Artificial intelligence-assisted decision making: Prediction of optimal level of distal mesorectal margin during transanal total mesorectal excision (taTME) using deep neural network modeling.

BACKGROUND: With steep posterior anorectal angulation, transanal total mesorectal excision (taTME) may have a risk of dissection in the wrong plane or starting higher up, resulting in leaving distal mesorectum behind. Although the distal mesorectal margin can be assessed by preoperative MRI, it needs skilled radiologist and high-definition image for accurate evaluation. This study developed a deep neural network (DNN) to predict the optimal level of distal mesorectal margin. METHODS: A total of 182 pelvic MRI images extracted from the cancer image archive (TCIA) database were included. A DNN was developed using gender, the degree of anterior and posterior anorectal angles as input variables while the difference between anterior and posterior mesorectal distances from anal verge was selected as a target. The predictability power was assessed by regression values (R) which is the correlation between the predicted outputs and actual targets. RESULTS: The anterior angle was an obtuse angle while the posterior angle varied from acute to obtuse with mean angle difference 35.5°±14.6. The mean difference between the anterior and posterior mesorectal end distances was 18.6±6.6mm. The developed DNN had a very close correlation with the target during training, validation, and testing (R=0.99, 0.81, and 0.89, P<0.001). The predicted level of distal mesorectal margin was closely correlated with the actual optimal level (R=0.91, P<0.001). CONCLUSIONS: Artificial intelligence can assist in either making or confirming the preoperative decisions. Furthermore, the developed model can alert the surgeons for this potential risk and the necessity of re-positioning the proctectomy incision.

Risk factors for complications following sacral neuromodulation for faecal incontinence: Long-term follow-up.

AIM: Sacral neuromodulation (SNM) has become a standard surgical treatment for faecal incontinence (FI). Prior studies have reported various adverse events of SNM, including suboptimal therapeutic response, infection, pain, haematoma, and potential need for redo SNM. The aim of this study was to identify the risk factors associated with long-term complications of SNM. METHOD: This retrospective cohort reviewed patients who underwent two-stage SNM for FI at our institution between 2011-2021. Preoperative baseline characteristics and follow-up were obtained from the medical record and/or by telephone interview. Management and outcome of each postoperative event were evaluated by univariate and multivariate regression analyses. RESULTS: A total of 291 patients (85.2% female) were included in this study. Postoperative complications were recorded in 219 (75.2%) patients and 154 (52.9%) patients required surgical intervention to treat complications. The most common postoperative event was loss of efficacy (46.4%). Other common adverse events were problems at the implant site (pain, infection, etc.) in 16.5% and pain during stimulation in 11.7%. Previous vaginal delivery (OR 2.74, p = 0.003) and anal surgery (OR = 2.46, p = 0.039) were independent predictors for complications. Previous colorectal (OR = 2.04, p = 0.026) and anal (OR = 1.98, p = 0.022) surgery and history of irritable bowel syndrome (IBS) (OR = 3.49, p = 0.003) were independent predictors for loss of efficacy. CONCLUSION: Postoperative adverse events are frequently recorded after SNM. Loss of efficacy is the most common. Previous colorectal or anal surgery, vaginal delivery, and IBS are independent risk factors for complications.

Non-operative management of rectal cancer: Highlighting the controversies.

There remains much ambiguity on what non-operative management (NOM) of rectal cancer truly entails in terms of the methods to be adopted and the best algorithm to follow. This is clearly shown by the discordance between various national and international guidelines on NOM of rectal cancer. The main aim of the NOM strategy is organ preservation and avoiding unnecessary surgical intervention, which carries its own risk of morbidity. A highly specific and sensitive surveillance program must be devised to avoid patients undergoing unnecessary surgical interventions. In many studies, NOM, often interchangeably called the Watch and Wait strategy, has been shown as a promising treatment option when undertaken in the appropriate patient population, where a clinical complete response is achieved. However, there are no clear guidelines on patient selection for NOM along with the optimal method of surveillance.

Trans­anal minimally invasive surgery (TAMIS) versus rigid platforms for local excision of early rectal cancer: a systematic review and meta-analysis of the literature.

