Endoscopic obstruction is associated with higher risk of acute events requiring emergency operation in colorectal cancer patients

Endoscopic obstruction predominantly occurs in right-side colon cancer and endoscopic obstruction with tumor size ≤ 5 cm seems poor prognosis in colorectal cancer

Background

Endoscopic obstruction (eOB) is associated with a poor prognosis in colorectal cancer (CRC). Our study aimed to investigate the association between tumor location and eOB, as well as the prognostic differences among non-endoscopic obstruction (N-eOB), eOB with tumor size ≤ 5 cm, and eOB with tumor size > 5 cm in non-elderly patients.

Methods

We retrospectively reviewed the clinicopathological variables of 230 patients with CRC who underwent curative surgery. The multivariable logistic regression model was used to identify risk factors for eOB. The association between eOB with tumor size ≤ 5 cm and disease-free survival (DFS) was evaluated using multivariate cox regression analysis.

Results

A total of 87 patients had eOB while 143 had N-eOB. In multivariate analysis, preoperative carcinoembryonic antigen (p = 0.014), tumor size (p = 0.010), tumor location (left-side colon; p = 0.033; rectum; p < 0.001), and pT stage (T3, p = 0.009; T4, p < 0.001) were significant factors of eOB. The DFS rate for eOB with tumor size ≤ 5 cm was significantly lower (p < 0.001) in survival analysis. The eOB with tumor size ≤ 5 cm (p = 0.012) was an unfavorable independent factor for DFS.

Conclusions

The patients with eOB were significantly associated with right-side colon cancer as opposed to left-side colon cancer and rectal cancer. The eOB with tumor size ≤ 5 cm was an independent poor prognostic factor. Further studies are needed to target these high-risk groups.

Palliative stenting for malignant colorectal stenosis in the elderly

Objectives

Self‐expandable metal stents are widely used for the treatment of malignant colorectal stenosis (MCS). In elderly individuals with MCS, self‐expandable metal stents are often used as a palliative treatment, but prophylactic stent placement is not recommended. We investigated the efficacy and safety of self‐expandable metal stents for the elderly in a palliative setting, specifically in a prophylactic setting.

Methods

Elderly patients with MCS who received a palliative stent (the stent group) or palliative stoma (the stoma group) were retrospectively enrolled between April 2017 and June 2022, and the prognosis and complication rates were assessed. Additionally, patients in the stent group were divided into symptomatic and asymptomatic subgroups, and prognosis, stent patency, and complication rates were evaluated.

Results

During the study period, 31 patients with a mean age of 85.4 years and 12 patients with a mean age of 82.0 years were enrolled in the stent and stoma groups, respectively. While overall survival and complication rates were comparable, the length of hospital stay was significantly shorter in the stent group. Of the 31 patients in the stent group, 16 asymptomatic patients received prophylactic stenting, which was not associated with increased complication rates.

Conclusions

Palliative stents for MCS appear to be effective and safe even in the elderly, and thus, prophylactic stents can be considered for asymptomatic patients.

Prognostic Implications of Endoscopic Obstruction in Patients with Pathological Stage II Colon Cancers: a Single-Center Retrospective Cohort Study

BACKGROUND

The prognostic effect of endoscopic obstruction (eOB) on the survival of stage II colon cancer patients and the role of eOB in guiding postoperative adjuvant chemotherapy of stage II colon cancer are little known.

METHODS

In this retrospective, single-center cohort study, patients who had undergone curative surgery and preoperative colonoscope for stage II colon carcinoma were included. The eOB was defined as severe luminal colon obstruction that prevented the standard colonoscope from passing beyond the tumor. The association between eOB and stage II colon cancer survival and the predictive role of eOB for adjuvant chemotherapy were evaluated using multivariate Cox regression analysis.

RESULTS

Of 1102 included patients, 616 (55.9%) had eOB and 486 (44.1%) had no eOB. The median follow-up was 49 months (interquartile range, 38-68 months). Kaplan-Meier curves showed that patients with eOB had poor 5-year overall survival (OS; 85.3% vs. 95.3%, p < 0.001) compared to patients without eOB. Five-year disease-free survival (DFS; 78.5% vs. 87.6%, p = 0.004) was also poor in these patients. Multivariate analysis demonstrated eOB was a significant prognostic factor for poor OS (hazard ratio [HR] = 2.531, p < 0.001), but not for DFS (p = 0.081). Even when patients with clinical colonic obstruction were excluded from the population with eOB, the worse OS (HR = 2.262, p = 0.001) was observed. The OS and DFS of eOB patients improved slightly after adjuvant chemotherapy, but there was no statistical significance.

CONCLUSIONS

Stage II colon cancer patients with eOB have a poor prognosis. However, whether eOB can guide adjuvant chemotherapy still needs further study.

