Spectrum of Advanced Colorectal Neoplasia and Anticipated Yield of Average-Risk Screening in Veterans Under Age 50.

The incidence of early onset colorectal cancer, or colorectal cancer (CRC) diagnosed before age 50, is increasing.1 In response, multiple societal guidelines in the United States now recommend initiating CRC screening at age 45 in average-risk individuals (ie, those without high-risk clinical characteristics, such as bleeding, or iron deficiency anemia), inflammatory bowel disease, or family history of colorectal neoplasia.2 The Veterans Health Administration (VHA) is the largest integrated health system in the United States and is contending with how best to expand CRC screening access to this younger population in the setting of limited colonoscopy resources. Understanding the rate and anatomic location of colorectal neoplasia in Veterans younger than age 50 can inform the expected yield of different screening modalities. Prior work has shown that individuals undergoing colonoscopy for low-risk diagnostic indications have equivalent risk of colorectal neoplasia as those undergoing average-risk screening.3 This study and a recent meta-analysis4 reported that 3.6% (95% confidence interval, 1.9%-6.7%) to 3.7% (95% confidence interval, 3.0%-4.7%) of average-risk individuals age 45-49 have advanced colorectal neoplasia (ACN), defined as an advanced polyp or carcinoma; however, data specific to the VHA population are lacking.

Contributions of Adenocarcinoma and Carcinoid Tumors to Early-Onset Colorectal Cancer Incidence Rates in the United States.

BACKGROUND: Early-onset colorectal cancer (EOCRC) incidence rates (IRs) are rising, according to previous cancer registry analyses. However, analysis of histologic subtypes, including adenocarcinoma (the focus of CRC screening and diagnostic testing) and carcinoid tumors (which are classified as "colorectal cancer" in SEER [Surveillance, Epidemiology, and End Results] databases but have a distinct pathogenesis and are managed differently from adenocarcinoma), has not been reported. OBJECTIVE: To assess EOCRC IRs and changes in IRs over time, stratified by histology. DESIGN: Retrospective analysis. SETTING: Yearly IRs according to SEER 18 data from 2000 to 2016 on age-specific colon-only, rectal-only, and combined-site CRC cases, stratified by histology ("overall" CRC [all histologic subtypes], adenocarcinoma, and carcinoid tumors) and age. PATIENTS: 119 624 patients with CRC. MEASUREMENTS: IRs per 100 000 population, changes in 3-year average annual IRs (pooled IRs from 2000 to 2002 vs. those from 2014 to 2016), and annual percentage change (APC) in persons aged 20 to 29, 30 to 39, 40 to 49, and 50 to 54 years. RESULTS: The steepest changes in adenocarcinoma 3-year average annual IRs were for rectal-only cases in persons aged 20 to 29 years (+39% [0.33 to 0.46 per 100 000]; P < 0.050) and 30 to 39 years (+39% [1.92 to 2.66 per 100 000]; P < 0.050) and colon-only cases in those aged 30 to 39 years (+20% [3.30 to 3.97 per 100 000]; P < 0.050). Corresponding APCs were 1.6% (P < 0.050), 2.2% (P < 0.050), and 1.2% (P < 0.050), respectively. In persons aged 40 to 49 years, 3-year average annual IRs increased in both colon-only (+13% [12.21 to 13.85 per 100 000]; P < 0.050) and rectal-only (+16% [7.50 to 8.72 per 100 000]; P < 0.050) subsites. Carcinoid tumors were common, representing approximately 4% to 20% of all colorectal and 8% to 34% of all rectal cancer cases, depending on age group and calendar year. Colon-only carcinoid tumors were rare. Colorectal carcinoid tumor IRs increased more steeply than adenocarcinoma in all age groups, thus affecting the contribution of carcinoid tumors to overall cancer cases over time. These changes were driven by rectal subsites and were most pronounced in persons aged 50 to 54 years, in whom rectal carcinoid tumors increased by 159% (2.36 to 6.10 per 100 000) between 2000 to 2002 and 2014 to 2016, compared with 10% for adenocarcinoma (18.07 to 19.84 per 100 000), ultimately accounting for 22.6% of all rectal cancer cases. LIMITATION: Population-based data. CONCLUSION: These findings underscore the importance of assessing histologic CRC subtypes independently. Doing so may lead to a better understanding of the drivers of temporal changes in overall CRC incidence and a more accurate measurement of outcomes from efforts to reduce adenocarcinoma risk, and can guide future research. PRIMARY FUNDING SOURCE: None.