BACKGROUND: Available platforms for local excision (LE) of early rectal cancer are rigid or flexible [trans­anal minimally invasive surgery (TAMIS)]. We systematically searched the literature to compare outcomes between platforms. METHODS: PRISMA-compliant search of PubMed and Scopus databases until September 2022 was undertaken in this random-effect meta-analysis. Statistical heterogeneity was assessed using I2 statistic. Studies comparing TAMIS versus rigid platforms for LE for early rectal cancer were included. Main outcome measures were intraoperative and short-term postoperative outcomes and specimen quality. RESULTS: 7 studies were published between 2015 and 2022, including 931 patients (423 females); 402 underwent TAMIS and 529 underwent LE with rigid platforms. Techniques were similar for operative time (WMD 11.1, 95%CI - 2.6 to 25, p = 0.11), percentage of defect closure (OR 0.7, 95%CI 0.06-8.22, p = 0.78), and peritoneal violation (OR 0.41, 95%CI 0.12-1.43, p = 0.16). Rigid platforms had higher rates of short-term complications (19.1% vs 14.2, OR 1.6, 95%CI 1.07-2.4, p = 0.02), although no significant differences were seen for major complications (OR 1.41, 95%CI 0.61-3.23, p = 0.41). Patients in the rigid platforms group were 3-times more likely to be re-admitted within 30 days compared to the TAMIS group (OR 3.1, 95%CI 1.07-9.4, p = 0.03). Rates of positive resection margins (rigid platforms: 7.6% vs TAMIS: 9.34%, OR 0.81, 95%CI 0.42-1.55, p = 0.53) and specimen fragmentation (rigid platforms: 3.3% vs TAMIS: 4.4%, OR 0.74, 95%CI 0.33-1.64, p = 0.46) were similar between the groups. Salvage surgery was required in 5.5% of rigid platform patients and 6.2% of TAMIS patients (OR 0.8, 95%CI 0.4-1.8, p = 0.7). CONCLUSION: TAMIS or rigid platforms for LE seem to have similar operative outcomes and specimen quality. The TAMIS group demonstrated lower readmission and overall complication rates but did not significantly differ for major complications. The choice of platform should be based on availability, cost, and surgeon's preference.

Low-pressure versus standard-pressure pneumoperitoneum in minimally invasive colorectal surgery: a systematic review, meta-analysis, and meta-regression analysis.

Background: We aimed to assess the efficacy and safety of low-pressure pneumoperitoneum (LPP) in minimally invasive colorectal surgery. Methods: A PRISMA-compliant systematic review/meta-analysis was conducted, searching PubMed, Scopus, Google Scholar, and clinicaltrials.gov for randomized-controlled trials assessing outcomes of LPP vs standard-pressure pneumoperitoneum (SPP) in colorectal surgery. Efficacy outcomes [pain score in post-anesthesia care unit (PACU), pain score postoperative day 1 (POD1), operative time, and hospital stay] and safety outcomes (blood loss and postoperative complications) were analyzed. Risk of bias2 tool assessed bias risk. The certainty of evidence was graded using GRADE. Results: Four studies included 537 patients (male 59.8%). LPP was undertaken in 280 (52.1%) patients and associated with lower pain scores in PACU [weighted mean difference: -1.06, 95% confidence interval (CI): -1.65 to -0.47, P = 0.004, I 2 = 0%] and POD1 (weighted mean difference: -0.49, 95% CI: -0.91 to -0.07, P = 0.024, I 2 = 0%). Meta-regression showed that age [standard error (SE): 0.036, P < 0.001], male sex (SE: 0.006, P < 0.001), and operative time (SE: 0.002, P = 0.027) were significantly associated with increased complications with LPP. In addition, 5.9%-14.5% of surgeons using LLP requested pressure increases to equal the SPP group. The grade of evidence was high for pain score in PACU and on POD1 postoperative complications and major complications, and blood loss, moderate for operative time, low for intraoperative complications, and very low for length of stay. Conclusions: LPP was associated with lower pain scores in PACU and on POD1 with similar operative times, length of stay, and safety profile compared with SPP in colorectal surgery. Although LPP was not associated with increased complications, older patients, males, patients undergoing laparoscopic surgery, and those with longer operative times may be at risk of increased complications.

