Clinical Decision Making in Inflammatory Bowel Disease Mimics: Practice Management from Inflammatory Bowel Disease LIVE.

Background: Since 2009, inflammatory bowel disease (IBD) specialists have utilized "IBD LIVE," a weekly live video conference with a global audience, to discuss the multidisciplinary management of their most challenging cases. While most cases presented were confirmed IBD, a substantial number were diseases that mimic IBD. We have categorized all IBD LIVE cases and identified "IBD-mimics" with consequent clinical management implications. Methods: Cases have been recorded/archived since May 2018; we reviewed all 371 cases from May 2018-February 2023. IBD-mimics were analyzed/categorized according to their diagnostic and therapeutic workup. Results: Confirmed IBD cases made up 82.5% (306/371; 193 Crohn's disease, 107 ulcerative colitis, and 6 IBD-unclassified). Sixty-five (17.5%) cases were found to be mimics, most commonly medication-induced (n = 8) or vasculitis (n = 7). The evaluations that ultimately resulted in correct diagnosis included additional endoscopic biopsies (n = 13, 21%), surgical exploration/pathology (n = 10, 16.5%), biopsies from outside the GI tract (n = 10, 16.5%), genetic/laboratory testing (n = 8, 13%), extensive review of patient history (n = 8, 13%), imaging (n = 5, 8%), balloon enteroscopy (n = 5, 8%), and capsule endoscopy (n = 2, 3%). Twenty-five patients (25/65, 38%) were treated with biologics for presumed IBD, 5 of whom subsequently experienced adverse events requiring discontinuation of the biologic. Many patients were prescribed steroids, azathioprine, mercaptopurine, or methotrexate, and 3 were trialed on tofacitinib. Conclusions: The diverse presentation of IBD and IBD-mimics necessitates periodic consideration of the differential diagnosis, and reassessment of treatment in presumed IBD patients without appropriate clinical response. The substantial differences and often conflicting treatment approaches to IBD versus IBD-mimics directly impact the quality and cost of patient care.

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.

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.

Oncologic outcomes following transanal total mesorectal excision: the United States experience.

AIM: The benefits and short-term outcomes of transanal total mesorectal excision (taTME) for rectal cancer have been demonstrated previously, but questions remain regarding the oncologic outcomes following this challenging procedure. The purpose of this study was to analyze the oncologic outcomes following taTME at high-volume centers in the USA. METHODS: This was a multicenter, retrospective observational study of 8 tertiary care centers. All consecutive taTME cases for primary rectal cancer performed between 2011 and 2020 were included. Clinical, histopathologic, and oncologic data were analyzed. Primary endpoints were rate of local recurrence, distal recurrence, 3-year disease recurrence, and 3-year overall survival. Secondary endpoints included perioperative complications and TME specimen quality. RESULTS: A total of 391 patients were included in the study. The median age was 57 years (IQR: 49, 66), 68% of patients were male, and the median BMI was 27.4 (IQR: 24.1, 31.0). TME specimen was complete or near complete in 94.5% of cases and the rates of positive circumferential radial margin and distal resection margin were 2.0% and 0.3%, respectively. Median follow-up time was 30.7 months as calculated using reverse-KM estimator (CI 28.1-33.8) and there were 9 cases (2.5%) of local recurrence not accounting for competing risk. The 3-year estimated rate of disease recurrence was 19% (CI 15-25%) and the 3-year estimated overall survival was 90% (CI 87-94%). CONCLUSION: This large multicenter study confirms the oncologic safety and perioperative benefits of taTME for rectal cancer when performed by experienced surgeons at experienced referral centers.

Immunotherapy in Stage III-IV Colon Cancer: A Propensity Score-Matched Analysis of the National Cancer Database.

