Rural-Urban Disparities in Colorectal Cancer Screening, Diagnosis, Treatment, and Survivorship Care: A Systematic Review and Meta-Analysis.

BACKGROUND: Rural residents have a higher prevalence of colorectal cancer (CRC) mortality compared to urban individuals. Policies have been aimed at improving access to CRC screening to reduce these outcomes. However, little attention has been paid to other determinants of CRC-related outcomes, such as stage at diagnosis, treatment, or survivorship care. The main objective of this analysis was to evaluate literature describing differences in CRC screening, stage at diagnosis, treatment, and survivorship care between rural and urban individuals. MATERIALS AND METHODS: We conducted a systematic review of electronic databases using a combination of MeSH and free-text search terms related to CRC screening, stage at diagnosis, treatment, survivorship care, and rurality. We identified 921 studies, of which 39 were included. We assessed methodological quality using the ROBINS-E tool and summarized findings descriptively. A meta-analysis was performed of studies evaluating CRC screening using a random-effects model. RESULTS: Seventeen studies reported disparities between urban and rural populations in CRC screening, 12 on treatment disparities, and 8 on staging disparities. We found that rural individuals were significantly less likely to report any type of screening at any time period (pooled odds ratio = 0.81, 95% CI, 0.76-0.86). Results were inconclusive for disparities in staging at diagnosis and treatment. One study reported a lower likelihood of use of CRC survivorship care for rural individuals compared to urban individuals. CONCLUSION: There remains an urgent need to evaluate and address CRC disparities in rural areas. Investigators should focus future work on assessing the quality of staging at diagnosis, treatment, and survivorship care in rural areas.

Hereditary Cancer Clinics Improve Adherence to NCCN Germline Testing Guidelines for Pancreatic Cancer.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis, with a 5-year overall survival rate of 10%. In November 2018, NCCN recommended that all patients with PDAC receive genetic counseling (GC) and germline testing regardless of family history. We hypothesized that patients with PDAC were more likely to be referred for testing after this change to the guidelines, regardless of presumed predictive factors, and that compliance would be further improved following the implementation of a hereditary cancer clinic (HCC). METHODS: We conducted a single-institution retrospective analysis of patients diagnosed with PDAC from June 2017 through December 2021 at University of California, Irvine. We compared rates of genetics referral among patients in different diagnostic eras: the 18-month period before the NCCN Guideline change (pre-NCCN era: June 2017 through November 2018), 14 months following the change (post-NCCN era: December 2018 through January 2020), and 18 months after the creation of an HCC (HCC era: June 2020 through December 2021). Family and personal cancer history, genetics referral patterns, and results of GC were recorded. Data were compared using chi-square, Fisher exact, and multivariate analyses. RESULTS: A total of 335 patients were treated for PDAC (123 pre-NCCN, 109 post-NCCN, and 103 HCC) at University of California, Irvine. Demographics across groups were comparable. Prior to the guideline changes, 30% were referred to GC compared with 54.7% in the post-NCCN era. After the implementation of the HCC, 77.4% were referred to GC (P<.0001). The odds ratio (OR) for referral to GC among patients with a positive family history of cancer progressively decreased following the change (pre-NCCN era: OR, 11.90 [95% CI, 3.00-80.14]; post-NCCN era: OR, 3.39 [95% CI, 1.13-10.76]; HCC era: OR, 3.11 [95% CI, 0.95-10.16]). CONCLUSIONS: The 2018 updates to the NCCN Guidelines for PDAC recommending germline testing for all patients with PDAC significantly increased GC referral rates at our academic medical center. Implementation of an HCC further boosted compliance with guidelines.

The impact of the California state lockdown during the COVID-19 pandemic on management of patients with pancreatic ductal adenocarcinoma.