An artificial intelligence-designed predictive calculator of conversion from minimally invasive to open colectomy in colon cancer.

Minimally invasive surgery is safe and effective in colorectal cancer. Conversion to open surgery may be associated with adverse effects on treatment outcomes. This study aimed to assess risk factors of conversion from minimally invasive to open colectomy for colon cancer and impact of conversion on short-term and survival outcomes. This case-control study included colon cancer patients undergoing minimally invasive colectomy from the National Cancer Database (2015-2019). Logistic regression analyses were conducted to determine independent predictors of conversion from laparoscopic and robotic colectomy to open surgery. 26,546 patients (mean age: 66.9 ± 13.1 years) were included. Laparoscopic and robotic colectomies were performed in 79.1% and 20.9% of patients, respectively, with a 10.6% conversion rate. Independent predictors of conversion were male sex (OR: 1.19, p = 0.014), left-sided cancer (OR: 1.35, p < 0.001), tumor size (OR: 1, p = 0.047), stage II (OR: 1.25, p = 0.007) and stage III (OR: 1.47, p < 0.001) disease, undifferentiated carcinomas (OR: 1.93, p = 0.002), subtotal (OR: 1.25, p = 0.011) and total (OR: 2.06, p < 0.001) colectomy, resection of contiguous organs (OR: 1.9, p < 0.001), and robotic colectomy (OR: 0.501, p < 0.001). Conversion was associated with higher 30- and 90-day mortality and unplanned readmission, longer hospital stay, and shorter overall survival (59.8 vs 65.3 months, p < 0.001). Male patients, patients with bulky, high-grade, advanced-stage, and left-sided colon cancers, and patients undergoing extended resections are at increased risk of conversion from minimally invasive to open colectomy. The robotic platform was associated with reduced odds of conversion. However, surgeons' technical skills and criteria for conversion could not be assessed.

Predictors and Impact of Ileus on Outcomes After Laparoscopic Right Colectomy: A Case-Control Study.

BACKGROUND: Ileus is a common complication of major abdominal surgery, including colorectal resection. The present study aimed to assess the predictors of ileus after laparoscopic right colectomy for colon cancer. METHODS: This study was a retrospective case-control analysis of a prospective IRB-approved database of patients who underwent laparoscopic right colectomy at the Department of Colorectal Surgery, Cleveland Clinic Florida. Patients who developed ileus after right colectomy were compared to patients without ileus to determine the risk factors of ileus. RESULTS: The present study included 270 patients with a mean age of 68.7 years. Thirty-six patients (13.3%) experienced ileus after laparoscopic right colectomy. The median duration of ileus was 6 days. Factors associated with ileus were age (71.6 vs 68.2 years, P = .158), emergency colectomy (11.1% vs 3.9%, P = .082), extended hemicolectomy (19.4% vs 6.8%, P = .021), green gastrointestinal anastomosis (GIA) 4.8mm staple height cartridge (19% vs 8.1%, P = .114), and longer operative time (177.9 vs 160.4 minutes, P = .157). The only independent predictor of ileus was extended colectomy (OR: 16.7, P = .003). CONCLUSIONS: Increased age, emergency surgery, green GIA cartridge, and longer operative times were associated with ileus, yet the only independent predictor of ileus was extended right hemicolectomy.

Association between body mass index and short-term outcomes of laparoscopic right hemicolectomy for colon cancer.

