Time to Colonoscopy After Abnormal Stool-Based Screening and Risk for Colorectal Cancer Incidence and Mortality

Cancer Screening in Low- and Middle-Income Countries

The worldwide cancer burden is growing, and populations residing in low- and middle-income countries (LMICs) are experiencing a disproportionate extent of this growth. Breast, colorectal, and cervical cancers are among the top 10 most frequently diagnosed malignancies, and they also account for a substantial degree of cancer mortality internationally. Effective screening strategies are available for all three of these cancers. Individuals from LMICs face substantial cost and access barriers to early detection programs, and late stage at diagnosis continues to be a major cause for cancer mortality in these communities. This chapter will review the epidemiology of breast, colorectal, and cervical cancers, and will explore prospects for improving global control through novel approaches to screening in cost-constrained environments.

Maximizing scarce colonoscopy resources: the crucial role of stool-based tests

During the COVID-19 pandemic, health systems, including federally qualified health centers, experienced disruptions in colorectal cancer (CRC) screening. National organizations called for greater use of at-home stool-based testing followed by colonoscopy for those with abnormal test results to limit (in-person) colonoscopy exams to people with acute symptoms or who were high risk. This stool-test-first strategy may also be useful for adults with low-risk adenomas who are due for surveillance colonoscopy. We argue that colonoscopy is overused as a first-line screening method in low- and average-risk adults and as a surveillance tool among adults with small adenomas. Yet, simultaneously, many people do not receive much-needed colonoscopies. Delivering the right screening tests at intervals that reduce the risk of CRC, while minimizing patient inconvenience and procedural risks, can strengthen health-care systems. Risk stratification could improve efficiency of CRC screening, but because models that adequately predict risk are years away from clinical use, we need to optimize use of currently available technology-that is, low-cost fecal testing followed by colonoscopy for those with abnormal test results. The COVID-19 pandemic highlighted the urgent need to adapt to resource constraints around colonoscopies and showed that increased use of stool-based testing was possible. Learning how to adapt to such constraints without sacrificing patients' health, particularly for patients who receive care at federally qualified health centers, should be a priority for CRC prevention research.

A Cell-free DNA Blood-Based Test for Colorectal Cancer Screening

BACKGROUND

Colorectal cancer is the third most diagnosed cancer in adults in the United States. Early detection could prevent more than 90% of colorectal cancer-related deaths, yet more than one third of the screening-eligible population is not up to date with screening despite multiple available tests. A blood-based test has the potential to improve screening adherence, detect colorectal cancer earlier, and reduce colorectal cancer-related mortality.

METHODS

We assessed the performance characteristics of a cell-free DNA (cfDNA) blood-based test in a population eligible for colorectal cancer screening. The coprimary outcomes were sensitivity for colorectal cancer and specificity for advanced neoplasia (colorectal cancer or advanced precancerous lesions) relative to screening colonoscopy. The secondary outcome was sensitivity to detect advanced precancerous lesions.

RESULTS

The clinical validation cohort included 10,258 persons, 7861 of whom met eligibility criteria and were evaluable. A total of 83.1% of the participants with colorectal cancer detected by colonoscopy had a positive cfDNA test and 16.9% had a negative test, which indicates a sensitivity of the cfDNA test for detection of colorectal cancer of 83.1% (95% confidence interval [CI], 72.2 to 90.3). Sensitivity for stage I, II, or III colorectal cancer was 87.5% (95% CI, 75.3 to 94.1), and sensitivity for advanced precancerous lesions was 13.2% (95% CI, 11.3 to 15.3). A total of 89.6% of the participants without any advanced colorectal neoplasia (colorectal cancer or advanced precancerous lesions) identified on colonoscopy had a negative cfDNA blood-based test, whereas 10.4% had a positive cfDNA blood-based test, which indicates a specificity for any advanced neoplasia of 89.6% (95% CI, 88.8 to 90.3). Specificity for negative colonoscopy (no colorectal cancer, advanced precancerous lesions, or nonadvanced precancerous lesions) was 89.9% (95% CI, 89.0 to 90.7).

CONCLUSIONS

In an average-risk screening population, this cfDNA blood-based test had 83% sensitivity for colorectal cancer, 90% specificity for advanced neoplasia, and 13% sensitivity for advanced precancerous lesions. (Funded by Guardant Health; ECLIPSE ClinicalTrials.gov number, NCT04136002.).

The value of hypersensitivity quantitative fecal immunochemical test in early colorectal cancer detection

At present, both the incidence and mortality rates of colorectal cancer are on the rise, making early screening a crucial tool in reducing the fatality rate. Although colonoscopy is the recommended method according to the guidelines, compliance tends to be poor. The fecal immunochemical test (FIT), a new technology that uses latex immunoturbidimetry to detect fecal blood, offers high specificity and sensitivity. Additionally, it is low-cost, easy to operate, and less likely to be affected by food and drugs, thus improving the compliance rate for population screening. Compared to other screening techniques, FIT represents a safer and more accurate option. This article reviews the application of FIT in early colorectal cancer screening.

Screening for Colorectal Cancer: The Role of Clinical Laboratories

BACKGROUND

Colorectal cancer (CRC) is a leading cause of cancer incidence and mortality. Screening can result in reductions in incidence and mortality, but there are many challenges to uptake and follow-up.

CONTENT

Here, we will review the changing epidemiology of CRC, including increasing trends for early and later onset CRC; evidence to support current and emerging screening strategies, including noninvasive stool and blood-based tests; key challenges to ensuring uptake and high-quality screening; and the critical role that clinical laboratories can have in supporting health system and public health efforts to reduce the burden of CRC on the population.

SUMMARY

Clinical laboratories have the opportunity to play a seminal role in optimizing early detection and prevention of CRC.

Abnormal Colorectal Cancer Test Follow-Up: A Quality Improvement Initiative at a Federally Qualified Health Center

INTRODUCTION/OBJECTIVES

Colonoscopy completion rates after an abnormal fecal immunochemical test (FIT) are suboptimal, resulting in missed opportunities for early detection and prevention of colorectal cancer. Patient navigation and structured follow-up may improve colonoscopy completion, but implementation of these strategies is not widespread.

METHODS

We conducted a quality improvement study using a Plan-Do-Study-Act (PDSA) Model to increase colonoscopy completion after abnormal FIT in a large federally qualified health center serving a diverse and low-income population. Intervention components included patient navigation, and a checklist to promote completion of key steps required for abnormal FIT follow-up. Primary outcome was proportion of patients achieving colonoscopy completion within 6 months of abnormal FIT, assessed at baseline for 156 patients pre-intervention, and compared to 208 patients during the intervention period from April 2017 to December 2019. Drop offs at each step in the follow-up process were assessed.

RESULTS

Colonoscopy completion improved from 21% among 156 patients with abnormal FIT pre-intervention, to 38% among 208 patients with abnormal FIT during the intervention (P < .001; absolute increase: 17%, 95% CI: 6.9%-25.2%). Among the 130 non-completers during the intervention period, lack of completion was attributable to absence of colonoscopy referral for 7.7%; inability to schedule a pre-colonoscopy specialist visit for 71.5%; failure to complete a pre-colonoscopy visit for 2.3%; the absence of colonoscopy scheduling for 9.2%; failure to show for a scheduled colonoscopy for 9.2%.

