Barriers and proposed solutions to at-home colorectal cancer screening tests in medically underserved health centers across three US regions to inform a randomized trial.

INTRODUCTION: At-home colorectal cancer (CRC) screening is an effective way to reduce CRC mortality, but screening rates in medically underserved groups are low. To plan the implementation of a pragmatic randomized trial comparing two population-based outreach approaches, we conducted qualitative research on current processes and barriers to at-home CRC screening in 10 community health centers (CHCs) that serve medically underserved groups, four each in Massachusetts and California, and two tribal facilities in South Dakota. METHODS: We conducted 53 semi-structured interviews with clinical and administrative staff at the participating CHCs. Participants were asked about CRC screening processes, categorized into eight domains: patient identification, outreach, risk assessment, fecal immunochemical test (FIT) workflows, FIT-DNA (i.e., Cologuard) workflows, referral for a follow-up colonoscopy, patient navigation, and educational materials. Transcripts were analyzed using a Rapid Qualitative Analysis approach. A matrix was used to organize and summarize the data into four sub-themes: current process, barriers, facilitators, and solutions to adapt materials for the intervention. RESULTS: Each site's process for stool-based CRC screening varied slightly. Interviewees identified the importance of offering educational materials in English and Spanish, using text messages to remind patients to return kits, adapting materials to address health literacy needs so patients can access instructions in writing, pictures, or video, creating mailed workflows integrated with a tracking system, and offering patient navigation to colonoscopy for patients with an abnormal result. CONCLUSION: Proposed solutions across the three regions will inform a multilevel intervention in a pragmatic trial to increase CRC screening uptake in CHCs.

The Revised United States Preventive Services Task Force Screening Recommendations and Racial/Ethnic Differences in Colorectal Cancer Screening in a Boston Healthcare System.

INTRODUCTION: To evaluate the impact of the updated United States Preventive Services Task Force colorectal cancer (CRC) screening recommendations on screening rates in a large health system. METHODS: We reviewed Massachusetts General Brigham electronic health record data for individuals eligible for CRC screening between January 3, 2020, and January 5, 2023, and calculated whether age-eligible individuals were up-to-date with CRC screening. RESULTS: There were large declines in the percentage of individuals who were up-to-date with CRC screening for all racial/ethnic groups, with non-Hispanic Asians being largest (-13.5%). DISCUSSION: Health systems should implement culturally tailored strategies to reach and screen newly eligible individuals for CRC screening to prevent worsening disparities in CRC.

Community collaboration to advance racial/ethnic equity in colorectal Cancer screening: Protocol for a multilevel intervention to improve screening and follow-up in community Health centers.

INTRODUCTION: Colorectal cancer (CRC) screening utilization is low among low-income, uninsured, and minority populations that receive care in community health centers (CHCs). There is a need for evidence-based interventions to increase screening and follow-up care in these settings. METHODS: A multilevel, multi-component pragmatic cluster randomized controlled trial is being conducted at 8 CHCs in two metropolitan areas (Boston and Los Angeles), with two arms: (1) Mailed FIT outreach with text reminders, and (2) Mailed FIT-DNA with patient support. We also include an additional CHC in Rapid City (South Dakota) that follows a parallel protocol for FIT-DNA but is not randomized due to lack of a comparison group. Eligible individuals in participating clinics are primary care patients ages 45-75, at average-risk for CRC, and overdue for CRC screening. Participants with abnormal screening results are offered navigation for follow-up colonoscopy and CRC risk assessment. RESULTS: The primary outcome is the completion rate of CRC screening at 90 days. Secondary outcomes include the screening completion rate at 180 days and the rate of colonoscopy completion within 6 months among participants with an abnormal result. Additional goals are to enhance our understanding of facilitators and barriers to CRC risk assessment in CHC settings. CONCLUSIONS: This study assesses the effectiveness of two multilevel interventions to increase screening participation and follow-up after abnormal screening in under-resourced clinical settings, informing future efforts to address CRC disparities. TRIAL REGISTRATION: NCT05714644.

Impact of racial disparities in follow-up and quality of colonoscopy on colorectal cancer outcomes.