BACKGROUND: Laparoscopic right hemicolectomy can be technically challenging in patients with increased body mass index, reportedly associated with higher surgical site infection (SSI) and incisional hernia rates. We aimed to assess the association between increased body mass index and short-term outcomes of laparoscopic right hemicolectomy. METHODS: This retrospective cohort study included patients with colon cancer who underwent laparoscopic right hemicolectomy between 2011 and 2021. Patients were managed with a standardized care protocol that comprised preoperative, intraoperative, and postoperative measures and were divided according to body mass index-normal body mass index (18-24.9 kg/m2), overweight (25-29.9 kg/m2), and obesity (≥30 kg/m2). Body mass index groups were compared for baseline characteristics and outcomes. The main outcome measures were operative time, hospital stay, 30-day complications, reoperation, number of harvested lymph nodes, and resection status. RESULTS: A total of 270 patients (50% male sex; mean age: 68.7 ± 13.5 years) were included-28.5% had normal body mass index, 47% were overweight, and 24.5% had obesity. Mean operative times in obese and overweight patients were significantly longer than patients with normal body mass index (172.1 and 168.8 versus 143.3 minutes, P = .01). Compared to normal body mass index, obesity was associated with significantly higher odds of incisional SSI (odds ratio: 9.29, P = .039). Body mass index had a significant positive correlation with operation time (r = 0.205, P = .004) and incisional SSI (r = 0.126, P = .04). Body mass index groups had similar hospital stays, 30-day complications and mortality, anastomotic leak, ileus, and reoperation. CONCLUSION: Patients with increased body mass index had longer operative times and higher SSI rates, yet similar hospital stays and comparable 30-day complication rates, mortality, and reoperation to patients with normal body mass index.

Multicenter validation of an artificial intelligence (AI)-based platform for the diagnosis of acute appendicitis.

BACKGROUND: The current scores used to help diagnose acute appendicitis have a "gray" zone in which the diagnosis is usually inconclusive. Furthermore, the universal use of CT scanning is limited because of the radiation hazards and/or limited resources. Hence, it is imperative to have an accurate diagnostic tool to avoid unnecessary, negative appendectomies. METHODS: This was an international, multicenter, retrospective cohort study. The diagnostic accuracy of the artificial intelligence platform was assessed by sensitivity, specificity, negative predictive value, the area under the receiver curve, precision curve, F1 score, and Matthews correlation coefficient. Moreover, calibration curve, decision curve analysis, and clinical impact curve analysis were used to assess the clinical utility of the artificial intelligence platform. The accuracy of the artificial intelligence platform was also compared to that of CT scanning. RESULTS: Two data sets were used to assess the artificial intelligence platform: a multicenter real data set (n = 2,579) and a well-qualified synthetic data set (n = 9736). The platform showed a sensitivity of 92.2%, specificity of 97.2%, and negative predictive value of 98.7%. The artificial intelligence had good area under the receiver curve, precision, F1 score, and Matthews correlation coefficient (0.97, 86.7, 0.89, 0.88, respectively). Compared to CT scanning, the artificial intelligence platform had a better area under the receiver curve (0.92 vs 0.76), specificity (90.9 vs 53.3), precision (99.8 vs 98.9), and Matthews correlation coefficient (0.77 vs 0.72), comparable sensitivity (99.2 vs 100), and lower negative predictive value (67.6 vs 99.5). Decision curve analysis and clinical impact curve analysis intuitively revealed that the platform had a substantial net benefit within a realistic probability range from 6% to 96%. CONCLUSION: The current artificial intelligence platform had excellent sensitivity, specificity, and accuracy exceeding 90% and may help clinicians in decision making on patients with suspected acute appendicitis, particularly when access to CT scanning is limited.

Predictors of nodal positivity in clinically under-staged patients with colon cancer: A National Cancer Database study and proposal of a predictive scoring system.

BACKGROUND: Colon cancer pathological and clinical staging may be disoncordant. This study assessed patients with colon cancer in whom the nodal status was clinically understaged. METHODS: Patients with stage I-III clinical node-negative colon cancer from the National Cancer Database were included. Regression analyses were conducted to elucidate risk factors for clinical nodal understaging and a scoring system was developed to identify high-risk patients. RESULTS: The study included 94,945 patients with 78.4 â€‹% of patients correctly staged and 21.6 â€‹% clinically understaged. The predictors of nodal positivity in clinically understaged patients were age <65 (OR 1.43), left-sided tumors (OR 1.41), elevated CEA (OR 2.03), moderately (OR 1.81) or poorly/undifferentiated tumors (OR 3.76), T1 tumors (OR 1.29), signet-ring cell histology (OR 2.26), and microsatellite-stable tumors (OR 1.4). CONCLUSION: Patients with colon cancer and the above factors are more likely to have their nodal status clinically understaged. A scoring system has been developed to identify high-risk patients.

Predictors of lymph node metastasis and survival in radically resected rectal neuroendocrine tumors: A Surveillance, Epidemiology, and End Results (SEER) database analysis.