CONCLUSIONS

Patient navigation and structured follow-up appear to improve colonoscopy completion after abnormal FIT. Additional strategies are needed to achieve optimal rates of completion.

SIED-GISCOR recommendations for colonoscopy in screening programs: Part I - Diagnostic

The implementation of FIT programs reduces incidence and mortality from CRC in the screened subjects. The ultimate efficacy for CRC morbidity and mortality prevention in a FIT program depends on the colonoscopy in FIT+ subjects that has the task of detecting and removing these advanced lesions. Recently, there has been growing evidence on factors that influence the quality of colonoscopy specifically withing organized FIT programs, prompting to dedicated interventions in order to maximize the benefit/harm ratio of post-FIT colonoscopy. This document focuses on the diagnostic phase of colonoscopy, providing indications on how to standardise colonoscopy in FIT+ subjects, regarding timing of examination, management of antithrombotic therapy, bowel preparation, competence and sedation.

Developing Patient-Refined Messaging for Follow-Up Colonoscopy After Abnormal Fecal Testing in Hispanic Communities: Key Learnings from Virtual Boot Camp Translation

Colorectal cancer (CRC) is a leading cause of cancer death in the US. Screening by fecal immunochemical test (FIT) is a strategy to lower CRC rates. Unfortunately, only half of patients with an abnormal FIT result complete the follow-up colonoscopy, an essential component of screening. We used virtual Boot Camp Translation (BCT), to elicit input from partners to develop messaging/materials to motivate patients to complete a follow-up colonoscopy. Participants were Hispanic, ages 50 to 75 years, and Spanish-speaking. All materials were developed in English and Spanish. The first meeting included expert presentations that addressed colorectal health. The two follow-up sessions obtained feedback on messaging/materials developed based on themes from the first meeting. Ten participants attended the first meeting and eight attended the follow-up sessions. The two key barriers to follow-up colonoscopy after abnormal FIT noted by participants were (a) lack of colonoscopy awareness and (b) fear of the colonoscopy procedure. We learned that participants valued simple messaging to increase knowledge and alleviate concerns, patient-friendly outreach materials, and increased access to health information. Using virtual BCT, we included participant feedback to design culturally relevant health messages to promote follow-up colonoscopy after abnormal fecal testing among Hispanic patients served by community clinics.

Impact of the COVID-19 pandemic on the mortality among patients with colorectal cancer in Hiroshima, Japan: A large cancer registry study

BACKGROUND

This retrospective cohort study aimed to evaluate the impact of the COVID-19 pandemic on colorectal cancer care and mortality using a large cancer registry in Hiroshima Prefecture, Japan. The study aimed to estimate the all-cause mortality rates within 1 year of diagnosis among colorectal cancer patients diagnosed during the pandemic period (2020 and 2021) compared to those diagnosed during the pre-pandemic period (2018 and 2019).

METHODS

The day of diagnosis was set as Day 0 and Cox regression models were utilized to estimate crude hazard ratios (HRs) and adjusted HRs, accounting for age, sex, cancer stage, and treatment status. Two sensitivity analyses of overall survival were performed with different cutoffs of the pre-pandemic/pandemic periods and year-to-year comparisons. Subgroup analyses were performed using likelihood ratio tests.

RESULTS

A total of 15,085 colorectal cancer patients were included, with 6499 eligible for follow-up. A median age of included patients was 72 years old, of which 59% were male. The distribution of cancer stages showed little variation between the pre-pandemic and pandemic periods. With a median follow-up of 177 days, the number of events was 316/3111 (173 events per 1000 person-years [E/1000PY], 95% confidence interval [CI]: 154-192 E/1000PY) in the pre-pandemic period, and 326/2746 (245 E/1000PY, 95% CI: 220-274 E/1000PY) in the pandemic period (crude HR: 1.42, 95% CI: 1.22-1.66; adjusted HR: 1.25, 95% CI: 1.07-1.46). The two sensitivity analyses and subgroup analyses consistently supported these findings.

CONCLUSIONS

The study revealed an increased colorectal cancer mortality during the pandemic period, suggesting a continuous impact of the COVID-19 pandemic on the known and unknown risk factors for colorectal cancer for several years. Further studies are necessary to mitigate the adverse effects on patient outcomes.

Assessing patterns in cancer screening use by race and ethnicity during the coronavirus pandemic using electronic health record data

BACKGROUND

Efforts to prevent the spread of the coronavirus led to dramatic reductions in nonemergency medical care services during the first several months of the COVID-19 pandemic. Delayed or missed screenings can lead to more advanced stage cancer diagnoses with potentially worse health outcomes and exacerbate preexisting racial and ethnic disparities. The objective of this analysis was to examine how the pandemic affected rates of breast and colorectal cancer screenings by race and ethnicity.

METHODS

We analyzed panels of providers that placed orders in 2019-2020 for mammogram and colonoscopy cancer screenings using electronic health record (EHR) data. We used a difference-in-differences design to examine the extent to which changes in provider-level mammogram and colonoscopy orders declined over the first year of the pandemic and whether these changes differed across race and ethnicity groups.

RESULTS

We found considerable declines in both types of screenings from March through May 2020, relative to the same months in 2019, for all racial and ethnic groups. Some rebound in screenings occurred in June through December 2020, particularly among White and Black patients; however, use among other groups was still lower than expected.

CONCLUSIONS

This research suggests that many patients experienced missed or delayed screenings during the first few months of the pandemic, which could lead to detrimental health outcomes. Our findings also underscore the importance of having high-quality data on race and ethnicity to document and understand racial and ethnic disparities in access to care.

Potential global loss of life expected due to COVID-19 disruptions to organised colorectal cancer screening

Background

Screening for colorectal cancer (CRC) decreases cancer burden through removal of precancerous lesions and early detection of cancer. The COVID-19 pandemic has disrupted organised CRC screening programs worldwide, with some programs completely suspending screening and others experiencing significant decreases in participation and diagnostic follow-up. This study estimated the global impact of screening disruptions on CRC outcomes, and potential effects of catch-up screening.

Methods

Organised screening programs were identified in 29 countries, and data on participation rates and COVID-related changes to screening in 2020 were extracted where available. Four independent microsimulation models (ASCCA, MISCAN-Colon, OncoSim, and Policy1-Bowel) were used to estimate the long-term impact on CRC cases and deaths, based on decreases to screening participation in 2020. For countries where 2020 participation data were not available, changes to screening were approximated based on excess mortality rates. Catch-up strategies involving additional screening in 2021 were also simulated.

Findings

In countries for which direct data were available, organised CRC screening volumes at a country level decreased by an estimated 1.3-40.5% in 2020. Globally, it is estimated that COVID-related screening decreases led to a deficit of 7.4 million fewer faecal screens performed in 2020. In the absence of any organised catch-up screening, this would lead to an estimated 13,000 additional CRC cases and 7,900 deaths globally from 2020 to 2050; 79% of the additional cases and 85% of additional deaths could have been prevented with catch-up screening, respectively.