Progress of colorectal cancer screening in United States: Past achievements and future challenges.

The United States has seen progress with colorectal cancer with both falling incidence and mortality rates. Factoring into this decline, the significance of early detection and removal of precancerous lesions through screening must be underscored. With the advancement of screening modalities, attention has been directed towards optimizing the quality of screening and detecting adenomas. Colorectal cancer screening has been a major agenda item for national gastroenterology societies, culminating in a major victory with passage of the Balanced Budget Act that allowed for Medicare coverage of colorectal cancer screening. Colonoscopy as the primary screening modality was solidified in the 1990s after landmark studies demonstrated its superiority over modalities for detecting precancerous polyps. Despite progress, colorectal cancer screening disparities between race and gender continue to exist. Legislative efforts are on-going and include the SCREEN Act and Dent Act that aim to further improve access to screening. The National Colorectal Cancer Roundtable has launched colorectal cancer screening initiatives targeting at risk populations. Today, the current goal of these initiatives is to reach colorectal screening rate of 80% of eligible patients by 2018. With these initiatives, efforts to narrow the gaps in screening disparities and lower overall mortality have been prioritized and continued by the medical community. This review article details colorectal cancer screening progress to date and highlights major studies and initiatives that have solidified its success in the United States.

KRAS Testing, Tumor Location, and Survival in Patients With Stage IV Colorectal Cancer: SEER 2010-2013.

Purpose:KRAS mutations and tumor location have been associated with response to targeted therapy among patients with stage IV colorectal cancer (CRC) in various trials. This study performed the first population-based examination of associations between KRAS mutations, tumor location, and survival, and assessed factors associated with documented KRAS testing. Methods: Patients with stage IV adenocarcinoma of the colon/rectum diagnosed from 2010 to 2013 were extracted from SEER data. Analyses of patient characteristics, KRAS testing, and tumor location were conducted using logistic regression. Cox proportional hazards models assessed relationships between KRAS mutations, tumor location, and risk of all-cause death. Results: Of 22,542 patients, 30% received KRAS testing, and 44% of these had mutations. Those tested tended to be younger, married, and metropolitan area residents, and have private insurance or Medicare. Rates of KRAS testing also varied by registry (range, 20%-46%). Patients with right-sided colon cancer (vs left-sided) tended to be older, female, and black; have mucinous, KRAS-mutant tumors; and have a greater risk of death (hazard ratio [HR], 1.27; 95% CI, 1.22-1.32). KRAS mutations were not associated with greater risk of death in the overall population; however, they were associated with greater risk of death among patients with left-sided colon cancer (HR, 1.19; 95% CI, 1.05-1.33). Conclusions: This large population-based study showed that among patients initially diagnosed with stage IV CRC, right-sided colon cancer was associated with greater risk of death compared with left-sided cancer, and KRAS mutations were only associated with risk of death in left-sided colon cancer. An unexpected finding was that among patients with stage IV disease, right-sided cancer was more commonly seen in black patients versus whites. Future studies should further explore these associations and determine the role of biology versus treatment differences. In addition, use of KRAS testing is increasing, but there is wide geographic variation wherein disparities related to insurance coverage and rurality may warrant further study.

Population-Based Lynch Syndrome Screening by Microsatellite Instability in Patients ≤50: Prevalence, Testing Determinants, and Result Availability Prior to Colon Surgery.