BACKGROUND: Rectal neuroendocrine tumors are uncommon tumor types. Lymph node metastases may occur in up to 40%, potentially impacting decision-making. We aimed to assess risk factors for lymph node metastases of rectal neuroendocrine tumors and their association with overall and cancer-specific survival. METHODS: This retrospective case-control study involved patients with stage I to III rectal neuroendocrine tumors who underwent radical resection. Data were derived from the Surveillance, Epidemiology, and End Results database (2000-2020). Patients with pathologic evidence of lymph node metastases were compared to those without lymph node metastases for baseline patient and tumor characteristics. The main outcomes were lymph node metastases, overall survival, and cancer-specific survival. RESULTS: In total, 580 patients (50.9% male; mean age: 58.9 years) were included. The lymph node metastases rate was 37.1%. Independent predictors of lymph node metastases were Grade 2 neuroendocrine tumors (odds ratio: 8.06; P = .001), neuroendocrine carcinoma (odds ratio: 2.59, P = .006), large-cell neuroendocrine carcinoma (odds ratio: 4.89; P = .017), T2 tumors (odds ratio: 6.44; P < .001), T3 tumors (odds ratio: 27.5; P < .001), and T4 tumors (odds ratio: 17.3; P < .001). Lymph node metastases were associated with shorter restricted mean overall survival (40.8 vs 52.7 months; P < .001) and cancer-specific survival (41.3 vs 54.8 months; P < .001). When adjusted for other confounders, the nodal status of rectal neuroendocrine tumors was not independently associated with overall (hazard ratio = 1.56; P = .165) or cancer-specific survival (hazard ratio = 1.69; P = .158). Significant factors associated with worse overall survival and cancer-specific survival were age, tumor size, neuroendocrine carcinomas, large-cell neuroendocrine carcinomas, and the number of positive lymph nodes. CONCLUSIONS: Lymph node metastases of rectal neuroendocrine tumors were more likely associated with high-grade, large-sized, and T2 to T4 tumors. The number of involved lymph nodes was an independent predictor of overall and cancer-specific survival. Other independent survival predictors were tumor grade, size, and T stage.

Effect of neoadjuvant therapy regimens on lymph nodes yield in rectal cancer.

BACKGROUND AND OBJECTIVES: Pathological nodal staging is relevant to postoperative decision-making and a prognostic marker of cancer survival. This study aimed to assess the effect of different total neoadjuvant therapy (TNT) regimens on lymph node status following total mesorectal excision (TME) for locally advanced rectal cancer (LARC). METHODS: A retrospective cohort study of patients treated for node-positive clinical stage 3 LARC with TNT between January 2015 and August 2022. Patients were stratified into induction therapy and consolidation therapy groups. Variables collated included patient demographics, clinical and radiological characteristics of the tumor, and pathology of the resected specimen. Primary outcome was total harvested lymph nodes. RESULTS: Ninety-seven patients were included (57 [58.8%] males; mean age of 58.5 ± 11.4 years). The induction therapy group included 85 (87.6%) patients while 12 (12.4%) patients received consolidation therapy. A median interquartile range value of 22.00 (5.00-72.00) harvested lymph nodes was recorded for the induction therapy group in comparison to 16.00 (16.00-47.00) in the consolidation therapy arm (p = 0.487). Overall pathological complete response rate was 34%. CONCLUSION: Total harvested nodes from resected specimens were marginally lower in the consolidation therapy group. Induction therapy may be preferrable to optimize postoperative specimen staging.

Splenic flexure mobilization in left-sided colonic and rectal resections: A meta-analysis and meta-regression of factors associated with anastomotic leak and complications.