SUMMARY: Immunotherapy for the systemic treatment of cancer offers new treatment possibilities for advanced malignancies. Despite promising initial results, evidence on efficacy of immunotherapy for colon cancer is lacking. Thus, we aimed to assess short-term and long-term outcomes of immunotherapy in patients with advanced colon cancer. A US National Cancer Database was searched for patients with stage III-IV colonic adenocarcinoma between 2010 and 2019. Propensity score matching was used to classify the cohort into 2 groups: patients who received immunotherapy and controls. Main outcome measures were primary outcome was overall survival (OS). A total of 23,778 patients with stage III-IV colonic adenocarcinoma were treated with immunotherapy during the study period compared to 114,753 controls. Immunotherapy treated patients were younger (median age 61 vs. 67 y; P<0.001), more often male (57.3% vs. 50.7%, P<0.001), had more private insurance (44.1% vs. 33.7%; P<0.001), had more left-sided tumors (49.5% vs. 39.1%; P<0.001) and liver metastasis (80.2% vs. 61.7%; P<0.001) than controls. Immunotherapy patients received more standard chemotherapy (49.8% vs. 41.6%; P<0.001). After propensity-score matching, mean OS was significantly shorter in the immunotherapy group compared with controls (34.7 vs. 36.2 mo; P=0.008). Cox regression analysis demonstrated that immunotherapy was associated with increased risk for mortality (HR: 1.1; 95% CI: 1.02-1.18; P=0.005). Patients who received immunotherapy had lower 90-day mortality rates compared with controls (2.3% vs. 3.6%; P=0.004), but the groups had equivalent 30-day mortality rates (0.7% vs. 0.8%; P=0.76). Immunotherapy showed no improvement in OS in patients with stage III-IV colon cancer.

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.

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.

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.

Association between microsatellite status and characteristics and outcomes of early-onset compared to late-onset rectal cancer.

BACKGROUND: Microsatellite instability (MSI) is an important prognosticator for colorectal cancer (CRC). The present study aimed to assess the impact of MSI status on the characteristics and outcomes of early-onset compared to late-onset rectal cancer. METHODS: This retrospective cohort study used data from the US National Cancer Database (2004-2019) to assess the baseline characteristics, treatment patterns, short-term outcomes, and overall survival (OS) of early-onset rectal adenocarcinoma affecting patients < 50 years compared to late-onset rectal adenocarcinoma according to the MSI status. RESULTS: The present study included 48,407 patients (59.9% male) with rectal cancer, 17.3% of patients were < 50 years and 6.3% had MSI-H tumors. In the early-onset group, patients with MSI-H tumors had a lower mean age (41.5 vs 43 years, p < 0.001) and presented less often with stage IV disease (22.1% vs 17.7%, p = 0.03) and liver metastasis (9.1% vs 13.5%, p = 0.011) than patients with MSS tumors. In the late-onset group, patients with MSI-H and MSS tumors had similar demographics, disease stage, and metastatic pattern, yet MSI-H patients more often received neoadjuvant radiation therapy (58.9% vs 55.1%, p = 0.009) and neoadjuvant systemic therapy (40% vs 36.2%, p = 0.005). In both age groups, MSI-H tumors were associated with more pathologic T3-4 stage and were more likely mucinous and poorly differentiated carcinomas than MSS tumors. The median OS of MSI-H tumors was similar to MSS tumors (108.09 vs 102.31 months, p = 0.1), whether in the early-onset (139.5 vs 134.2 months, p = 0.821) or late-onset groups (106.1 vs 104.3 months, p = 0.236). CONCLUSIONS: In both age groups, MSI-H rectal cancers were more often mucinous and poorly differentiated carcinomas and had pT3-4 stage more often than MSS cancers. MSI-H rectal cancers tend to present less often with distant metastases and nodal involvement than MSS cancers only in early-onset, but not in late-onset rectal cancers. The association between MSI status and survival was not notable in this study, whether in the early-onset or late-onset groups.

A national database analysis of the evolution of outcomes of surgery for anal melanoma.

