Addressing overuse and overdiagnosis in colorectal cancer screening for average-risk individuals

Stool DNA testing for early detection of colorectal cancer: systematic review using the HTA Core Model® for Rapid Relative Effectiveness Assessment

Background

Stool DNA testing for early detection of colorectal cancer (CRC) is a non-invasive technology with the potential to supplement established CRC screening tests. The aim of this health technology assessment was to evaluate effectiveness and safety of currently CE-marked stool DNA tests, compared to other CRC tests in CRC screening strategies in an asymptomatic screening population.

Methods

The assessment was carried out following the guidelines of the European Network for Health Technology Assessment (EUnetHTA). This included a systematic literature search in MED-LINE, Cochrane and EMBASE in 2018. Manufacturers were asked to provide additional data. Five patient interviews helped assessing potential ethical or social aspects and patients' experiences and preferences. We assessed the risk of bias using QUADAS-2, and the quality of the body of evidence using GRADE.

Results

We identified three test accuracy studies, two of which investigated a multitarget stool DNA test (Cologuard®, compared fecal immunochemical test (FIT)) and one a combined DNA stool assay (ColoAlert®, compared to guaiac-based fecal occult blood test (gFOBT), Pyruvate Kinase Isoenzyme Type M2 (M2-PK) and combined gFOBT/M2-PK). We found five published surveys on patient satisfaction. No primary study investigating screening effects on CRC incidence or on overall mortality was found. Both stool DNA tests showed in direct comparison higher sensitivity for the detection of CRC and (advanced) adenoma compared to FIT, or gFOBT, respectively, but had lower specificity. However, these comparative results may depend on the exact type of FIT used. The reported test failure rates were higher for stool DNA testing than for FIT. The certainty of evidence was moderate to high for Cologuard® studies, and low to very low for the ColoAlert® study which refers to a former version of the product and yielded no direct evidence on the test accuracy for ad-vanced versus non-advanced adenoma.

Conclusions

ColoAlert® is the only stool DNA test currently sold in Europe and is available at a lower price than Cologuard®, but reliable evidence is lacking. A screening study including the current product version of ColoAlert® and suitable comparators would, therefore, help evaluate the effectiveness of this screening option in a European context.

Colorectal Cancer Screening within Colonoscopy Capacity Constraints: Can FIT-Based Programs Save More Lives by Trading off More Sensitive Test Cutoffs against Longer Screening Intervals?

Introduction. Colorectal cancer (CRC) prevention programs using fecal immunochemical testing (FIT) in screening rely on colonoscopy for secondary and surveillance testing. Colonoscopy capacity is an important constraint. Some European programs lack sufficient capacity to provide optimal screening intensity regarding age ranges, intervals, and FIT cutoffs. It is currently unclear how to optimize programs within colonoscopy capacity constraints. Design. Microsimulation modeling, using the MISCAN-Colon model, was used to determine if more effective CRC screening programs can be identified within constrained colonoscopy capacity. A total of 525 strategies were modeled and compared, varying 3 key screening parameters: screening intervals, age ranges, and FIT cutoffs, including previously unevaluated 4- and 5-year screening intervals (using a lifetime horizon and 100% adherence). Results were compared with the policy decisions taken in Ireland to provide CRC screening within available colonoscopy capacity. Outcomes estimated net costs, quality-adjusted life-years (QALYs), and required colonoscopies. The optimal strategies within finite colonoscopy capacity constraints were identified. Results. Combining a reduced FIT cutoff of 10 µg Hb/g, an extended screening interval of 4 y and an age range of 60–72 y requires 6% fewer colonoscopies, reduces net costs by 23% while preventing 15% more CRC deaths and saving 16% more QALYs relative to a strategy (FIT 40 µg Hb/g, 2-yearly, 60–70 year) approximating current policy. Conclusion. Previously overlooked longer screening intervals may optimize cancer prevention with finite colonoscopy capacity constraints. Changes could save lives, reduce costs, and relieve colonoscopy capacity pressures. These findings are relevant to CRC screening programs across Europe that employ FIT-based testing, which face colonoscopy capacity constraints.

Effectiveness, benefit harm and cost effectiveness of colorectal cancer screening in Austria

BACKGROUND

Clear evidence on the benefit-harm balance and cost effectiveness of population-based screening for colorectal cancer (CRC) is missing. We aim to systematically evaluate the long-term effectiveness, harms and cost effectiveness of different organized CRC screening strategies in Austria.

METHODS

A decision-analytic cohort simulation model for colorectal adenoma and cancer with a lifelong time horizon was developed, calibrated to the Austrian epidemiological setting and validated against observed data. We compared four strategies: 1) No Screening, 2) FIT: annual immunochemical fecal occult blood test age 40-75 years, 3) gFOBT: annual guaiac-based fecal occult blood test age 40-75 years, and 4) COL: 10-yearly colonoscopy age 50-70 years. Predicted outcomes included: benefits expressed as life-years gained [LYG], CRC-related deaths avoided and CRC cases avoided; harms as additional complications due to colonoscopy (physical harm) and positive test results (psychological harm); and lifetime costs. Tradeoffs were expressed as incremental harm-benefit ratios (IHBR, incremental positive test results per LYG) and incremental cost-effectiveness ratios [ICER]. The perspective of the Austrian public health care system was adopted. Comprehensive sensitivity analyses were performed to assess uncertainty.