AIM: Splenic flexure mobilization (SFM) is commonly performed during left-sided colon and rectal resections. The aim of the present systematic review was to assess the outcomes of SFM in left-sided colon and rectal resections and the risk factors for complications and anastomotic leak (AL). METHOD: This study was a PRISMA-compliant systematic review. PubMed, Scopus and Web of Science were searched for studies that assessed the outcomes of sigmoid and rectal resections with or without SFM. The primary outcomes were AL and total complications, and the secondary outcomes were individual complications, operating time, conversion to open surgery, length of hospital stay (LOS) and pathological and oncological outcomes. RESULTS: Nineteen studies including data on 81 116 patients (49.1% male) were reviewed. SFM was undertaken in 40.7% of patients. SFM was associated with a longer operating time (weighted mean difference 24.50, 95% CI 14.47-34.52, p < 0.0001) and higher odds of AL (OR 1.19, 95% CI 1.06-1.33, p = 0.002). Both groups had similar odds of total complications, splenic injury, anastomotic stricture, conversion to open surgery, (LOS), local recurrence, and overall survival. A secondary analysis of rectal cancer cases only showed similar outcomes for SFM and the control group. CONCLUSIONS: SFM was associated with a longer operating time and higher odds of AL, yet a similar likelihood of total complications, splenic injury, anastomotic stricture, conversion to open surgery, LOS, local recurrence, and overall survival. These conclusions must be cautiously interpreted considering the numerous study limitations. SFM may have only been selectively undertaken in cases in which anastomotic tension was suspected. Therefore, the suboptimal anastomoses may have been the reason for SFM rather than the SFM being causative of the anastomotic insufficiencies.

Obesity and overweight are associated with worse survival in early-onset colorectal cancer.

BACKGROUND: Obesity and its associated lifestyle are known risk factors for early-onset colorectal cancer and are associated with poor postoperative and survival outcomes in older patients. We aimed to investigate the impact of obesity on the outcomes of early-onset colorectal cancers. METHODS: Retrospective review of all patients undergoing primary resection of colon or rectal adenocarcinoma at our institution between 2015-2022. Patients who had palliative resections, resections performed at another institution, appendiceal tumors, and were underweight were excluded. The primary endpoint was survival according to the patient's body mass index: normal weight (18-24.9 kg/m2), overweight (25-29.9 kg/m2), and obesity (≥30 kg/m2). Patient and tumor characteristics and survival were compared between the three groups. RESULTS: A total of 279 patients aged <50 years with colorectal cancer were treated at our hospital; 120 were excluded from the analysis for the following reasons: main treatment or primary resection performed at another hospital (n = 97), no resection/palliative resection (n = 23), or body mass index <18 kg/m2 (n = 2). Of these, 157 patients were included in the analysis; 61 (38.9%) were overweight and 45 (28.7%) had obesity. Except for a higher frequency of hypertension in the overweight (P = .062) and obese (P = .001) groups, no differences in patient or tumor characteristics were observed. Mean overall survival was 89 months with normal weight, 92 months with overweight, and 65 months with obesity (P = .032). Mean cancer-specific survival was 95 months with normal weight, 94 months with overweight, and 68 months with obesity (P = .018). No statistically significant difference in disease-free survival (75 vs 70 vs 59 months, P = .844) was seen. CONCLUSION: Individuals with early-onset colorectal cancer who are overweight or obese present with similar tumor characteristics and postoperative morbidity to patients with normal weight. However, obesity may have a detrimental impact on their survival. Addressing obesity as a modifiable risk factor might improve early-onset colorectal cancer prognosis.

Local vs radical resection of stage I-III rectal cancer in very elderly patients: an exact matched analysis of the National Cancer Database.

BACKGROUND: Treatment of elderly patients with cancer is challenging as they can be overtreated with respect to frailty or undertreated because of advanced age. Maintaining a good quality of life is essential for this population. This study aimed to assess the difference in overall survival and short-term outcomes according to the extent of rectal cancer resection in patients aged ≥80 years. METHODS: In this retrospective cohort study, very elderly patients with stage I-III rectal cancer aged ≥80 years were identified from the National Cancer Database (2004-2019). Patients were divided into 2 groups: radical resection and local excision. The groups were matched using exact matched analysis for clinical T and N stage, tumor size, and neoadjuvant treatment. The main outcome measures were overall survival, hospital stay, 30-day unplanned readmissions, and short-term mortality. RESULTS: A total of 9634 patients were included (local excision = 2710; radical resection = 6924). After matching, 1106 patients were included in each group with a median follow-up of 49.9 and 51.7 months, respectively. The radical resection group had statistically significantly longer overall survival than did the local excision group (60 vs 57.2 months, P = .026). Local excision was associated with shorter length of stay (1 vs 7 days. P < .001), lower 30-day mortality (odds ratio: 0.43; 95% CI: 0.25-0.75, P = .003), lower 90-day mortality (odds ratio: 0.47, 95% CI: 0.32-0.68, P < .001), and lower 30-day readmission (odds ratio: 0.49, 95% CI: 0.33-0.74, P < .001). A subgroup analysis of matched patients with cTis-T2 and N0 tumors who underwent curative surgery revealed similar results. CONCLUSION: Radical resection of rectal cancer in very elderly patients has a modest survival benefit, whereas local excision has lower odds of readmission and short-term mortality.