OBJECTIVES: As there are no US population-based studies examining Lynch syndrome (LS) screening frequency by microsatellite instability (MSI) and immunohistochemistry (IHC), we seek to quantitate statewide rates in patients aged ≤50 years using data from a Centers for Disease Control and Prevention-funded Comparative Effectiveness Research (CER) project and identify factors associated with testing. Screening rates in this young, high-risk population may provide a best-case scenario as older patients, potentially deemed lower risk, may undergo testing less frequently. We also seek to determine how frequently MSI/IHC results are available preoperatively, as this may assist with decisions regarding colonic resection extent. METHODS: Data from all Louisiana colorectal cancer (CRC) patients aged ≤50 years diagnosed in 2011 were obtained from the Louisiana Tumor Registry CER project. Registry researchers and physicians analyzed data, including pathology and MSI/IHC. RESULTS: Of the 2,427 statewide all-age CRC patients, there were 274 patients aged ≤50 years, representing health care at 61 distinct facilities. MSI and/or IHC were performed in 23.0% of patients. Testing-associated factors included CRC family history (P<0.0045), urban location (P<0.0370), and care at comprehensive cancer centers (P<0.0020) but not synchronous/metachronous CRC or MSI-like histology. Public hospital screening was disproportionately low (P<0.0217). Of those tested, MSI and/or IHC was abnormal in 21.7%. Of those with abnormal IHC, staining patterns were consistent with LS in 87.5%. MSI/IHC results were available preoperatively in 16.9% of cases. CONCLUSIONS: Despite frequently abnormal MSI/IHC results, LS screening in young, high-risk patients is low. Provider education and disparities in access to specialized services, particularly in underserved populations, are possible contributors. MSI/IHC results are infrequently available preoperatively.

A multi-cancer early detection blood test using machine learning detects early-stage cancers lacking USPSTF-recommended screening.

US Preventive Services Task Force (USPSTF) guidelines recommend single-cancer screening for select cancers (e.g., breast, cervical, colorectal, lung). Advances in genome sequencing and machine learning have facilitated the development of blood-based multi-cancer early detection (MCED) tests intended to complement single-cancer screening. MCED tests can interrogate circulating cell-free DNA to detect a shared cancer signal across multiple tumor types. We report real-world experience with an MCED test that detected cancer signals in three individuals subsequently diagnosed with cancers of the ovary, kidney, and head/neck that lack USPSTF-recommended screening. These cases illustrate the potential of MCED tests to detect early-stage cancers amenable to cure.

The rising tide of early-onset colorectal cancer: a comprehensive review of epidemiology, clinical features, biology, risk factors, prevention, and early detection.

The incidence of early-onset colorectal cnacer-ie, colorectal cancer diagnosed in patients under the age of 50 years- has been increasing around the world. This Series paper provides a comprehensive review on the topic of early-onset colorectal cancer, including examining the epidemiology of early-onset colorectal cancer around the world, clinical and pathological features, genetic and epigenetic landscapes, and emerging data on the clinical risk factors associated with this malignancy. Evidence-based approaches to prevention and early detection are also presented.

Cost-Effectiveness of Outreach Strategies for Stool-Based Colorectal Cancer Screening in a Medicaid Population.

Outreach, including patient navigation, has been shown to increase the uptake of colorectal cancer (CRC) screening in underserved populations. This analysis evaluates the cost-effectiveness of triennial multi-target stool DNA (mt-sDNA) versus outreach, with or without a mailed annual fecal immunochemical test (FIT), in a Medicaid population. A microsimulation model estimated the incremental cost-effectiveness ratio using quality-adjusted life years (QALY), direct costs, and clinical outcomes in a cohort of Medicaid beneficiaries aged 50-64 years, over a lifetime time horizon. The base case model explored scenarios of either 100% adherence or real-world reported adherence (51.3% for mt-sDNA, 21.1% for outreach with FIT and 12.3% for outreach without FIT) with or without real-world adherence for follow-up colonoscopy (66.7% for all). Costs and outcomes were discounted at 3.0%. At 100% adherence to both screening tests and follow-up colonoscopy, mt-sDNA costed more and was less effective compared with outreach with or without FIT. When real-world adherence rates were considered for screening strategies (with 100% adherence for follow-up colonoscopy), mt-sDNA resulted in the greatest reduction in incidence and mortality from CRC (41.5% and 45.8%, respectively) compared with outreach with or without FIT; mt-sDNA also was cost-effective versus outreach with and without FIT ($32,150/QALY and $22,707/QALY, respectively). mt-sDNA remained cost-effective versus FIT, with or without outreach, under real-world adherence rates for follow-up colonoscopy. Outreach or navigation interventions, with associated real-world adherence rates to screening tests, should be considered when evaluating the cost-effectiveness of CRC screening strategies in underserved populations.

