Proliferation, apoptosis and their regulatory protein expression in colorectal adenomas and serrated lesions.

BACKGROUND: Adenomas and serrated lesions represent heterogeneous sets of early precursors in the colorectum with varying malignant potential. They are often distinguished by their histopathologic differences, but little is known about potential differences in regulation of epithelial proliferation and apoptosis. METHODS: We conducted a protein expression analysis using tissue microarrays of 625 colorectal adenomas and 142 serrated lesions to determine potential differences in regulation of epithelial proliferation and apoptosis. We quantitated proliferation with Ki-67; apoptosis with activated caspase-3 (CASP3); up- and down-regulators of proliferation with cyclin D1, p16INK2, and p21Cip1; and apoptosis regulators with BAX, BCL2, and survivin. Linear mixed effects models and circos diagrams were used to determine relationships among expression and lesion characteristics. RESULTS: Adenomas had a significantly higher CASP-3 labeling index (LI) than serrated lesions, resulting in a lower net growth ratio (Ki-67 LI/activated CASP-3 LI, p-value<0.0001). Cyclin D1 LI, p16 LI and p21 LI were lower in adenomas compared to serrated lesions, while expression of both BCL2 and BAX were higher (p <0.001). Among adenomas, cyclin D1 LI and p16 LI levels increased with greater villous component, and the highest BAX expression was detected in adenomas larger than 2 cm (both p<0.0001). Right-sided adenomas had higher CASP3 LI than left colorectal adenomas (p = 0.008). Significant differences in cyclin D1 LI, p21 LI and survivin LI were also observed across histopathologic subtypes of serrated lesions. CONCLUSIONS: Our findings demonstrate different patterns of regulatory protein expression in adenomas than serrated lesions, especially involving apoptosis. ClinicalTrials.gov Identifier: NCT00272324.

Prevalence of Advanced Colorectal Neoplasia in Veterans: Effects of Age, Sex, and Race/Ethnicity.

GOAL: We sought to quantify the independent effects of age, sex, and race/ethnicity on risk of colorectal cancer (CRC) and advanced neoplasia (AN) in Veterans. STUDY: We conducted a retrospective, cross-sectional study of Veterans aged 40 to 80 years who had diagnostic or screening colonoscopy between 2002 and 2009 from 1 of 14 Veterans Affairs Medical Centers. Natural language processing identified the most advanced finding and location (proximal, distal). Logistic regression was used to examine the adjusted, independent effects of age, sex, and race, both overall and in screening and diagnostic subgroups. RESULTS: Among 90,598 Veterans [mean (SD) age 61.7 (9.4) y, 5.2% (n=4673) were women], CRC and AN prevalence was 1.3% (n=1171) and 8.9% (n=8081), respectively. Adjusted CRC risk was higher for diagnostic versus screening colonoscopy [odds ratio (OR)=3.79; 95% confidence interval (CI), 3.19-4.50], increased with age, was numerically (but not statistically) higher for men overall (OR=1.53; 95% CI, 0.97-2.39) and in the screening subgroup (OR=2.24; 95% CI, 0.71-7.05), and was higher overall for Blacks and Hispanics, but not in screening. AN prevalence increased with age, and was present in 9.2% of men and 3.9% of women [adjusted OR=1.90; 95% CI, 1.60-2.25]. AN risk was 11% higher in Blacks than in Whites overall (OR=1.11; 95% CI, 1.04-1.20), was no different in screening, and was lower in Hispanics (OR=0.74; 95% CI, 0.55-0.98). Women had more proximal CRC (63% vs. 39% for men; P=0.03), but there was no difference in proximal AN (38.3% for both genders). CONCLUSIONS: Age and race were associated with AN and CRC prevalence. Blacks had a higher overall prevalence of both CRC and AN, but not among screenings. Men had increased risk for AN, while women had a higher proportion of proximal CRC. These findings may be used to tailor when and how Veterans are screened for CRC.

Increased Risk of Colorectal Cancer Tied to Advanced Colorectal Polyps: An Untapped Opportunity to Screen First-Degree Relatives and Decrease Cancer Burden.

