Current mismatch repair deficiency tumor testing practices and capabilities: A survey of Australian pathology providers

Improving Lynch syndrome detection: a mixed-methods process evaluation of a hybrid type III effectiveness-implementation trial

INTRODUCTION

Translating evidence-based practices into real-world healthcare settings is challenging, particularly in the rapidly evolving field of genomics. A pragmatic two-arm cluster-randomized clinical trial (Hide and Seek Project - HaSP) tested two implementation approaches for improving hereditary cancer referral practices with one key distinction: implementation strategies that were designed 1) explicitly using psychological theory, or 2) using healthcare professional intuition. This mixed-methods process evaluation aimed to provide insights into how and why change occurred by examining contextual determinants, identifying mechanisms of action, and exploring the role of theory.

METHODS

Post-implementation interviews were conducted with Implementation Leads and clinicians from participating HaSP sites. Transcripts were analysed using a mixed inductive and deductive approach, guided by the updated Consolidated Framework for Implementation Research (2.0). Findings were triangulated with other HaSP process evaluation data sources, including HaSP focus group observations, HaSP research team focus groups, MDT observations, and Implementation Lead project logs. Logic models and case studies were developed to articulate causal processes underlying strategy effectiveness and conditions necessary for implementation success.

RESULTS

Eighteen participants from seven HaSP sites were interviewed. Qualitative analysis identified themes related to Lynch syndrome complexity, pandemic disruptions, operational challenges, information technology constraints, multidisciplinary collaboration, cultural determinants, attitudes towards change, the value of theory, adaptations, and implementation support. Within these themes, a total of 39 contextual determinants were identified, with barriers and facilitators spanning 18 CFIR constructs across five domains. Logic models and case studies highlighted a number of mechanisms of action, producing variable clinical outcomes. Process evaluation findings, interpreted together with HaSP trial outcomes, indicate that theory-based implementation strategies may better support Lynch syndrome detection practices compared to intuition-based strategies.

CONCLUSIONS

The information gained from this process evaluation deepens understanding of the factors influencing the success of hospital-specific implementation strategies within the HaSP framework. Potential pathways for optimising the effectiveness of the overall HaSP implementation approach have been identified.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry, ACTRN12618001072202. Registered 27 June 2018, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=375348&isReview=true .

Development, Evaluation, and User Testing of a Decision-Making Toolkit to Promote Organizations to Implement Universal Tumor Screening for Lynch Syndrome

INTRODUCTION

The Implementing Universal Lynch Syndrome Screening (IMPULSS) study explained institutional variation in universal tumor screening (UTS) with the goal of identifying ways to aid organizational decision-makers in implementing and optimizing Lynch syndrome UTS programs.

METHODS

After applying the Consolidated Framework for Implementation Research (CFIR 1.0) to analyze interviews with 66 stakeholders across 9 healthcare systems to develop a toolkit for implementation, we adapted the International Patient Decision Aid Standards (IPDAS) to assess toolkit potential to aid decision-making consistent with organizational values. We then conducted user testing with two experienced and four non-experienced implementers of UTS to improve the content and functionality of the toolkit and assess its acceptability and appropriateness.

RESULTS

Toolkit components were organized to address findings related to CFIR 1.0 constructs of evidence strength and quality, relative advantage, cost, engaging, planning, executing, and reflecting and evaluating. A home page was added to direct users to different sections based on whether they are deciding to implement UTS, planning for implementation, improving an existing UTS program, or considering a different approach to identify patients with Lynch syndrome. Upon initial evaluation, 31 of 64 IPDAS criteria were met by the original toolkit. All users rated the toolkit as acceptable and appropriate for assisting organizational decision-making and identified multiple areas for improvement. Numerous iterative changes were made to the toolkit, resulting in meeting 17 of the previously unmet IPDAS criteria.

CONCLUSION

We demonstrate the rigorous development of a toolkit guided by the CFIR and show how user testing helped improve the toolkit to ensure it is acceptable, appropriate, and meets most IPDAS criteria relevant to organizational values-based decision-making.