BACKGROUND: The benefits of colorectal cancer (CRC) screening programs rely on completing follow-up colonoscopy when a noncolonoscopy test is abnormal and on quality of colonoscopy screening as measured by the endoscopists' adenoma detection rate. Existing data demonstrate substantially lower follow-up colonoscopy rates and adenoma detection rate for Black Americans than White Americans. However, the contributions of racial differences in follow-up colonoscopy and adenoma detection rate on CRC outcomes have not been rigorously evaluated. METHODS: We used established and validated CRC-Adenoma Incidence and Mortality (CRC-AIM) model as our analysis platform, with inputs from published literature that report lower follow-up colonoscopy rates and adenoma detection rate in Black adults compared with White adults (15% and 10% lower, respectively). We simulated screening with annual fecal immunochemical test, triennial multitarget stool DNA, and colonoscopy every 10 years between ages 45 and 75 years using real-world utilization of the screening modalities vs no screening. We reported lifetime outcomes per 1000 Black adults. RESULTS: Elimination of Black-White disparities in follow-up colonoscopy rates would reduce CRC incidence and mortality by 5.2% and 9.3%, respectively, and improve life-years gained with screening by 3.4%. Elimination of Black-White disparities in endoscopists' adenoma detection rate would reduce CRC incidence and mortality by 9.4% and improve life-years gained by 3.7%. Elimination of both disparities would reduce CRC incidence and mortality by 14.6% and 18.7%, respectively, and improve life-years gained by 7.1%. CONCLUSIONS: This modeling study predicts eliminating racial differences in follow-up colonoscopy rates, and quality of screening colonoscopy would substantially reduce Black-White disparities in CRC incidence and mortality.

Colorectal Cancer Screening Rates at Federally Qualified Health Centers From 2014 to 2022: Incomplete Recovery From COVID-19 and Worsening Disparities.

INTRODUCTION: Federally Qualified Health Centers (FQHC) provide preventive health services such as colorectal cancer (CRC) screening to low-income and underinsured individuals. Overall CRC screening participation in the United States declined during the COVID-19 pandemic and recovered by 2021; however, trends in underresourced settings are unknown. METHODS: Using Uniform Data System data from 2014 to 2022, we assessed trends in FQHC CRC screening rates nationally, in California, and in Los Angeles County and determined clinic-level factors associated with recent screening rate changes. For each FQHC, we calculated the screening rate change from 2019 to 2020, 2020 to 2021, and 2020 to 2022. We used mixed-effects linear regression to determine clinic-level characteristics associated with each screening rate change. RESULTS: Across all FQHC (n = 1,281), 7,016,181 patients were eligible for CRC screening in 2022. Across the United States and in California, median screening rates increased from 2014 to 2019, severely declined in 2020, and failed to return to prepandemic levels by 2022. Both nationally and in California, CRC screening declined most dramatically from 2019 to 2020 in FQHC serving majority Hispanic/Latino patients or a high proportion of patients experiencing homelessness. From 2020 to 2022, screening rates did not recover completely in US FQHC, with disproportionate recovery among FQHC serving majority non-Hispanic Black patients. DISCUSSION: CRC screening rates at FQHC did not return to prepandemic levels by 2022, and recovery varied by FQHC patient characteristics. Tailored interventions addressing low and decreasing CRC screening rates in FQHC are urgently needed to mitigate worsening CRC disparities.

Vulnerability and Colorectal screening during the pandemic.

Objective: Disparities in colorectal cancer (CRC) screening prevalence across United States neighborhoods may reflect social inequities that create barriers to accessing and completing preventive health services. Our objective was to identify whether neighborhood social vulnerability was associated with a change in CRC screening prevalence in Boston neighborhoods during the COVID-19 pandemic. Methods: Adults ages 50-74 years due for CRC screening who received primary care at one of 35 primary care practices affiliated with Massachusetts General Hospital or Brigham and Women's Hospital (Boston, MA), 3/1/2020 to 3/1/2022. The Social Vulnerability Index (SVI) is an aggregate measure of neighborhood social factors often used by public health authorities to examine neighborhood susceptibility to many health outcomes. Results: In 2020, 74.9 % of eligible individuals were up to date with CRC screening and this fell to 67.4 % in 2022 (p < 0.001). In 2020, 36.2 % of eligible patients lived in a neighborhood above the 80th percentile of SVI, consistent with high social vulnerability, while the same value was 35.1 % in 2022. There was no association between the change in screening prevalence and SVI: a decrease of 5.5 % screened in neighborhoods with SVI ≤ 80 compared to a decrease of 3.6 % in neighborhoods with SVI > 80 (p = 0.79). Conclusions: The COVID-19 pandemic equalized the prevalence of CRC screening across Boston-area neighborhoods despite pre-existing geographic disparities in screening prevalence and SVI. Strategies to ensure equitable participation in CRC screening to promote health equity should be considered to promote equitable pandemic recovery.