Advanced adenomas represent a subset of colorectal polyps that are known to confer an increased risk of colorectal neoplasia to the affected individual and their first-degree relatives (FDRs). Accordingly, professional guidelines suggest earlier and more intensive screening for FDRs of those with advanced adenomas similar to FDRs of those with colorectal cancer (CRC). Although the risk to family members is less clear among patients with advanced serrated polyps, they are often considered in the same category. Unfortunately, there is a growing concern that patients, endoscopists, and primary care providers are unaware of the familial risk associated with these polyps, leaving a wide gap in screening these high-risk individuals. Herein, we propose a standardized language around advanced colorectal polyps and present a detailed review of the literature on associated familial risk. We outline the challenges to implementing the current screening recommendations and suggest approaches to overcome these limitations, including a proposed new colonoscopy quality metric to capture communication of familial CRC risk. Improving screening in these high-risk groups has the potential to substantially reduce the burden of CRC.

Evidenced-Based Screening Strategies for a Positive Family History.

The most commonly recognized high-risk group for colorectal cancer (CRC) is individuals with a positive family history. It is generally recognized that those with a first-degree relative (FDR) with CRC are at a 2-fold or higher risk of CRC or advanced neoplasia. FDRs of patients with advanced adenomas have a similarly increased risk. Accordingly, all major US guidelines recommend starting CRC screening by age 40 in these groups. Barriers to screening this group include patient lack of knowledge on family and polyp history, provider limitations in collecting family history, and insufficient application of guidelines.

Potential impact of family history-based screening guidelines on the detection of early-onset colorectal cancer.

BACKGROUND: Initiating screening at an earlier age based on cancer family history is one of the primary recommended strategies for the prevention and detection of early-onset colorectal cancer (EOCRC), but data supporting the effectiveness of this approach are limited. The authors assessed the performance of family history-based guidelines for identifying individuals with EOCRC. METHODS: The authors conducted a population-based, case-control study of individuals aged 40 to 49 years with (2473 individuals) and without (772 individuals) incident CRC in the Colon Cancer Family Registry from 1998 through 2007. They estimated the sensitivity and specificity of family history-based criteria jointly recommended by the American Cancer Society, the US Multi-Society Task Force on CRC, and the American College of Radiology in 2008 for early screening, and the age at which each participant could have been recommended screening initiation if these criteria had been applied. RESULTS: Family history-based early screening criteria were met by approximately 25% of cases (614 of 2473 cases) and 10% of controls (74 of 772 controls), with a sensitivity of 25% and a specificity of 90% for identifying EOCRC cases aged 40 to 49 years. Among 614 individuals meeting early screening criteria, 98.4% could have been recommended screening initiation at an age younger than the observed age of diagnosis. CONCLUSIONS: Of CRC cases aged 40 to 49 years, 1 in 4 met family history-based early screening criteria, and nearly all cases who met these criteria could have had CRC diagnosed earlier (or possibly even prevented) if earlier screening had been implemented as per family history-based guidelines. Additional strategies are needed to improve the detection and prevention of EOCRC for individuals not meeting family history criteria for early screening.

Poor Knowledge of Personal and Familial Colorectal Cancer Risk and Screening Recommendations Associated with Advanced Colorectal Polyps.

BACKGROUND AND AIMS: Advanced colorectal polyps (adenoma or sessile serrated polyp ≥ 1 cm, adenoma with villous features, adenoma with high-grade dysplasia, or any sessile serrated polyps with dysplasia) are associated with an increased risk of future advanced colorectal neoplasia and confer an increased risk of advanced neoplasia to first-degree family members. Professional societies therefore recommend more intensive surveillance of these polyps and earlier screening for first-degree relatives. The aim of this study was to assess knowledge of personal and familial risk and recommendations among patients with advanced colorectal polyps and identify predictors of knowledge. METHODS: An online survey was designed to assess the domains of knowledge and risk perception regarding personal and familial colorectal cancer risk and screening recommendations. After expert review and pilot testing, the 37-item survey was electronically sent to all patients diagnosed with an advanced colon or rectal polyp under the age of 60. Patient report of polyp findings was compared to documented findings in the medical record. Univariable and multivariable regressions were performed to evaluate predictors of knowledge. RESULTS: One hundred thirty-seven out of 344 (39.8%) eligible patients responded to the survey. 28.5% of participants reported that the polyp they had removed was precancerous. 54.8% of participants reported that they have a higher risk of CRC, and 65.2% reported that they should be undergoing colonoscopy surveillance in 3 years or less. 40.1% reported that their first-degree family members are at increased CRC risk, and 38.0% reported that first-degree family members should get earlier screening. Participants reported their endoscopists as their top source of information about risk and recommendations, though only 7.3% of endoscopists made recommendations for family members. Female gender and higher income were predictors of accurate knowledge, as endoscopist was the main source of knowledge. CONCLUSIONS: Patients with advanced colorectal polyps have poor knowledge of personal and familial CRC risk and recommendations. Endoscopists who remove advanced polyps are in an ideal position to educate their patients about their personal risk and the risk and recommendations for first-degree family members.