BACKGROUND AND OBJECTIVES: The SARS-COVID-19 pandemic significantly limited healthcare access. We sought to evaluate whether California's lockdown in March 2020 affected staging and time to treatment of pancreatic ductal adenocarcinoma (PDAC). We hypothesized that patients diagnosed after the lockdown would have longer time to treatment and higher stage at presentation. METHODS: We retrospectively identified and categorized 1294 patients presenting to five University of California healthcare systems with a new diagnosis of PDAC into "pre-lockdown" and "post-lockdown" groups based on timing of pathologic diagnosis. RESULTS: In the 12 months pre-lockdown, 835 patients were diagnosed with PDAC, and 459 patients in the 6 months post-lockdown. Demographics, staging, and treatment type were similar between eras. There was a decreased male:female ratio post- versus pre-lockdown (0.97 vs. 1.25; p = 0.03). Time from symptom onset to first treatment was significantly increased among females post-lockdown (p = 0.001). However, overall time from diagnosis to first treatment was shorter in the post-lockdown era (median 23 vs. 26 days, p < 0.001). CONCLUSIONS: The COVID-19 lockdown did not significantly delay initial presentation, diagnosis, or treatment of newly diagnosed PDAC patients. Time from diagnosis to first treatment was shorter post-lockdown. Reduced healthcare utilization for minor complaints and increased telehealth utilization may have contributed.

Clinical implications of conflicting variant interpretations in the cancer genetics clinic.

PURPOSE: The aim of this study was to describe the clinical impact of commercial laboratories issuing conflicting classifications of genetic variants. METHODS: Results from 2000 patients undergoing a multigene hereditary cancer panel by a single laboratory were analyzed. Clinically significant discrepancies between the laboratory-provided test reports and other major commercial laboratories were identified, including differences between pathogenic/likely pathogenic and variant of uncertain significance (VUS) classifications, via review of ClinVar archives. For patients carrying a VUS, clinical documentation was assessed for evidence of provider awareness of the conflict. RESULTS: Fifty of 975 (5.1%) patients with non-negative results carried a variant with a clinically significant conflict, 19 with a pathogenic/likely pathogenic variant reported in APC or MUTYH, and 31 with a VUS reported in CDKN2A, CHEK2, MLH1, MSH2, MUTYH, RAD51C, or TP53. Only 10 of 28 (36%) patients with a VUS with a clinically significant conflict had a documented discussion by a provider about the conflict. Discrepant counseling strategies were used for different patients with the same variant. Among patients with a CDKN2A variant or a monoallelic MUTYH variant, providers were significantly more likely to make recommendations based on the laboratory-reported classification. CONCLUSION: Our findings highlight the frequency of variant interpretation discrepancies and importance of clinician awareness. Guidance is needed on managing patients with discrepant variants to support accurate risk assessment.

Differential Effects of Race, Socioeconomic Status, and Insurance on Disease-Specific Survival in Rectal Cancer.