RESULTS

The most effective strategies were FIT and COL. gFOBT was less effective and more costly than FIT. Moving from COL to FIT results in an incremental unintended psychological harm of 16 additional positive test results to gain one life-year. COL was cost saving compared to No Screening. Moving from COL to FIT has an ICER of 15,000 EUR per LYG.

CONCLUSIONS

Organized CRC-screening with annual FIT or 10-yearly colonoscopy is most effective. The choice between these two options depends on the individual preferences and benefit-harm tradeoffs of screening candidates.

Identifying Coordination and Continuity of Care Indicators for Population-Based Cancer Screening Programs: A Delphi Study

BACKGROUND

Continuity of care and care coordination are critical issues in virtually all healthcare systems. European guidelines for the quality of screening programs for breast and colorectal cancer describe process, structure, and outcome indicators, but none specifically evaluate coordination and continuity of care during the cancer screening process.

OBJECTIVE

The aim of this study was to identify indicators reflecting care coordination and continuity in population-based breast and colorectal cancer screening program.

METHODS

A two-round Delphi study was conducted in a sample of 30 cancer screening nurses to identify quality indicators.

RESULTS

The final Delphi consensus resulted in six core indicators for the cancer screening program: adequacy of the referral of the target population from the screening program to other health services, waiting time for referral to other health services, understanding of the screening program by professionals involved in the process, effective information flow between professionals involved in the process, participants' perception of the screening program, and, finally, participants' understanding of information about the program.

CONCLUSION

The evaluation of indicators is crucial for quality improvement and should allow a measuring system to be established that would allow a comparison of outcomes for all population-based cancer screening programs.

Population-based Cancer Screening: Measurement of Coordination and Continuity of Care

BACKGROUND

European guidelines for the quality of screening programs for breast and colorectal cancer describe process, structure, and outcome indicators. However, none of them specifically evaluate coordination and continuity of care during the cancer screening process.

OBJECTIVES

The aim of this study was to identify and adapt care quality indicators related to the coordination and continuity of the cancer screening process to assess nursing care in cancer screening programs.

METHODS

The indicators proposed in this study were selected in 2 phases. The first consisted of a literature review, and the second was made by consensus of an expert group. An electronic literature search was conducted, through June 2016. From a total of 225 articles retrieved, 14 studies met inclusion criteria, and these 14 documents were delivered to the group of experts for evaluation and to propose a final list of agreed-upon indicators.

RESULTS

The group of experts selected 7 indicators: adequacy and waiting time derivation of participants, delivery and availability of the report of the process, understanding professionals involved in the process, and satisfaction and understanding of participants.

CONCLUSIONS

These indicators should help identify areas for improvement and measure the outcome of coordination and continuity of care.

IMPLICATIONS FOR PRACTICE

The results provided a common set of indicators to evaluate the coordination and continuity of care for cancer screening and to consequently assess the contribution of nursing care in cancer screening programs. The identification and adaptation of these quality indicators will help to identify areas for improvement and measure the effect of coordination and continuity of care.

Ethical issues with colorectal cancer screening-a systematic review

RATIONALE, AIMS, AND OBJECTIVES

Colorectal cancer (CRC) screening is widely recommended and implemented. However, sometimes CRC screening is not implemented despite good evidence, and some types of CRC screening are implemented despite lack of evidence. The objective of this article is to expose and elucidate relevant ethical issues in the literature on CRC screening that are important for open and transparent deliberation on CRC screening.

METHODS

An axiological question-based method is used for exposing and elucidating ethical issues relevant in HTA. A literature search in MEDLINE, Embase, PsycINFO, PubMed Bioethics subset, ISI Web of Knowledge, Bioethics Literature Database (BELIT), Ethics in Medicine (ETHMED), SIBIL Base dati di bioetica, LEWI Bibliographic Database on Ethics in the Sciences and Humanities, and EUROETHICS identified 870 references of which 114 were found relevant according to title and abstract. The content of the included papers were subject to ethical analysis to highlight the ethical issues, concerns, and arguments.

RESULTS

A wide range of important ethical issues were identified. The main benefits are reduced relative CRC mortality rate, and potentially incidence rate, but there is no evidence of reduced absolute mortality rate. Potential harms are bleeding, perforation, false test results, overdetection, overdiagnosis, overtreatment (including unnecessary removal of polyps), and (rarely) death. Other important issues are related to autonomy and informed choice equity, justice, medicalization, and expanding disease.

CONCLUSION

A series of important ethical issues have been identified and need to be addressed in open and transparent deliberation on CRC screening.