Economic evaluation of genetic screening for Lynch syndrome in Germany

[Gender-specific differences in the development of colorectal cancer in Lynch syndrome patients-A systematic review]

BACKGROUND

Lynch syndrome (LS) is the most frequent hereditary tumor syndrome and is associated with an increased risk of colorectal cancer (CRC). While gene-specific and age-specific differences are considered in patient surveillance, gender-specific risks in the development of CRC have been reported in many studies but are not consistently documented.

OBJECTIVE

This systematic review aims to investigate gender-specific differences in CRC development among LS patients.

MATERIAL AND METHODS

A systematic literature search following PRISMA 2020 guidelines was conducted in the PubMed, Ovid, The Cochrane Library and Web of Science databases. A total of 688 studies were screened, and 41 met the inclusion criteria.

RESULTS

Men have a higher risk of CRC and develop CRC earlier compared to women.

CONCLUSION

These findings indicate gender-specific differences in the risk of CRC among LS patients, although they do not currently justify separate surveillance strategies.

Evaluating the Value for Money of Precision Medicine from Early Cycle to Market Access: A Comprehensive Review of Approaches and Challenges

OBJECTIVES

This study aimed to perform a comprehensive review of modeling approaches and methodological and policy challenges in the economic evaluation (EE) of precision medicine (PM) across clinical stages.

METHODS

First, a systematic review was performed to assess the approaches of EEs in the past 10 years. Next, a targeted review of methodological articles was conducted for methodological and policy challenges in performing EEs of PM. All findings were synthesized into a structured framework that focused on patient population, Intervention, Comparator, Outcome, Time, Equity and ethics, Adaptability and Modeling aspects, named the "PICOTEAM" framework. Finally, a stakeholder consultation was conducted to understand the major determinants of decision making in PM investment.

RESULTS

In 39 methodological articles, we identified major challenges to the EE of PM. These challenges include that PM applications involve complex and evolving clinical decision space, that clinical evidence is sparse because of small subgroups and complex pathways in PM settings, a one-time PM application may have lifetime or intergenerational impacts but long-term evidence is often unavailable, and that equity and ethics concerns are exceptional. In 275 EEs of PM, current approaches did not sufficiently capture the value of PM compared with targeted therapies, nor did they differentiate Early EEs from Conventional EEs. Finally, policy makers perceived the budget impact, cost savings, and cost-effectiveness of PM as the most important determinants in decision making.

CONCLUSIONS

There is an urgent need to modify existing guidelines or develop a new reference case that fits into the new healthcare paradigm of PM to guide decision making in research and development and market access.

Economic evaluations of predictive genetic testing: A scoping review

Predictive genetic testing can provide information about whether or not someone will develop or is likely to develop a specific condition at a later stage in life. Economic evaluation can assess the value of money for such testing. Studies on the economic evaluation of predictive genetic testing have been carried out in a variety of settings, and this research aims to conduct a scoping review of findings from these studies. We searched the PubMed, Web of Science, Embase, and Cochrane databases with combined search terms, from 2019 to 2022. Relevant studies from 2013 to 2019 in a previous systematic review were also included. The study followed the recommended stages for undertaking a scoping review. A total of 53 studies were included, including 33 studies from the previous review and 20 studies from the search of databases. A significant number of studies focused on the US, UK, and Australia (34%, 23%, and 11%). The most frequently included health conditions were cancer and cardiovascular diseases (68% and 19%). Over half of the studies compared predictive genetic testing with no genetic testing, and the majority of them concluded that at least some type of genetic testing was cost-effective compared to no testing (94%). Some studies stated that predictive genetic testing is becoming more cost-effective with the trend of lowering genetic testing costs. Studies on predictive genetic testing covered various health conditions, particularly cancer and cardiovascular diseases. Most studies indicated that predictive genetic testing is cost-effective compared to no testing.

MyLynch: A Patient-Facing Clinical Decision Support Tool for Genetically-Guided Personalized Medicine in Lynch Syndrome

Lynch syndrome (LS) is a hereditary cancer susceptibility condition associated with varying cancer risks depending on which of the five causative genes harbors a pathogenic variant; however, lifestyle and medical interventions provide options to lower those risks. We developed MyLynch, a patient-facing clinical decision support (CDS) web application that applies genetically-guided personalized medicine (GPM) for individuals with LS. The tool was developed in R Shiny through a patient-focused iterative design process. The knowledge base used to estimate patient-specific risk leveraged a rigorously curated literature review. MyLynch informs LS patients of their personal cancer risks, educates patients on relevant interventions, and provides patients with adjusted risk estimates, depending on the interventions they choose to pursue. MyLynch can improve risk communication between patients and providers while also encouraging communication among relatives with the goal of increasing cascade testing. As genetic panel testing becomes more widely available, GPM will play an increasingly important role in patient care, and CDS tools offer patients and providers tailored information to inform decision-making. MyLynch provides personalized cancer risk estimates and interventions to lower these risks for patients with LS.

A review of the cost-effectiveness of genetic testing for germline variants in familial cancer

BACKGROUND

Targeted germline testing is recommended for those with or at risk of breast, ovarian, or colorectal cancer. The affordability of genetic sequencing has improved over the past decade, therefore the cost-effectiveness of testing for these cancers is worthy of reassessment.

OBJECTIVE

To systematically review economic evaluations on cost-effectiveness of germline testing in breast, ovarian, or colorectal cancer.

METHODS

A search of PubMed and Embase databases for cost-effectiveness studies on germline testing in breast, ovarian, or colorectal cancer, published between 1999 and May 2022. Synthesis of methodology, cost-effectiveness, and reporting (CHEERS checklist) was performed.