BACKGROUND: National Comprehensive Cancer Network guideline adherence improves cancer outcomes. In rectal cancer, guideline adherence is distributed differently by race/ethnicity, socioeconomic status, and insurance. OBJECTIVE: This study aimed to determine the independent effects of race/ethnicity, socioeconomic status, and insurance status on rectal cancer survival after accounting for differences in guideline adherence. DESIGN: This was a retrospective study. SETTINGS: The study was conducted using the California Cancer Registry. PATIENTS: This study included patients aged 18 to 79 years diagnosed with rectal adenocarcinoma between January 1, 2004, and December 31, 2017, with follow-up through November 30, 2018. Investigators determined whether patients received guideline-adherent care. MAIN OUTCOME MEASURES: ORs and 95% CIs were used for logistic regression to analyze patients receiving guideline-adherent care. Disease-specific survival analysis was calculated using Cox regression models. RESULTS: A total of 30,118 patients were examined. Factors associated with higher odds of guideline adherence included Asian and Hispanic race/ethnicity, managed care insurance, and high socioeconomic status. Asians (HR, 0.80; 95% CI, 0.72-0.88; p < 0.001) and Hispanics (HR, 0.91; 95% CI, 0.83-0.99; p = 0.0279) had better disease-specific survival in the nonadherent group. Race/ethnicity were not factors associated with disease-specific survival in the guideline adherent group. Medicaid disease-specific survival was worse in both the nonadherent group (HR, 1.56; 95% CI, 1.40-1.73; p < 0.0001) and the guideline-adherent group (HR, 1.18; 95% CI, 1.08-1.30; p = 0.0005). Disease-specific survival of the lowest socioeconomic status was worse in both the nonadherent group (HR, 1.42; 95% CI, 1.27-1.59) and the guideline-adherent group (HR, 1.20; 95% CI, 1.08-1.34). LIMITATIONS: Limitations included unmeasured confounders and the retrospective nature of the review. CONCLUSIONS: Race, socioeconomic status, and insurance are associated with guideline adherence in rectal cancer. Race/ethnicity was not associated with differences in disease-specific survival in the guideline-adherent group. Medicaid and lowest socioeconomic status had worse disease-specific survival in both the guideline nonadherent group and the guideline-adherent group. See Video Abstract at http://links.lww.com/DCR/B954 . EFECTOS DIFERENCIALES DE LA RAZA, EL NIVEL SOCIOECONMICO COBERTURA SOBRE LA SUPERVIVENCIA ESPECFICA DE LA ENFERMEDAD EN EL CNCER DE RECTO: ANTECEDENTES: El cumplimiento de las guías de la National Comprehensive Cancer Network mejora los resultados del cáncer. En el cáncer de recto, el cumplimiento de las guías se distribuye de manera diferente según la raza/origen étnico, nivel socioeconómico y el cobertura médica.OBJETIVO: Determinar los efectos independientes de la raza/origen étnico, el nivel socioeconómico y el estado de cobertura médica en la supervivencia del cáncer de recto después de tener en cuenta las diferencias en el cumplimiento de las guías.DISEÑO: Este fue un estudio retrospectivo.ENTORNO CLINICO: El estudio se realizó utilizando el Registro de Cáncer de California.PACIENTES: Pacientes de 18 a 79 años diagnosticados con adenocarcinoma rectal entre el 1 de enero de 2004 y el 31 de diciembre de 2017 con seguimiento hasta el 30 de noviembre de 2018. Los investigadores determinaron si los pacientes recibieron atención siguiendo las guías.PRINCIPALES MEDIDAS DE RESULTADO: Se utilizaron razones de probabilidad e intervalos de confianza del 95 % para la regresión logística para analizar a los pacientes que recibían atención con adherencia a las guías. El análisis de supervivencia específico de la enfermedad se calculó utilizando modelos de regresión de Cox.RESULTADOS: Se analizaron un total de 30.118 pacientes. Los factores asociados con mayores probabilidades de cumplimiento de las guías incluyeron raza/etnicidad asiática e hispana, seguro de atención administrada y nivel socioeconómico alto. Los asiáticos e hispanos tuvieron una mejor supervivencia específica de la enfermedad en el grupo no adherente HR 0,80 (95 % CI 0,72 - 0,88, p < 0,001) y HR 0,91 (95 % CI 0,83 - 0,99, p = 0,0279). La raza o el origen étnico no fueron factores asociados con la supervivencia específica de la enfermedad en el grupo que cumplió con las guías. La supervivencia específica de la enfermedad de Medicaid fue peor tanto en el grupo no adherente HR 1,56 (IC del 95 % 1,40 - 1,73, p < 0,0001) como en el grupo adherente a las guías HR 1,18 (IC del 95 % 1,08 - 1,30, p = 0,0005). La supervivencia específica de la enfermedad del nivel socioeconómico más bajo fue peor tanto en el grupo no adherente HR 1,42 (IC del 95 %: 1,27 a 1,59) como en el grupo adherente a las guías HR 1,20 (IC del 95 %: 1,08 a 1,34).LIMITACIONES: Las limitaciones incluyeron factores de confusión no medidos y la naturaleza retrospectiva de la revisión.CONCLUSIONES: La raza, el nivel socioeconómico y cobertura médica están asociados con la adherencia a las guías en el cáncer de recto. La raza/etnicidad no se asoció con diferencias en la supervivencia específica de la enfermedad en el grupo que cumplió con las guías. Medicaid y el nivel socioeconómico más bajo tuvieron peor supervivencia específica de la enfermedad tanto en el grupo que no cumplió con las guías como en los grupos que cumplieron. Consulte Video Resumen en http://links.lww.com/DCR/B954 . (Traducción- Dr. Francisco M. Abarca-Rendon).

Assessment of Attitudes Toward Initiation of Immediate Adjuvant Chemotherapy for Colon Cancer.

