation (P = 0.000, OR 20.017, 95% CI 4.191–95.609); chronic obstructive pulmonary disease (COPD) (P = 0.009, OR 8.151, 95% CI 1.674–39.676); forced expiratory volume in 1 s / Forced vital capacity (FEV1/FVC) (P = 0.040, OR 0.966, 95% CI 0.935–0.998); and surgical method (P = 0.024, OR 0.425, 95% CI 0.202–0.891). The area under the curve was 0.865, and the consistency index was 0.367. The Hosmer–Lemeshow test indicated excellent model fit (P = 0.367). The calibration curve closely approximated the ideal diagonal line. DCA showed a significant net benefit of the predictive model for postoperative ICU admission.ConclusionPredictors of ICU admission following radical CRC resection include age, preoperative serum albumin level, nutritional risk screening, atrial fibrillation, COPD, FEV1/FVC, and surgical route. The predictive nomogram and online tool support clinical decision-making for postoperative ICU admission in patients undergoing radical CRC surgery.Trial registrationDespite the retrospective nature of this study, we have proactively registered it with the Chinese Clinical Trial Registry. The registration number is ChiCTR2200062210, and the date of registration is 29/07/2022.

522 A Snapshot Audit of Incisional Hernia Rates Following Colorectal Cancer Resection

Abstract Aim Incisional hernia is a common complication of colorectal surgery. Recent European Hernia Society guidelines recommend strategies such as small bites closure and off-midline incisions to reduce incisional hernia rates. We aimed to evaluate our centres incisional hernia rate and performance against these categories Method All patients undergoing surgery for colorectal cancer in 2020 were included. Operative details including incision location and closure method were collected. Post-operative CT scans were assessed and correlated with clinic letters to determine presence of incisional hernia. Patients were excluded if they underwent re-operation through the midline within 12 months, or if had no imaging after 12 months. Results 118 patients were included. The incisional hernia rate was 31.4% at a mean follow-up of 24.9 months. Large bites closure (Hughes or loop PDS, n=80) had a higher incisional hernia rate compared to small bite closure ( n=38) (35.0% vs 23.6%). Incisional hernia rates were 44.1% in laparotomy incisions, 37.2% in midline extraction sites, 8% in Pfannensteil extraction sites and 0% in transverse extraction sites. Overall, IH rates in midline incisions were 40.7%, compared to 6.3% in off-midline incisions. Conclusions Incisional Hernia rates remain high following colorectal cancer surgery in our institution. Small bites closure and off-midline incisions appear to reduce this risk, but use of these techniques remains low. Work is ongoing to identify and implement strategies to improve uptake of small bites and off-midline incisions.

1297 Factors Influencing Lymph Node Retrieval and Staging in Colorectal Cancer Resections: A Single-Centre Study

Abstract Aim The American Joint Committee on Cancer (AJCC) recommends examination of a minimum of 12 total dissected lymph nodes to stage rectal cancer accurately. This study aimed to explore the factors influencing lymph node (LN) retrieval and their impact on nodal positivity and N category in colorectal cancer (CRC) staging. Method This retrospective single-centre study included patients with CRC who underwent laparoscopic excision by a single colorectal surgeon between July 2021 and July 2023. Data were extracted from the hospital's electronic database, with exclusion criteria for benign conditions. Results The average number of LNs in this cohort was 17.95±6.55. At least 12 LNs were recovered in 90.91% of the cases. The right colon was the most common tumour site. Right hemicolectomy, transverse colon resection, and sigmoid colectomy achieved 100% compliance with the adequate retrieval criteria. An increase in LN retrieval was observed with higher T stages. A positive linear correlation was observed between the number of harvested LNs and the length of the resected bowel. No significant difference in LN yield was observed between node-positive and node-negative cases. Conclusions Tumour site emerged as a significant factor influencing LN retrieval in CRC resections. While age and sex showed no substantial impact, tumour size and extent of resected bowel positively correlated with LN counts. The overall lymph node yield had no effect on node positivity, indicating that, following a careful inspection of the specimen, a lower lymph node yield may be deemed sufficient.