Racial Disparities in Receipt of Guideline-Concordant Care for Early-Onset Colorectal Cancer in the United States.

PURPOSE: Young individuals racialized as Black are more likely to die after a colorectal cancer (CRC) diagnosis than individuals racialized as White in the United States. This study examined racial disparities in receipt of timely and guideline-concordant care among individuals racialized as Black and White with early-onset CRC. METHODS: Individuals age 18-49 years racialized as non-Hispanic Black and White (self-identified) and newly diagnosed with CRC during 2004-2019 were selected from the National Cancer Database. Patients who received recommended care (staging, surgery, lymph node evaluation, chemotherapy, and radiotherapy) were considered to have received guideline-concordant care. Odds ratios (ORs) were adjusted for age and sex. The decomposition method was used to estimate the relative contribution of demographic characteristics (age and sex), comorbidities, health insurance, and facility type to the racial disparity in receipt of guideline-concordant care. The product-limit method was used to evaluate differences in time to treatment between patients racialized as Black and White. RESULTS: Of the 84,882 patients with colon cancer and 62,573 patients with rectal cancer, 20.8% and 14.5% were racialized as Black, respectively. Individuals racialized as Black were more likely to not receive guideline-concordant care for colon (adjusted OR [aOR], 1.18 [95% CI, 1.14 to 1.22]) and rectal (aOR, 1.27 [95% CI, 1.21 to 1.33]) cancers. Health insurance explained 28.2% and 21.6% of the disparity among patients with colon and rectal cancer, respectively. Individuals racialized as Black had increased time to adjuvant chemotherapy for colon cancer (hazard ratio [HR], 1.28 [95% CI, 1.24 to 1.32]) and neoadjuvant chemoradiation for rectal cancer (HR, 1.42 [95% CI, 1.37 to 1.47]) compared with individuals racialized as White. CONCLUSION: Patients with early-onset CRC racialized as Black receive worse and less timely care than individuals racialized as White. Health insurance, a modifiable factor, was the largest contributor to racial disparities in receipt of guideline-concordant care in this study.

Birth Cohort Colorectal Cancer (CRC): Implications for Research and Practice.

Colorectal cancer (CRC) epidemiology is changing due to a birth cohort effect, first recognized by increasing incidence of early onset CRC (EOCRC, age <50 years). In this paper, we define "birth cohort CRC" as the observed phenomenon, among individuals born 1960 and later, of increasing CRC risk across successive birth cohorts, rising EOCRC incidence, increasing incidence among individuals aged 50 to 54 years, and flattening of prior decreasing incidence among individuals aged 55 to 74 years. We demonstrate birth cohort CRC is associated with unique features, including increasing rectal cancer (greater than colon) and distant (greater than local) stage CRC diagnosis, and increasing EOCRC across all racial/ethnic groups. We review potential risk factors, etiologies, and mechanisms for birth cohort CRC, using EOCRC as a starting point and describing importance of viewing these through the lens of birth cohort. We also outline implications of birth cohort CRC for epidemiologic and translational research, as well as current clinical practice. We postulate that recognition of birth cohort CRC as an entity-including and extending beyond rising EOCRC-can advance understanding of risk factors, etiologies, and mechanisms, and address the public health consequences of changing CRC epidemiology.

Developing an electronic health record measure of low-value esophagogastroduodenoscopy for GERD at a large academic health system.