INTRODUCTION: Early initiation of chemotherapy after surgery for colon cancer has survival benefits. Immediate adjuvant chemotherapy (IAC) involves giving chemotherapy during surgical resection and immediately postoperatively. This novel approach has been shown to be safe, eliminating delays in adjuvant treatment that could increase the risk of micro-metastatic spread. The aim of this study was to assess the willingness of the general public to accept IAC. MATERIALS AND METHODS: Between March and April 2021, 800 telephone interviews were conducted with a sample of adult New York State residents. The Survey Research Institute of Cornell University conducted all surveys. Kruskal-Wallis, chi-squared, and Fisher's tests were conducted using R 4.0.2. RESULTS: Three scenarios were presented: (1) receiving IAC resulting in improved survival and quality of life, (2) finishing chemotherapy earlier without survival impact, and (3) finishing chemotherapy earlier but with possible side effects. Respondents with higher education were more likely to accept (1) & (2), males were more likely to accept (2) & (3), higher income respondents were more likely to accept (1) & (3), and those with more work hours were more likely to accept (2). Lastly, 16% responded they would be very or extremely likely, and 52% respondents would be somewhat likely or likely to accept intraoperative chemotherapy, even if it may not be necessary. CONCLUSIONS: Respondents were likely to accept IAC if offered. Given the known risk of delayed adjuvant chemotherapy (AC) in colon cancer, further research is warranted to determine the survival and quality of life (QOL) benefits of IAC.

Adoptive T-Cell Therapy in Advanced Colorectal Cancer: A Systematic Review.

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths in the US. For the vast majority of patients with advanced CRC (ie, for those in whom metastatic tumors are unresectable), treatment is palliative and typically involves chemotherapy, biologic therapy, and/or immune checkpoint inhibition. In recent years, the use of adoptive T-cell therapy (ACT), leveraging the body's own immune system to recognize and target cancer, has become increasingly popular. Unfortunately, while ACT has been successful in the treatment of hematological malignancies, it is less efficacious in advanced CRC due in part to a lack of productive immune infiltrate. This systematic review was conducted to summarize the current data for the efficacy and safety of ACT in advanced CRC. We report that ACT is well tolerated in patients with advanced CRC. Favorable survival estimates among patients with advanced CRC receiving ACT demonstrate promise for this novel treatment paradigm. However, additional stage I/II clinical trials are needed to establish the efficacy and safety of ACT in patients with CRC.

The impact of gender, race, socioeconomic status, and treatment on outcomes in esophageal cancer: A population-based analysis.

BACKGROUND: African Americans and Hispanics are reported to have higher mortality from esophageal cancer (EC) than Caucasians. In this study, we analyzed the independent effects of race, gender, treatment, and socioeconomic status (SES) on overall survival (OS). METHODS: Data for all EC cases between 2004 and 2010 with follow-up through 2012 were obtained from the California Cancer Registry. We conducted descriptive analyses of clinical variables and survival analyses by Kaplan-Meier and Cox proportional hazards methods. RESULTS: African Americans and Hispanics were more likely to be in the lower SES strata and less likely to receive surgery than Caucasians in this cohort. The proportion of patients receiving chemotherapy and radiotherapy was similar across different racial/ethnic groups. After adjustment for stage, grade, histology, treatments, and SES in multivariate analyses, the mortality risk in African Americans (hazard ratio [HR] 0.96, 95% confidence interval [CI] 0.85-1.07) and Hispanics (HR 0.96, 95% CI 0.89-1.07) did not differ from Caucasians (HR = 1.00, referent), with histology, SES, and surgery largely accounting for unadjusted OS differences. We also observed that African American men had higher adjusted risk of death relative to Caucasian men (HR 1.24, 95% CI 1.07-1.42), but this effect was not observed for African American women compared to Caucasian women (HR 1.12, 95% CI 0.94-1.35). CONCLUSIONS: Race is not an independent risk factor for OS in our population-based analysis of EC cases. Rather, observed differences in OS by race/ethnicity result from differences in cancer histology, SES, surgery, and gender. Our findings support further health disparities research for this disease.

Trends in colorectal cancer admissions and stage at presentation: impact of screening.

BACKGROUND: Colorectal cancer (CRC) incidence is rising among patients under age 50. As such, we set out to determine the proportion of CRC-related hospital admissions and distribution of colon cancer by stage in different age groups. METHODS: The NIS database for 2002-2012 was used to investigate trends of colorectal cancer resection by age, and the ACS NSQIP database for 2012-2013 was used to investigate contemporary stage at diagnosis for colon cancer in different age groups. RESULTS: A total of 1,198,421 patients were admitted to a hospital with a diagnosis of CRC and captured by the NIS database. Although the number of hospitalized CRC patients decreased from 2002 to 2012, the observed decrease was predominant in patients older than 65 years (P < 0.01) and in colon cancer compared to rectal cancer patients (P < 0.01). The proportion of patients younger than 65 years increased from 32.8 % in 2002 to 41.1 % in 2012, and the proportion of patients under age 50 increased from 9 to 12 %. In the NSQIP database, the age <50 group also had a significantly higher proportion of advanced disease (stage III/IV) compared to patients age 50 and older (62.3 vs. 47.5 %, P < 0.01). In 2012, it was observed that most patients with rectal cancer were younger than 65 years (55.8 %). CONCLUSION: There was a steady decrease in the number of hospitalized patients with colorectal cancer during the last decade, primarily attributable to a decrease in the older than 65 years age patients and colon cancer patients. The proportion of hospitalized patients age <50 is rising. In addition, patients younger than 50 years were more likely to have advanced disease compared to older patients.