BACKGROUND: This study assessed trends in treatment and outcomes of anal melanomas over a 17-year period. METHODS: NCDB was searched for patients with anal melanoma (2004-2020). Receiver-operating characteristic curve analysis was used to determine cutoff year marking increased overall survival (OS) of anal melanoma. Characteristics, treatments, and outcomes in consecutive time periods were compared. RESULTS: A total of 815 patients (mean age: 67.2 years; 59.4% female) were included: 354 in Period 1 (2004-2012) and 461 in Period 2 (2013-2020). Period 2 included fewer abdominoperineal resections (18% vs. 28%, p = 0.002), more local tumor excisions (61.1% vs. 55%, p = 0.002), more often immunotherapy (odds ratio [OR]: 3.41, 95% confidence interval [CI]: 2.22-5.22, p < 0.001) and less often chemotherapy (OR: 0.516, 95% CI: 0.352-0.755, p < 0.001) administered and longer median OS (25.2 vs. 19.8 months, p = 0.006). Independent predictors of worse OS were older age (hazard ratio [HR]: 1.02, p = 0.012), higher Charlson score (HR: 2.32, p = 0.02), and greater number of positive lymph nodes (HR: 1.15, p < 0.001); conversely private insurance (HR: 0.385, p = 0.008) was predictive of increased OS. CONCLUSIONS: Anal melanoma patients diagnosed between 2013 and 2020 underwent fewer abdominoperineal resections and more local excisions than patients diagnosed between 2004 and 2013. Increased immunotherapy and longer median OS were noted in period two. Age and private insurance were significant predictors of OS, remaining constant across time periods.

Trends in management and outcomes of colon cancer in the United States over 15 years: Analysis of the National Cancer Database.

Management of colon cancer has changed over the last few decades. We assessed the trends in management and outcomes using the US National Cancer Database (NCDB). A retrospective analysis of all patients with colonic adenocarcinoma between 2005 and 2019 was conducted. The cohort was divided into three equal time periods: Period 1 (2005-2009), Period 2 (2010-2014), and Period 3 (2015-2019) to examine treatment and outcomes trends. The primary outcome was 5-year overall survival (OS). The study included 923,275 patients. A significant increase in patients with stage IV disease was noted in Period 3 compared to Period 1 (47.9% vs. 27.9%, respectively), whereas a reciprocal reduction was seen in patients with locally advanced disease (stage II: 20.8%-12%; stage III: 14.5%-7.7%). Use of immunotherapy significantly increased from 0.3% to 7.6%. Mean 5-year OS increased (43.6 vs. 42.1 months) despite the increase in metastatic disease and longer time from diagnosis to definitive surgery (7 vs. 14 days). A reduction in 30-day readmission (5.1%-4.2%), 30- (3.9%-2.8%), and 90-day mortality (7.1%-5%) was seen. Laparoscopic and robotic surgery increased from 45.8% to 53.1% and 2.9% to 12.7%, respectively. Median postoperative length of hospital stay decreased by 2 days. Rate of positive resection margins (7.2%-6%) and median number of examined lymph nodes (14-16) also improved. Minimally invasive surgery and immunotherapy for colon cancer significantly increased in recent years. Patient outcomes including OS improved over time.

Colonic Diverticulosis at Colonoscopy in Africa: A Systematic Review and Meta-Analysis of Pooled Estimates.

INTRODUCTION: There is need to ascertain any epidemiologic shift of diverticulosis among Africans with traditionally high fiber diet consumption patterns and rare diverticulosis prevalence. METHODS: We systematically searched PubMed, Scopus, Cochrane Library, African Journal Online (AJOL), and Google Scholar. Eligibility criteria included full-text observational and experimental human colonoscopy studies on asymptomatic and symptomatic African population from 1985 to 2022. Case reports, conference abstracts, dissertations, systematic reviews, and studies lacking colonoscopy findings were excluded. NIH quality assessment tool for observational cohort and cross-sectional studies was used to assess risk of bias. Meta-analysis was performed using the random-effect model. Heterogeneity was assessed using inconsistency (I2) statistics. RESULTS: Thirty studies were included. Pooled prevalence rate of colonic diverticulosis in the last decade (2012-2022) has increased to 9.7% (95% CI 6.5-13.4; I2 = 97.3%) from 3.5% (95% CI 1.4-6.4; I2 = 62.7%). The highest regional prevalence rate was in West African studies at 11.3% (95% CI 7.6-14.9; I2 = 96.2%). Proportion of individuals with diverticulosis ≥50 years and male sex were 86.9% (95% CI 80.5-92.1) and 65.2% (95% CI 55.0-74.8), respectively. The left colon had the highest diverticulosis frequency (37% [148/400]). Bleeding/inflammation complications were sparingly detected (OR 0.2 [95% CI 0.03-0.75; p < 0.0001]). CONCLUSION: An increasing utilization of colonoscopy revealed approximately a threefold increase in the prevalence rate of colonic diverticulosis in Africa. This pathology was most common in males aged >50. Left colon was predominantly affected. Further studies are needed to demonstrate the effect of westernization of diet.