Real-world study on microsatellite instability and mismatch repair deficiency testing patterns among patients with metastatic colorectal cancer in Spain

PURPOSE

Clinical practice guidelines recommend that all patients with metastatic colorectal cancer (mCRC) should be tested for mismatch repair deficiency (dMMR) or microsatellite instability-high (MSI-H). We aimed to describe the dMMR/MSI-H testing practice in patients with mCRC in Spanish centers.

METHODS

Multicenter, observational retrospective study that included patients newly diagnosed with mCRC or who progressed to a metastatic stage from early/localized stages.

RESULTS

Three hundred patients were included in the study from May 2020 through May 2021, with a median age of 68 years, and two hundred twenty-five (75%) had stage IV disease at initial diagnosis; two hundred eighty-four patients received first-line treatment, and dMMR/MSI-H testing was performed in two hundred fifty-one (84%) patients. The results of the dMMR/MSI-H tests were available in 61 (24%) of 251 patients before the diagnosis of metastatic disease and in 191 (81%) of 236 evaluable patients for this outcome before the initiation of first-line treatment. Among the 244 patients who were tested for dMMR/MSI-H with IHC or PCR, 14 (6%) were MMR deficient. The most frequent type of first-line treatment was the combination of chemotherapy and biological agent, that was received by 71% and 50% of patients with MMR proficient and deficient tumors, respectively, followed by chemotherapy alone, received in over 20% of patients in each subgroup. Only 29% of dMMR/MSI-H tumors received first-line immunotherapy.

CONCLUSION

Our study suggests that a high proportion of patients with mCRC are currently tested for dMMR/MSI-H in tertiary hospitals across Spain. However, there is still room for improvement until universal testing is achieved.

TRIAL REGISTRATION

Not applicable.

In person and virtual process mapping experiences to capture and explore variability in clinical practice: application to genetic referral pathways across seven Australian hospital networks

Genetic referral for Lynch syndrome (LS) exemplifies complex clinical pathways. Identifying target behaviours (TBs) for change and associated barriers requires structured group consultation activities with busy clinicians - consolidating implementation activities whilst retaining rigour is crucial. This study aimed to: i) use process mapping to gain in-depth understandings of site-specific LS testing and referral practices in Australian hospitals and support identification of TBs for change, ii) explore if barriers to identified TBs could be identified through process mapping focus-group data, and iii) demonstrate pandemic-induced transition from in-person to virtual group interactive process mapping methods. LS clinical stakeholders attended interactive in-person or virtual focus groups to develop site-specific "process maps" visually representing referral pathways. Content analysis of transcriptions informed site-specific process maps, then clinical audit data was compared to highlight TBs for change. TBs were reviewed in follow-up focus groups. Secondary thematic analysis explored barriers to identified TBs, coded against the Theoretical Domains Framework (TDF). The transition from in-person to pandemic-induced virtual group interactive process mapping methods was documented. Process mapping highlighted six key areas of clinical practice variation across sites and site-specific TBs for change were identified. Key barriers to identified TBs emerged, categorised to seven TDF domains. Process mapping revealed variations in clinical practices surrounding LS referral between sites. Incorporating qualitative perspectives enhances process mapping by facilitating identification of TBs for change and barriers, providing a pathway to developing targeted interventions. Virtual process mapping activities produced detailed data and enabled comprehensive map development.