Attitudes of physicians and patients toward immediate and intraoperative chemotherapy treatment in colon cancer.

INTRODUCTION: We have shown in a Phase I trial that immediate adjuvant chemotherapy (IAC) during surgical resection and immediately postoperative is safe and feasible in patients with colon cancer (CC). IAC avoids delays in adjuvant treatment and has the potential to improve survival and quality of life. We aim to determine patients and providers attitudes toward this novel multidisciplinary treatment approach. METHODS: Two web-based surveys were administered to newly diagnosed CC patients, survivors, surgeons and oncologists. Surveys assessed treatment preferences and perceived barriers to IAC. Chi-square tests were conducted to compare differences between patients' and providers' responses. RESULTS: Responses were collected from 35 patients and 40 providers. Patients were more willing to: (1) proceed with IAC to finish treatment earlier thus possibly improving quality of life (p = 0.001); (2) proceed with IAC despite potential side effects (p < 0.001); and (3) proceed with a dose of intraoperative chemotherapy even if on final pathology, may not have been needed (p = 0.002). Patients were more likely to indicate no barriers to collaborative care (p = 0.001) while providers were more likely to cite that it is time consuming, thus a barrier to participation (p = 0.001), has scheduling challenges (p = 0.001), and physicians are not available to participate (p = 0.003). CONCLUSIONS: We observed a discordance between what providers and patients value in perioperative and adjuvant CC treatment. Patients are willing to accept IAC despite potential side effects and without survival benefit, highlighting the importance of understanding patient preference.

A Phase 1 Study of Cabozantinib and Trifluridine/Tipiracil in Metastatic Colorectal Adenocarcinoma.

INTRODUCTION: This study determined the safety and recommended phase 2 dose (RP2D) of the multikinase inhibitor cabozantinib in combination with trifluridine/tipiracil (FTD/TPI) in refractory metastatic colorectal carcinoma (mCRC). PATIENTS AND METHODS: Single institution investigator-initiated phase 1 study using 3+3 design. Eligible mCRC patients had received prior standard regimens. Cabozantinib was given orally (p.o.) at 20 mg (dose level [DL] 0) or 40 mg (DL 1) daily on days 1-28, and FTD/TPI p.o. at 35 mg/m2 on days 1-5 and 8-12 every 28 days. Prophylactic growth-factor support was allowed. RESULTS: Fifteen patients were enrolled. Median age 56 years (31-80), male (12/15), ECOG 0/1 = 9/6. Three patients were treated at DL 0 and another nine were treated at DL 1, none exhibiting a DLT. Most common any grade (G) treatment related adverse events (TRAE) were diarrhea (50%), nausea (42%), neutropenia (42%), fatigue (33%), and rash (25%). G3-4 TRAE were neutropenia (25%) and thrombocytopenia, hypokalemia, and weight loss (each 8%). No serious TRAE or G5 were reported. The RP2D was determined to be DL 1. Median PFS was 3.8 months (95% CI 1.9-6.8) and disease control rate was 86.7%. CONCLUSION: The combination of cabozantinib and FTD/TPI is feasible and tolerable at standard doses with the use of growth factors and showed encouraging clinical activity in refractory mCRC. CLINICALTRIALS: GOV: NCT04868773.

Everolimus causing severe hypertriglyceridemia and acute pancreatitis.

Everolimus is an mTOR inhibitor commonly used to treat metastatic pancreatic neuroendocrine tumors (pNETs) and renal cell carcinoma, and for posttransplant immunosuppression. This report presents a case of a 36-year-old man being treated with everolimus for a metastatic pNET who developed severe hypertriglyceridemia and acute pancreatitis. The incidence of hypertriglyceridemia reported in large prospective randomized trials is reviewed and the management of hypertriglyceridemic pancreatitis is discussed. Careful monitoring of triglyceride levels and dose adjustments of everolimus together with lipid-lowering therapy can allow patients to continue this medication. Because there are increasing indications for the use of everolimus, prescribing oncologists must be cognizant of the common and serious side effects.