RESULTS

The incremental cost-effectiveness ratios (ICERs; in 2021-adjusted US$) for germline testing versus the standard care option in hereditary breast or ovarian cancer (HBOC) across target settings were as follows: (1) population-wide testing: 344-2.5 million/QALY; (2) women with high-risk: dominant = 78,118/QALY, 8,337-59,708/LYG; (3) existing breast or ovarian cancer: 3,012-72,566/QALY, 39,835/LYG; and (4) metastatic breast cancer: 158,630/QALY. Likewise, ICERs of germline testing for colorectal cancer across settings were: (1) population-wide testing: 132,200/QALY, 1.1 million/LYG; (2) people with high-risk: 32,322-76,750/QALY, dominant = 353/LYG; and (3) patients with existing colorectal cancer: dominant = 54,122/QALY, 98,790-6.3 million/LYG. Key areas of underreporting were the inclusion of a health economic analysis plan (100% of HBOC and colorectal studies), engagement of patients and stakeholders (95.4% of HBOC, 100% of colorectal studies) and measurement of outcomes (18.2% HBOC, 38.9% of colorectal studies).

CONCLUSION

Germline testing for HBOC was likely to be cost-effective across most settings, except when used as a co-dependent technology with the PARP inhibitor, olaparib in metastatic breast cancer. In colorectal cancer studies, testing was cost-effective in those with high-risk, but inconclusive in other settings. Cost-effectiveness was sensitive to the prevalence of tested variants, cost of testing, uptake, and benefits of prophylactic measures. Policy advice on germline testing should emphasize the importance of these factors in their recommendations.

Evaluating the quality of the economic evidence in colorectal cancer genomics studies

The increase in the use of genome-based screening and diagnostic tests adds to the overall costs of oncologic care for colorectal cancer. This, in turn, has resulted in an increase in published economic analyses. Aim: To perform a systematic literature review of the available economic evidence evaluating the value of genomic testing for colorectal cancer and appraise the quality of the economic studies conducted to date. Methods: A systematic review of the literature for economic studies of colorectal cancer genomics from January 2006 through October 2020, and evaluation of study quality using the Quality of Health Economic Studies (QHES) instrument was conducted. The validated QHES was then applied to a final set of articles that met eligibility criteria. Results: Our search of the literature initially yielded 12,859 records. A final set of 49 articles met our inclusion criteria. The QHES score ranged from 24 to 100, with an average score of 82. Most of the studies (n = 40, 82%) scored above 75 and were considered of good quality. Conclusion: Our analysis revealed that most of the economic analyses of colorectal cancer genomic molecular diagnostics in the literature may be of good quality. There is, however, some variation in methodological rigor between the articles.

Cost-effectiveness of population-wide genomic screening for Lynch syndrome in the United States

PURPOSE

Genomic screening for Lynch syndrome (LS) could prevent colorectal cancer (CRC) by identifying high-risk patients and instituting intensive CRC screening. We estimated the cost-effectiveness of a population-wide LS genomic screening vs family history-based screening alone in an unselected US population.

METHODS

We developed a decision-analytic Markov model including health states for precancer, stage-specific CRC, and death and assumed an inexpensive test cost of $200. We conducted sensitivity and threshold analyses to evaluate model uncertainty.

RESULTS

Screening unselected 30-year-olds for LS variants resulted in 48 (95% credible range [CR] = 35-63) fewer overall CRC cases per 100,000 screened individuals, leading to 187 quality-adjusted life-years (QALYs; 95% CR = 123-260) gained at an incremental cost of $24.6 million (95% CR = $20.3 million-$29.1 million). The incremental cost-effectiveness ratio was $132,200, with an 8% and 71% probability of being cost-effective at $100,000 and $150,000 per QALY willingness-to-pay thresholds, respectively.

CONCLUSION

Population LS screening may be cost-effective in younger patient populations under a $150,000 willingness-to-pay per QALY threshold and with a relatively inexpensive test cost. Further reductions in testing costs and/or the inclusion of LS testing within a broader multiplex screening panel are needed for screening to become highly cost-effective.

A systematic review of the methodological quality of economic evaluations in genetic screening and testing for monogenic disorders

PURPOSE

Understanding the value of genetic screening and testing for monogenic disorders requires high-quality, methodologically robust economic evaluations. This systematic review sought to assess the methodological quality among such studies and examined opportunities for improvement.

METHODS

We searched PubMed, Cochrane, Embase, and Web of Science for economic evaluations of genetic screening/testing (2013-2019). Methodological rigor and adherence to best practices were systematically assessed using the British Medical Journal checklist.

RESULTS

Across the 47 identified studies, there were substantial variations in modeling approaches, reporting detail, and sophistication. Models ranged from simple decision trees to individual-level microsimulations that compared between 2 and >20 alternative interventions. Many studies failed to report sufficient detail to enable replication or did not justify modeling assumptions, especially for costing methods and utility values. Meta-analyses, systematic reviews, or calibration were rarely used to derive parameter estimates. Nearly all studies conducted some sensitivity analysis, and more sophisticated studies implemented probabilistic sensitivity/uncertainty analysis, threshold analysis, and value of information analysis.

CONCLUSION

We describe a heterogeneous body of work and present recommendations and exemplar studies across the methodological domains of (1) perspective, scope, and parameter selection; (2) use of uncertainty/sensitivity analyses; and (3) reporting transparency for improvement in the economic evaluation of genetic screening/testing.

Swiss cost-effectiveness analysis of universal screening for Lynch syndrome of patients with colorectal cancer followed by cascade genetic testing of relatives

Background

We estimated the cost-effectiveness of universal DNA screening for Lynch syndrome (LS) among newly diagnosed patients with colorectal cancer (CRC) followed by cascade screening of relatives from the Swiss healthcare system perspective.

Methods

We integrated decision trees with Markov models to calculate incremental cost per quality-adjusted life-year saved by screening all patients with CRC (alternative strategy) compared with CRC tumour-based testing followed by DNA sequencing (current strategy).