OBJECTIVES: Low-value esophagogastroduodenoscopies (EGDs) for uncomplicated gastro-oesophageal reflux disease (GERD) can harm patients and raise patient and payer costs. We developed an electronic health record (EHR) 'eMeasure' to detect low-value EGDs. DESIGN: Retrospective cohort of 518 adult patients diagnosed with GERD who underwent initial EGD between 1 January 2019 and 31 December 2019. SETTING: Outpatient primary care and gastroenterology clinics at a large, urban, academic health centre. PARTICIPANTS: Adult primary care patients at the University of California Los Angeles who underwent initial EGD for GERD in 2019. MAIN OUTCOME MEASURES: EGD appropriateness criteria were based on the American College of Gastroenterology 2012 guidelines. An initial EGD was considered low-value if it lacked a documented guideline-based indication, including alarm symptoms (eg, iron-deficiency anaemia); failure of an 8-week proton pump inhibitor trial or elevated Barrett's oesophagus risk. We performed manual chart review on a random sample of 204 patients as a gold standard of the eMeasure's validity. We estimated EGD costs using Medicare physician and facility fee rates. RESULTS: Among 518 initial EGDs performed (mean age 53 years; 54% female), the eMeasure identified 81 (16%) as low-value. The eMeasure's sensitivity was 42% (95% CI 22 to 61) and specificity was 93% (95% CI 89 to 96). Stratifying across clinics, 62 (74.6%) low-value EGDs originated from 2 (12.5%) out of 16 clinics. Total cost for 81 low-value EGDs was approximately US$75 573, including US$14 985 in patients' out-of-pocket costs. CONCLUSIONS: We developed a highly specific eMeasure that showed that low-value EGDs occurred frequently in our healthcare system and were concentrated in a minority of clinics. These results can inform future QI efforts at our institution, such as best practice alerts for the ordering physician. Moreover, this open-source eMeasure has a much broader potential impact, as it can be integrated into any EHR and improve medical decision-making at the point of care.

Black-White disparities in colorectal cancer outcomes: a simulation study of screening benefit.

The US Black population has higher colorectal cancer (CRC) incidence rates and worse CRC survival than the US White population, as well as historically lower rates of CRC screening. The Surveillance, Epidemiology, and End Results incidence rate data in people diagnosed between the ages of 20 and 45 years, before routine CRC screening is recommended, were analyzed to estimate temporal changes in CRC risk in Black and White populations. There was a rapid rise in rectal and distal colon cancer incidence in the White population but not the Black population, and little change in proximal colon cancer incidence for both groups. In 2014-2018, CRC incidence per 100 000 was 17.5 (95% confidence interval [CI] = 15.3 to 19.9) among Black individuals aged 40-44 years and 16.6 (95% CI = 15.6 to 17.6) among White individuals aged 40-44 years; 42.3% of CRCs diagnosed in Black patients were proximal colon cancer, and 41.1% of CRCs diagnosed in White patients were rectal cancer. Analyses used a race-specific microsimulation model to project screening benefits, based on life-years gained and lifetime reduction in CRC incidence, assuming these Black-White differences in CRC risk and location. The projected benefits of screening (via either colonoscopy or fecal immunochemical testing) were greater in the Black population, suggesting that observed Black-White differences in CRC incidence are not driven by differences in risk. Projected screening benefits were sensitive to survival assumptions made for Black populations. Building racial disparities in survival into the model reduced projected screening benefits, which can bias policy decisions.

Use of a mixed-methods approach to develop a guidebook with messaging to encourage colorectal cancer screening among Black individuals 45 and older.

INTRODUCTION: Colorectal cancer (CRC) is the second leading cause of cancer-related deaths in the United States and disproportionately impacts Black individuals. Here, we describe the mixed-methods approach used to develop a tailored message guidebook to promote CRC screening among Black individuals in the setting of recently updated screening guidelines. METHODS: This mixed-methods study included 10 in-depth qualitative interviews and 490 surveys in a nationally representative sample of unscreened Black individuals age ≥ 45. Messages were developed based on American Cancer Society (ACS) and National Colorectal Cancer Roundtable (NCCRT) research findings, tested among Black individuals using MaxDiff analytic methods, and reviewed by a multi-sector expert advisory committee of NCCRT members. RESULTS: The most frequently reported screening barrier in all age groups was self-reported procrastination (40.0% in age 45-49, 42.8% for age 50-54, 34.2% for age ≥ 55). Reasons for procrastination varied by age and included financial concerns, COVID-19 concerns, and fear of the test and bowel preparation. Additional screening barriers included lack of symptoms, provider recommendation, and family history of CRC. Most individuals age 45-49 preferred to receive screening information from a healthcare provider (57.5%); however, only 20% reported that a provider had initiated a screening conversation. CONCLUSIONS: We identified age-specific barriers to CRC screening and tailored messaging to motivate participation among unscreened Black people age ≥ 45. Findings informed the development of the NCCRT and ACS guidebook for organizations and institutions aiming to increase CRC screening participation in Black individuals.

Individuals With a Family History of Colorectal Cancer Warrant Tailored Interventions to Address Patient-Reported Barriers to Screening.