Disparities in Receipt of National Comprehensive Cancer Network Guideline-Adherent Care and Outcomes among Women with Triple-Negative Breast Cancer by Race/Ethnicity, Socioeconomic Status, and Insurance Type.

BACKGROUND: The National Comprehensive Cancer Network guidelines were designed to improve patient outcomes. Here, we examine factors that may contribute to outcomes and guideline adherence in patients with triple-negative breast cancer. METHODS: This was a retrospective cohort study of women with triple-negative breast cancer using the California Cancer Registry. Adherent treatment was defined as the receipt of a combination of surgery, lymph node assessment, adjuvant radiation, and/or chemotherapy. A multivariable logistic regression was used to determine the effects of independent variables on adherence to the NCCN guidelines. Disease-specific survival was calculated using Cox regression analysis. RESULTS: A total of 16,858 women were analyzed. Black and Hispanic patients were less likely to receive guideline-adherent care (OR 0.82, 95%CI 0.73-0.92 and OR 0.87, 95%CI 0.79-0.95, respectively) compared to White patients. Hazard ratios adjusted for adherent care showed that Black patients had increased disease-specific mortality (HR 1.28, 95%CI 1.16-1.42, p < 0.0001) compared to White patients. CONCLUSIONS: A significant majority of breast cancer patients in California continue to receive non-guideline-adherent care. Non-Hispanic Black patients and patients from lower SES quintile groups were less likely to receive guideline-adherent care. Patients with non-adherent care had worse disease-specific survival compared to recipients of NCCN guideline-adherent care.

Population-Based Analysis of National Comprehensive Cancer Network (NCCN) Guideline Adherence for Patients with Anal Squamous Cell Carcinoma in California.

PURPOSE: We analyzed adherence to the National Comprehensive Cancer Network treatment guidelines for anal squamous cell carcinoma in California and the associated impacts on survival. METHODS: This was a retrospective study of patients in the California Cancer Registry aged 18 to 79 years with recent diagnoses of anal squamous cell carcinoma. Predefined criteria were used to determine adherence. Adjusted odds ratios and 95% confidence intervals were estimated for those receiving adherent care. Disease-specific survival (DSS) and overall survival (OS) were examined with a Cox proportional hazards model. RESULTS: 4740 patients were analyzed. Female sex was positively associated with adherent care. Medicaid status and low socioeconomic status were negatively associated with adherent care. Non-adherent care was associated with worse OS (Adjusted HR 1.87, 95% CI = 1.66, 2.12, p < 0.0001). DSS was worse in patients receiving non-adherent care (Adjusted HR 1.96, 95% CI = 1.56, 2.46, p < 0.0001). Female sex was associated with improved DSS and OS. Black race, Medicare/Medicaid, and low socioeconomic status were associated with worse OS. CONCLUSIONS: Male patients, those with Medicaid insurance, or those with low socioeconomic status are less likely to receive adherent care. Adherent care was associated with improved DSS and OS in anal carcinoma patients.

Phase IIa Clinical Biomarker Trial of Dietary Arginine Restriction and Aspirin in Colorectal Cancer Patients.

After potentially curative treatment, colorectal cancer (CRC) patients remain at high risk for recurrence, second primary CRC, and high-risk adenomas. In combination with existing data, our previous findings provide a rationale for reducing tissue polyamines as tertiary prevention in non-metastatic CRC patients. The goal of this study was to demonstrate rectal tissue polyamine reduction in optimally treated stage I-III CRC patients after intervention with daily oral aspirin + dietary arginine restriction. A single-institution phase IIa clinical trial was conducted. Patients were treated with aspirin 325 mg/day and an individualized dietary regimen designed to reduce arginine intake by ≥30% over a 12-week study period. Dietary intake, endoscopy with rectal biopsies, and phlebotomy were performed pre- and post-intervention. The primary endpoint was to demonstrate ≥50% decrease in rectal tissue putrescine levels from baseline as a measure of polyamine reduction in the target tissue. Twenty eligible patients completed the study. After study intervention, mean dietary arginine intake decreased from 3.7 g/day ± 1.3 SD to 2.6 g/day ± 1.2 SD (29.7% decrease, p < 0.02 by Sign test). Mean plasma arginine levels decreased from 46.0 ng/mL ± 31.5 SD at baseline to 35 ng/mL ± 21.7 SD (p < 0.001). Rectal tissue putrescine levels were 0.90 nMol/mg-protein pre-intervention and 0.99 nMol/mg-protein post-intervention (p < 0.64, NS). No significant differences were observed for the other tissue polyamines investigated: spermidine (p < 0.13), spermine (p < 0.21), spermidine:spermine ratio (p < 0.71). Among CRC survivors, treatment with daily oral aspirin and an individualized dietary arginine restriction intervention resulted in lower calculated dietary arginine intake and plasma arginine levels but did not affect rectal tissue polyamine levels.