Results

The alternative strategy has an incremental cost-effectiveness ratio of CHF65 058 compared with the current strategy, which is cost-effective according to Swiss standards. Based on annual incidence of CRC in Switzerland, universal DNA screening correctly identifies all 123 patients with CRC with LS, prevents 17 LS deaths and avoids 19 CRC cases, while the current strategy leads to 32 false negative results and 253 LS cases lost to follow-up. One way and probabilistic sensitivity analyses showed that universal DNA testing is cost-effective in around 80% of scenarios, and that the cost of DNA testing and the number of invited relatives per LS case determine the cost-effectiveness ratio.

Conclusion

Results can inform policymakers, healthcare providers and insurance companies about the costs and benefits associated with universal screening for LS and cascade genetic testing of relatives.

Cost-Effectiveness Analysis of Molecular Screening to Identify Lynch Syndrome in the Patients with Colorectal Cancer

Background: Identifying Lynch syndrome (LS) in patients with colorectal cancer (CRC) and monitoring their relatives can increase the life expectancy of these patients. Objectives: The aim of this study was to analyze the cost-effectiveness of 5 molecular testing strategies to screen LS among patients with newly diagnosed CRC and to conduct preventive surveillance in their first-degree relatives. Methods: A decision tree model was designed to identify the number of LS mutations and the related costs in the CRC patients. Five strategies were modeled, i.e., Amsterdam II criteria, microsatellite instability (MSI) testing, immunohistochemistry (IHC), and next-generation sequencing (NGS). A Markov model was also used to estimate the long-term outcome of monitoring (including colonoscopy and taking aspirin) among relatives of those patients with CRC who carried LS. Results: All strategies were cost-effective compared with no testing condition. The 2 most cost-effective strategies were strategy 2 (IHC testing followed by NGS testing) and strategy 4 (MSI testing followed by NGS testing), with the ICER of 4,604$ and 4,748$ per quality-adjusted life year (QALY), respectively. Based on one-way sensitivity analysis of IHC sensitivity, the Cost of colonoscopy, MSI sensitivity, and the number of families who inherited LS had the most effect on the results. Conclusions: The findings suggested that from an Iranian health care system perspective, IHC testing followed by NGS testing could be regarded as the most cost-effective strategy compared to the other strategies. These results can be useful in offering to screen LS in newly diagnosed CRC patients.

Model-Based Re-Examination of the Effectiveness of Tumor/Immunohistochemistry and Direct-to-Sequencing Protocols for Lynch Syndrome Case Finding in Endometrial Cancer

PURPOSE

Despite widespread provision of Lynch syndrome (LS) screening programs, questions remain about the most effective and efficient protocol for LS case finding. The purpose of this study was to explore the performance of the two protocols widely shown to be the most efficient and effective, respectively: immunohistochemical (IHC) staining of tumor and direct-to-sequencing (DtS) in endometrial cancer populations.

METHODS

Simulation models were developed to explore performance of the IHC and DtS protocols, updated to reflect current evidence. Analyses explicitly account for protocol complexity and failure points, as well as decreased sequencing costs. Key outcomes are percent of LS cases identified, total protocol costs and efficiency, and break-even analyses of sequencing costs. All costs are in 2020 US dollars (USD).

RESULTS

Under plausible conditions, the IHC protocol is expected to identify 40%-78% of LS cases and DtS protocol from 49% to 97%. When the key variable success in proceeding to sequencing is fixed for both protocols at 50%, 75%, and 100%, the DtS protocol is 9%, 12%, and 16% better at case finding, respectively, than the IHC protocol. The break-even cost of sequencing is about $488 USD when the outcome is total direct testing protocol costs; it is about $670 USD when the outcome is cost per LS case detected.

CONCLUSION

This study quantifies the plausible differences in the clinical effectiveness and cost-effectiveness of the two LS case-finding protocols. We demonstrate the large influence of success in proceeding to sequencing and potential impact of decreasing sequencing prices.

Cost-effectiveness of Active Identification and Subsequent Colonoscopy Surveillance of Lynch Syndrome Cases

BACKGROUND & AIMS

The province of Ontario, Canada is considering immunohistochemical followed by cascade analyses of all patients who received a diagnosis of colorectal cancer (CRC) at an age younger than 70 years to identify individuals with Lynch syndrome. We evaluated the costs and benefits of testing for Lynch syndrome and determined the optimal surveillance interval for first-degree relatives (FDRs) found to have Lynch syndrome.

METHODS

We developed a patient flow diagram to determine costs and yield of immunohistochemical testing for Lynch syndrome in CRC cases and, for those found to have Lynch syndrome, their FDRs, accounting for realistic uptake. Subsequently, we used the MISCAN-colon model to compare costs and benefits of annual, biennial, and triennial surveillance in FDRs identified with Lynch syndrome vs colonoscopy screening every 10 years (usual care for individuals without a diagnosis of Lynch syndrome).

RESULTS

Testing 1000 CRC cases was estimated to identify 20 CRC index cases and 29 FDRs with Lynch syndrome at a cost of $310,274. Despite the high cost of Lynch syndrome tests, offering the FDRs with Lynch syndrome biennial colonoscopy surveillance was cost-effective at $8785 per life-year gained compared with usual care because of a substantial increase in life-years gained (+122%) and cost savings in CRC care. Triennial surveillance was more costly and less effective, and annual surveillance showed limited additional benefit compared with biennial surveillance.

CONCLUSIONS

Immunohistochemical testing for Lynch syndrome in persons younger than 70 years who received a diagnosis of CRC and then testing FDRs of those found to have Lynch syndrome provide a good balance between costs and long-term benefits. Colonoscopy surveillance every 2 years is the optimal surveillance interval for patients with Lynch syndrome.