Shifts in the Proportion of Distant Stage Early-Onset Colorectal Adenocarcinoma in the United States.

BACKGROUND: Carcinoids, frequently classified as "colorectal cancer" contribute to rising early-onset colorectal cancer (EOCRC) incidence rates (IR) and have distinct staging distributions compared to often advanced stage adenocarcinomas (screening target). Thus, assessing temporal shifts in early-onset distant stage adenocarcinoma can impact public health. METHODS: 2000-2016 Surveillance Epidemiology and End Results (SEER) 18 yearly adenocarcinoma IRs were stratified by stage (in situ, localized, regional, distant), age (20-29, 30-39, 40-49, 50-54-year-olds), subsite (colorectal, rectal-only, colon-only), and race [non-Hispanic whites, non-Hispanic Blacks (NHB), Hispanics] in 103,975 patients. Three-year average annual IR changes (pooled 2000-2002 IRs compared with 2014-2016) and cancer stage proportions (percent contribution of each cancer stage) were calculated. RESULTS: Comparing 2000-2002 with 2014-2016, the steepest percent increases are in distant stage cancers. Colon-only, distant adenocarcinoma increased most in 30-39-year-olds (49%, 0.75/100,000→1.12/100,00, P < 0.05). Rectal-only, distant stage increases were steepest in 20-29-year-olds (133%, 0.06/100,000→0.14/100,000, P < 0.05), followed by 30-39-year-olds (97%, 0.39/100,000→0.77/100,000, P < 0.05) and 40-49-year-olds (48%, 1.38/100,000→2.04/100,000, P < 0.05). Distant stage proportions (2000-2002 to 2014-2016) increased for colon-only and rectal-only subsites in young patients with the largest increases for rectal-only in 20-29-year-olds (18%→31%) and 30-39-year-olds (20%→29%). By race, distant stage proportion increases were largest for rectal-only in 20-29-year-old NHBs (0%→46%) and Hispanics (28%→41%). Distant colon proportion increased most in 20-29-year-old NHBs (20%→34%). CONCLUSIONS: Youngest patients show greatest burdens of distant colorectal adenocarcinoma. Although affecting all races, burdens are higher in NHB and Hispanic subgroups, although case counts remain relatively low. IMPACT: Optimizing earlier screening initiatives and risk-stratifying younger patients by symptoms and family history are critical to counteract rising distant stage disease.

Impact of Relative Dose Intensity of FOLFOX Adjuvant Chemotherapy on Risk of Death Among Stage III Colon Cancer Patients.

BACKGROUND: The National Comprehensive Cancer Network (NCCN) guidelines have recommended tailored chemotherapy for stage III high-risk (T4 and/or N2) and low-risk (T1-T3 and N1) colon cancer since 2018. Studies have investigated the effect of relative dose intensity (RDI) of FOLFOX on stage III colon cancer survival, however, none has performed a stratified analysis by risk profiles. This study aims to identify the FOLFOX optimal RDI for high-risk and low-risk stage III colon cancer patients. METHODS: Data on 407 eligible patients, diagnosed with stage III colon cancer in 2011 who received FOLFOX, were collected by 8 population-based cancer registries. Multivariable Cox model and Fine-Gray competing risks model were employed to explore Optimal RDI defined as the lowest RDI administered without significant differences in either overall or cause-specific death. RESULTS: Among the 168 high-risk patients, the optimal RDI cut-off was 70% (HR = 1.59 with 95% CI: 0.69-3.66 in overall mortality; HR = 1.24 with 95% CI: 0.42-3.64 in cause-specific mortality when RDI < 70% vs. RDI ≥ 70%). Among the 239 low-risk patients, none of the evaluated cut-offs were associated with significant differences in risk of death between comparison groups. The lowest assessed RDI was 45%, HR = 0.80; 95% CI: 0.24 to 2.73 for overall mortality and HR = 0.53; 95% CI: 0.06 to 4.95 for cause-specific mortality, when RDI <45% versus RDI ≥45%. CONCLUSIONS: There is no significant harm on the risk of death when reducing RDI by <30% for high-risk patients. For the low-risk patients, we found that RDI as low as 45% did not significantly affect the risk of death.

