Para-aortic Lymph Node Dissection for Colorectal Cancer: Predicting Pathologic Lymph Node Positivity and Optimizing Outcomes.

INTRODUCTION: In colorectal cancer, the presence of para-aortic lymph nodes (PALN) indicates extraregional disease. Appropriately selecting patients for whom PALN dissection will provide oncologic benefit remains challenging. This study identified factors to predict survival among patients undergoing PALN dissection for colorectal cancer. METHODS: An institutional database was queried for patients who underwent curative-intent resection of clinically positive PALN for colorectal cancer between 2007 and 2020. Preoperative radiologic images were reviewed, and patients who did and did not have positive PALN on final pathology were compared. Survival analysis was performed to evaluate the impact of pathologically positive PALN on recurrence-free (RFS) and overall survival (OS). RESULTS: Of 74 patients who underwent PALN dissection, 51 had PALN metastasis at the time of primary tumor diagnosis, whereas 23 had metachronous PALN disease. Preoperative chemotherapy ± radiotherapy was given in 60 cases (81.1%), and 28 (37.8%) had pathologically positive PALN. Independent factors associated with positive PALN pathology included metachronous PALN disease and pretreatment and posttreatment radiographically abnormal PALN. On multivariable analysis, pathologically positive PALN was significantly associated with decreased RFS (hazard ratio 3.90) and OS (HR 4.49). Among patients with pathologically positive PALN, well/moderately differentiated histology was associated with better OS, and metachronous disease trended toward an association with better OS. CONCLUSIONS: Pathologically positive PALN are associated with poorer RFS and OS after PALN dissection for colorectal cancer. Clinicopathologic factors may predict pathologic PALN positivity. Curative-intent surgery may provide benefit, especially in patients with well-to-moderately differentiated primary tumors and possibly metachronous PALN disease.

Total Neoadjuvant Therapy for Rectal Cancer: Which Regimens to Use?

Total neoadjuvant therapy (TNT) is a novel strategy for rectal cancer that administers both (chemo)radiotherapy and systemic chemotherapy before surgery. TNT is expected to improve treatment compliance, tumor regression, organ preservation, and oncologic outcomes. Multiple TNT regimens are currently available with various combinations of the treatments including induction or consolidation chemotherapy, triplet or doublet chemotherapy, and long-course chemoradiotherapy or short-course radiotherapy. Evidence on TNT is rapidly evolving with new data on clinical trials, and no definitive consensus has been established on which regimens to use for improving outcomes. Clinicians need to understand the advantages and limitations of the available regimens for multidisciplinary decision making. This article reviews currently available evidence on TNT for rectal cancer. A decision making flow chart is provided for tailor-made use of TNT regimens based on tumor location and local and systemic risk.

The current multidisciplinary management of rectal cancer.

Multidisciplinary management of rectal cancer has rapidly evolved over the last several years. This review describes recent data surrounding total neoadjuvant therapy, organ preservation, and management of lateral pelvic lymph nodes. It then presents our treatment algorithm for management of rectal cancer at The University of Texas MD Anderson Cancer Center in the context of this and other existing literature. As part of this discussion, the review describes how we tailor management based upon both patient and tumor-related factors in an effort to optimize patient outcomes.

Evolving survival gains in patients with young-onset colorectal cancer and synchronous resectable liver metastases.

We aimed to evaluate the practice and the associated outcomes of surgical treatment for young-onset colorectal cancer (YOCRC) patients presenting with synchronous liver metastases. The study cohort was divided into two groups according to surgery date: 131 patients in the early era (EE, 1998-2011) and 179 in the contemporary era (CE, 2012-2020). The CE had a higher rate of node-positive primary tumors, higher carcinoembryonic antigen level, and lower rate of RAS/BRAF mutations. The CE had higher rates of reverse or combined resection, multi-drug prehepatectomy chemotherapy, and two-stage hepatectomy. The median survival was 8.4 years in the CE and 4.3 years in the EE (p = 0.011). On multivariate analysis, hepatectomy in the CE was independently associated with improved overall survival (HR 0.48, p = 0.001). With a combination of perioperative systemic therapy, careful selection of treatment approach, and coordinated resections, durable cure can be achieved in YOCRC patients.

Lung surveillance following colorectal cancer pulmonary metastasectomy: Utilization of clinicopathologic risk factors to guide strategy.