Cost-effectiveness analysis of genetic diagnostic strategies for Lynch syndrome in Italy

Lynch syndrome (LS) is an autosomal dominant condition caused by pathogenic variants in mismatch repair (MMR) genes that predispose individuals to different malignancies, such as colorectal cancer (CRC) and endometrial cancer. Current guidelines recommended testing for LS in individuals with newly diagnosed CRC to reduce cancer morbidity and mortality in relatives. Economic evaluations in support of such approach, however, are not available in Italy. We developed a decision-analytic model to analyze the cost-effectiveness of LS screening from the perspective of the Italian National Health System. Three testing strategies: the sequencing of all MMR genes without prior tumor analysis (Strategy 1), a sequential IHC and MS-MLPA analysis (Strategy 2), and an age-targeted strategy with a revised Bethesda criteria assessment before IHC and methylation-specific MLPA for patients ≥ than 70 years old (Strategy 3) were analyzed and compared to the “no testing” strategy. Quality Adjusted Life Years (QALYs) in relatives after colonoscopy, aspirin prophylaxis and an intensive gynecological surveillance were estimated through a Markov model. Assuming a CRC incidence rate of 0.09% and a share of patients affected by LS equal to 2.81%, the number of detected pathogenic variants among CRC cases ranges, in a given year, between 910 and 1167 depending on the testing strategy employed. The testing strategies investigated, provided one-time to the entire eligible population (CRC patients), were associated with an overall cost ranging between €1,753,059.93-€10,388,000.00. The incremental cost-effectiveness ratios of the Markov model ranged from €941.24 /QALY to €1,681.93 /QALY, thus supporting that “universal testing” versus “no testing” is cost-effective, but not necessarily in comparison with age-targeted strategies. This is the first economic evaluation on different testing strategies for LS in Italy. The results might support the introduction of cost-effective recommendations for LS screening in Italy.

The Current Practice of Lynch Syndrome Diagnosis and Management in Italy: A Qualitative Assessment

BACKGROUND

Lynch syndrome (LS) is the most frequent form of hereditary colorectal cancer (CRC; up to 3-5% of the total CRC burden) and predisposes to the development of other cancers. Multidisciplinary diagnostic strategies are relevant both to the index cases and to their at-risk relatives, but their implementation is still limited. Our study aimed to explore LS testing practices in Italy.

METHODS

In order to ascertain the current practice of LS diagnosis and management, we conducted a qualitative assessment by sending a questionnaire to health care professionals at 4 Italian hospitals selected as "models" representing different hospital settings. Based on the surveys, we reconstructed the management pathways for CRC patients in terms of diagnostic strategies and health professionals involved.

RESULTS

Seven of the 8 invited professionals filled in the questionnaire. Noncompliance with the latest guidelines was reported, as no tumor "screening" was performed on CRC cases. The lack of a structured multidisciplinary team who manages CRC patients from risk assessment to diagnosis and follow-up was reported. The availability of professionals and laboratory technologies differ widely between hospitals. As for cascade testing of at-risk relatives, a systematic and active approach was absent in all the considered hospitals.

CONCLUSIONS

Our study shows that no structured and standardized pathways for the diagnosis and management of LS patients are currently in place in Italy. We envisage that by extending our research to further experiences and countries, an increasing awareness of the topic can be translated into a health gain for hereditary CRC patients and their at-risk relatives.

Lethal privacy: Quantifying life years lost if the right to informational self-determination guides genetic screening for Lynch syndrome

Genetic relatives of hereditary colorectal cancer patients with Lynch syndrome (LS) are at risk of cancer. Testing both colorectal cancer patients and relatives of mutation carriers for LS allows targeted prevention. However, this could mean disclosing sensitive health data to family members. In light of potential trade-offs between cost-effectiveness and patient privacy, this study investigates the implications of increasing test uptake in Germany. Out of 22 screening strategies for LS, the non-dominated and current German strategies were assessed from the perspective of the statutory health insurance. Life years gained by increased prevention were estimated with Markov models. The effects and implications of different test uptake rates in index patients and their relatives were investigated by scenario analysis. Privacy limitations could yield health gains of up to 2500 undiscounted life years for first-degree relatives of index patients and substantially improve cost-effectiveness. However, this approach may contradict the right to informational self-determination. This study demonstrates the effect higher LS test uptakes could have on the lives and rights of colorectal cancer patients and their relatives. It shows potential conflicts between the efficient use of health care resources on the one hand and reasonable consideration of patient autonomy on the other.

Comparison of Universal Versus Age-Restricted Screening of Colorectal Tumors for Lynch Syndrome Using Mismatch Repair Immunohistochemistry: A Cohort Study

BACKGROUND

Guidelines recommend screening all patients with newly diagnosed colorectal cancer (CRC) for Lynch syndrome (LS). However, the efficiency of universal LS screening in elderly populations has not been well studied.

OBJECTIVE

To compare the performance of age-restricted and universal LS screening using reflex mismatch repair (MMR) immunohistochemistry (IHC) of CRC tumors.

DESIGN

Retrospective cohort study.

SETTING

A large, diverse, community-based health care system.

PARTICIPANTS

3891 persons with newly diagnosed CRC who had LS screening between 2011 and 2016.

MEASUREMENTS

Diagnostic yield of different LS screening strategies.

RESULTS

Sixty-three LS cases (diagnostic yield, 1.62%) were identified by universal screening, with only 5 (7.9%) detected after age 70 years and 1 (1.6%) detected after age 80 years. When all patients with CRC who had universal screening were used as the denominator, 58 LS cases (diagnostic yield, 1.49% [95% CI, 1.13% to 1.92%]) were identified in patients with CRC diagnosed at or before age 70 years, 60 LS cases (diagnostic yield, 1.54% [CI, 1.18% to 1.98%]) were identified in those with CRC diagnosed at or before age 75 years, and 62 LS cases (diagnostic yield, 1.59% [CI, 1.22% to 2.04%]) were identified in those with CRC diagnosed at or before age 80 years. Using 75 years as the upper age limit for screening missed 3 of 63 (4.8%) LS cases but resulted in 1053 (27.1%) fewer cases requiring tumor MMR IHC. Using 80 years as the upper age limit missed 1 of 63 (1.6%) LS cases and resulted in 668 (17.2%) fewer cases requiring tumor MMR IHC.