Interpretation

COVID-19-related disruptions to screening will cause excess CRC cases and deaths, but appropriately implemented catch-up screening could have reduced the burden by over 80%. Careful management of any disruption is key to improving the resilience of colorectal cancer screening programs.

Funding

The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by Cancer Council New South Wales, Health Canada, and Dutch National Institute for Public Health and Environment.

Reach and effectiveness of a centralized navigation program for patients with positive fecal immunochemical tests requiring follow-up colonoscopy

Completion rates for follow-up colonoscopies after an abnormal fecal immunochemical test (FIT) are suboptimal in federally qualified health center (FQHC) settings. We implemented a screening intervention that included mailed FIT outreach to North Carolina FQHC patients from June 2020 to September 2021 and centralized patient navigation to support patients with abnormal FITs in completing follow-up colonoscopy. We evaluated the reach and effectiveness of navigation using electronic medical record data and navigator call logs detailing interactions with patients. Reach assessments included the proportion of patients successfully contacted by phone and who agreed to participate in navigation, intensity of navigation provided (including types of barriers to colonoscopy identified and total navigation time), and differences in these measures by socio-demographic characteristics. Effectiveness outcomes included colonoscopy completion, timeliness of follow-up colonoscopy (i.e., within 9 months), and bowel prep adequacy. Among 514 patients who completed a mailed FIT, 38 patients had an abnormal result and were eligible for navigation. Of these, 26 (68%) accepted navigation, 7 (18%) declined, and 5 (13%) could not be contacted. Among navigated patients, 81% had informational needs, 38% had emotional barriers, 35% had financial barriers, 12% had transportation barriers, and 42% had multiple barriers to colonoscopy. Median navigation time was 48.5 min (range: 24-277 min). Colonoscopy completion differed across groups - 92% of those accepting navigation completed colonoscopy within 9 months, versus 43% for those declining navigation. We found that centralized navigation was widely accepted in FQHC patients with abnormal FIT, and was an effective strategy, resulting in high colonoscopy completion rates.

Inappropriate Multi-Target Stool DNA Use for Colorectal Cancer Screening: Risks, Compliance, and Outcomes

Background Inappropriate or "off-label" use of multi-target stool DNA (mt-sDNA) tests refers to their use in patients for whom colonoscopy or no testing at all is warranted. Examples include a positive family history of colorectal cancer, a history of inflammatory bowel disease, or medical issues necessitating diagnostic colonoscopy, among others. Current understanding of off-label mt-sDNA use for colorectal cancer screening, its associated risks, and outcomes is lacking. We examined off-label mt-sDNA prescription and compliance with testing in an outpatient setting in southeast Michigan. Aims The primary aims of the study were determining the extent of off-label mt-sDNA testing and compliance, and results of all testing, as well as demographic factors associated with off-label prescriptions. The secondary aims were to examine explanations for incomplete testing and factors contributing to successful completion. Methods Using a retrospective design, we identified mt-sDNA orders from outpatient internal medicine clinics between January 1, 2018, to July 31, 2019, to evaluate the proportion of off-label mt-sDNA, results of testing, and follow-up colonoscopies up to one year after order placement. Patients were categorized as "off-label" if any inappropriate criteria were met. Statistical analysis was performed for primary and secondary outcomes. Results From 679 mt-sDNA orders within the study period, 81 (12.1%) had at least one off-label criterion for testing. In total, 404/679 (59.5%) patients completed testing. Lack of follow-up comprised the majority of incompletions (216/275; 78.6%). Only 52 (70.3%) out of 74 positive results were followed by diagnostic colonoscopy. Retired employment status (OR = 1.87; 95%CI, 1.17-2.98; P = 0.008) and age of 76 years or older (OR = 2.28; 95%CI, 0.99-5.21; P = 0.044) were significantly associated with increased risk of off-label mt-sDNA prescription. Increasing age range was associated with higher test completion (χ2 (5) = 12.085, p = 0.034). Multinomial logistic regression revealed an increasing age range (OR = 1.29; 95% CI, 1.09-1.54; P = 0.004), predictive of a positive mt-sDNA result for both groups. There was no significant difference between off-label or on-label groups in the mean number of resected polyps or pathology scores on follow-up colonoscopy. Conclusions Off-label mt-sDNA use remains a concern in the outpatient setting. Compliance for test completion and follow-up colonoscopy for positive results require further improvement. Our findings shed new light on the factors associated with off-label testing while reiterating its burden. We also describe common reasons for incomplete tests in an attempt to augment future colorectal cancer (CRC) screening initiatives.

Postponing colonoscopy for 6 months in high-risk population increases colorectal cancer detection in China

BACKGROUND AND AIMS

Colonoscopy is an important colorectal cancer (CRC) screening modality; however, not all high-risk groups identified by fecal immunochemical test (FIT) and/or high-risk factor questionnaire (HRFQ) undergo colonoscopy in time. The impact of delays in colonoscopy on CRC detection among high-risk populations remains poorly understood, warranting further clarification.

METHODS

A retrospective study was conducted among CRC high-risk population identified by Tianjin CRC screening program. According to the colonoscopy results after HRFQ and FIT, patients were classified into CRC, advanced adenoma, non-advanced adenoma, and normal groups. The time interval between CRC screening and colonoscopy was investigated and its relationship with colonoscopy results. Logistic regression was performed to explore the risk factors of CRC detection.

RESULTS

Among the high-risk population without a history of CRC or polyps, 49,810 underwent HRFQ, FIT, and colonoscopy, and a time interval of fewer than 6 months was found for 79.56% of patients (n = 39,630). People with positive FIT were more likely to undergo colonoscopy within 6 months, and detection rates of CRC and/or advanced adenoma were positively related to time intervals. Similar results were found in people with a negative FIT but positive HRFQ. A time interval longer than 6 months was a significant predictor of CRC detection in high-risk populations.

CONCLUSION

For high-risk people identified by CRC screening, especially those with a positive FIT, a time interval of 6 months was associated with an increased probability of CRC detection. Our findings emphasize that populations at high risk should undergo colonoscopy at least within 6 months.

Delphi Initiative for Early-Onset Colorectal Cancer (DIRECt) International Management Guidelines

BACKGROUND & AIMS

Patients with early-onset colorectal cancer (eoCRC) are managed according to guidelines that are not age-specific. A multidisciplinary international group (DIRECt), composed of 69 experts, was convened to develop the first evidence-based consensus recommendations for eoCRC.

METHODS

After reviewing the published literature, a Delphi methodology was used to draft and respond to clinically relevant questions. Each statement underwent 3 rounds of voting and reached a consensus level of agreement of ≥80%.

RESULTS

The DIRECt group produced 31 statements in 7 areas of interest: diagnosis, risk factors, genetics, pathology-oncology, endoscopy, therapy, and supportive care. There was strong consensus that all individuals younger than 50 should undergo CRC risk stratification and prompt symptom assessment. All newly diagnosed eoCRC patients should receive germline genetic testing, ideally before surgery. On the basis of current evidence, endoscopic, surgical, and oncologic treatment of eoCRC should not differ from later-onset CRC, except for individuals with pathogenic or likely pathogenic germline variants. The evidence on chemotherapy is not sufficient to recommend changes to established therapeutic protocols. Fertility preservation and sexual health are important to address in eoCRC survivors. The DIRECt group highlighted areas with knowledge gaps that should be prioritized in future research efforts, including age at first screening for the general population, use of fecal immunochemical tests, chemotherapy, endoscopic therapy, and post-treatment surveillance for eoCRC patients.