Quantifying the impact of adherence to screening strategies on colorectal cancer incidence and mortality.

Current recommendations of The US Preventive Services Task Force (USPSTF) on colorectal cancer (CRC) screening strategies are based on models that assume 100% adherence. Since adherence can have a large effect on screening outcomes, we aimed to compare the effectiveness of CRC screening strategies under reported adherence rates at the population level. We developed and validated a microsimulation model to assess the effectiveness of colonoscopy (COL), flexible sigmoidoscopy (FS), high-sensitivity guaiac fecal occult blood-test (HS-gFOBT), fecal immunochemical test (FIT), multitarget stool DNA test (FIT-DNA), computed tomography colonography (CTC), and methylated SEPT9 DNA test (SEPT9) in terms of CRC incidence and mortality, incremental life years gained (LYG), number of colonoscopies, and adverse events for men and women 50 years or older over their lifetime. We assessed outcomes under 100% adherence rates and reported adherence rates. We also performed sensitivity analyses to evaluate the impact of varying adherence levels on CRC outcomes. Assuming 100% adherence, FIT-DNA, FIT, HS-gFOBT, and SEPT9 averted 42-45 CRC cases and 25-26 CRC deaths, COL 46 cases and 26 deaths, CTC 39 cases and 23 deaths, FS 32 cases and 19 deaths per 1000 individuals. Assuming reported adherence, SEPT9 averted 37 CRC cases and 23 CRC deaths, COL 34 cases and 20 deaths, FIT-DNA, FIT, CTC and HS-gFOBT 16-25 cases and 10-16 deaths per 1000 individuals. LYG reflected the effectiveness of each strategy in reducing CRC cases and deaths. Adverse events were more common for COL (3.7 per 1000 screened) and annual SEPT9 (3.4 per 1000 screened), and proportional to the number of colonoscopies. Among the screening strategies recommended by USPSTF, colonoscopy results in the largest benefit when we account for adherence. Adherence rates higher than 65%-70% would be required for any stool or blood-based screening modality to match the benefits of colonoscopy.

NCCN Guidelines Insights: Genetic/Familial High-Risk Assessment: Colorectal, Version 2.2019.

Identifying individuals with hereditary syndromes allows for improved cancer surveillance, risk reduction, and optimized management. Establishing criteria for assessment allows for the identification of individuals who are carriers of pathogenic genetic variants. The NCCN Guidelines for Genetic/Familial High-Risk Assessment: Colorectal provide recommendations for the assessment and management of patients with high-risk colorectal cancer syndromes. These NCCN Guidelines Insights focus on criteria for the evaluation of Lynch syndrome and considerations for use of multigene testing in the assessment of hereditary colorectal cancer syndromes.

Folic acid supplementation and risk of colorectal neoplasia during long-term follow-up of a randomized clinical trial.