Ostomy continence devices: a systematic review of the literature and meta-analysis.

AIM: Colostomy complication rates range widely from 10% to 70%. The psychological burden on patients, leading to lifestyle changes and decreased quality of life (QoL), is one of the largest factors. The aim of this work was to assess the history and efficacy of ostomy continence devices in improving continence and QoL. METHOD: In this PRISMA-compliant systematic review and meta-analysis, we searched PubMed, Scopus, Google Scholar and clinicaltrials.gov for studies on continence devices for all ostomies up to April 2023. Primary outcomes were continence and improvement in QoL. Secondary outcomes were leakage, patient's device preference and complications. Risk of Bias 2 and the revised tool to assess risk of bias in non-randomized studies of interventions (ROBINS-1) were used to assess risk of bias. Certainty of evidence was graded using GRADE. RESULTS: Twenty-two studies assessed devices from 1978 to 2022. The two main types identified were ball-valve devices and plug systems. Conseal and Vitala were the two main devices with significant evidence allowing for pooled analyses. Conseal, the only currently marketed device, had a pooled rate of continence of 67.4%, QoL improvement was 74.9%, patient preference over a traditional appliance was 69.1%, leakage was 10.1% and complications was 13.7%. Since 2011, five studies have investigated experimental devices on both human and animal models. CONCLUSION: Ostomy continence has been a long-standing goal without a consistently reliable solution. We propose that selective and short-term usage of continence devices may lead to improved continence and QoL in ostomy patients. Further research is needed to develop a reliable daily device for ostomy continence. Future investigation should include the needs of ileostomates.

A Propensity Score-Matched Analysis of the Impact of Neoadjuvant Radiation Therapy on the Outcomes of Stage II and III Mucinous Rectal Carcinoma.