INTRODUCTION: Population health interventions to increase colorectal cancer (CRC) screening rates often exclude individuals with a family history of CRC, and interventions to increase screening in this high-risk group are rare. We aimed to determine the screening rate and barriers and facilitators to screening in this population to inform interventions to increase screening participation. METHODS: We performed a retrospective chart review and cross-sectional survey of patients excluded from mailed fecal immunochemical test (FIT) outreach because of a family history of CRC in a large health system. We used χ 2 , Fisher exact, and Student t tests to compare demographic and clinical characteristics of patients overdue and not overdue for screening. We then administered a survey (mailed and telephone) to overdue patients to assess barriers and facilitators to screening. RESULTS: There were 296 patients excluded from mailed FIT outreach, and 233 patients had a confirmed family history of CRC. Screening participation was low (21.9%), and there were no significant demographic or clinical differences between those overdue and not overdue for screening. There were 79 survey participants. Major patient-reported barriers to screening colonoscopy were patient forgetfulness (35.9%), fear of pain during colonoscopy (17.7%), and hesitancy about bowel preparation (29.4%). To facilitate screening colonoscopy, patients recommended reminders (56.3%), education about familial risk (50%), and colonoscopy education (35.9%). DISCUSSION: Patients with a family history of CRC who are excluded from mailed FIT outreach have low screening rates and report multiple mutable barriers to screening. They warrant targeted efforts to increase screening participation.

Racial and Ethnic Disparities in Early-Onset Colorectal Cancer Survival.

BACKGROUND: Young adults diagnosed with colorectal cancer (CRC) comprise a growing, yet understudied, patient population. We estimated 5-year relative survival of early-onset CRC and examined disparities in survival by race-ethnicity in a population-based sample. METHODS: We used the National Cancer Institute's Surveillance, Epidemiology, and End Results program of cancer registries to identify patients diagnosed with early-onset CRC (20-49 years of age) between January 1, 1992, and December 31, 2013. For each racial-ethnic group, we estimated 5-year relative survival, overall and by sex, tumor site, and stage at diagnosis. To illustrate temporal trends, we compared 5-year relative survival in 1992-2002 vs 2003-2013. We also used Cox proportional hazards regression models to examine the association of race-ethnicity and all-cause mortality, adjusting for age at diagnosis, sex, county type (urban vs rural), county-level median household income, tumor site, and stage at diagnosis. RESULTS: We identified 33,777 patients diagnosed with early-onset CRC (58.5% White, 14.0% Black, 13.0% Asian, 14.5% Hispanic). Five-year relative survival ranged from 57.6% (Black patients) to 69.1% (White patients). Relative survival improved from 1992-2002 to 2003-2013 for White patients only; there was no improvement for Black, Asian, or Hispanic patients. This pattern was similar by sex, tumor site, and stage at diagnosis. In adjusted analysis, Black (adjusted hazard ratio [aHR], 1.42; 95% confidence interval [CI], 1.36-1.49), Asian (aHR, 1.06; 95% CI, 1.01-1.12), and Hispanic (aHR, 1.16; 95% CI, 1.10-1.21) race-ethnicity were associated with all-cause mortality. CONCLUSION: Our study adds to the well-documented disparities in CRC in older adults by demonstrating persistent racial-ethnic disparities in relative survival and all-cause mortality in patients with early-onset CRC.

Development and validation of a new ICD-10-based screening colonoscopy overuse measure in a large integrated healthcare system: a retrospective observational study.

BACKGROUND: Low-value use of screening colonoscopy is wasteful and potentially harmful to patients. Decreasing low-value colonoscopy prevents procedural complications, saves patient time and reduces patient discomfort, and can improve access by reducing procedural demand. The objective of this study was to develop and validate an electronic measure of screening colonoscopy overuse using International Classification of Diseases, Tenth Edition codes and then apply this measure to estimate facility-level overuse to target quality improvement initiatives to reduce overuse in a large integrated healthcare system. METHODS: Retrospective national observational study of US Veterans undergoing screening colonoscopy at 119 Veterans Health Administration (VHA) endoscopy facilities in 2017. A measure of screening colonoscopy overuse was specified by an expert workgroup, and electronic approximation of the measure numerator and denominator was performed ('electronic measure'). The electronic measure was then validated via manual record review (n=511). Reliability statistics (n=100) were calculated along with diagnostic test characteristics of the electronic measure. The measure was then applied to estimate overall rates of overuse and facility-level variation in overuse among all eligible patients. RESULTS: The electronic measure had high specificity (99%) and moderate sensitivity (46%). Adjusted positive predictive value and negative predictive value were 33% and 95%, respectively. Inter-rater reliability testing revealed near perfect agreement between raters (k=0.81). 269 572 colonoscopies were performed in VHA in 2017 (88 143 classified as screening procedures). Applying the measure to these 88 143 screening colonoscopies, 24.5% were identified as potential overuse. Median facility-level overuse was 22.5%, with substantial variability across facilities (IQR 19.1%-27.0%). CONCLUSIONS: An International Classification of Diseases, Tenth Edition based electronic measure of screening colonoscopy overuse has high specificity and improved sensitivity compared with a previous International Classification of Diseases, Ninth Edition based measure. Despite increased focus on reducing low-value care and improving access, a quarter of VHA screening colonoscopies in 2017 were identified as potential low-value procedures, with substantial facility-level variability.