CONCLUSIONS

The DIRECt group produced the first consensus recommendations on eoCRC. All statements should be considered together with the accompanying comments and literature reviews. We highlighted areas where research should be prioritized. These guidelines represent a useful tool for clinicians caring for patients with eoCRC.

Development and validation of postoperative circulating tumor DNA combined with clinicopathological risk factors for recurrence prediction in patients with stage I-III colorectal cancer

BACKGROUND

Circulating tumor DNA (ctDNA) detection following curative-intent surgery could directly reflect the presence of minimal residual disease, the ultimate cause of clinical recurrence. However, ctDNA is not postoperatively detected in ≥ 50% of patients with stage I-III colorectal cancer (CRC) who ultimately recur. Herein we sought to improve recurrence risk prediction by combining ctDNA with clinicopathological risk factors in stage I-III CRC.

METHODS

Two independent cohorts, both consisting of early-stage CRC patients who underwent curative surgery, were included: (i) the discovery cohort (N = 124) with tumor tissues and postoperative plasmas for ctDNA determination; and (ii) the external validation cohort (N = 125) with available ctDNA results. In the discovery cohort, somatic variations in tumor tissues and plasmas were determined via a 733-gene and 127-gene next-generation sequencing panel, respectively.

RESULTS

In the discovery cohort, 17 of 108 (15.7%) patients had detectable ctDNA. ctDNA-positive patients had a significantly high recurrence rate (76.5% vs. 16.5%, P < 0.001) and short recurrence-free survival (RFS; P < 0.001) versus ctDNA-negative patients. In addition to ctDNA status, the univariate Cox model identified pathologic stage, lymphovascular invasion, nerve invasion, and preoperative carcinoembryonic antigen level associated with RFS. We combined the ctDNA and clinicopathological risk factors (CTCP) to construct a model for recurrence prediction. A significantly higher recurrence rate (64.7% vs. 8.1%, P < 0.001) and worse RFS (P < 0.001) were seen in the high-risk patients classified by the CTCP model versus those in the low-risk patients. Receiver operating characteristic analysis demonstrated that the CTCP model outperformed ctDNA alone at recurrence prediction, which increased the sensitivity of 2 year RFS from 49.6% by ctDNA alone to 87.5%. Harrell's concordance index, calibration curve, and decision curve analysis also suggested that the CTCP model had good discrimination, consistency, and clinical utility. These results were reproduced in the validation cohort.

CONCLUSION

Combining postoperative ctDNA and clinical risk may better predict recurrence than ctDNA alone for developing a personalized postoperative management strategy for CRC.

Rates of Follow-up Colonoscopy After a Positive Stool-Based Screening Test Result for Colorectal Cancer Among Health Care Organizations in the US, 2017-2020

IMPORTANCE

Noninvasive stool-based screening tests (SBTs) are effective alternatives to colonoscopy. However, a positive SBT result requires timely follow-up colonoscopy (FU-CY) to complete the colorectal cancer screening paradigm.

OBJECTIVES

To evaluate FU-CY rates after a positive SBT result and to assess the association of the early COVID-19 pandemic with FU-CY rates.

DESIGN, SETTING, AND PARTICIPANTS

This mixed-methods cohort study included retrospective analysis of deidentified administrative claims and electronic health records data between June 1, 2015, and June 30, 2021, from the Optum Labs Data Warehouse and qualitative, semistructured interviews with clinicians from 5 health care organizations (HCOs). The study population included data from average-risk primary care patients aged 50 to 75 years with a positive SBT result between January 1, 2017, and June 30, 2020, at 39 HCOs.

MAIN OUTCOMES AND MEASURES

The primary outcome was the FU-CY rate within 1 year of a positive SBT result according to patient age, sex, race, ethnicity, insurance type, Charlson Comorbidity Index (CCI), and prior SBT use.

RESULTS

This cohort study included 32 769 individuals (16 929 [51.7%] female; mean [SD] age, 63.1 [7.1] years; 2092 [6.4%] of Black and 28 832 [88.0%] of White race; and 825 [2.5%] of Hispanic ethnicity). The FU-CY rates were 43.3% within 90 days of the positive SBT result, 51.4% within 180 days, and 56.1% within 360 days (n = 32 769). In interviews, clinicians were uniformly surprised by the low FU-CY rates. Rates varied by race, ethnicity, insurance type, presence of comorbidities, and SBT used. In the Cox proportional hazards regression model, the strongest positive association was with multitarget stool DNA use (hazard ratio, 1.63 [95% CI, 1.57-1.68] relative to fecal immunochemical tests; P < .001), and the strongest negative association was with the presence of comorbidities (hazard ratio, 0.64 [95% CI, 0.59-0.71] for a CCI of >4 relative to 0; P < .001). The early COVID-19 pandemic was associated with lower FU-CY rates.

CONCLUSIONS AND RELEVANCE

This study found that FU-CY rates after a positive SBT result for colorectal cancer screening were low among an average-risk population, with the median HCO achieving a 53.4% FU-CY rate within 1 year. Socioeconomic factors and the COVID-19 pandemic were associated with lower FU-CY rates, presenting opportunities for targeted intervention by clinicians and health care systems.

Extent of Follow-Up on Abnormal Cancer Screening in Multiple California Public Hospital Systems: A Retrospective Review

BACKGROUND

Inequitable follow-up of abnormal cancer screening tests may contribute to racial/ethnic disparities in colon and breast cancer outcomes. However, few multi-site studies have examined follow-up of abnormal cancer screening tests and it is unknown if racial/ethnic disparities exist.

OBJECTIVE

This report describes patterns of performance on follow-up of abnormal colon and breast cancer screening tests and explores the extent to which racial/ethnic disparities exist in public hospital systems.

DESIGN

We conducted a retrospective cohort study using data from five California public hospital systems. We used multivariable robust Poisson regression analyses to examine whether patient-level factors or site predicted receipt of follow-up test.

MAIN MEASURES

Using data from five public hospital systems between July 2015 and June 2017, we assessed follow-up of two screening results: (1) colonoscopy after positive fecal immunochemical tests (FIT) and (2) tissue biopsy within 21 days after a BIRADS 4/5 mammogram.

KEY RESULTS

Of 4132 abnormal FITs, 1736 (42%) received a follow-up colonoscopy. Older age, Medicaid insurance, lack of insurance, English language, and site were negatively associated with follow-up colonoscopy, while Hispanic ethnicity and Asian race were positively associated with follow-up colonoscopy. Of 1702 BIRADS 4/5 mammograms, 1082 (64%) received a timely biopsy; only site was associated with timely follow-up biopsy.

CONCLUSION

Despite the vulnerabilities of public-hospital-system patients, follow-up of abnormal cancer screening tests occurs at rates similar to that of patients in other healthcare settings, with colon cancer screening test follow-up occurring at lower rates than follow-up of breast cancer screening tests. Site-level factors have larger, more consistent impact on follow-up rates than patient sociodemographic traits. Resources are needed to identify health system-level factors, such as test follow-up processes or data infrastructure, that improve abnormal cancer screening test follow-up so that effective health system-level interventions can be evaluated and disseminated.