Evaluating Multiple Next-Generation Sequencing-Derived Tumor Features to Accurately Predict DNA Mismatch Repair Status

Identifying tumor DNA mismatch repair deficiency (dMMR) is important for precision medicine. Tumor features, individually and in combination, derived from whole-exome sequenced (WES) colorectal cancers (CRCs) and panel-sequenced CRCs, endometrial cancers (ECs), and sebaceous skin tumors (SSTs) were assessed for their accuracy in detecting dMMR. CRCs (n = 300) with WES, where mismatch repair status was determined by immunohistochemistry, were assessed for microsatellite instability (MSMuTect, MANTIS, MSIseq, and MSISensor), Catalogue of Somatic Mutations in Cancer tumor mutational signatures, and somatic mutation counts. A 10-fold cross-validation approach (100 repeats) evaluated the dMMR prediction accuracy for i) individual features, ii) Lasso statistical model, and iii) an additive feature combination approach. Panel-sequenced tumors (29 CRCs, 22 ECs, and 20 SSTs) were assessed for the top performing dMMR predicting features/models using these three approaches. For WES CRCs, 10 features provided >80% dMMR prediction accuracy, with MSMuTect, MSIseq, and MANTIS achieving ≥99% accuracy. The Lasso model achieved 98.3% accuracy. The additive feature approach, with three or more of six of MSMuTect, MANTIS, MSIseq, MSISensor, insertion-deletion count, or tumor mutational signature small insertion/deletion 2 + small insertion/deletion 7 achieved 99.7% accuracy. For the panel-sequenced tumors, the additive feature combination approach of three or more of six achieved accuracies of 100%, 95.5%, and 100% for CRCs, ECs, and SSTs, respectively. The microsatellite instability calling tools performed well in WES CRCs; however, an approach combining tumor features may improve dMMR prediction in both WES and panel-sequenced data across tissue types.

Rates and outcomes of testing for lynch syndrome in a national colorectal cancer screening programme

BACKGROUND

Lynch Syndrome (LS), the most common cause of hereditary colorectal cancer (CRC), is characterised by pathogenic variants in mismatch repair (MMR) genes. Universal testing of all CRCs for LS can increase detection. Rates and outcomes of testing in Ireland's national CRC screening programme have not been examined previously.

METHODS

CRCs diagnosed at two screening sites between 2015 and 2020 were identified. Patient records were used to determine if CRCs had been tested for MMR deficiency and if detected, what downstream testing to rule out LS or genetic testing to confirm LS was undertaken.

RESULTS

Over five years, 206 CRCs were diagnosed. Testing for LS was carried out for 100% of CRCs at site A and 69% of CRCs at site B. Of CRCs tested for LS, 14 (8%) were MMR deficient. After downstream testing for BRAF mutation or hypermethylation of MLH1, three CRCs were identified as potentially LS-related. Of these two individuals declined genetic testing and one was lost to follow-up.

CONCLUSIONS

By 2020 both sites had implemented universal testing of all CRCs for LS. A small number of individuals were identified as being eligible for genetic testing for LS, however those offered declined testing and one individual was lost to follow up. This highlights the importance of universal testing and the need for referral pathways to ensure all appropriate individuals are referred onwards to genetic services.

Stakeholders' views of integrating universal tumour screening and genetic testing for colorectal and endometrial cancer into routine oncology

Mainstream genetic testing in routine oncology care requires implementation research to inform intervention design. In Australia, funding is available for oncology health professionals (OHP) to organise genetic testing (GT) for eligible colorectal and endometrial cancer patients as part of their routine care. To assess the health system ability to incorporate this practice change, we conducted an implementation survey using the Consolidated Framework for Implementation Research (CFIR). The online survey was available from April to September 2020 to OHP and genetic health professional (GHP). In total, 198 respondents attempted the survey, with 158 completed and 27 partial responses: 26% were GHP, 66% OHP and 8% pathologists. Of all responders, 50% were female, mainly practicing in public hospital settings (57%) in an urban location (80%) and with an 18-60 years plus age range. The majority of respondents saw the relative advantage of aligning GT to abnormal universal tumour screening (UTS) results, with 77% of GHP and 78% of OHP agreeing it would streamline care for patients. There was disagreement across healthcare professional groups about knowledge and self-efficacy, with 45% of GHP not viewing oncologists as 'feeling confident' to use genetic test results for treatment management decisions, while 62% of OHP felt confident in their ability. Both OHP and GHP's indicated embedding a genetic counsellor in oncology or having a genetics point of contact to support integrating of GT through UTS as favourable interventions. Implementation research findings allow for the design of targeted interventions and a model for GT integration into oncology.