A human vascularized microtumor model of patient-derived colorectal cancer recapitulates clinical disease.

Accurately modeling tumor biology and testing novel therapies on patient-derived cells is critically important to developing therapeutic regimens personalized to a patient's specific disease. The vascularized microtumor (VMT), or "tumor-on-a-chip," is a physiologic preclinical cancer model that incorporates key features of the native human tumor microenvironment within a transparent microfluidic platform, allowing rapid drug screening in vitro. Herein we optimize methods for generating patient-derived VMT (pVMT) using fresh colorectal cancer (CRC) biopsies and surgical resections to test drug sensitivities at the individual patient level. In response to standard chemotherapy and TGF-ßR1 inhibition, we observe heterogeneous responses between pVMT derived from 6 patient biopsies, with the pVMT recapitulating tumor growth, histological features, metabolic heterogeneity, and drug responses of actual CRC tumors. Our results suggest that a translational infrastructure providing rapid information from patient-derived tumor cells in the pVMT, as established in this study, will support efforts to improve patient outcomes.

NCI Rectal-Anal Task Force consensus recommendations for design of clinical trials in rectal cancer.

The optimal management of locally advanced rectal cancer is rapidly evolving. The National Cancer Institute Rectal-Anal Task Force convened an expert panel to develop consensus on the design of future clinical trials of patients with rectal cancer. A series of 82 questions and subquestions, which addressed radiation and neoadjuvant therapy, patient perceptions, rectal cancer populations of special interest, and unique design elements, were subject to iterative review using a Delphi analytical approach to define areas of consensus and those in which consensus is not established. The task force achieved consensus on several areas, including the following: 1) the use of total neoadjuvant therapy with long-course radiation therapy either before or after chemotherapy, as well as short-course radiation therapy followed by chemotherapy, as the control arm of clinical trials; 2) the need for greater emphasis on patient involvement in treatment choices within the context of trial design; 3) efforts to identify those patients likely, or unlikely, to benefit from nonoperative management or minimally invasive surgery; 4) investigation of the utility of circulating tumor DNA measurements for tailoring treatment and surveillance; and 5) the need for identification of appropriate end points and recognition of challenges of data management for patients who enter nonoperative management trial arms. Substantial agreement was reached on priorities affecting the design of future clinical trials in patients with locally advanced rectal cancer.

Role of obesity in a randomized placebo-controlled trial of difluoromethylornithine (DFMO) + sulindac for the prevention of sporadic colorectal adenomas.

BACKGROUND: Chemoprevention with the polyamine-inhibitory regimen difluoromethylornithine (DFMO) + sulindac markedly reduces risk of recurrent adenoma in colorectal adenoma patients. Obesity is associated with risk of colorectal adenoma and colorectal cancer. This study investigates how obesity influences risk of recurrent adenoma after prolonged treatment with DFMO + sulindac versus placebo. METHODS: Our analysis included subjects enrolled in the phase III colorectal adenoma prevention clinical trial investigating DFMO + sulindac versus placebo. Patients were classified by obesity (body mass index, BMI ≥ 30 kg/m(2)) status at baseline. Pearson χ(2) statistic and Mann-Whitney U test were used to compare baseline characteristics, including rectal tissue polyamine levels. Log-binomial regression analysis was used to determine the risk ratio (RR) of recurrent adenomas, adjusted for covariates and an interaction term for obesity and treatment. RESULTS: The final analytic cohort was comprised of 267 patients. In separate regression models, the risk of adenoma recurrence after treatment compared to placebo was similar for obese (RR = 0.32, 95 % CI 15-71) and non-obese patients (RR = 0.27, 95 % CI 15-49). No significant interaction was detected between obesity, treatment, and risk of colorectal adenoma in the full regression model (p (interaction) = 0.91). CONCLUSIONS: Obesity does not substantially modify the colorectal adenoma risk reduction ascribed to DFMO + sulindac versus placebo.