Patterns of initial colorectal cancer screenings after turning 50 years old and follow-up rates of colonoscopy after positive stool-based testing among the average-risk population

OBJECTIVES

Effective colorectal cancer (CRC) screening requires proper adherence beginning at the recommended screening age. For those with positive results on stool-based tests (SBTs), a follow-up colonoscopy is warranted. The objectives of this study were to 1) examine initial screening rates after turning 50 years old; and 2) assess rates of follow-up colonoscopy after a positive SBT.

METHODS

This retrospective study used de-identified administrative claims data from 01/01/2006 to 06/30/2020 for commercially insured and Medicare Advantage enrollees. For objective 1, the index year was the year enrollees turned 50. Rates of CRC screening during and after the index year were captured. For objective 2, the index date was the claim date of a fecal immunochemical test (FIT) or multitarget stool DNA test (mt-sDNA) where linked lab data indicated a positive test result. Rates and time to follow-up colonoscopy after a positive SBT were assessed.

RESULTS

Approximately 53% of enrollees initiated CRC screening within five years after turning 50 (50+ cohort N = 718,562). Among enrollees with an available lab result indicating a positive SBT (N = 7329; 2110 FIT and 5219 mt-sDNA), overall follow-up colonoscopy within 6 months of the positive result was less than optimal (65%) and varied by modality; 72% vs 46% (p < .001) among enrollees with a positive mt-sDNA test compared to FIT test, respectively.

CONCLUSION

There is potential for improving CRC screening among the eligible average-risk population, both to start screening once they reach the screening-eligible age, and to complete the CRC screening paradigm after a positive stool-based screen.

Third Asia-Pacific consensus recommendations on colorectal cancer screening and postpolypectomy surveillance

The Asia-Pacific region has the largest number of cases of colorectal cancer (CRC) and one of the highest levels of mortality due to this condition in the world. Since the publishing of two consensus recommendations in 2008 and 2015, significant advancements have been made in our knowledge of epidemiology, pathology and the natural history of the adenoma-carcinoma progression. Based on the most updated epidemiological and clinical studies in this region, considering literature from international studies, and adopting the modified Delphi process, the Asia-Pacific Working Group on Colorectal Cancer Screening has updated and revised their recommendations on (1) screening methods and preferred strategies; (2) age for starting and terminating screening for CRC; (3) screening for individuals with a family history of CRC or advanced adenoma; (4) surveillance for those with adenomas; (5) screening and surveillance for sessile serrated lesions and (6) quality assurance of screening programmes. Thirteen countries/regions in the Asia-Pacific region were represented in this exercise. International advisors from North America and Europe were invited to participate.

CircHADHA-augmented autophagy suppresses tumor growth of colon cancer by regulating autophagy-related gene via miR-361

Colon cancer undergoes a traditional pathway from colon polyps to colon cancer. It is of great significance to investigate the key molecules involved in carcinogenesis from polyps to malignancies. Circular RNAs (circRNAs) are stably expressed in human body fluids such as plasma. Here, we demonstrated a differential expression pattern of plasma circRNAs in healthy individuals, colon polyp patients and colon cancer patients using circRNA Arraystar microarray. We explored that circRNA HADHA (circHADHA) was upregulated in plasma from polyp patients, whereas it was downregulated in plasma from colon cancer patients. Overexpression of circHADHA promoted autophagy in colon epithelial cells. Moreover, in colon cancer cells, overexpression of circHADHA promoted autophagy, whereas it inhibited cell proliferation and colony formation. CircHADHA increased the expression of ATG13 via miR-361 in both colon epithelial and cancer cells. ATG13 knockdown reduced autophagy even in the presence of circHADHA in colon cancer cells. Furthermore, the growth of circHADHA-overexpressing colon cancer cell-derived xenograft tumors was significantly decreased compared with control tumors in nude mice. In conclusion, circHADHA was differentially expressed in the plasma of healthy individuals, colon polyp patients and colon cancer patients. CircHADHA promoted autophagy by regulating ATG13 via miR-361 in both colon epithelial and cancer cells. CircHADHA suppressed tumor growth by inducing cell autophagy in colon cancer cells. CircHADHA potentially serves as a biomarker for screening of precursor colon cancer and a therapeutic target for colon cancer treatment.

COVID-19 Pandemic Had Minimal Impact on Colonoscopy Completion After Colorectal Cancer Red Flag Sign or Symptoms in US Veterans

BACKGROUND

Delays in colonoscopy work-up for red flag signs or symptoms of colorectal cancer (CRC) during the COVID-19 pandemic are not well characterized.

AIMS

To examine colonoscopy uptake and time to colonoscopy after red flag diagnosis, before and during the COVID-19 pandemic.

METHODS

Cohort study of adults ages 50-75 with iron deficiency anemia (IDA), hematochezia, or abnormal stool blood test receiving Veterans Health Administration (VHA) care from April 2019 to December 2020. Index date was first red flag diagnosis date, categorized into "pre" (April-December 2019) and "intra" (April-December 2020) policy implementation prioritizing diagnostic procedures, allowing for a 3-month "washout" (January-March 2020) period. Outcomes were colonoscopy completion and time to colonoscopy pre- vs. intra-COVID-19, examined using multivariable Cox models with hazard ratios (aHRs) and 95% confidence intervals (CIs).

RESULTS

There were 52,539 adults with red flag signs or symptoms (pre-COVID: 25,154; washout: 7527; intra-COVID: 19,858). Proportion completing colonoscopy was similar pre- vs. intra-COVID-19 (27.0% vs. 26.5%; p = 0.24). Median time to colonoscopy among colonoscopy completers was similar for pre- vs. intra-COVID-19 (46 vs. 42 days), but longer for individuals with IDA (60 vs. 49 days). There was no association between time period and colonoscopy completion (aHR: 0.99, 95% CI 0.95-1.03).

CONCLUSIONS

Colonoscopy work-up of CRC red flag signs and symptoms was not delayed within VHA during the COVID-19 pandemic, possibly due to VHA policies supporting prioritization and completion. Further work is needed to understand how COVID-19 policies on screening and surveillance impact CRC-related outcomes, and how to optimize colonoscopy completion after a red flag diagnosis.

Evaluation of a multimedia outreach campaign for a multi-target stool DNA test for colorectal cancer screening among non-medicare employer population in the United States

Regular and timely screenings for colorectal cancer (CRC) can improve survival through early cancer detection. The current prospective intervention study assessed the effectiveness of a CRC screening outreach campaign via a multi-media campaign featuring articles in a multi-topic benefits newsletter that was both printed/mailed to homes and emailed to Metro Nashville Public Schools (MNPS) employees and their dependents in the United States. Individuals were included if they were between 45 and 64 years old. The mailed newsletter was sent to 5631 active employees, 868 under 65 retirees, and 4046 retirees with Medicare. The open rate was the highest for the third email (n = 3018; 53.3%). The click-through rate was also the highest for the third email (n = 203;6.7%). Among those who opened at least one of the emails or received a mailed newsletter, 119 members completed the assessment (conversion rate = 3.9%). Among this population, the mt-sDNA completion rate was 64.5% (69 orders completed out of 107 ordered mt-sDNA kits). All 6 patients with a positive mt-sDNA result underwent a follow-up colonoscopy (FU-CY) with the mean (±SD) days to FU-CY among those with positive mt-sDNA test results was 49 (±27) days (median = 42 days). Using emails in conjunction with other targeted interventions to outreach and educate members regarding CRC screening may be an effective strategy to enhance mt-sDNA completion rates.