BACKGROUND: The Aspirin/Folate Polyp Prevention Study previously found folic acid increased risk of advanced and multiple colorectal adenomas during a surveillance colonoscopy interval starting about 3 y after randomization. OBJECTIVE: We conducted secondary analyses to evaluate folic acid effects with additional follow-up after treatment was stopped. METHODS: In total, 1021 participants recently diagnosed with colorectal adenomas were randomly assigned to 1 mg/d of folic acid (n = 516) or placebo (n = 505), with or without aspirin, beginning 6 July 1994. The original 3-y treatment period was extended into a subsequent colonoscopy interval, but eventually stopped prematurely on 1 October 2004. With additional post-treatment follow-up, a total of 663 participants who extended treatment completed a second colonoscopic surveillance interval after the initial 3-y follow-up. In addition, 490 participants provided information regarding a subsequent surveillance colonoscopy occurring before completion of follow-up on 31 May 2012, including 325 who had agreed to extended treatment. Study endpoints included conventional adenomas, sessile serrated adenomas/polyps (SSA/Ps), or colorectal cancer, and RRs with 95% CIs were adjusted for baseline characteristics associated with availability of follow-up. RESULTS: Among those who extended treatment, any colorectal neoplasia was found in 118 (36%) participants assigned to placebo and 146 (43%) assigned to folic acid during the second surveillance interval (RR: 1.21; 95% CI: 0.99, 1.47; P = 0.06). Increased risk of SSA/P with extended folic acid supplementation was statistically significant during the second surveillance interval (RR: 1.94; 95% CI: 1.02, 3.68; P = 0.04). There was no evidence of post-treatment effects for any colorectal neoplasia (RR: 1.01; 95% CI: 0.80, 1.28; P = 0.94), and the post-treatment effect for SSA/P was no longer statistically significant (RR: 1.38; 95% CI: 0.59, 3.19; P = 0.46). CONCLUSIONS: Delayed treatment effects were not observed, but folic acid may increase SSA/P risk. This trial was registered at clinicaltrials.gov as NCT00272324.

Body Composition and Aspirin Dose for Colorectal Adenoma Prevention in a Randomized Clinical Trial.

BACKGROUND: Visceral adiposity is a risk factor for colorectal adenomas, and aspirin is an established chemopreventive agent. Evidence from clinical trials suggests the effectiveness of aspirin at preventing cardiovascular disease and cancer may require higher doses for higher body weight. METHODS: Body mass index, body surface area, fat-free mass, and fat mass were calculated from baseline height and weight in 1,121 participants of the Aspirin/Folate Polyp Prevention Study, a double-blind, placebo-controlled, 3 × 2 factorial randomized clinical trial of low-dose (81 mg/day) or high-dose (325 mg/day) aspirin and/or 1 mg/day folic acid to prevent metachronous colorectal adenomas. Participants were treated during a surveillance colonoscopy interval of approximately 3 years. Risk ratios (RR) with 95% confidence intervals (CI) for any colorectal neoplasia and high-risk adenoma (HRA, advanced or ≥3 adenomas) were estimated from log-linear regression. RESULTS: We did not find evidence to suggest aspirin dose-response differed by body composition measurements, including weight alone. Among those weighing ≥ 80 kg, treatment effects for low-dose aspirin (RR for colorectal neoplasia, 0.75; 95% CI, 0.60-0.94; RR for HRA, 0.52; 95% CI, 0.31-0.86) and high-dose aspirin (RR for colorectal neoplasia, 0.88; 95% CI, 0.72-1.08; RR for HRA, 0.68; 95% CI, 0.43-1.09) were not meaningfully different than for those weighing 70-79 kg or <70 kg. CONCLUSIONS: Measurements of body composition calculated from height and weight did not modify aspirin treatment effects for colorectal adenoma prevention. IMPACT: Aspirin dosing strategies accounting for body weight suggested in previous trials of colorectal cancer may not apply to adenomas.

Ability of known susceptibility SNPs to predict colorectal cancer risk for persons with and without a family history.

Before SNP-based risk can be incorporated in colorectal cancer (CRC) screening, the ability of these SNPs to estimate CRC risk for persons with and without a family history of CRC, and the screening implications need to be determined. We estimated the association with CRC of a 45 SNP-based risk using 1181 cases and 999 controls, and its correlation with CRC risk predicted from detailed family history. We estimated the predicted change in the distribution across predefined risk categories, and implications for recommended screening commencement age, from adding SNP-based risk to family history. The inter-quintile risk ratio for colorectal cancer risk of the SNP-based risk was 3.28 (95% CI 2.54-4.22). SNP-based and family history-based risks were not correlated (r = 0.02). For persons with no first-degree relatives with CRC, screening could commence 4 years earlier for women (5 years for men) in the highest quintile of SNP-based risk. For persons with two first-degree relatives with CRC, screening could commence 16 years earlier for men and women in the highest quintile, and 7 years earlier for the lowest quintile. This 45 SNP panel in conjunction with family history, can identify people who could benefit from earlier screening. Risk reclassification by 45 SNPs could inform targeted screening for CRC prevention, particularly in clinical genetics settings when mutations in high-risk genes cannot be identified. Yet to be determined is cost-effectiveness, resources requirements, community, patient and clinician acceptance, and feasibility with potentially ethical, legal and insurance implications.