LIMITATION

Persons who were eligible for but did not complete germline analysis were excluded from calculations of performance characteristics.

CONCLUSION

The incremental diagnostic yield decreased substantially after age 70 to 75 years. Stopping reflex CRC screening for LS after age 80 years may be reasonable because of very low efficiency, particularly in resource-limited settings, but this merits further investigation. Studies evaluating the effect of diagnosing LS in elderly persons on their family members are needed.

PRIMARY FUNDING SOURCE

Kaiser Permanente Northern California Division of Research.

Testing strategies to reduce morbidity and mortality from Lynch syndrome

OBJECTIVE

Lynch syndrome (LS) has an autosomal dominant inheritance pattern and is associated with increased risk for colorectal cancer (CRC) and other cancers. Various strategies are used to identify patients at risk and offer surveillance and preventive programs, the cost effectiveness of which is much dependent on the prevalence of LS in a population. Universal testing (UT) is proposed as an effective measure, targeting all newly diagnosed CRC patients under a certain age.

MATERIALS AND METHODS

LS cases were identified in a cohort of 572 consecutive CRC patients. Immunohistochemistry was performed in 539 cases, using antibodies against mismatch repair proteins MLH1, PMS2, MSH2, and MSH6. Microsatellite instability and gene mutation screening were performed in 57 cases.

RESULTS

In total 11 pathogenic variants were detected, identifying LS in 1.9% of new CRC cases. Comparing the results with current clinical methods, 2 pathogenic variants were found with Amsterdam criteria and 9 when using either Bethesda guidelines or our institution's prior clinical criteria. Pathogenic variants in MSH6 were the most common in our series. We also found different outcomes using different age cut offs.

CONCLUSION

Our study demonstrates that UT of tumors before age on onset at 75 years would most likely be cost-efficient and essentially equivalent to applying the Bethesda guidelines or our institution's prior clinical criteria on all new CRC.

Mismatch repair deficiency assessment by immunohistochemistry: for Lynch syndrome screening and beyond

While mismatch repair (MMR) deficiency has been studied extensively, the assessment of MMR status in colorectal and other cancers remains highly relevant, particularly in light of recent data demonstrating that MMR deficiency is a strong predictor for treatment benefit with immune checkpoint inhibitors across multiple tumor types. In colorectal cancer, there is a growing consensus in support of routine MMR testing for Lynch syndrome screening, to inform prognosis and adjuvant chemotherapy use in early stage disease, and to predict response to immunotherapy in advanced disease. Here, we provide a review of the Ventana MMR Immunohistochemistry Panel, which was recently approved by the US FDA for use in Lynch syndrome screening.

Performance of tumor testing for Lynch syndrome identification in patients with colorectal cancer: A retrospective single-center study

Objective:

To investigate the performance of tumor testing approaches in the identification of Lynch syndrome (LS) in a single-center cohort of people with colorectal cancer (CRC).

Methods:

A retrospective analysis of data stored in a dedicated database was carried out to identify patients with CRC suspected for LS who were referred to Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy, between 1999 and 2014. The sensitivity and specificity of immunohistochemistry (IHC) for mismatch repair (MMR) proteins and microsatellite instability (MSI) analysis (alone or combined) were calculated with respect to the presence of causative MMR germline variants.

Results:

A total of 683 patients with CRC suspected for LS were identified. IHC results of MMR protein analysis and MSI were assessed in 593 and 525 CRCs, respectively, while germline analysis was performed in 418 patients based on the IHC or MSI test result and/or clinical features. Univariate and multivariate analysis revealed a significant correlation of pathogenic MMR germline variants with all clinicopathologic features including Amsterdam criteria, presence of endometrial cancer, CRC site, age at onset, stage, and grade. The highest odds ratio values were observed for IHC and MSI (17.1 and 8.8, respectively). The receiver operating characteristic curve and area under the curve values demonstrated that IHC alone or combined with other clinicopathologic parameters was an excellent test for LS identification.

Conclusions:

This study confirms the effectiveness of tumor testing to identify LS among patients with CRC. Although IHC and MSI analysis were similarly effective, IHC could be a better strategy for LS identification as it is less expensive and more feasible.

Molecular testing for Lynch syndrome in people with colorectal cancer: systematic reviews and economic evaluation

BACKGROUND

Inherited mutations in deoxyribonucleic acid (DNA) mismatch repair (MMR) genes lead to an increased risk of colorectal cancer (CRC), gynaecological cancers and other cancers, known as Lynch syndrome (LS). Risk-reducing interventions can be offered to individuals with known LS-causing mutations. The mutations can be identified by comprehensive testing of the MMR genes, but this would be prohibitively expensive in the general population. Tumour-based tests - microsatellite instability (MSI) and MMR immunohistochemistry (IHC) - are used in CRC patients to identify individuals at high risk of LS for genetic testing. MLH1 (MutL homologue 1) promoter methylation and BRAF V600E testing can be conducted on tumour material to rule out certain sporadic cancers.

OBJECTIVES

To investigate whether testing for LS in CRC patients using MSI or IHC (with or without MLH1 promoter methylation testing and BRAF V600E testing) is clinically effective (in terms of identifying Lynch syndrome and improving outcomes for patients) and represents a cost-effective use of NHS resources.

REVIEW METHODS

Systematic reviews were conducted of the published literature on diagnostic test accuracy studies of MSI and/or IHC testing for LS, end-to-end studies of screening for LS in CRC patients and economic evaluations of screening for LS in CRC patients. A model-based economic evaluation was conducted to extrapolate long-term outcomes from the results of the diagnostic test accuracy review. The model was extended from a model previously developed by the authors.