Three-Year Interval for the Multi-Target Stool DNA Test for Colorectal Cancer Screening: A Longitudinal Study.

Data supporting the clinical utility of multi-target stool DNA (mt-sDNA) at the guideline-recommended 3-year interval have not been reported.Between April 2015 and July 2016, candidates for colorectal cancer screening whose providers prescribed the mt-sDNA test were enrolled. Participants with a positive baseline test were recommended for colonoscopy and completed the study. Those with a negative baseline test were followed annually for 3 years. In year 3, the mt-sDNA test was repeated and colonoscopy was recommended independent of results. Data were analyzed using the Predictive Summary Index (PSI), a measure of the gain in certainty for dichotomous diagnostic tests (where a positive value indicates a net gain), and by comparing observed versus expected colorectal cancers and advanced precancerous lesions.Of 2,404 enrolled subjects, 2,044 (85%) had a valid baseline mt-sDNA result [284 (13.9%) positive and 1,760 (86.1%) negative]. Following participant attrition, the year 3 intention to screen cohort included 591 of 1,760 (33.6%) subjects with valid mt-sDNA and colonoscopy results, with no colorectal cancers and 63 advanced precancerous lesions [22 (34.9%) detected by mt-sDNA] and respective PSI values of 0% (P = 1) and 9.3% (P = 0.01). The observed 3-year colorectal cancer yield was lower than expected (one-sided P = 0.09), while that for advanced precancerous lesions was higher than expected (two-sided P = 0.009).Repeat mt-sDNA screening at a 3-year interval resulted in a statistically significant gain in detection of advanced precancerous lesions. Due to absence of year 3 colorectal cancers, the PSI estimate for colorectal cancer was underpowered and could not be reliably quantified. Larger studies are required to assess the colorectal cancer study findings. PREVENTION RELEVANCE: Understanding the 3-year yield of mt-sDNA for colorectal cancer and advanced precancerous polyps is required to ensure the clinical appropriateness of the 3-year interval and to optimize mt-sDNA's screening effectiveness.

The Impact of Prebiotic, Probiotic, and Synbiotic Supplements and Yogurt Consumption on the Risk of Colorectal Neoplasia among Adults: A Systematic Review.

Prebiotic and probiotic supplementation and yogurt consumption (a probiotic food) alter gut microbial diversity, which may influence colorectal carcinogenesis. This systematic review evaluates the existing literature on the effect of these nutritional supplements and yogurt consumption on colorectal neoplasia incidence among adults. We systematically identified ten randomized controlled trials and observational studies in adults age ≥ 18 without baseline gastrointestinal disease. Prebiotics included inulin, fructooligosaccharides, galactooligosaccharides, xylooligosaccharides, isomaltooligosaccharides, and ß-glucans. Probiotics included bacterial strains of Lactobacillus, Bifidobacterium, Saccharomyces, Streptococcus, Enterococcus, Bacillus, Pediococcus, Leuconostoc, and Escherichia coli. Synbiotic supplements, a mixture of both prebiotic and probiotic supplements, and yogurt, a commonly consumed dietary source of live microbes, were also included. We defined colorectal neoplasia as colorectal adenomas, sessile serrated polyps, and colorectal cancer (CRC). Overall, findings suggest a moderate decrease in risk of adenoma and CRC for high levels of yogurt consumption compared to low or no consumption. Prebiotic supplementation was not associated with colorectal neoplasia risk. There was some evidence that probiotic supplementation may be associated with lower risk of adenomas but not with CRC incidence. Higher yogurt consumption may be associated with lower incidence of colorectal neoplasia. We found little evidence to suggest that prebiotic or probiotic supplements are associated with significant decreases in CRC occurrence.