Prediction of anastomotic insufficiency based on the mucosal microbiome prior to colorectal surgery: a proof-of-principle study

Anastomotic leakage (AL) is a potentially life-threatening complication following colorectal cancer (CRC) resection. In this study, we aimed to unravel longitudinal changes in microbial structure before, during, and after surgery and to determine if microbial alterations may be predictive for risk assessment between sufficient anastomotic healing (AS) and AL prior surgery. We analysed the microbiota of 134 colon mucosal biopsies with 16S rRNA V1-V2 gene sequencing. Samples were collected from three location sites before, during, and after surgery, and patients received antibiotics after the initial collection and during surgery. The microbial structure showed dynamic surgery-related changes at different time points. Overall bacterial diversity and the abundance of some genera such as Faecalibacterium or Alistipes decreased over time, while the genera Enterococcus and Escherichia_Shigella increased. The distribution of taxa between AS and AL revealed significant differences in the abundance of genera such as Prevotella, Faecalibacterium and Phocaeicola. In addition to Phocaeicola, Ruminococcus2 and Blautia showed significant differences in abundance between preoperative sample types. ROC analysis of the predictive value of these genera for AL revealed an AUC of 0.802 (p = 0.0013). In summary, microbial composition was associated with postoperative outcomes, and the abundance of certain genera may be predictive of postoperative complications.

Early Postoperative Prediction of Complications and Readmission After Colorectal Cancer Surgery Using an Artificial Neural Network.

Early predictors of postoperative complications can risk-stratify patients undergoing colorectal cancer surgery. However, conventional regression models have limited power to identify complex nonlinear relationships among a large set of variables. We developed artificial neural network models to optimize the prediction of major postoperative complications and risk of readmission in patients undergoing colorectal cancer surgery. This study aimed to develop an artificial neural network model to predict postoperative complications using postoperative laboratory values and compare the accuracy of models to standard regression methods. This retrospective study included patients who underwent elective colorectal cancer resection between January 1, 2016, and July 31, 2021. Clinical data, cancer stage, and laboratory data from postoperative days 1 to 3 were collected. Complications and readmission risk models were created using multivariable logistic regression and single-layer neural networks. National Cancer Institute-Designated Comprehensive Cancer Center. Adult patients with colorectal cancer. The accuracy of predicting postoperative major complications, readmissions, and anastomotic leaks using the area under the receiver operating characteristic curve. Neural networks had larger areas under the curve for predicting major complications compared to regression models (neural network 0.811; regression model 0.724, p < 0.001). Neural networks also showed an advantage in predicting anastomotic leak ( p = 0.036) and readmission using postoperative day 1 to 2 values ( p = 0.014). Single-center, retrospective design limited to cancer operations. In this study, we generated a set of models for the early prediction of complications after colorectal surgery. The neural network models provided greater discrimination than the models based on traditional logistic regression. These models may allow for early detection of postoperative complications as early as postoperative day 2. See the Video Abstract . ANTECEDENTES:Los predictores tempranos de complicaciones postoperatorias pueden estratificar el riesgo de los pacientes sometidos a cirugía de cáncer colorrectal. Sin embargo, los modelos de regresión convencionales tienen un poder limitado para identificar relaciones no lineales complejas entre un gran conjunto de variables. Desarrollamos modelos de redes neuronales artificiales para optimizar la predicción de complicaciones postoperatorias importantes y riesgo de reingreso en pacientes sometidos a cirugía de cáncer colorrectal.OBJETIVO:El objetivo de este estudio fue desarrollar un modelo de red neuronal artificial para predecir complicaciones postoperatorias utilizando valores de laboratorio postoperatorios y comparar la precisión de estos modelos con los métodos de regresión estándar.DISEÑO:Este estudio retrospectivo incluyó a pacientes que se sometieron a resección electiva de cáncer colorrectal entre el 1 de enero de 2016 y el 31 de julio de 2021. Se recopilaron datos clínicos, estadio del cáncer y datos de laboratorio del día 1 al 3 posoperatorio. Se crearon modelos de complicaciones y riesgo de reingreso mediante regresión logística multivariable y redes neuronales de una sola capa.AJUSTE:Instituto Nacional del Cáncer designado Centro Oncológico Integral.PACIENTES:Pacientes adultos con cáncer colorrectal.PRINCIPALES MEDIDAS DE RESULTADO:Precisión de la predicción de complicaciones mayores postoperatorias, reingreso y fuga anastomótica utilizando el área bajo la curva característica operativa del receptor.RESULTADOS:Las redes neuronales tuvieron áreas bajo la curva más grandes para predecir complicaciones importantes en comparación con los modelos de regresión (red neuronal 0,811; modelo de regresión 0,724, p < 0,001). Las redes neuronales también mostraron una ventaja en la predicción de la fuga anastomótica ( p = 0,036) y el reingreso utilizando los valores del día 1-2 postoperatorio ( p = 0,014).LIMITACIONES:Diseño retrospectivo de un solo centro limitado a operaciones de cáncer.CONCLUSIONES:En este estudio, generamos un conjunto de modelos para la predicción temprana de complicaciones después de la cirugía colorrectal. Los modelos de redes neuronales proporcionaron una mayor discriminación que los modelos basados en regresión logística tradicional. Estos modelos pueden permitir la detección temprana de complicaciones posoperatorias tan pronto como el segundo día posoperatorio. (Traducción-Dr. Mauricio Santamaria ).