RESULTS

Ten studies were identified that evaluated the diagnostic test accuracy of MSI and/or IHC testing for identifying LS in CRC patients. For MSI testing, sensitivity ranged from 66.7% to 100.0% and specificity ranged from 61.1% to 92.5%. For IHC, sensitivity ranged from 80.8% to 100.0% and specificity ranged from 80.5% to 91.9%. When tumours showing low levels of MSI were treated as a positive result, the sensitivity of MSI testing increased but specificity fell. No end-to-end studies of screening for LS in CRC patients were identified. Nine economic evaluations of screening for LS in CRC were identified. None of the included studies fully matched the decision problem and hence a new economic evaluation was required. The base-case results in the economic evaluation suggest that screening for LS in CRC patients using IHC, BRAF V600E and MLH1 promoter methylation testing would be cost-effective at a threshold of £20,000 per quality-adjusted life-year (QALY). The incremental cost-effectiveness ratio for this strategy was £11,008 per QALY compared with no screening. Screening without tumour tests is not predicted to be cost-effective.

LIMITATIONS

Most of the diagnostic test accuracy studies identified were rated as having a risk of bias or were conducted in unrepresentative samples. There was no direct evidence that screening improves long-term outcomes. No probabilistic sensitivity analysis was conducted.

CONCLUSIONS

Systematic review evidence suggests that MSI- and IHC-based testing can be used to identify LS in CRC patients, although there was heterogeneity in the methods used in the studies identified and the results of the studies. There was no high-quality empirical evidence that screening improves long-term outcomes and so an evidence linkage approach using modelling was necessary. Key determinants of whether or not screening is cost-effective are the accuracy of tumour-based tests, CRC risk without surveillance, the number of relatives identified for cascade testing, colonoscopic surveillance effectiveness and the acceptance of genetic testing. Future work should investigate screening for more causes of hereditary CRC and screening for LS in endometrial cancer patients.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016033879.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Hereditary Nonpolyposis Colorectal Cancer and Cancer Syndromes: Recent Basic and Clinical Discoveries

Approximately one-third of individuals diagnosed with colorectal cancer have a family history of cancer, suggesting that CRCs may result from a heritable component. Despite the availability of current gene-identification techniques, only 5% of all CRCs emerge from well-identifiable inherited causes for predisposition, including polyposis and nonpolyposis syndromes. Hereditary nonpolyposis colorectal cancer represents a large proportion of cases, and robustly affected patients are at increased risk for early onset, synchronous, and metachronous colorectal malignancies and extracolonic malignancies. HNPCC encompasses several cancer syndromes, such as Lynch syndrome, Lynch-like syndrome, and familial colorectal cancer type X, which have remarkable clinical presentations and overlapping genetic profiles that make clinical diagnosis a challenging task. Therefore, distinguishing between the HNPCC disorders is crucial for physicians as an approach to tailor different recommendations for patients and their at-risk family members according to the risks for colonic and extracolonic cancer associated with each syndrome. Identification of these potential patients through epidemiological characteristics and new genetic testing can estimate the individual risk, which informs appropriate cancer screening, surveillance, and/or treatment strategies. In the past three years, many appealing and important advances have been made in our understanding of the relationship between HNPCC and CRC-associated syndromes. The knowledge from the genetic profile of cancer syndromes and unique genotype-phenotype profiles in the different syndromes has changed our cognition. Therefore, this review presents and discusses HNPCC and several common nonpolyposis syndromes with respect to molecular phenotype, histopathologic features, and clinical presentation.

Clinical penetrance in hereditary hemochromatosis: estimates of the cumulative incidence of severe liver disease among HFE C282Y homozygotes

Iron overload (hemochromatosis) can cause serious, symptomatic disease that is preventable if detected early and managed appropriately. The leading cause of hemochromatosis in populations of predominantly European ancestry is homozygosity of the C282Y variant in the HFE gene. Screening of adults for iron overload or associated genotypes is controversial, largely because of a belief that severe phenotypes are uncommon, although cascade testing of first-degree relatives of patients is widely endorsed. We contend that severe liver disease (cirrhosis or hepatocellular cancer) is not at all uncommon among older males with hereditary hemochromatosis. Our review of the published data from a variety of empirical sources indicates that roughly 1 in 10 male HFE C282Y homozygotes is likely to develop severe liver disease during his lifetime unless iron overload is detected early and treated. New evidence from a randomized controlled trial of treatment allows for evidence-based management of presymptomatic patients. Although population screening for HFE C282Y homozygosity faces multiple barriers, a potentially effective strategy for increasing the early detection and prevention of clinical iron overload and severe disease is to include HFE C282Y homozygosity in lists of medically actionable gene variants when reporting the results of genome or exome sequencing.

Personalized medicine in colorectal cancer diagnosis and treatment: a systematic review of health economic evaluations

Background

Due to its epidemiological relevance, several studies have been performed to assess the cost-effectiveness of diagnostic tests and treatments in colorectal cancer (CRC) patients.

Objective

We reviewed economic evaluations on diagnosis of inherited CRC-syndromes and genetic tests for the detection of mutations associated with response to therapeutics.

Methods

A systematic literature review was performed by searching the main literature databases for relevant papers on the field, published in the last 5 years.

Results

20 studies were included in the final analysis: 14 investigating the cost-effectiveness of hereditary-CRC screening; 5 evaluating the cost-effectiveness of KRAS mutation assessment before treatment; and 1 study analysing the cost-effectiveness of genetic tests for early-stage CRC patients prognosis. Overall, we found that: (a) screening strategies among CRC patients were more effective than no screening; (b) all the evaluated interventions were cost-saving for certain willingness-to-pay (WTP) threshold; and (c) all new CRC patients diagnosed at age 70 or below should be screened. Regarding patients treatment, we found that KRAS testing is economically sustainable only if anticipated in patients with non-metastatic CRC (mCRC), while becoming unsustainable, due to an incremental cost-effectiveness ratio (ICER) beyond the levels of WTP-threshold, in all others evaluated scenarios.