BACKGROUND: Appropriately selected patients clearly benefit from resection of colorectal cancer (CRC) pulmonary metastases (PMs). However, there remains equipoise surrounding optimal chest surveillance strategies following pulmonary metastasectomy. We aimed to identify risk factors that may inform chest surveillance in this population. METHODS: Patients who underwent CRC pulmonary metastasectomy were identified from a single institution's prospectively maintained surgical database. Clinicopathologic and genomic characteristics were collected. Patients were stratified by diagnosis of subsequent PM within 6 months of the index lung resection. Multivariate modeling was used to evaluate risk factors. RESULTS: A total of 197 patients met the study's inclusion criteria, of whom 52.3% (n = 103) developed subsequent PM, at a median of 9.51 months following the index metastasectomy. Patients with KRAS alterations (odds ratio [OR], 3.073; 95% confidence interval [CI], 1.363-6.926; P = .007), TP53 alterations (OR, 3.109; 95% CI, 1.318-7.341; P = .010) were found to be at risk of PM diagnosis within 6 months of the index metastasectomy, while those with an APC alteration (OR, .218; 95% CI, 0.080-0.598; P = .003) were protected. Moreover, patients who received systemic therapy within 3 months of the initial PM diagnosis also were more likely to develop early lung recurrence (OR, 2.105; 95% CI, 0.971-4.563; P = .059). CONCLUSIONS: Patients with KRAS alterations, TP53 alterations, and no APC alterations developed early recurrence in the lung following pulmonary metastasectomy, as did those who received chemotherapy after their initial PM diagnosis. As such, these groups benefit from early lung imaging after metastasectomy, as chest surveillance protocols should be based on patient-centered clinicopathologic and genomic risk factors.

Do resected colorectal cancer patients need early chest imaging? Impact of clinicopathologic characteristics on time to development of pulmonary metastases.

BACKGROUND AND OBJECTIVES: For patients with colorectal cancer (CRC), the lung is the most common extra-abdominal site of distant metastasis. However, practices for chest imaging after colorectal resection vary widely. We aimed to identify characteristics that may indicate a need for early follow-up imaging. METHODS: We retrospectively reviewed charts of patients who underwent CRC resection, collecting clinicopathologic details and oncologic outcomes. Patients were grouped by timing of pulmonary metastases (PM) development. Analyses were performed to investigate odds ratio (OR) of PM diagnosis within 3 months of CRC resection. RESULTS: Of 1600 patients with resected CRC, 233 (14.6%) developed PM, at a median of 15.4 months following CRC resection. Univariable analyses revealed age, receipt of systemic therapy, lymph node ratio (LNR), lymphovascular and perineural invasion, and KRAS mutation as risk factors for PM. Furthermore, multivariable regression showed neoadjuvant therapy (OR: 2.99, p < 0.001), adjuvant therapy (OR: 6.28, p < 0.001), LNR (OR: 28.91, p < 0.001), and KRAS alteration (OR: 5.19, p < 0.001) to predict PM within 3 months post-resection. CONCLUSIONS: We identified clinicopathologic characteristics that predict development of PM within 3 months after primary CRC resection. Early surveillance in such patients should be emphasized to ensure timely identification and treatment of PM.

Endoscopic and imaging outcomes of PD-1 therapy in localised dMMR colorectal cancer.

BACKGROUND: Neoadjuvant immune checkpoint blockade (IO) is emerging as a therapeutic option for patients with deficient mismatch repair (dMMR) colorectal cancer (CRC) given high pathological response rates. The aim of the study was to characterise imaging and endoscopic response to IO. METHODS: A retrospective analysis of patients with localised dMMR CRC that received at least one cycle of neoadjuvant anti-PD-1 therapy was conducted. Endoscopy, imaging, and pathological outcomes were reviewed to determine response to treatment according to standardised criteria. RESULTS: Thirty-eight patients had received IO for the treatment of localised CRC (median eight cycles). Among evaluable cases (n = 31 for endoscopy and n = 34 for imaging), the best endoscopic response was complete response (CR) in 45% of cases, and the best radiographic response was CR in 23% of cases. Imaging CR rate after ≤4 cycles of IO (n = 1) was 6% compared to 44% after >4 IO cycles (n = 7). Among 28 patients with imaging and endoscopy available, a discrepancy in best response was noted in 15 (54%) cases. At a median follow-up of 28.2 months from IO start, 18 patients underwent surgical resection of which 11 (61%) had pathological CR (pCR). Despite pCR or no evidence of progression ≥6 months after completion of IO among non-operatively managed patients, 72% and 42% of patients had non-CR on imaging and endoscopy, respectively. CONCLUSIONS: Discrepancies between imaging and endoscopy are prevalent, and irregularities identified on these modalities can be identified despite pathological remission. Improved clinical response criteria are warranted.