The health and economic impact of implementation strategies for improving detection of hereditary cancer patients—protocol for an in-depth cost-effectiveness evaluation with microsimulation modelling

Background

Patients with Lynch syndrome (an inherited cancer predisposition syndrome) remain largely underdiagnosed despite clinically and cost-effective testing strategies to detect patients. This is largely due to poor referral rates for high-risk patients for consideration of genetic testing. Targeted approaches to improve the implementation of guidelines and thus uptake rates of genetic testing require the use of limited and valuable healthcare resources. Decision makers must carefully balance the potential health impacts of implementation approaches against the associated costs, similar to when assessing the direct impact of health interventions. This protocol outlines the methods used to conduct an economic evaluation of different implementation approaches aimed at improving referral rates of high-risk patients, including estimating implementation approach costs.

Methods

A cluster randomised controlled trial (the Hide and Seek Project, HaSP) is underway to compare two different implementation approaches aimed at improving referral rates, and thus detection, of Lynch syndrome among colorectal cancer patients across eight Australian hospital networks. An in-depth process evaluation is being conducted alongside the trial and includes measures to collect comprehensive data on both implementation and intervention costs. These costs, in addition to HaSP outcome data, will be incorporated as inputs into an existing microsimulation model—Policy1-Lynch—to project the downstream economic and health impacts and determine the more cost-effective implementation approach from the Australian healthcare perspective.

Discussion

The ability to model the impact of different implementation approaches will enable the most efficient way of improving Lynch syndrome detection. The approach used in this study could also be applied to assess other implementation approaches aimed at increasing the uptake of cost-effective health interventions.

Trial registration

ANZCTR, ACTRN12618001072202. Registered on 27 June 2018.

Understanding implementation success: protocol for an in-depth, mixed-methods process evaluation of a cluster randomised controlled trial testing methods to improve detection of Lynch syndrome in Australian hospitals

INTRODUCTION

In multisite intervention trials, implementation success often varies widely across settings. Process evaluations are crucial to interpreting trial outcomes and understanding contextual factors and causal chains necessary for successful implementation. Lynch syndrome is a hereditary cancer predisposition conferring an increased risk of colorectal, endometrial and other cancer types. Despite systematic screening protocols to identify Lynch syndrome, the condition remains largely underdiagnosed. The Hide and Seek Project ('HaSP') is a cluster randomised controlled trial determining the effectiveness of two approaches to improving Lynch syndrome detection at eight Australian hospital networks. To enhance widespread implementation of optimal Lynch syndrome identification, there is a need to understand not only what works, but also why, in what contexts, and at what costs. Here we describe an in-depth investigation of factors influencing successful implementation of procedures evaluated in the HaSP trial.

METHODS AND ANALYSIS

A mixed-methods, theory-driven process evaluation will be undertaken in parallel to the HaSP trial. Data will include: interviews of Implementation Leads and Lynch syndrome stakeholders, pre-post implementation questionnaires, audio analysis of meetings and focus groups, observation of multidisciplinary team meetings, fidelity checklists and project log analysis. Results will be triangulated and coded, drawing on the Theoretical Domains Framework, Consolidated Framework for Implementation Research and Proctor's implementation outcomes.

ETHICS AND DISSEMINATION

Use of a theory-based process evaluation will enhance interpretation and generalisability of HaSP trial findings, and contribute to the implementation research field by furthering understanding of the conditions necessary for implementation success. Ethical approval has been granted and results will be disseminated via publications in peer-reviewed journals and conference presentations. At trial completion, key findings will be fed back to sites to enable refinement of intervention strategies, both in the context of Lynch syndrome and for the possible generalisability of intervention components in other genetic and broader clinical specialties.

HASP TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (Identifier: ACTRN12618001072202). Registered 27 June 2018. http://www.ANZCTR.org.au/ACTRN12618001072202.aspx.