Conclusions

The poor evidence in the field, combined to the number of assumptions done to perform the models, lead us to a high level of uncertainty on the cost-effectiveness of genetic evaluations in CRC, suggesting that major research is required in order to assess the best combination among detection tests, type of genetic test screening and targeted-therapy.

Electronic supplementary material

The online version of this article (10.1186/s12962-018-0085-z) contains supplementary material, which is available to authorized users.

Which Lynch syndrome screening programs could be implemented in the "real world"? A systematic review of economic evaluations

Purpose

Lynch syndrome (LS) screening can significantly reduce cancer morbidity and mortality in mutation carriers. Our aim was to identify cost-effective LS screening programs that can be implemented in the “real world.”

Methods

We performed a systematic review of full economic evaluations of genetic screening for LS in different target populations; health outcomes were estimated in life-years gained or quality-adjusted life-years.

Results

Overall, 20 studies were included in the systematic review. Based on the study populations, we identified six categories of LS screening program: colorectal cancer (CRC)–based, endometrial cancer–based, general population–based, LS family registry–based, cascade testing–based, and genetics clinic–based screening programs. We performed an in-depth analysis of CRC-based LS programs, classifying them into three additional subcategories: universal, age-targeted, and selective. In five studies, universal programs based on immunohistochemistry, either alone or in combination with the BRAF test, were cost-effective compared with no screening, while in two studies age-targeted programs with a cutoff of 70 years were cost-effective when compared with age-targeted programs with lower age thresholds.

Conclusion

Universal or <70 years–age-targeted CRC-based LS screening programs are cost-effective and should be implemented in the “real world.”

Performance of Lynch syndrome predictive models in quantifying the likelihood of germline mutations in patients with abnormal MLH1 immunoexpression

Lynch syndrome (LS) accounts for up to 4 % of all colorectal cancers (CRC). Detection of a pathogenic germline mutation in one of the mismatch repair genes is the definitive criterion for LS diagnosis, but it is time-consuming and expensive. Immunohistochemistry is the most sensitive prescreening test and its predictive value is very high for loss of expression of MSH2, MSH6, and (isolated) PMS2, but not for MLH1. We evaluated if LS predictive models have a role to improve the molecular testing algorithm in this specific setting by studying 38 individuals referred for molecular testing and who were subsequently shown to have loss of MLH1 immunoexpression in their tumors. For each proband we calculated a risk score, which represents the probability that the patient with CRC carries a pathogenic MLH1 germline mutation, using the PREMM_1,2,6 and MMRpro predictive models. Of the 38 individuals, 18.4 % had a pathogenic MLH1 germline mutation. MMRpro performed better for the purpose of this study, presenting a AUC of 0.83 (95 % CI 0.67-0.9; P < 0.001) compared with a AUC of 0.68 (95 % CI 0.51-0.82, P = 0.09) for PREMM_1,2,6. Considering a threshold of 5 %, MMRpro would eliminate unnecessary germline mutation analysis in a significant proportion of cases while keeping very high sensitivity. We conclude that MMRpro is useful to correctly predict who should be screened for a germline MLH1 gene mutation and propose an algorithm to improve the cost-effectiveness of LS diagnosis.

Genomic sequencing in clinical practice: applications, challenges, and opportunities

The development of massively parallel sequencing (or next-generation sequencing) has facilitated a rapid implementation of genomic sequencing in clinical medicine. Genomic sequencing (GS) is now an essential tool for evaluating rare disorders, identifying therapeutic targets in neoplasms, and screening for prenatal aneuploidy. Emerging applications, such as GS for preconception carrier screening and predisposition screening in healthy individuals, are being explored in research settings and utilized by members of the public eager to incorporate genomic information into their health management. The rapid pace of adoption has created challenges for all stakeholders in clinical GS, from standardizing variant interpretation approaches in clinical molecular laboratories to ensuring that nongeneticist clinicians are prepared for new types of clinical information. Clinical GS faces a pivotal moment, as the vast potential of new quantities and types of data enable further clinical innovation and complicated implementation questions continue to be resolved.

Hereditary Colorectal Cancer Syndromes

Awareness of hereditary colorectal cancer syndromes is important to facilitate their identification because affected patients are at increased risk for early onset, synchronous, and metachronous colorectal malignancies, and certain extracolonic malignancies depending on the syndrome. Identification of an affected individual allows for screening and early interventions for patients and their at-risk kindred. Genetic counseling and testing is important to the care of these patients. As knowledge of the genetic basis of these syndromes grows, unique genotype-phenotype profiles allow clinicians to tailor surveillance and treatment strategies based on individual risk.

Universal molecular screening does not effectively detect Lynch syndrome in clinical practice

BACKGROUND

Lynch syndrome (LS) due to an inherited damaging mutation in mismatch repair (MMR) genes comprises 3% of all incident colorectal cancer (CRC). Molecular testing using immunohistochemistry (IHC) for MMR proteins is a recommended screening tool to identify LS in incident CRC. This study assessed outcomes of population-based routine molecular screening for diagnosis of LS in a regional center.

METHODS

We conducted a prospective, consecutive case series study of universal IHC testing on cases of resected CRC from September 2004-December 2013. Referred cases with abnormal IHC results that attended a familial cancer clinic were assessed according to modified Bethesda criteria (until 2009) or molecular criteria (from 2009).

RESULTS

1612 individuals underwent resection for CRC in the study period and had MMR testing by IHC. Of these, 274 cases (16.9%) exhibited loss of expression of MMR genes. The mean age at CRC diagnosis was 68.1 years (± standard deviation 12.7) and the mean age of those with an IHC abnormality was 71.6 (± 11.8). A total of 82 (29.9%) patients with an abnormal result were seen in a subspecialty familial cancer clinic. Patients aged under 50 (p = 0.009) and those with loss of MSH6 staining (p = 0.027) were more likely to be referred and to attend. After germ-line sequencing, 0.6% (10 of 82) were identified as having a clinically significant abnormality. A further eight probands with pathogenic germ-line mutations were identified from other referrals to the service over the same time period.