MDT-How it is important in rectal cancer.

The concept of multidisciplinary team discussion of patient's care has been a part of routine medical practice for several decades [Monson et al. in Bull Am Coll Surg 101:45-46, 2016; NHS. Improving outcomes in colorectal cancer-the manual. (Guidance on commissioning cancer services-improving outcomes). 1997.]. The idea of bringing multiple specialties and ancillary services together to help optimize patient outcomes has been implemented in several clinical arenas from burns to physical medicine and rehabilitation to oncology. In the oncology realm, multidisciplinary tumor boards (MDTs) originated as a broad-based meeting that would permit the review and discussion of cancer patients to optimize treatment strategies [Cancer Co. Optimal Resources for Cancer Care: 2020 Standards. Chicago, IL: 2019.]. Over time, as further specialization occurred and clinical treatment algorithms have become more complex, multidisciplinary tumor boards have become more disease site specific. In this article we will discuss the importance of MDTs, specifically focusing on rectal cancer MDTs including their impact on treatment planning as well as the unique interplay of clinical specialties that provide internal quality control and improvement. Additionally, we will discuss some of the potential benefits of MDTs beyond the direct impact on patient care and review some of the challenges of implementation.

Impact of cumulative operative time on postoperative complication risk in simultaneous resections of colorectal liver metastases and primary tumors.

BACKGROUND: Simultaneous resection of colorectal liver metastases (CLM) and primary colorectal cancers (CRC) is nuanced without firm rules for selection. This study aimed to identify factors associated with morbidity after simultaneous resection. METHODS: Using a prospective database, patients undergoing simultaneous CLM-CRC resection from 1/1/2017-7/1/2020 were analyzed. Regression modeling estimated impact of colorectal resection type, Kawaguchi-Gayet (KG) hepatectomy complexity, and perioperative factors on 90-day complications. RESULTS: Overall, 120 patients underwent simultaneous CLM-CRC resection. Grade≥2 complications occurred in 38.3% (n = 46); these patients experienced longer length of stay (median LOS 7.5 vs. 4, p < 0.001) and increased readmission (39% vs. 1.4%, p < 0.001) compared to patients with zero or Grade 1 complications. Median OR time was 298 min. Patients within highest operative time quartile (>506 min) had higher grade≥2 complications (57%vs. 23%, p = 0.04) and greater than 4-fold increased odds of grade≥2 morbidity (OR 4.3, 95% CI (Confidence Interval) 1.41-13.1, p = 0.01). After adjusting for Pringle time, KG complexity and colorectal resection type, increasing operative time was associated with grade≥2 complications, especially for resections in highest quartile of operative time (OR 7.28, 95% CI 1.73-30.6, p = 0.007). CONCLUSION: In patients undergoing simultaneous CLM-CRC resection, prolonged operative time is independently associated with grade≥2 complications. Awareness of cumulative operative time may inform intraoperative decision-making by surgical teams.

Chemotherapy and Abdominal Wall Closure Technique Increase the Probability of Postoperative Ventral Incisional Hernia in Patients With Colon Cancer.

BACKGROUND: Chemotherapy is associated with postoperative ventral incisional hernia (PVIH) after right hemicolectomy (RHC) for colon cancer, and abdominal wall closure technique may affect PVIH. We sought to identify clinical predictors of PVIH. METHODS: We retrospectively analyzed patients who underwent RHC for colon cancer from 2008-2018 and later developed PVIH. Time to PVIH was analyzed with Kaplan-Meier analysis, clinical predictors were identified with multivariable Cox proportional hazards modeling, and the probability of PVIH given chemotherapy and the suture technique was estimated with Bayesian analysis. RESULTS: We identified 399 patients (209 no adjuvant chemotherapy and 190 adjuvant chemotherapy), with an overall PVIH rate of 38%. The 5-year PVIH rate was 55% for adjuvant chemotherapy, compared with 38% for none (log-rank P < .05). Adjuvant chemotherapy (hazard ratio [HR] 1.65, 95% confidence interval [CI] 1.18-2.31, P < .01), age (HR .99, 95% CI .97-1.00, P < .01), body mass index (HR 1.02, 95% CI 1.00-1.04, P < .01), and neoadjuvant chemotherapy (HR 1.92, 95% CI 1.21-3.00, P < .01) were independently associated with PVIH. Postoperative ventral incisional hernia was more common overall in patients who received adjuvant chemotherapy (46% compared with 30%, P < .01). In patients who received adjuvant chemotherapy, the probability of PVIH for incision closure with #1 running looped polydioxanone was 42%, compared with 59% for incision closure with #0 single interrupted polyglactin 910. DISCUSSION: Exposure to chemotherapy increases the probability of PVIH after RHC, and non-short stitch incision closure further increases this probability, more so than age or body mass index. The suture technique deserves further study as a modifiable factor in this high-risk population.