Effect of Chronic Comorbidities on Follow-up Colonoscopy After Positive Colorectal Cancer Screening Results: A Population-Based Cohort Study

INTRODUCTION

Fecal occult blood tests (FOBTs) are colorectal cancer screening tests used to identify individuals requiring further investigation with colonoscopy. Delayed colonoscopy after positive FOBT (FOBT+) is associated with poorer cancer outcomes. We assessed the effect of comorbidity on colonoscopy receipt within 12 months after FOBT+.

METHODS

Population-based healthcare databases from Ontario, Canada, were linked to assemble a cohort of 50-74-year-old individuals with FOBT+ results between 2008 and 2017. The associations between comorbidities and colonoscopy receipt within 12 months after FOBT+ were examined using multivariable cause-specific hazard regression models.

RESULTS

Of 168,701 individuals with FOBT+, 80.5% received colonoscopy within 12 months. In multivariable models, renal failure (hazard ratio [HR] 0.71, 95% confidence interval [CI] 0.62-0.82), heart failure (HR 0.77, CI 0.75-0.80), and serious mental illness (HR 0.88, CI 0.85-0.92) were associated with the lowest colonoscopy rates, compared with not having each condition. The number of medical conditions was inversely associated with colonoscopy uptake (≥4 vs 0: HR 0.64, CI 0.58-0.69; 3 vs 0: HR 0.75, CI 0.72-0.78; and 2 vs 0: HR 0.87, CI 0.85-0.89). Having both medical and mental health conditions was associated with a lower colonoscopy uptake relative to no comorbidity (HR 0.88, CI 0.87-0.90).

DISCUSSION

Persons with medical and mental health conditions had lower colonoscopy rates after FOBT+ than those without these conditions. Better strategies are needed to optimize colorectal cancer screening and follow-up in individuals with comorbidities.

Pandemic-resilient target setting in colorectal cancer screening for vulnerable older population

BACKGROUND

Colorectal cancer screening (CRCS) needs to be pandemic-resilient to avoid long-lasting shutdowns; however, realistic participation target remains unelucidated. This study aimed to identify the lowest acceptable participation rate in CRCS during a pandemic, focusing on vulnerable older populations who require urgent intervention.

METHODS

This nationwide cross-sectional study included 80,946 inpatients aged 70-85 years who were first diagnosed with colorectal cancer (CRC) after 70 years of age, between April 1, 2014 and March 31, 2019, in Japan. To evaluate the association between area-level CRCS participation rate and individual early CRC detection, a multilevel logistic regression model was constructed. The mandatorily implemented screening rates were converted to the total screening rate equivalents (TSREs), which reflect the remaining contributions of voluntarily provided screenings.

RESULTS

Early detections during stages 0-I were significantly observed when primary screening rate was ≥38% (TSRE) and combined follow-up rate was ≥85%. For early detection during Tis-T1, primary screening rate ≥ 38% (TSRE) and combined follow-up rate ≥ 90% were necessary. For follow-up rates ≥70% or ≥75%, there were cases where missed detection of Tis-T1 were observed.

CONCLUSION

The results indicate that, even during pandemic, CRCS should achieve a primary screening rate of 38% and follow-up rate of 85% for vulnerable older populations. These values, lower than the current desirable rates, suggest the maximum possible compromise in balancing the resources between cancer screening and pandemic measures. Moreover, they also indicate the minimum target for shifting to fecal immunochemical test-focused program. Further explorations with varied CRCS settings are necessary for verification.

Changes in Cancer Screening in the US During the COVID-19 Pandemic

IMPORTANCE

Health care was disrupted in the US during the first quarter of 2020 with the emergence of the COVID-19 pandemic. Early reports in selected samples suggested that cancer screening services decreased greatly, but population-based estimates of cancer screening prevalence during 2020 have not yet been reported.

OBJECTIVE

To examine changes in breast cancer (BC), cervical cancer (CC), and colorectal cancer (CRC) screening prevalence with contemporary national, population-based Behavioral Risk Factor Surveillance System (BRFSS) data.

DESIGN, SETTING, AND PARTICIPANTS

This survey study included respondents from the 2014, 2016, 2018, and 2020 BRFSS surveys who were eligible for BC (women aged 50-74 years), CC (women aged 25-64 years), and CRC (women and men aged 50-75 years) screening. Data analysis was performed from September 2021 to February 2022.

EXPOSURES

Calendar year.

MAIN OUTCOMES AND MEASURES

Self-reported receipt of a recent (defined as in the past year) BC, CC, and CRC screening test. Adjusted prevalence ratios (aPRs) comparing 2020 vs 2018 prevalence and 95% CIs were computed.

RESULTS

In total, 479 248 individuals were included in the analyses of BC screening, 301 453 individuals were included in CC screening, and 854 210 individuals were included in CRC screening, In 2020, among respondents aged 50 to 75 years, 14 815 (11.4%) were Black, 12 081 (12.6%) were Hispanic, 156 198 (67.3%) were White, and 79 234 (29.9%) graduated from college (all percentages are weighted). After 4 years (2014-2018) of nearly steady prevalence, past-year BC screening decreased by 6% between 2018 and 2020 (from 61.6% in 2018 to 57.8% in 2020; aPR, 0.94; 95% CI, 0.92-0.96), and CC screening decreased by 11% (from 58.3% in 2018 to 51.9% in 2020; aPR, 0.89; 95% CI, 0.87-0.91). The magnitude of these decreases was greater in people with lower educational attainment and Hispanic persons. CRC screening prevalence remained steady; past-year stool testing increased by 7% (aPR, 1.07; 95% CI, 1.02-1.12), offsetting a 16% decrease in colonoscopy (aPR, 0.84; 95% CI, 0.82-0.88) between 2018 and 2020.

CONCLUSIONS AND RELEVANCE

In this survey study, stool testing increased and counterbalanced a decrease in colonoscopy during 2020, and BC and CC screening modestly decreased. How these findings might be associated with outcomes is not yet known, but they will be important to monitor, especially in populations with lower socioeconomic status, who experienced greater screening decreases during the COVID-19 pandemic.

Barriers Associated with Inadequate Follow-up of Abnormal Fecal Immunochemical Test Results in a Safety-Net System: A Mixed-Methods Analysis

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Less than 50% of patients with an abnormal FIT result had a documented reason.

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Patient-level (e.g., declined colonoscopy) reasons were most frequently documented.

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Interviews revealed discordance in documented and patient-reported reasons.

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Mixed-methods analyses are needed to improve colonoscopy after abnormal FIT results.