CONCLUSIONS

While technically accurate, the yield of 'universal' IHC in detecting new Lynch probands is limited by real-world factors that reduce referrals and genetic testing. We propose an alternative approach for universal, incident case detection of Lynch syndrome with 'one-stop' MMR testing and sequencing.

Cost-effectiveness of routine screening for Lynch syndrome in endometrial cancer patients up to 70years of age

PURPOSE

To assess cost-effectiveness of routine screening for Lynch Syndrome (LS) in endometrial cancer (EC) patients ≤70years of age.

METHODS

Consecutive EC patients ≤70years of age were screened for LS by analysis of microsatellite instability, immunohistochemistry and MLH1 hypermethylation. Costs and health benefit in life years gained (LYG) included surveillance for LS carriers among EC patients and relatives. We calculated incremental cost-effectiveness ratios (ICERs) comparing LS screening among EC patients ≤70years with ≤50years and the revised Bethesda guidelines.

RESULTS

Screening for LS in 179 EC patients identified 7 LS carriers; 1 was ≤50 and 6 were 51-70years. Per age category 18 and 9 relatives were identified as LS carrier. Screening resulted in 74,7 LYG (45,4 and 29,3 LYG per age category). The ICER for LS screening in EC patients ≤70 compared with ≤50years was €5,252/LYG. The revised Bethesda guidelines missed 4/7 (57%) LS carriers among EC patients. The ICER for LS screening in EC patients ≤70years of age compared with the revised Bethesda guidelines was €6,668/LYG. Both ICERs remained <€16,000/LYG in sensitivity analyses.

CONCLUSION

Routine LS screening in EC patients ≤70years is a cost-effective strategy, allowing colorectal cancer prevention in EC patients and their relatives.

Cost-Effectiveness Analysis of Different Genetic Testing Strategies for Lynch Syndrome in Taiwan

Patients with Lynch syndrome (LS) have a significantly increased risk of developing colorectal cancer (CRC) and other cancers. Genetic screening for LS among patients with newly diagnosed CRC aims to identify mutations in the disease-causing genes (i.e., the DNA mismatch repair genes) in the patients, to offer genetic testing for relatives of the patients with the mutations, and then to provide early prevention for the relatives with the mutations. Several genetic tests are available for LS, such as DNA sequencing for MMR genes and tumor testing using microsatellite instability and immunohistochemical analyses. Cost-effectiveness analyses of different genetic testing strategies for LS have been performed in several studies from different countries such as the US and Germany. However, a cost-effectiveness analysis for the testing has not yet been performed in Taiwan. In this study, we evaluated the cost-effectiveness of four genetic testing strategies for LS described in previous studies, while population-specific parameters, such as the mutation rates of the DNA mismatch repair genes and treatment costs for CRC in Taiwan, were used. The incremental cost-effectiveness ratios based on discounted life years gained due to genetic screening were calculated for the strategies relative to no screening and to the previous strategy. Using the World Health Organization standard, which was defined based on Taiwan’s Gross Domestic Product per capita, the strategy based on immunohistochemistry as a genetic test followed by BRAF mutation testing was considered to be highly cost-effective relative to no screening. Our probabilistic sensitivity analysis results also suggest that the strategy has a probability of 0.939 of being cost-effective relative to no screening based on the commonly used threshold of $50,000 to determine cost-effectiveness. To the best of our knowledge, this is the first cost-effectiveness analysis for evaluating different genetic testing strategies for LS in Taiwan. The results will be informative for the government when considering offering screening for LS in patients newly diagnosed with CRC.

Assessing the Costs and Cost-Effectiveness of Genomic Sequencing

Despite dramatic drops in DNA sequencing costs, concerns are great that the integration of genomic sequencing into clinical settings will drastically increase health care expenditures. This commentary presents an overview of what is known about the costs and cost-effectiveness of genomic sequencing. We discuss the cost of germline genomic sequencing, addressing factors that have facilitated the decrease in sequencing costs to date and anticipating the factors that will drive sequencing costs in the future. We then address the cost-effectiveness of diagnostic and pharmacogenomic applications of genomic sequencing, with an emphasis on the implications for secondary findings disclosure and the integration of genomic sequencing into general patient care. Throughout, we ground the discussion by describing efforts in the MedSeq Project, an ongoing randomized controlled clinical trial, to understand the costs and cost-effectiveness of integrating whole genome sequencing into cardiology and primary care settings.

When is Genomic Testing Cost-Effective? Testing for Lynch Syndrome in Patients with Newly-Diagnosed Colorectal Cancer and Their Relatives

Varying estimates of the cost-effectiveness of genomic testing applications can reflect differences in study questions, settings, methods and assumptions. This review compares recently published cost-effectiveness analyses of testing strategies for Lynch Syndrome (LS) in tumors from patients newly diagnosed with colorectal cancer (CRC) for either all adult patients or patients up to age 70 along with cascade testing of relatives of probands. Seven studies published from 2010 through 2015 were identified and summarized. Five studies analyzed the universal offer of testing to adult patients with CRC and two others analyzed testing patients up to age 70; all except one reported incremental cost-effectiveness ratios (ICERs) < $ 100,000 per life-year or quality-adjusted life-year gained. Three studies found lower ICERs for selective testing strategies using family history-based predictive models compared with universal testing. However, those calculations were based on estimates of sensitivity of predictive models derived from research studies, and it is unclear how sensitive such models are in routine clinical practice. Key model parameters that are influential in ICER estimates included 1) the number of first-degree relatives tested per proband identified with LS and 2) the cost of gene sequencing. Others include the frequency of intensive colonoscopic surveillance, the cost of colonoscopy, and the inclusion of extracolonic surveillance and prevention options.