Meat consumption, ornithine decarboxylase gene polymorphism, and outcomes after colorectal cancer diagnosis.

BACKGROUND: Dietary arginine and meat consumption are implicated in colorectal cancer (CRC) progression via polyamine-dependent processes. Polymorphism in the polyamine-regulatory gene, ornithine decarboxylase 1 (Odc1, rs2302615) is prognostic for CRC-specific mortality. Here, we examined joint effects of meat consumption and Odc1 polymorphism on CRC-specific mortality. MATERIALS AND METHODS: The analytic cohort was comprised of 329 incident stage I-III CRC cases diagnosed 1994-1996 with follow- up through March 2008. Odc1 genotyping was conducted using primers that amplify a 172-bp fragment containing the polymorphic base at +316. Dietary questionnaires were administered at cohort entry. Multivariate Cox proportional hazards regression analysis for CRC-specific mortality was stratified by tumor, node, metastasis (TNM) stage, and adjusted for clinically relevant variables, plus meat consumption (as a continuous variable, i.e., the number of medium-sized servings/week), Odc1 genotype, and a term representing the meat consumption and Odc1 genotype interaction. The primary outcome was the interaction of Odc1 and meat intake on CRC-specific mortality, as assessed by departures from multiplicative joint effects. RESULTS: Odc1 genotype distribution was 51% GG, 49% GA/AA. In the multivariate model, there was a significant interaction between meat consumption and Odc1 genotype, P-int = 0.01. Among Odc1 GA/AA CRC cases in meat consumption Quartiles 1-3, increased mortality risk was observed when compared to GG cases (adjusted hazards ratio (HR) = 7.06 [95% CI 2.34-21.28]) - a difference not found among cases in the highest dietary meat consumption Quartile 4. CONCLUSIONS: Effects of meat consumption on CRC-specific mortality risk differ based on genetic polymorphism at Odc1. These results provide further evidence that polyamine metabolism and its modulation by dietary factors such as meat may have relevance to CRC outcomes.

Population-based evaluation of adenosquamous carcinoma of the colon and rectum.

BACKGROUND: Information about adenosquamous carcinoma of the colon and rectum is scarce because of its extremely low incidence. OBJECTIVE: The aim of this study was to examine the prognostic significance of a histological diagnosis of adenosquamous carcinoma in comparison with adenocarcinoma of the colon and rectum. DESIGN: This study was retrospective in design. SETTING: California Cancer Registry data from 1994 through 2004 with follow-up through 2008 were analyzed. PATIENTS: Patients were included whose cancer of the colon and rectum, excluding the anus with a tumor histology of adenocarcinoma and adenosquamous carcinoma, was surgically treated. MAIN OUTCOME MEASURES: The primary outcomes measured were histology-specific survival analyses (with the use of the Kaplan-Meier method), and overall and colorectal-specific mortality (with the use of multivariable Cox proportional hazards regression analyses). RESULTS: A total of 111,263 adenocarcinoma and adenosquamous carcinoma of colon and rectal cancer cases were identified (adenocarcinoma, 99.91%; adenosquamous carcinoma, 0.09%). There was no significant difference in sex, age, race, and socioeconomic status between the 2 groups. The most common location of adenocarcinoma and adenosquamous carcinoma was the right and transverse colon. The adenosquamous carcinoma group was significantly associated with a higher rate of metastasis at the time of operation (adenosquamous carcinoma, 36.56% vs adenocarcinoma, 13.92%) and with poorly differentiated tumor grade (adenosquamous carcinoma, 65.96% vs adenocarcinoma, 19.74%) in comparison with the adenocarcinoma group. The median overall survival time was significantly greater in the adenocarcinoma group (82.4 months) in comparison with the adenosquamous carcinoma group (35.3 months). With the use of multivariable hazard regression analyses, adenosquamous carcinoma histology was independently associated with increased overall mortality (hazard ratio, 1.67) and colorectal-specific mortality (hazard ratio, 1.69) in comparison with adenocarcinoma. CONCLUSIONS: This is one of the largest studies of adenosquamous carcinoma of the colon and rectum to date. This uncommon colorectal cancer subtype was associated with higher overall and colorectal-specific mortality in comparison with adenocarcinoma. Among colorectal cancer cases, adenosquamous carcinoma histology should be considered a poor prognostic feature.