Association between the expression of epithelial-mesenchymal transition (EMT)-related markers and oncologic outcomes of colorectal cancer.

BACKGROUND: Epithelial-mesenchymal transition (EMT) is a key step in the development of colorectal cancer (CRC) that confers metastatic capabilities to cancer cells. The present study aimed to assess the immunohistochemical (IHC) expression and impact of EMT markers, including E-cadherin, Vimentin, ß-catenin, and SMAD4, on the oncologic outcomes of CRC. METHODS: This was a retrospective review of 118 CRC patients. Tissue slides were retrieved from the slide archive and five tissue microarray construction blocks were constructed. IHC for E-cadherin, Vimentin, ß-catenin, and SMAD4 was done. The main outcome was the association between abnormal marker expression and overall survival (OS), and disease-free survival (DFS). RESULTS: Adenocarcinomas accounted for 71.2% of tumors, whereas 25.4% and 3.4% were mucinous and signet ring cell carcinomas. The rates of lymphovascular invasion and perineural invasion were 72.9% and 20.3%, respectively. There was a positive, significant correlation, and association between the four markers. Abnormal expression of E-cadherin was associated with significantly lower OS (p < 0.0001) and similar DFS (p = 0.06). Abnormal Vimentin expression was associated with a significantly higher rate of distant metastasis (p = 0.005) and significantly lower OS and DFS (p < 0.0001). Abnormal expression of ß-catenin was associated with significantly lower OS (p < 0.0001) and similar DFS (p = 0.15). Abnormal expression of SMAD4 was associated with significantly lower OS and DFS (p < 0.0001). Abnormal expression of all four markers was associated with a higher disease recurrence, lower OS, and lower DFS. CONCLUSION: Abnormal expression of each marker was associated with lower OS, whereas abnormal expression of Vimentin and SMAD4 only was associated with lower DFS.

Characteristics and outcomes of large (≥5 cm) colonic adenocarcinomas and comparing outcomes of minimally invasive and open surgery for stage I to III disease.

BACKGROUND: Colon cancer prognosis is primarily dependent on the stage at diagnosis, but tumor size and location may also impact prognosis. This study aimed to assess the characteristics and outcomes of patients with ≥5 cm colonic adenocarcinomas and compare outcomes of open and minimally invasive surgery for stage I to III large colonic adenocarcinomas. METHODS: The National Cancer Database (2010-2019) was searched for patients with colonic adenocarcinomas ≥5 cm. Outcomes of patients who underwent minimally invasive surgery or open surgery were compared after propensity-score matching. The primary outcome was 5-year overall survival and, secondarily, hospital stay, surgical margins, and short-term mortality. RESULTS: A total of 126,959 patients were included (22.1% of all diagnosed adenocarcinomas). 56% of tumors were right-sided, 32.6% were left-sided, and 11.4% were in the transverse colon. Stage IV disease was recorded in 34.6% of patients. Lymphovascular invasion, perineural invasion, and Kirsten rat sarcoma viral oncogene homolog mutations were recorded in 35.7%, 14.9%, and 41.6% of patients. The rate of positive surgical margins was 9.8%. Median hospital stay was 6 (interquartile range: 4-8) days. 30- and 90-day mortality rates were 4.1% and 7.5%, respectively. After matching, 15,228 patients in the open surgery group were matched to a similar number in the minimally invasive surgery group. The minimally invasive surgery group was associated with significantly lower rates of 30- and 90-day mortality, positive surgical margins, shorter hospital stay, and longer median overall survival (110.6 vs 86.6 months, P < .001) than did open surgery. CONCLUSION: Large colonic adenocarcinomas are mostly right-sided or transverse and present at a more advanced stage with adverse pathologic features. Minimally invasive surgery was associated with better overall survival and short-term benefits when compared with open surgery.