Development and validation of artificial intelligence models for preoperative prediction of inferior mesenteric artery lymph nodes metastasis in left colon and rectal cancer

BACKGROUND

Dissection of lymph nodes at the roots of the inferior mesenteric artery (IMAN) should be offered only to selected patients at a major risk of developing IMAN involvement. The aim of this study is to present the first artificial intelligence (AI) models to predict IMAN metastasis risk in the left colon and rectal cancer patients.

METHODS

A total of 2891 patients with descending colon including splenic flexure, sigmoid colon and rectal cancer undergoing major primary surgery and IMAN dissection were included as a study cohort, which was then split into a training set (67%) and a testing set (33%). Feature selection was conducted using the least absolute shrinkage and selection operator (LASSO) regression model. Seven AI algorithms, namely Support Vector Machine (SVM), Logistic Regression (LR), Extreme Gradient Boosting (XGB), Light Gradient Boosting (LGB), Decision Tree Classifier (DTC), Random Forest (RF) classifier, and Multilayer Perceptron (MLP), as well as traditional multivariate LR model were employed to construct predictive models. The optimal hyperparameters were determined with 5 fold cross-validation. The predictive performance of models and the expert surgeon was assessed and compared in the testing set independently.

RESULTS

The IMAN involvement incidence was 4.6%. The optimal set of features selected by LASSO included 10 characteristics: neoadjuvant treatment, age, synchronous liver metastasis, synchronous lung metastasis, signet ring adenocarcinoma, neural invasion, lymphovascular invasion, CA199, endoscopic obstruction, T stage evaluated by MRI. The most accurate model derived from MLP showed excellent prediction power with area under the receiver operating characteristic curve (AUROC) of 0.873 and produced 81.0% recognition sensitivity and 82.5% specificity in the testing set independently. In contrast, the judgment of IMAN metastasis by expert surgeon yield rather imprecise and unreliable results with a significantly lower AUROC of 0.509. Additionally, the proposed MLP had the highest net benefits and the largest reduction of unnecessary IMAN dissection without the cost of additional involved IMAN missed.

CONCLUSION

MLP model was able to maintain its prediction accuracy in the testing set better than other models and expert surgeons. Our MLP model could be used to help identify IMA nodal metastasis and to select candidates for individual IMAN dissection.

Risk factors for metachronous peritoneal carcinomatosis after radical resection for patients with nonmetastatic pT3-4 colon cancer

BACKGROUND

Patients with nonmetastatic pT3-4 colon cancers are prone to develop metachronous peritoneal carcinomatosis (mPC). Risk factors for mPC and the influence of mutant kirsten rat sarcoma viral oncogene (KRAS)/neuroblastoma rat sarcoma (NRAS)/v-raf murine sarcoma viral oncogene homolog B1 (BRAF) and DNA mismatch repair (MMR) status on mPC remain to be described in these patients.

METHOD

All enrolled patients were identified from the prospectively collected colorectal cancer database of a tertiary referral hospital between 2013 and 2018. Multivariate analysis was used to identify risk factors associated with mPC.

RESULTS

Of the 1689 patients with nonmetastatic pT3-4 colon carcinoma, 8.4% (142/1689) progressed to mPC. Endoscopic obstruction (HR = 3.044, p < 0.001), elevated CA125 (HR = 1.795, p = 0.009), pT (T4a vs. T3, HR = 2.745, p < 0.001; T4b vs. T3, HR = 3.167, p = 0.001), pN (N1 vs. N0, HR = 2.592, p < 0.001; N2 vs. N0, HR = 4.049, p < 0.001), less than 12 lymph nodes harvested (HR = 2.588, p < 0.001), mucinous or signet ring cell carcinoma (HR = 1.648, p = 0.038), perineural invasion (HR = 1.984, p < 0.001), and adjuvant chemotherapy (HR = 1.522, p = 0.039) were strongly related to mPC but that mutant KRAS/NRAS/BRAF and MMR status was not associated with mPC.

CONCLUSION

This study identified the high-risk factors for mPC in patients with nonmetastatic pT3-4 colon carcinoma, and these factors should be considered in selective preventive therapy and close follow-up for patients subsequently deemed to have high risk for mPC.

Incidence of and Risk Factors for Gastroepiploic Lymph Node Involvement in Patients with Cancer of the Transverse Colon Including the Hepatic Flexure

BACKGROUND

To define the incidence of gastroepiploic lymph node (GLN) metastasis in patients with cancer of the transverse colon, including the hepatic flexure, and to identify the preoperative predictors of GLN involvement in a large-volume center in China.

METHODS

This retrospective monocentric cross-sectional study respected the STROBE statement. Of 3208 consecutive patients who underwent colon cancer resection, a total of 371 patients with cancer of the transverse colon including the hepatic flexure who underwent complete mesocolic excision and GLN resection in our center were retrospectively reviewed between November 2010 and November 2017. Logistic regression was performed to identify predictors of GLN metastasis. Endoscopic obstruction was defined as a luminal obstruction of the colon severe enough to prevent the colonoscope from passing beyond the tumor regardless of the presenting symptoms.