Germline Cancer Risk Profiles of Patients With Young-Onset Colorectal Cancer: Findings From a Prospective Universal Germline Testing and Telegenetics Program.

BACKGROUND: Colorectal cancer is being increasingly diagnosed in people younger than 50 years. An inheritable cancer predisposition has been reported in 22% of the young-onset cases. Assessment of germline risk is critical for personalized cancer care. OBJECTIVE: The study aimed to implement universal germline cancer risk assessment and testing and to define the germline cancer risk profiles of patients presenting with young-onset disease. DESIGN: This is a prospective cohort study. SETTINGS: This study was conducted at a tertiary-referral academic medical center. PATIENTS: This study included newly diagnosed patients presenting to surgical clinics between September 2019 and February 2021 who were treated on a standardized care pathway including the universal germline risk assessment. INTERVENTIONS: Patients received educational material on young-onset disease, genetic testing, and insurance coverage followed by genetic counseling (either remotely by telegenetics or in person). Consenting patients were assessed on a 47-gene common hereditary cancer panel. MAIN OUTCOME MEASURES: The primary outcome was a proportion of patients with identifiable germline cancer predisposition. RESULTS: Among 500 patients with colorectal cancer, 185 (37%) were 50 years of age or younger (median: 44). A family history was absent for the majority of patients (123; 67%), and in 15 patients, tumors (8.1%) were deficient in DNA mismatch repair. Germline testing was completed in 130 patients (70%); the remainder were pending (7%), deceased (1%), or declined (22%). Pathogenic germline mutations were identified in 25 of 130 (19%) patients: 12 in mismatch repair genes and 13 in other genes. A variant of uncertain significance was found in 23 (18%) patients. Importantly, a pathogenic germline mutation was identified in 12% of the patients without a family history (versus 32% with; p = 0.015) and in 13% of those with proficient mismatch repair colorectal cancers (versus 71% if deficient; p < 0.001). LIMITATIONS: The study is limited by its implementation at a single tertiary academic institution. CONCLUSIONS: One in 5 patients with young-onset disease harbored germline cancer predisposition. This detection rate, coupled with a high level of interest and acceptance from patients and feasibility of implementation, supports universal germline cancer risk assessment in this patient population. See Video Abstract at http://links.lww.com/DCR/B925 . PERFILES DE RIESGO DE CNCER DE LNEA GERMINAL DE PACIENTES CON CNCER COLORRECTAL DE INICIO JOVEN HALLAZGOS DE UN PROGRAMA UNIVERSAL PROSPECTIVO DE PRUEBAS DE LNEA GERMINAL Y TELEGENTICA: ANTECEDENTES:El cáncer colorrectal se diagnostica cada vez más en personas menores de 50 años. Se ha informado una predisposición hereditaria al cáncer en el 22 % de los casos de aparición temprana. La evaluación del riesgo de la línea germinal es fundamental para la atención personalizada del cáncer.OBJETIVO:Implementar la evaluación y las pruebas universales de riesgo de cáncer de línea germinal, y definir los perfiles de riesgo de cáncer de línea germinal de los pacientes que presentan una enfermedad de aparición temprana.DISEÑO:Un estudio de cohorte prospectivo.AJUSTE:Un centro médico académico de referencia terciaria.PACIENTES:Los pacientes recién diagnosticados que se presentaron en clínicas quirúrgicas entre Septiembre de 2019 y Febrero de 2021 fueron tratados en una vía de atención estandarizada que incluye una evaluación de riesgo de línea germinal universal.INTERVENCIÓN:Los pacientes recibieron material educativo sobre enfermedades de aparición temprana, pruebas genéticas y cobertura de seguro, seguido de asesoramiento genético (ya sea a distancia por telegenética o en persona). Los pacientes que dieron su consentimiento fueron evaluados en un panel de cánceres hereditarios comunes de 47 genes.MEDIDA DE RESULTADO PRINCIPAL:Proporción de pacientes con predisposición identificable al cáncer de línea germinal.RESULTADOS:Entre 500 pacientes con cáncer colorrectal, 185 (37%) tenían 50 años o menos (mediana: 44). No había antecedentes familiares en la mayoría (123, 67%) y 15 tumores (8,1%) eran deficientes en la reparación del desajuste de ácido desoxirribonucleico. La prueba de línea germinal se completó en 130 pacientes (70%); el resto estaban pendientes (7%), fallecidos (1%) o declinados (22%). Se identificaron mutaciones patogénicas de la línea germinal en 25 (de 130, 19%) pacientes: 12 en genes de reparación de errores de emparejamiento y 13 en otros genes. Se encontró una variante de significado incierto en 23 (18%) pacientes. Es importante señalar que se identificó una mutación germinal patogénica en el 12% de los pacientes sin antecedentes familiares (frente al 32% con; p = 0,015) y en el 13% de aquellos con cánceres colorrectales competentes en la reparación de errores de emparejamiento (frente al 71% si eran deficientes; p < 0,001).LIMITACIÓN:Implementado en una sola institución académica terciaria.CONCLUSIÓN:Uno de cada cinco pacientes con enfermedad de inicio joven albergaba predisposición al cáncer de línea germinal. Esta tasa de detección, junto con un alto nivel de interés y aceptación por parte de los pacientes y la viabilidad de la implementación, respaldan la evaluación universal del riesgo de cáncer de línea germinal en esta población de pacientes. Consulte el Video Resumen en http://links.lww.com/DCR/B925 . (Traducción-Dr. Yesenia Rojas-Khalil ).