BACKGROUND: Patients with mucinous rectal carcinoma tend to present in advanced stage with a poor prognosis. OBJECTIVE: This study aimed to assess the effect of neoadjuvant radiation therapy on outcomes of patients with stage II and III mucinous rectal carcinomas using data from the National Cancer Database. DESIGN: Retrospective analysis of prospective national databases. SETTING: National Cancer Database between 2004 and 2019. PATIENTS: Patients with mucinous rectal carcinoma. INTERVENTION: Patients who did or did not receive neoadjuvant radiation therapy were matched using the nearest-neighbor propensity score method for age, clinical stage, neoadjuvant systemic treatment, and surgery type. MAIN OUTCOME MEASURES: Main outcomes of the study were numbers of total harvested and positive lymph nodes, disease downstaging after neoadjuvant radiation, and overall survival. Other outcomes were hospital stay, short-term mortality, and readmission. RESULTS: A total of 3062 patients (63.5% men) with stage II and III mucinous rectal carcinoma were included, 2378 of whom (77.7%) received neoadjuvant radiation therapy. After 2:1 propensity score matching, 143 patients in the no neoadjuvant group were matched to 286 patients in the neoadjuvant group. The mean overall survival was similar (77.3 vs 81.9 months; p = 0.316). Patients who received neoadjuvant radiation therapy were less often diagnosed with pathologic T3 and 4 disease (72.3% vs 81.3%, p = 0.013) and more often had pathologic stage 0 and 1 disease (16.4% vs 11.2%, p = 0.001), yet with a higher stage III disease (49.7% vs 37.1%, p = 0.001). Neoadjuvant radiation was associated with fewer examined lymph nodes (median: 14 vs 16, p = 0.036) and positive lymph nodes than patients who did not receive neoadjuvant radiation. Short-term mortality, readmission, hospital stay, and positive surgical margins were similar. LIMITATIONS: Retrospective study and missing data on disease recurrence. CONCLUSIONS: Patients with mucinous rectal carcinoma who received neoadjuvant radiation therapy had marginal downstaging of disease, fewer examined and fewer positive lymph nodes, and similar overall survival to patients who did not receive neoadjuvant radiation. See Video Abstract . UN ANLISIS EMPAREJADO POR PUNTUACIN DE PROPENSIN DEL IMPACTO DE LA RADIOTERAPIA NEOADYUVANTE EN LOS RESULTADOS DEL CARCINOMA MUCINOSO DE RECTO EN ESTADIO IIIII: ANTECEDENTES:Los pacientes con carcinoma mucinoso de recto tienden a presentarse en estadio avanzado con mal pronóstico.OBJETIVO:Este estudio tuvo como objetivo evaluar el efecto de la radioterapia neoadyuvante en los resultados de pacientes con carcinomas mucinosos de recto en estadio II-III utilizando datos de la Base de Datos Nacional del Cáncer.DISEÑO:Análisis retrospectivo de bases de datos nacionales prospectivas.PACIENTES:Pacientes con carcinoma mucinoso de recto.AJUSTE:Base de datos nacional sobre el cáncer entre 2004 y 2019.INTERVENCIÓN:Los pacientes que recibieron o no radioterapia neoadyuvante fueron emparejados utilizando el método de puntuación de propensión del vecino más cercano por edad, estadio clínico, tratamiento sistémico neoadyuvante y tipo de cirugía.PRINCIPALES MEDIDAS DE VALORACIÓN:Los principales resultados del estudio fueron el número total de ganglios linfáticos extraídos y positivos, la reducción del estadio de la enfermedad después de la radiación neoadyuvante y la supervivencia general. Otros resultados fueron la estancia hospitalaria, la mortalidad a corto plazo y el reingreso.RESULTADOS:Se incluyeron 3.062 pacientes (63,5% hombres) con carcinoma mucinoso de recto estadio II-III, de los cuales 2.378 (77,7%) recibieron radioterapia neoadyuvante. Después de un emparejamiento por puntuación de propensión 2:1, 143 pacientes del grupo sin neoadyuvancia fueron emparejados con 286 del grupo neoadyuvante. La supervivencia global media fue similar (77,3 vs 81,9 meses; p = 0,316). A los pacientes que recibieron radiación neoadyuvante se les diagnosticó con menos frecuencia enfermedad pT3-4 (72,3% frente a 81,3%, p = 0,013) y con mayor frecuencia tenían enfermedad en estadio patológico 0-1 (16,4% frente a 11,2%, p = 0,001), aunque con una enfermedad en estadio III superior (49,7% vs 37,1%, p = 0,001). La radiación neoadyuvante se asoció con menos ganglios linfáticos examinados (mediana: 14 frente a 16, p = 0,036) y ganglios linfáticos positivos que los pacientes que no recibieron radiación neoadyuvante. La mortalidad a corto plazo, el reingreso, la estancia hospitalaria y los márgenes quirúrgicos positivos fueron similares.LIMITACIONES:Estudio retrospectivo y datos faltantes sobre recurrencia de la enfermedad.CONCLUSIONES:Los pacientes con carcinoma mucinoso de recto que recibieron radioterapia neoadyuvante tuvieron una reducción marginal de la enfermedad, menos ganglios linfáticos examinados y positivos, y una supervivencia general similar a la de los pacientes que no recibieron radiación neoadyuvante. (Traducción- Dr Ingrid Melo ).