RESULTS

The GLN involvement rate was 4.0 (2.0-6.1)%. Patients who had GLN involvement had a significantly higher rate of endoscopic obstruction (P = 0.030), higher rate of signet ring adenocarcinoma or lymphovascular invasion (P < 0.05), higher preoperative CEA level (P = 0.037), more advanced pN stage (P < 0.001) and more advanced M stage (P = 0.003) than the patients without GLN involvement. ROC curve analyses showed that the cutoff value for CEA was 17.0 ng/ml (46.7% sensitivity, 84.3% specificity, P = 0.037) for the prediction of GLN metastasis. Multivariate analysis showed that endoscopic obstruction, signet ring adenocarcinoma, a CEA level ≥17 ng/ml and M1 stage were independently correlated with the GLN metastasis.

CONCLUSION

The incidence rate of GLN metastasis was low. To the best of our knowledge, the present study was the first to evaluate the preoperative predictors of GLN metastasis. Combinations of predictive factors may be useful for stratifying patients at high risk of GLN metastasis.

Obstructive colon cancers at endoscopy are associated with advanced tumor stage and poor patient outcome. A retrospective study on 398 patients

BACKGROUND

The detection of obstructive colorectal cancer (CRC) masses during endoscopic examination hindering the passage of endoscope and precluding complete examination is not uncommon. The significance and implications of this finding on patients' prognosis and outcomes were not fully investigated and will be addressed in this study.

METHODS

In this retrospective cohort study, we reviewed endoscopy, surgery, pathology and oncology reports of patients diagnosed with CRC over a 10-year period (2007-2016). We compared surgical stages, histologic grades and overall survival between patients with subclinical obstructive tumors at endoscopy to those with nonobstructive tumors. We performed multivariate analysis to identify independent risk factors associated with advanced CRC stage at diagnosis.

RESULTS

A total of 144 patients had obstructive colonic tumors while 254 had nonobstructive tumors and constituted the control group. Obstructive CRC group was significantly associated with advanced tumor stage at diagnosis (69 vs. 42%, OR = 3.018, 95% CI, 1.951-4.670; P < 0.01) and had prominently higher rates of moderate to poorly differentiated tumors (64.5 vs. 38.4%; P < 0.001) when compared to non-obstructive controls. Patients with obstructive tumors were significantly associated with decreased five years overall survival (53.4 vs. 67.3% vs.; P < 0.01). Increased overall mortality was observed in survival curves of patients with obstructive tumors along all follow-up periods.

CONCLUSION

Even in the absence of clinical sequela, obstructive CRC at endoscopic level may be associated with higher stage at diagnosis and reduced overall survival. Further prospective studies are warranted to confirm these findings and address their implication on patients' management.

Emergency Presentations of Colorectal Cancer

Many colorectal carcinomas will present emergently with issues such as obstruction, perforation, and bleeding. Emergency surgery is associated with poor short- and long-term outcomes. For abnormality localizing to the colon proximal to the splenic flexure, surgical management with hemicolectomy is often a safe and appropriate approach. Obstructions are more common in the distal colon, however, where there is an evolving spectrum of surgical and nonsurgical options, most notably by the development of endoluminal stents. Perforation and bleeding are managed similarly to benign causes, as malignancy may be only part of a differential diagnosis at the time of an operation.

Association of Wilms' tumor 1 gene single-nucleotide polymorphism rs16754 with colorectal cancer

Colorectal cancer (CRC) is one of the leading causes of cancer-related mortality worldwide. Our recent study demonstrated that the expression of Wilms' tumor 1 gene (WT1) is associated with surgical outcome in CRC patients. The present study aimed to investigate the genetic association of the single-nucleotide polymorphism rs16754 in the WT1 gene with the occurrence of CRC, using an age-matched case-control study design. In addition, the correlation between genotype and WT1 expression was investigated. Genomic DNA samples from 104 CRC cases, aged 15-65 years, and 208 healthy controls, were genotyped for rs16754 using the TaqMan genotyping method. The genotype distribution conformed to the Hardy-Weinberg equilibrium (P=0.80). The overall minor allele frequency (MAF) of rs16754 (allele A) was 0.33. The MAF among CRC cases was significantly higher compared with that in controls (0.39 vs. 0.31, respectively; P=0.03). The AA genotype was significantly associated with the disease (odds ratio = 2.51, 95% confidence interval: 1.24-5.07, P=0.01). Cases with the AA genotype exhibited a significantly poorer 3-year overall survival (60%), compared with those with the GG or GA genotypes (80%) (log-rank test, P<0.01). Reverse transcription quantitative polymerase chain reaction analysis demonstrated that the expression of WT1 in tumor tissues was higher compared with that in normal tissue; however, there were no significant differences in its expression among different genotypes. Therefore, rs16754 was found to be associated with the occurrence and prognosis of CRC in our subjects.