Magnetic Resonance Imaging Directed Surgical Decision Making for Lateral Pelvic Lymph Node Dissection in Rectal Cancer After Total Neoadjuvant Therapy (TNT).

OBJECTIVE: Lateral pelvic lymph node (LPLN) metastases are an important cause of preventable local failure in rectal cancer. The aim of this study was to evaluate clinical and oncological outcomes following magnetic resonance imaging (MRI)-directed surgical selection for lateral pelvic lymph node dissection (LPLND) after total neoadjuvant therapy (TNT). METHODS: A retrospective consecutive cohort analysis was performed of rectal cancer patients with enlarged LPLN on pretreatment MRI. Patients were categorized as LPLND or non-LPLND. The main outcomes were lateral local recurrence rate, perioperative and oncological outcomes and factors associated with decision making for LPLND. RESULTS: A total of 158 patients with enlarged pretreatment LPLN and treated with TNT were identified. Median follow-up was 20 months (interquartile range 10-32). After multidisciplinary review, 88 patients (56.0%) underwent LPLND. Mean age was 53 (SD±12) years, and 54 (34.2%) were female. Total operative time (509 vs 429 minutes; P =0.003) was greater in the LPLND group, but median blood loss ( P =0.70) or rates of major morbidity (19.3% vs 17.0%) did not differ. LPLNs were pathologically positive in 34.1%. The 3-year lateral local recurrence rates (3.4% vs 4.6%; P =0.85) did not differ between groups. Patients with LPLNs demonstrating pretreatment heterogeneity and irregular margin (odds ratio, 3.82; 95% confidence interval: 1.65-8.82) or with short-axis ≥5 mm post-TNT (odds ratio 2.69; 95% confidence interval: 1.19-6.08) were more likely to undergo LPLND. CONCLUSIONS: For rectal cancer patients with evidence of LPLN metastasis, the appropriate selection of patients for LPLND can be facilitated by a multidisciplinary MRI-directed approach with no significant difference in perioperative or oncologic outcomes.

Adoption of Telemedicine for Postoperative Follow-Up After Inpatient Cancer-Related Surgery.