Upfront laparotomy versus conversion from minimally invasive surgery to open surgery in colon cancer: Is there a difference in outcomes?

BACKGROUND: It is unclear whether conversion from minimally invasive surgery to laparotomy in patients with colon cancer contributes to worse outcomes compared with those operated by laparotomy. In this study, we aimed to assess the implications of transitioning from minimally invasive surgery to laparotomy in patients with colon cancer compared with patients undergoing upfront laparotomy. METHODS: A retrospective analysis of the National Cancer Database, including patients with stages I to III colon cancer (2010-2019). Patients who underwent either upfront laparotomy (Open Surgery Group) or minimally invasive surgery converted to open surgery (Converted Surgery Group) were included. Groups were balanced using propensity-score matching. Primary outcome was overall survival, and secondary outcomes included 30- and 90-day mortality and 30-day readmission rates. RESULTS: The study included 65,083 operated patients with stage I to III colon cancer; 57,091 patients (87.7%) were included in the Open Surgery group and 7,992 (12.3%) in the Converted Surgery group. 93.5% were converted from laparoscopy, and 6.5% were converted from robotic surgery. After propensity-score matching, 7,058 patients were included in each group. Median overall survival was significantly higher in the Converted Surgery group (107.3 months) than in the Open Surgery group (101.5 months; P = .006). A survival benefit was seen in patients >65 years of age (79.5 vs 71.9 months; P = .001), left-sided disease (129.4 vs 114.5 months; P < .001), and with a high Charlson comorbidity index score (=3; 58.9 vs 42.3 months; P = .03). Positive margin rates were similar between the groups (6.3% vs 5.6%; P = .07). Converted patients had a higher 30-day readmission rate (6.7% vs 5.6%, P = .006) and shorter duration of stay (median, 5 vs 6 days, P < .001) than patients in the Open Surgery group. In addition, 30-day mortality was comparable between the groups (2.9% vs 3.5%; P = .07). CONCLUSION: Conversion to open surgery from minimally invasive surgery was associated with better overall survival compared with upfront open surgery. A survival benefit was mainly seen in patients >65 years of age, with significant comorbidities, and with left-sided tumors. We believe these data suggest that, in the absence of an absolute contraindication to minimally invasive surgery, it should be the preferred approach in patients with colon cancer.

Propensity-score matched outcomes of resection of stage IV primary colon cancer with and without simultaneous resection of liver metastases.

There is controversy in the best management of colorectal cancer liver metastasis (CLM). This study aimed to compare short-term and survival outcomes of simultaneous resection of CLM and primary colon cancer compared to resection of only colon cancer. This retrospective matched cohort study included patients from the National Cancer Database (2015-2019) with stage IV colon adenocarcinoma and synchronous liver metastases who underwent colectomy. Patients were divided into two groups: colectomy-only (resection of primary colon cancer only) and colectomy-plus (simultaneous resection of primary colon cancer and liver metastases). The groups were matched using the propensity score method. The primary outcome was short-term mortality and readmission. Secondary outcomes were conversion, hospital stay, surgical margins, and overall survival. 4082 (37.6%) of 10,862 patients underwent simultaneous resection of primary colon cancer and liver metastases. After matching, 2038 patients were included in each group. There were no significant differences between the groups in 30-days mortality (3.1% vs 3.8%, p = 0.301), 90-days (6.6% vs 7.7%, p = 0.205) mortality, 30-days unplanned readmission (7.2% vs 5.3%, p = 0.020), or conversion to open surgery (15.5% vs. 13.8%, p = 0.298). Patients in the colectomy plus group had a higher rate of lower incidence of positive surgical margins (13.2% vs. 17.2%, p = 0.001) and longer overall survival (median: 41.5 vs 28.4 months, p < 0.001). Synchronous resection of CLM did not increase the rates of short-term mortality, readmission, conversion from minimally invasive to open surgery, or hospital stay and was associated with a lower incidence of positive surgical margins.