No Evidence for Posttreatment Effects of Vitamin D and Calcium Supplementation on Risk of Colorectal Adenomas in a Randomized Trial.

Vitamin D and calcium supplementation are postulated to have chemopreventive effects against colorectal neoplasia, yet in our previously reported randomized trial, there was no overall efficacy of calcium and/or vitamin D3 against colorectal adenoma recurrence. It is possible vitamin D3 and calcium chemopreventive effects are not detectable until beyond the 3- to 5-year follow-up captured in that trial. Accordingly, we explored possible vitamin D and calcium effects on posttreatment (observational) adenoma occurrence. In this secondary analysis of the observational follow-up phase of the Vitamin D/Calcium Polyp Prevention Study, participants who completed the treatment phase were invited to be followed for one additional surveillance colonoscopy cycle. We evaluated adenoma occurrence risk at surveillance colonoscopy, with a mean of 55 ± 15 months after treatment follow-up, according to randomized treatment with vitamin D versus no vitamin D, calcium versus no calcium, and calcium plus vitamin D versus calcium alone. Secondary outcomes included advanced and multiple adenomas. Among the 1,121 participants with observational follow-up, the relative risk (95% confidence interval, CI) of any adenoma was 1.04 (0.93-1.17) for vitamin D versus no vitamin D; 0.95 (0.84-1.08) for calcium versus no calcium; 1.07 (0.91-1.25) for calcium plus vitamin D versus calcium; and 0.96 (0.81-1.15) for calcium plus vitamin D versus neither. Risks of advanced or multiple adenomas also did not differ by treatment. Our results do not support an association between supplemental calcium and/or vitamin D3 for 3 to 5 years and risk of recurrent colorectal adenoma at an average of 4.6 years after treatment.

Calcium and vitamin D supplementation and increased risk of serrated polyps: results from a randomised clinical trial.

OBJECTIVE: Serrated lesions such as sessile serrated adenomas or polyps (SSA/Ps) are important colorectal cancer precursors, but aetiological factors for these lesions are largely unknown. We aimed to determine the effects of calcium and vitamin D supplementation on the incidence of serrated polyps (SPs) in general and hyperplastic polyps and SSA/Ps specifically. DESIGN: Participants with one or more adenoma at baseline were randomised to receive 1200 mg/day of elemental calcium, 1000 IU/day of vitamin D3, both or neither agent. Treatment continued for 3 or 5 years, when risk of polyps was determined from surveillance colonoscopy (treatment phase). Outcomes after treatment ceased were also assessed (observational phase). Adjusted risk ratios (aRRs) of SPs were determined via multivariable generalised linear models. RESULTS: SPs were diagnosed in 565 of 2058 (27.5%) participants during the treatment phase and 329/1108 (29.7%) during the observational phase. In total, 211 SSA/Ps were identified during follow-up. In the treatment phase, there was no effect of either calcium or vitamin D on incidence of SSA/Ps. However, during the later observational phase, we observed elevated risks of SSA/Ps associated with calcium alone and calcium+vitamin D treatment (aRR (95% CI): 2.65 (1.43 to 4.91) and 3.81 (1.25 to 11.64), respectively). CONCLUSION: In a large multicentre chemoprevention study, we found evidence that calcium and vitamin D supplementation increased the risk of SSA/Ps. This appeared to be a late effect: 6-10 years after supplementation began. These possible risks must be weighed against the benefits of calcium and vitamin D supplementation. : Trial registration NUMBER: NCT00153816; Results.

Body mass index, calcium supplementation and risk of colorectal adenomas.