PURPOSE: The COVID-19 pandemic has resulted in significant changes in health care delivery, including the rapid adoption of telemedicine across multiple specialties and practice environments. This includes postoperative visits (POV), despite limited data on outcomes following these telemedicine POV. We sought to determine whether these types of visits successfully identify and address postoperative complications when compared with in-person POV. METHODS: This was a retrospective cohort study of patients undergoing elective inpatient cancer-related surgery from March 2020 through December 2020. The exposure variable was type of POV (telemedicine v in-person). The primary outcome was unplanned hospital readmission within 90 days, and secondary outcomes included 30-day readmission, length of stay of first readmission, and mortality. RESULTS: Five-hundred thirty-five patients underwent elective inpatient operations and met our inclusion criteria. Of these, 98 (18.5%) had an initial telemedicine POV. There was no difference in 90-day readmission on the basis of POV type (16.3% telemedicine v 16.5% in-person, P = .99). Reasons for readmission did not differ between patients who underwent a telemedicine POV compared with in-person POV (all P > .05). After adjustment for patients' demographic and clinical factors, telemedicine POV was not associated with 90-day readmission (odds ratio, 0.89; 95% CI, 0.43 to 1.70; P = .77). CONCLUSION: Telemedicine POV use adopted during the COVID-19 pandemic did not increase risk of readmission when compared with in-person visits following inpatient oncologic surgery. These data can help inform policy on the continued use and application of telemedicine after the pandemic.

What is the Risk for Peritoneal Metastases and Survival Afterwards in T4 Colon Cancers?

BACKGROUND: Patients with T4 colon adenocarcinomas have an increased risk of peritoneal metastases (PM) but the histopathologic risk factors for its development are not well-described. OBJECTIVE: The purpose of this study was to determine factors associated with PM, time to recurrence, and survival after recurrence among patients with T4 colon cancer. PATIENTS AND METHODS: Patients with pathologic T4 colon cancer who underwent curative resection from 2005 to 2017 were identified from a prospectively maintained institutional database and classified by recurrence pattern: (a) none - 68.8%; (b) peritoneal only - 7.9%; (c) peritoneal and extraperitoneal - 9.9%; and (d) extraperitoneal only - 13.2%. Associations between PM development and patient, primary tumor, and treatment factors were assessed. RESULTS: Overall, 151 patients were analyzed, with a median follow-up of 66.2 months; 27 patients (18%) developed PM (Groups B and C) and 20 (13%) patients recurred at non-peritoneal sites only (Group D). Median time to developing metastases was shorter for Groups B and C compared with Group D (B and C: 13.7 months; D: 46.7 months; p = 0.022). Tumor deposits (TDs) and nodal stage were associated with PM (p < 0.05), and TDs (p = 0.048) and LVI (p = 0.015) were associated with additional extraperitoneal recurrence. Eleven (41%) patients with PM underwent salvage surgery, and median survival after recurrence was associated with the ability to undergo cytoreduction (risk ratio 0.20, confidence interval 0.06-0.70). CONCLUSION: PM risk after resection of T4 colon cancer is independently associated with factors related to lymphatic spread, such as N stage and TDs. Well-selected patients can undergo cytoreduction with long-term survival. These findings support frequent postoperative surveillance and aggressive early intervention, including cytoreduction.

Definitive Intensity-Modulated Chemoradiation for Anal Squamous Cell Carcinoma: Outcomes and Toxicity of 428 Patients Treated at a Single Institution.

BACKGROUND: Although intensity-modulated radiation therapy (IMRT) is considered the standard of care for the treatment of squamous cell carcinoma of the anus (SCCA), few large series have reported oncologic outcomes and toxicities. In this retrospective report, we aim to describe outcomes and toxicities after IMRT-based chemoradiation (CRT) for the treatment of SCCA, evaluate the impact of dose escalation (>54 Gy), and compare concurrent fluoropyrimidine in combination with either mitomycin or with cisplatin as chemosensitizers. METHODS: Patients treated at The University of Texas MD Anderson Cancer Center between January 1, 2003 and December 31, 2018 with IMRT-based CRT were included. Median time to locoregional recurrence, time to colostomy, and overall survival were estimated using the Kaplan-Meier method. RESULTS: A total of 428 patients were included; median follow-up was 4.4 years. Three hundred and thirty-four patients (78.0%) were treated with concurrent cisplatin and fluoropyrimidine, and 160 (37.4%) with >54 Gy. Two- and 5-year freedom from locoregional failure, freedom from colostomy failure, and overall survival were 86.5% and 81.2%, respectively, 90.0% and 88.3%, respectively, and 93.6% and 85.8%, respectively. Neither dose escalation nor mitomycin-based concurrent chemotherapy resulted in improved outcomes. Mitomycin-based concurrent chemotherapy was associated with in approximately 2.5 times increased grade 3 or greater acute toxicity. Radiation dose >54 Gy was associated with approximately 2.6 times increased Grade 3 or greater chronic toxicity. CONCLUSIONS: Our results suggest IMRT-based CRT with concurrent fluoropyrimidine and cisplatin is a safe and feasible option for patient with SCCA and may cause less acute toxicity. The role for radiation dose escalation is unclear and requires further study.