In safety-net healthcare systems, colonoscopy completion within 1-year of an abnormal fecal immunochemical test (FIT) result rarely exceeds 50%. Understanding how electronic health records (EHR) documented reasons for missed colonoscopy match or differ from patient-reported reasons, is critical to optimize effective interventions to address this challenge. We conducted a convergent mixed-methods study which included a retrospective analysis of EHR data and semi-structured interviews of adults 50–75 years old, with abnormal FIT results between 2014 and 2020 in a large safety-net healthcare system. Of the 299 patients identified, 59.2% (n = 177) did not complete a colonoscopy within one year of their abnormal result. EHR abstraction revealed a documented reason for lack of follow-up colonoscopy in 49.2% (n = 87/177); patient-level (e.g., declined colonoscopy; 51.5%) and multi-factorial reasons (e.g., lost to follow-up; 37.9%) were most common. In 18 patient interviews, patient (e.g., fear of colonoscopy), provider (e.g., lack of result awareness), and system-level reasons (e.g., scheduling challenges) were most common. Only three reasons for lack of colonoscopy overlapped between EHR data and patient interviews (competing health issues, lack of transportation, and abnormal FIT result attributed to another cause). In a cohort of safety-net patients with abnormal FIT results, the most common reasons for lack of follow-up were patient-related. Our analysis revealed a discordance between EHR documented and patient-reported reasons for lack of colonoscopy after an abnormal FIT result. Mixed-methods analyses, as in the present study, may give us the greatest insight into modifiable determinants to develop effective interventions beyond quantitative and qualitative data analysis alone.

Life-years gained resulting from screening colonoscopy compared with follow-up colonoscopy after a positive stool-based colorectal screening test

Screening colonoscopies for colorectal cancer (CRC) are typically covered without patient cost-sharing, whereas follow-up colonoscopies for positive stool-based screening tests often incur patient costs. The objective of this analysis was to estimate and compare the life-years gained (LYG) per average-risk screening colonoscopy and follow-up colonoscopy after a positive stool-based test to better inform CRC coverage policy and reimbursement decisions. CRC outcomes from screening and follow-up colonoscopies versus no screening were estimated using CRC-AIM in a simulated population of average-risk individuals screened between ages 45-75 years. The LYG/colonoscopy per 1000 individuals was 0.09 for screening colonoscopy and 0.29 for follow-up colonoscopy. 0.01 and 0.04 CRC cases and 0.01 and 0.02 CRC deaths were averted per screening and follow-up colonoscopies, respectively. Coverage policies should be revised to encourage individuals to complete recommended screening processes.

Colonoscopy-Related Adverse Events in Patients With Abnormal Stool-Based Tests: A Systematic Review of Literature and Meta-analysis of Outcomes

INTRODUCTION

Colorectal cancer (CRC) screening programs based on the fecal immunochemical test (FIT) and guaiac-based fecal occult blood (gFOBT) are associated with a substantial reduction in CRC incidence and mortality. We conducted a systematic review and comprehensive meta-analysis to evaluate colonoscopy-related adverse events in individuals with a positive FIT or gFOBT.

METHODS

A systematic and detailed search was run in January 2021, with the assistance of a medical librarian for studies reporting on colonoscopy-related adverse events as part of organized CRC screening programs. Meta-analysis was performed using the random-effects model, and the results were expressed for pooled proportions along with relevant 95% confidence intervals (CIs).

RESULTS

A total of 771,730 colonoscopies were performed in patients undergoing CRC screening using either gFOBT or FIT across 31 studies. The overall pooled incidence of severe adverse events in the entire patient cohort was 0.42% (CI 0.20-0.64); I2 = 38.76%. In patients with abnormal gFOBT, the incidence was 0.2% (CI 0.1-0.3); I2 = 24.6%, and in patients with a positive FIT, it was 0.4% (CI 0.2-0.7); I2 = 48.89%. The overall pooled incidence of perforation, bleeding, and death was 0.13% (CI 0.09-0.21); I2 = 22.84%, 0.3% (CI 0.2-0.4); I2 = 35.58%, and 0.01% (CI 0.00-0.01); I2 = 33.21%, respectively.

DISCUSSION

Our analysis shows that in colonoscopies performed after abnormal stool-based testing, the overall risk of severe adverse events, perforation, bleeding, and death is minimal.

Timely Colonoscopy After Positive Fecal Immunochemical Tests in the Veterans Health Administration: A Qualitative Assessment of Current Practice and Perceived Barriers

INTRODUCTION

The Veterans Health Administration introduced a clinical reminder system in 2018 to help address process gaps in colorectal cancer screening, including the diagnostic evaluation of positive fecal immunochemical test (FIT) results. We conducted a qualitative study to explore the differences between facilities who performed in the top vs bottom decile for follow-up colonoscopy.

METHODS

Seventeen semistructured interviews with gastroenterology (GI) providers and staff were conducted at 9 high-performing and 8 low-performing sites.

RESULTS

We identified 2 domains, current practices and perceived barriers, and most findings were described by both high- and low-performing sites. Findings exclusive to 1 group mainly pertained to current practices, especially arranging colonoscopy for FIT-positive patients. We observed only 1 difference in the perceived barriers domain, which pertained to primary care providers.

DISCUSSION

These results suggest that what primarily distinguishes high- and low-performing sites is not a difference in barriers but rather in the GI clinical care process. Developing and disseminating patient education materials about the importance of diagnostic colonoscopy, eliminating in-person precolonoscopy visits when clinically appropriate, and involving GI in missed colonoscopy appointments and outside referrals should all be considered to increase follow-up colonoscopy rates. Our study illustrates the challenges of performing a timely colonoscopy after a positive FIT result and provides insights on improving the clinical care process for patients who are at substantially increased risk for colorectal cancer.

Operationalizing a Rideshare Intervention for Colonoscopy Completion: Barriers, Facilitators, and Process Recommendations

INTRODUCTION

Transportation is a common barrier to colonoscopy completion for colorectal cancer (CRC) screening. The study aims to identify the barriers, facilitators, and process recommendations to implement a rideshare non-emergency medical transportation (NEMT) intervention following colonoscopy completion within a safety-net healthcare setting.

METHODS

We used informal stakeholder engagement, story boards - a novel user-centered design technique, listening sessions and the nominal group technique to identify the barriers, facilitators, and process to implementing a rideshare NEMT program following colonoscopy completion in a large safety-net healthcare system.

RESULTS

Barriers to implementing a rideshare NEMT intervention for colonoscopy completion included: inability to expand an existing NEMT program beyond Medicaid patients and lack of patient chaperones with rideshare NEMT programs. Facilitators included: commercially available rideshare NEMT platforms that were lower cost and had shorter wait times than the alternative of taxis. Operationalizing and implementing a rideshare NEMT intervention in our healthcare system required the following steps: 1) identifying key stakeholders, 2) engaging stakeholder groups in discussion to identify barriers and solutions, 3) obtaining institutional sign-off, 4) developing a process for reviewing and selecting a rideshare NEMT program, 5) executing contracts, 6) developing a standard operating procedure and 7) training clinic staff to use the rideshare platform.