Lynch syndrome screening in gynaecological cancers: results of an international survey with recommendations for uniform reporting terminology for mismatch repair immunohistochemistry results

AIMS

Lynch syndrome (LS) is associated with an increased risk of developing endometrial carcinoma (EC) and ovarian carcinoma (OC). There is considerable variability in current practices and opinions related to screening of newly diagnosed patients with EC/OC for LS. An online survey was undertaken to explore the extent of these differences.

METHODS AND RESULTS

An online questionnaire was developed by a panel of experts and sent to all members of the British Association of Gynaecological Pathologists (BAGP) and the International Society of Gynecological Pathologists (ISGyP). Anonymised results were received and analysed. Thirty-six BAGP and 44 ISGyP members completed the survey. More than 90% of respondents were aware of the association of LS with both EC and OC, but 34% were not aware of specific guidelines for LS screening. Seventy-one per cent of respondents agreed that universal screening for LS should be carried out in all newly diagnosed EC cases, with immunohistochemistry (IHC) alone as the preferred approach. Only 36% of respondents currently performed IHC or microsatellite instability testing on all newly diagnosed EC cases, with most of the remaining respondents practising selective screening, based on clinical or pathological features or both. A significant minority of respondents (35%) believed that patient consent was required before performance of mismatch repair (MMR) protein IHC. Almost all respondents favoured the use of standardised terminology for reporting MMR protein staining results, and this is proposed herein.

CONCLUSION

There is wide support for universal LS screening in patients with EC, but this survey highlights areas of considerable variation in practice.

The predicted impact and cost-effectiveness of systematic testing of people with incident colorectal cancer for Lynch syndrome

OBJECTIVES

To evaluate the health impact and cost-effectiveness of systematic testing for Lynch syndrome (LS) in people with incident colorectal cancer (CRC) in Australia.

DESIGN, SETTING, PARTICIPANTS

We investigated the impact of LS testing strategies in a micro-simulation model (Policy1-Lynch), explicitly modelling the cost of testing all patients diagnosed with incident CRC during 2017, with detailed modelling of outcomes for patients identified as LS carriers (probands) and their at-risk relatives throughout their lifetimes. For people with confirmed LS, we modelled ongoing colonoscopic surveillance.

MAIN OUTCOME MEASURES

Cost-effectiveness of six universal tumour testing strategies (testing for DNA mismatch repair deficiencies) and of universal germline gene panel testing of patients with incident CRC; impact on cost-effectiveness of restricting testing by age at CRC diagnosis (all ages, under 50/60/70 years) and of colonoscopic surveillance interval (one, two years).

RESULTS

The cost-effectiveness ratio of universal tumour testing strategies (annual colonoscopic surveillance, no testing age limit) compared with no testing ranged from $28 915 to $31 904/life-year saved (LYS) (indicative willingness-to-pay threshold: $30 000-$50 000/LYS). These strategies could avert 184-189 CRC deaths with an additional 30 597-31 084 colonoscopies over the lifetimes of 1000 patients with incident CRC with LS and 1420 confirmed LS carrier relatives (164-166 additional colonoscopies/death averted). The most cost-effective strategy was immunohistochemistry and BRAF V600E testing (incremental cost-effectiveness ratio [ICER], $28 915/LYS). Universal germline gene panel testing was not cost-effective compared with universal tumour testing strategies (ICER, $2.4 million/LYS). Immunohistochemistry and BRAF V600E testing was cost-effective at all age limits when paired with 2-yearly colonoscopic surveillance (ICER, $11 525-$32 153/LYS), and required 4778-15 860 additional colonoscopies to avert 46-181 CRC deaths (88-103 additional colonoscopies/death averted).

CONCLUSIONS

Universal tumour testing strategies for guiding germline genetic testing of people with incident CRC for LS in Australia are likely to be cost-effective compared with no testing. Universal germline gene panel testing would not currently be cost-effective.