Quality and Location of the Surgical Episode Mediate a Large Proportion of Socioeconomic-Based Survival Disparities in Patients with Resected Stage I-III Colon Cancer.

INTRODUCTION: Lower socioeconomic status (SES) is associated with shorter overall survival (OS) in patients with locoregional colon cancer. We aimed to estimate: (1) the proportion of SES-based OS disparities mediated by disparities in the quality and location of surgical treatment in patients with resected stage I-III colon cancer and (2) the relative importance of components of surgical quality. PATIENTS AND METHODS: We examined patients ages 18-80 years with resected stage I-III colon adenocarcinoma using the 2010-2016 National Cancer Database. SES was defined at the zip code level. Inverse odds weighting mediation analysis was used to estimate the proportion mediated (PM) for nine treatment quality-related and facility-related factors and composite PMs in models including all nine mediators. Models compared high SES patients with each lower SES stratum. RESULTS: Among 171,009 patients, 5-year OS increased from 70.4% in low SES patients to 78.1% in high SES. When high SES patients were compared with low, lower-middle, and upper-middle SES patients, PM ranges among lower SES strata were: minimally invasive surgery 16.0-16.6%, lymph nodes examined 7.7-9.6%, positive margins 3.8-6.5%, length of stay 16.7-28.1%, readmissions insignificant to 3.7%, treatment at > 1 CoC facility 2.7-3.1%, facility type insignificant to 7.3%, facility volume 2.9-8.2%, and adjusted facility 90-day mortality rates 33.2-42.8%. Composite PMs were 76.9% (95% CI 61.3%, 92.4%) for low SES, 68.7% (95% CI 56.4%, 81.1%) for lower-middle SES, and 60.9% (95% CI 43.1%, 78.6%) for upper-middle SES. CONCLUSIONS: These data suggest that improving the quality of the surgical episode for disadvantaged patients undergoing resection for locoregional colon cancer could decrease SES-based survival disparities by over half.

High Rate of Positive Circumferential Resection Margin in Colon Cancer: A National Appraisal and Call for Action.

OBJECTIVE: To identify rates of positive circumferential resection margin (CRM) for colon cancer surgery in the US. SUMMARY BACKGROUND DATA: CRM is one of the most important determinants of local control in colorectal cancers. The extent to which CRM involvement exists after colon cancer surgery is unknown. METHODS: Colon cancer cases with resection 2010 to 2015 were identified from the National Cancer Data Base. Adjusting for patient and tumor characteristics, comparisons were made between cases with CRM > 1 mm (negative margin) and those with margin involved with tumor or ≤ 1 mm (positive margin, CRM+). Hospital-level analysis was performed, examining observed-to-expected CRM+ rates. RESULTS: In total, 170,022 cases were identified: 150,291 CRM- and 19,731 CRM+ (11.6%). Pathologic T-category was the greatest predictor of CRM+, with higher rates in pT4(25.8%), pT4A(24.7%), and pT4B(31.5%) versus pT1(4.5%), pT2(6.3%) and pT3 (10.9%, P < 0.001). Within pT4 patients, predictors of CRM+ included signet-ring histology (38.1% vs 26.7% nonmucinous, and 26.9% mucinous adenocarcinoma, P < 0.001), removing < 12 lymph nodes (36.5% vs 26.1% >12, P < 0.001), community facilities (32.7%) versus academic/research (23.6%, P < 0.001), year (30.1% 2010 vs 22.6% 2015, P < 0.001), and hospital volume (24.5% highest quartile vs 32.7% lowest, P < 0.001). Across 1288 hospitals, observed-to-expected ratios for CRM+ ranged from 0 to 7.899; 429 facilities had higher than expected rates. CONCLUSIONS: Overall rate of CRM+ in US colon cancer cases is high. Variation exists across hospitals, with higher than expected rates in many facilities. Although biology is a major influencing factor, CRM+ rates represent an area for multidisciplinary improvement in quality of colon cancer care.