Calcium supplementation (1,200 mg/day) did not significantly reduce colorectal adenomas in our recent randomized, controlled trial (Vitamin D/Calcium Polyp Prevention Study, VCPPS, 2004-2013) in contrast to our previous trial (Calcium Polyp Prevention Study, CPPS, 1988-1996). To reconcile these findings, we identified participant characteristics that differed between the study populations and modified the effect of calcium supplementation on adenomas or high-risk findings (advanced or multiple adenomas). Compared to the CPPS, more participants in the VCPPS were obese (body mass index (BMI) ≥30 kg/m2 ; 37.5% vs. 24.4%) and fewer had normal BMI (BMI <25 kg/m2 ; 18.5% vs. 31%). BMI appeared to modify the effect of calcium supplementation on adenomas and especially on high risk-findings: in the VCPPS, there was a 44% reduction in high-risk findings among individuals whose BMI was normal (RR = 0.56, 95% CI = 0.26-1.23), but not among overweight (RR = 1.09, 95% CI = 0.62-1.91) or obese (RR = 1.54, 95% CI = 0.92-2.57) individuals (pinteraction = 0.03). Similarly, in the CPPS, there was a 56% reduction in high-risk findings among individuals whose BMI was normal (RR = 0.44, 95% CI = 0.26-0.74), but not among overweight (RR = 0.87, 95% CI = 0.55-1.39) or obese (RR = 1.02, 95% CI = 0.57-1.82) individuals (pinteraction = 0.02). Standardization of each trial's findings to the BMI distribution in the other attenuated calcium's protective effect on adenomas in the CPPS but enhanced it in the VCPPS. In conclusion, 1,200 mg/day calcium supplementation may reduce risk of colorectal adenomas among those with normal BMI but not in overweight or obese individuals; and differences in BMI distribution partially account for the apparent difference in calcium efficacy between the two trials.

NCCN Guidelines Insights: Colorectal Cancer Screening, Version 1.2018.

The NCCN Guidelines for Colorectal Cancer (CRC) Screening outline various screening modalities as well as recommended screening strategies for individuals at average or increased-risk of developing sporadic CRC. The NCCN panel meets at least annually to review comments from reviewers within their institutions, examine relevant data, and reevaluate and update their recommendations. These NCCN Guidelines Insights summarize 2018 updates to the NCCN Guidelines, with a primary focus on modalities used to screen individuals at average-risk for CRC.

The impact of the rising colorectal cancer incidence in young adults on the optimal age to start screening: Microsimulation analysis I to inform the American Cancer Society colorectal cancer screening guideline.

BACKGROUND: In 2016, the Microsimulation Screening Analysis-Colon (MISCAN-Colon) model was used to inform the US Preventive Services Task Force colorectal cancer (CRC) screening guidelines. In this study, 1 of 2 microsimulation analyses to inform the update of the American Cancer Society CRC screening guideline, the authors re-evaluated the optimal screening strategies in light of the increase in CRC diagnosed in young adults. METHODS: The authors adjusted the MISCAN-Colon model to reflect the higher CRC incidence in young adults, who were assumed to carry forward escalated disease risk as they age. Life-years gained (LYG; benefit), the number of colonoscopies (COL; burden) and the ratios of incremental burden to benefit (efficiency ratio [ER] = ΔCOL/ΔLYG) were projected for different screening strategies. Strategies differed with respect to test modality, ages to start (40 years, 45 years, and 50 years) and ages to stop (75 years, 80 years, and 85 years) screening, and screening intervals (depending on screening modality). The authors then determined the model-recommended strategies in a similar way as was done for the US Preventive Services Task Force, using ER thresholds in accordance with the previously accepted ER of 39. RESULTS: Because of the higher CRC incidence, model-predicted LYG from screening increased compared with the previous analyses. Consequently, the balance of burden to benefit of screening improved and now 10-yearly colonoscopy screening starting at age 45 years resulted in an ER of 32. Other recommended strategies included fecal immunochemical testing annually, flexible sigmoidoscopy screening every 5 years, and computed tomographic colonography every 5 years. CONCLUSIONS: This decision-analysis suggests that in light of the increase in CRC incidence among young adults, screening may be offered earlier than has previously been recommended. Cancer 2018;124:2964-73. © 2018 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.