273 Outcomes Reported in Elective Colorectal Cancer Surgery Research for Older Patients: A Scoping Review

Abstract Aim This scoping review aimed to identify outcome measures for assessing the impact of elective colorectal cancer surgery on older patients, given their higher surgical risk and mortality rates. Conventional surgery-specific outcomes, like 5-year mortality rates, may not be appropriate, necessitating a focus on postoperative quality of life. The challenge lies in determining optimal outcomes to assess the effects of colorectal cancer resections in the older population. Method A comprehensive literature search of major electronic databases from inception to March 2023 was conducted. Studies exploring frail or elderly individuals with colorectal cancer undergoing elective surgery and reporting postoperative outcomes were included. Outcomes were classified as surgery-specific versus person-centred and summarised using a narrative synthesis. The type and rate of surgery-specific outcomes were tabulated. Results Of 1366 identified citations, 16 studies focused on person-centred outcomes and 66 exclusively on surgery-specific outcomes. Nine of the 16 ‘person-centred outcome’ studies reported discharge destination, with home discharge being predominant. Postoperative delirium ranged from 8.2% to 18.1% in six studies. Four studies explored geriatric syndromes and three analysed activities of daily living. Three studies reported a significant improvement in quality of life. The 66 ‘surgery-specific outcome’ studies assessed mortality (N=61); length of stay (N=40); postoperative complications (N=47); readmission (N=18); reoperation (N=16); and survival (N=42). Conclusions Person-centred outcomes are underreported, despite their importance in guiding patient management. Older patients require adequate information about their recovery after surgery to manage their lives better. Future research must address this gap to improve care for older patients undergoing elective colorectal cancer surgery.

Early follow-up colonoscopy after colorectal cancer resection detects significant pathology.

Colonoscopy is a key component of surveillance after colorectal cancer (CRC) resection. Surveillance intervals for colonoscopy vary across the world, with a limited evidence-base to support guidelines. To evaluate the timing and outcome of colonoscopies after CRC resection. Retrospective cohort study on prospectively collected data. Included adult patients under surveillance following CRC resection. Patients with organ transplant, inflammatory bowel disease or colon cancer syndromes were excluded. The outcomes of the first (up to) three follow-up colonoscopies were audited and classified for presence of advanced neoplasia (advanced adenoma or adenocarcinoma). 980 patients underwent at least one follow-up colonoscopy with a median time to first colonoscopy of 12.4 months. The findings included 2.7% CRC and 13.2% advanced adenoma. Older age, stage IV disease, and synchronous cancers at surgery were significantly associated with a finding of advanced neoplasia at first colonoscopy. 562 patients underwent a second colonoscopy (median of 35 months after the first surveillance colonoscopy) with findings of 1.8% CRC and 11.4% advanced adenoma. Advanced adenoma on prior colonoscopy was associated with finding advanced neoplasia at the second colonoscopy. 288 patients underwent a third colonoscopy (median of 37 months from the preceding colonoscopy), with similar outcomes of advanced neoplasia being associated with advanced adenoma at the previous colonoscopy. 43 (4.4%) patients developed CRC whilst on surveillance. Timely surveillance after CRC resection is important for detecting advanced neoplasia, and prolonged intervals between colonoscopies in the early years after surgery should be avoided.