Effectiveness of hepatitis C treatment with pegylated interferon and ribavirin in urban minority patients.

Randomized controlled trials of hepatitis C virus (HCV) therapy with pegylated interferon and ribavirin have demonstrated sustained viral response rates (SVRs) of 54%-63% (efficacy). Treatment results in clinical practice (effectiveness) may not be equivalent. The goal of this study was to assess the effectiveness of HCV treatment with pegylated interferon and ribavirin in a treatment-naïve, human immunodeficiency virus (HIV)-negative, United States urban population with many ethnic minority patients. We evaluated 2,370 outpatients for HCV therapy from 2001 to 2006 in the Faculty Practice of the Albert Einstein College of Medicine or the attending-supervised Montefiore Medical Center Liver Clinic. Care was supervised by one experienced physician under conditions of everyday clinical practice, and appropriate ancillary resources were made available to all patients. Two hundred fifty-five patients were treated with a mean age of 50 years (60% male, 40% female; 58% Hispanic, 20% African American, 9% Caucasian, 13% other; 68% genotype 1, the remainder genotypes 2 or 3). Patients had at least one liver biopsy. Intention-to-treat analysis (ITT) showed SVR in 14% of genotype 1 patients and 37% in genotype 2/3 patients (P < 0.001). SVR was significantly higher in faculty practice (27%) than in clinic patients (15%) by intention-to-treat (P = 0.01) but not per-protocol analysis (46% faculty practice, 34% clinic). 3.3% of 1,656 treatment-naïve, HIV antibody-negative individuals ultimately achieved SVR. Current hepatitis C therapies may sometimes be unavailable to, inappropriate for, and ineffective in United States urban patients. Treatment with pegylated interferon and ribavirin was less effective in this population than is implied by multinational phase III controlled trials. New strategies are needed to care for such patients.

Genetic Analysis of Archived Tumor Specimens for Hereditary Colorectal Cancer Syndromes in the Cajuns of Louisiana, a US Founder Population.

INTRODUCTION: The Louisiana Acadian region (population 1.2 million), home of the Cajuns, has among the highest US colorectal cancer (CRC) rates. Although Cajuns are a known genetic founder population, studies assessing for hereditary CRC have not been performed. METHODS: A retrospective review of 2 hospital cancer registries was performed to identify young (<55) Cajun CRC patients in Lafayette, Louisiana (the Acadian region population center), diagnosed from 2003 to 2016. Men were studied because of the higher likelihoods of retaining Cajun surnames for ancestry identification compared with women. Immunohistochemistry for mismatch repair proteins associated with the Lynch syndrome (LS) was performed on tumors. Germline sequencing was performed on adjacent normal tissue of these archived formalin-fixed paraffin-embedded surgical resection specimens for pathogenic variants underlying CRC-associated syndromes, including LS, familial adenomatous polyposis, and others. RESULTS: Of 9 young Cajuns, a germline analysis revealed LS in 2 (MLH1 frameshift, MLH1 missense pathogenic variants). Both had immunohistochemistry-deficient MLH1. Two others had the same adenomatous polyposis coli variant of unknown significance (2 algorithms predicting deleterious and probably damaging change), making this a potential familial adenomatous polyposis founder effect candidate. DISCUSSION: This is the first study assessing for hereditary CRC in a large US regional founder population. This small study did not identify clear Cajun founder pathogenic variants. However, larger studies are warranted, which could also help clarify the clinical significance of the adenomatous polyposis coli variant of unknown significance. This study is important because it demonstrates that a retrospective tumor analysis can be used to ascertain the prevalence of genetic susceptibility in specific populations.