DISCUSSION

Rideshare NEMT after procedural sedation is administered may improve colonoscopy completion rates and provide one solution to inadequate CRC screening. If successful, our rideshare model could be broadly applicable to other safety-net health systems, populations with high social needs, and settings where procedural sedation is administered.

Colorectal Cancer Screening and Yield in a Mailed Outreach Program in a Safety-Net Healthcare System

BACKGROUND

Screening with fecal immunochemical testing (FIT) reduces colorectal cancer mortality; however, screening remains low in underserved populations. Mailed outreach, including an invitation letter, FIT, and test instructions, is an evidence-based strategy to improve screening.

AIMS

To examine screening completion and yield in a mailed outreach program in a safety-net healthcare system.

METHODS

We identified and mailed outreach invitations to patients due for screening in a large safety-net system between September 1, 2018, and August 31, 2019. We examined: (1) screening completion, the proportion of patients completing FIT or screening colonoscopy within 6 months of the mailed invitation; and (2) timely diagnostic colonoscopy, the proportion of patients completing colonoscopy within 6 months of positive FIT.

RESULTS

We mailed 14,879 invitations to 13,190 patients. Nearly half (n = 6098, 46.2%) of patients completed screening: 4,896 (80.3%) completed FIT through mailed outreach; 1,114 (18.3%) FIT through usual care; and 88 (1.4%) screening colonoscopy through usual care. Of patients with a positive FIT (n = 289), 50.5% completed diagnostic colonoscopy within 6 months, 10.7% within 6-12 months, and 4.8% after 12 months. A total of 8 cancers and 83 advanced adenomas were detected in the 191 patients completing diagnostic colonoscopy.

CONCLUSION

After implementing and scaling up mailed outreach in a safety-net system, about half of patients completed screening, and the majority did so through mailed outreach. However, many patients failed to complete diagnostic colonoscopy after positive FIT. Results highlight the importance of adapting mailed outreach programs to local contexts and constraints of healthcare systems, in order to support efforts to improve CRC screening in underserved populations.

Screening and prevention of colorectal cancer

Mortality from colorectal cancer is reduced through screening and early detection; moreover, removal of neoplastic lesions can reduce cancer incidence. While understanding of the risk factors, pathogenesis, and precursor lesions of colorectal cancer has advanced, the cause of the recent increase in cancer among young adults is largely unknown. Multiple invasive, semi- and non-invasive screening modalities have emerged over the past decade. The current emphasis on quality of colonoscopy has improved the effectiveness of screening and prevention, and the role of new technologies in detection of neoplasia, such as artificial intelligence, is rapidly emerging. The overall screening rates in the US, however, are suboptimal, and few interventions have been shown to increase screening uptake. This review provides an overview of colorectal cancer, the current status of screening efforts, and the tools available to reduce mortality from colorectal cancer.

Impact of Patient Adherence to Stool-Based Colorectal Cancer Screening and Colonoscopy Following a Positive Test on Clinical Outcomes

Colorectal cancer-screening models commonly assume 100% adherence, which is inconsistent with real-world experience. The influence of adherence to initial stool-based screening [fecal immunochemical test (FIT), multitarget stool DNA (mt-sDNA)] and follow-up colonoscopy (after a positive stool test) on colorectal cancer outcomes was modeled using the Colorectal Cancer and Adenoma Incidence and Mortality Microsimulation Model. Average-risk individuals without diagnosed colorectal cancer at age 40 undergoing annual FIT or triennial mt-sDNA screening from ages 50 to 75 were simulated. Primary analyses incorporated published mt-sDNA (71%) or FIT (43%) screening adherence, with follow-up colonoscopy adherence ranging from 40% to 100%. Secondary analyses simulated 100% adherence for stool-based screening and colonoscopy follow-up (S1), published adherence for stool-based screening with 100% adherence to colonoscopy follow-up (S2), and published adherence for both stool-based screening and colonoscopy follow-up after positive mt-sDNA (73%) or FIT (47%; S3). Outcomes were life-years gained (LYG) and colorectal cancer incidence and mortality reductions (per 1,000 individuals) versus no screening. Adherence to colonoscopy follow-up after FIT had to be 4%-13% higher than mt-sDNA to reach equivalent LYG. The theoretical S1 favored FIT versus mt-sDNA (LYG 316 vs. 297; colorectal cancer incidence reduction 68% vs. 64%; colorectal cancer mortality reduction 76% vs. 72%). The more realistic S2 and S3 favored mt-sDNA versus FIT (S2: LYG 284 vs. 245, colorectal cancer incidence reduction 61% vs. 50%, colorectal cancer mortality reduction 69% vs. 59%; S3: LYG 203 vs. 113, colorectal cancer incidence reduction 43% vs. 23%, colorectal cancer mortality reduction 49% vs. 27%, respectively). Incorporating realistic adherence rates for colorectal cancer screening influences modeled outcomes and should be considered when assessing comparative effectiveness. PREVENTION RELEVANCE: Adherence rates for initial colorectal cancer screening by FIT or mt-sDNA and for colonoscopy follow-up of a positive initial test influence the comparative effectiveness of these screening strategies. Using adherence rates based on published data for stool-based testing and colonoscopy follow-up yielded superior outcomes with an mt-sDNA versus FIT-screening strategy.

Postoperative circulating tumor DNA as markers of recurrence risk in stages II to III colorectal cancer

BACKGROUND

Precise methods for postoperative risk stratification to guide the administration of adjuvant chemotherapy (ACT) in localized colorectal cancer (CRC) are still lacking. Here, we conducted a prospective, observational, and multicenter study to investigate the utility of circulating tumor DNA (ctDNA) in predicting the recurrence risk.

METHODS

From September 2017 to March 2020, 276 patients with stage II/III CRC were prospectively recruited in this study and 240 evaluable patients were retained for analysis, of which 1290 serial plasma samples were collected. Somatic variants in both the primary tumor and plasma were detected via a targeted sequencing panel of 425 cancer-related genes. Patients were treated and followed up per standard of care.

RESULTS

Preoperatively, ctDNA was detectable in 154 of 240 patients (64.2%). At day 3-7 postoperation, ctDNA positivity was associated with remarkably high recurrence risk (hazard ratio [HR], 10.98; 95%CI, 5.31-22.72; P < 0.001). ctDNA clearance and recurrence-free status was achieved in 5 out of 17 ctDNA-positive patients who were subjected to ACT. Likewise, at the first sampling point after ACT, ctDNA-positive patients were 12 times more likely to experience recurrence (HR, 12.76; 95%CI, 5.39-30.19; P < 0.001). During surveillance after definitive therapy, ctDNA positivity was also associated with extremely high recurrence risk (HR, 32.02; 95%CI, 10.79-95.08; P < 0.001). In all multivariate analyses, ctDNA positivity remained the most significant and independent predictor of recurrence-free survival after adjusting for known clinicopathological risk factors. Serial ctDNA analyses identified recurrence with an overall accuracy of 92.0% and could detect disease recurrence ahead of radiological imaging with a mean lead time of 5.01 months.

CONCLUSIONS

Postoperative serial ctDNA detection predicted high relapse risk and identified disease recurrence ahead of radiological imaging in patients with stage II/III CRC. ctDNA may be used to guide the decision-making in postsurgical management.