Developing national guidance on genetic testing for breast cancer predisposition: the role of economic evidence?

Proof of concept for multiplex amplicon sequencing for mutation identification using the MinION nanopore sequencer

Rapid, cost-effective identification of genetic variants in small candidate genomic regions remains a challenge, particularly for less well equipped or lower throughput laboratories. The application of Oxford Nanopore Technologies’ MinION sequencer has the potential to fulfil this requirement. We demonstrate a proof of concept for a multiplexing assay that pools PCR amplicons for MinION sequencing to enable sequencing of multiple templates from multiple individuals, which could be applied to gene-targeted diagnostics. A combined strategy of barcoding and sample pooling was developed for simultaneous multiplex MinION sequencing of 100 PCR amplicons. The amplicons are family-specific, spanning a total of 30 loci in DNA isolated from 82 human neurodevelopmental cases and family members. The target regions were chosen for further interrogation because a potentially disease-causative variant had been identified in affected individuals following Illumina exome sequencing. The pooled MinION sequences were deconvoluted by aligning to custom references using the minimap2 aligner software. Our multiplexing approach produced an interpretable and expected sequence from 29 of the 30 targeted genetic loci. The sequence variant which was not correctly resolved in the MinION sequence was adjacent to a five nucleotide homopolymer. It is already known that homopolymers present a resolution problem with the MinION approach. Interestingly despite equimolar quantities of PCR amplicon pooled for sequencing, significant variation in the depth of coverage (127×–19,626×; mean = 8321×, std err = 452.99) was observed. We observed independent relationships between depth of coverage and target length, and depth of coverage and GC content. These relationships demonstrate biases of the MinION sequencer for longer templates and those with lower GC content. We demonstrate an efficient approach for variant discovery or confirmation from short DNA templates using the MinION sequencing device. With less than 130 × depth of coverage required for accurate genotyping, the methodology described here allows for rapid highly multiplexed targeted sequencing of large numbers of samples in a minimally equipped laboratory with a potential cost as much 200 × less than that from Sanger sequencing.

Cost-effectiveness and comparative effectiveness of cancer risk management strategies in BRCA1/2 mutation carriers: a systematic review

PURPOSE

To review the evidence for the effectiveness and cost-effectiveness of cancer risk management interventions for BRCA carriers.

METHODS

Comparative effectiveness and cost-effectiveness analyses were identified by searching scientific and health economic databases. Eligible studies modeled the impact of a cancer risk management intervention in BRCA carriers on life expectancy (LE), cancer incidence, or quality-adjusted life years (QALYs), with or without costs.

RESULTS

Twenty-six economic evaluations and eight comparative effectiveness analyses were included. Combined risk-reducing salpingo-oophorectomy and prophylactic mastectomy resulted in the greatest LE and was cost-effective in most analyses. Despite leading to increased LE and QALYs, combined mammography and breast magnetic resonance imaging (MRI) was less likely to be cost-effective than either mammography or MRI alone, particularly for women over 50 and BRCA2 carriers. Variation in patient compliance to risk management interventions was incorporated in 11/34 studies with the remaining analyses assuming 100% adherence.

CONCLUSION

Prophylactic surgery and intensive breast screening are effective and cost-effective in models of BRCA carrier risk management. Findings were based predominantly on assuming perfect adherence to recommendations without assessment of the health-care resource use and costs related to engaging patients and maximizing compliance, meaning the real-world impact on clinical outcomes and resource use remains unclear.

Using Cost-Effectiveness Analysis to Quantify the Value of Genomic-Based Diagnostic Tests: Recommendations for Practice and Research

AIMS

New sequencing technologies allow increased opportunities to use genomic-based diagnostic tests (genomic tests) in routine clinical practice, which will impact healthcare budgets and patients' outcomes. This article aims to generate a list of recommendations on how the principles and methods of cost-effectiveness analysis (CEA) can be used to quantify the costs and benefits of genomic tests.

METHODS

A systematic literature search identified publications describing the use of CEA to evaluate genomic tests. Data were extracted as key concepts to produce a thematic list of previously described challenges and solutions to using CEA to evaluate genomic tests. Defining features of evaluating genomic tests were categorized into a list of key recommendations for applying methods in practice and for research needs.

RESULTS

Features producing challenges in the implementation of CEA to evaluate genomic tests were as follows: the ability of the tests to diagnose multiple disorders; potential consequences for future generations suggesting an infinite time horizon; and the potential need to consider nonhealth benefits.

CONCLUSIONS

CEA was identified as an appropriate evaluative framework for genomic tests, although standard methods may need modification and important method research questions remain. Key recommendations suggest a need for research to reflect: sharing genomic information across generations; genomic tests for multiple disorders; and health and nonhealth benefits.

Which BRCA genetic testing programs are ready for implementation in health care? A systematic review of economic evaluations

PURPOSE

There is considerable evidence regarding the efficacy and effectiveness of BRCA genetic testing programs, but whether they represent good use of financial resources is not clear. Therefore, we aimed to identify the main health-care programs for BRCA testing and to evaluate their cost-effectiveness.

METHODS

We performed a systematic review of full economic evaluations of health-care programs involving BRCA testing.

RESULTS

Nine economic evaluations were included, and four main categories of BRCA testing programs were identified: (i) population-based genetic screening of individuals without cancer, either comprehensive or targeted based on ancestry; (ii) family history (FH)-based genetic screening, i.e., testing individuals without cancer but with FH suggestive of BRCA mutation; (iii) familial mutation (FM)-based genetic screening, i.e., testing individuals without cancer but with known familial BRCA mutation; and (iv) cancer-based genetic screening, i.e., testing individuals with BRCA-related cancers.

CONCLUSIONS

Currently BRCA1/2 population-based screening represents good value for the money among Ashkenazi Jews only. FH-based screening is potentially very cost-effective, although further studies that include costs of identifying high-risk women are needed. There is no evidence of cost-effectiveness for BRCA screening of all newly diagnosed cases of breast/ovarian cancers followed by cascade testing of relatives, but programs that include tools for identifying affected women at higher risk for inherited forms are promising. Cost-effectiveness is highly sensitive to the cost of BRCA1/2 testing.Genet Med 18 12, 1171-1180.

A cost analysis of a cancer genetic service model in the UK

Technological advances in DNA sequencing have made gene testing fast and more affordable. Evidence of effectiveness and cost-effectiveness of genetic service models is essential for the successful translation of sequencing improvements for patient benefit, but remain sparse in the genetics literature. In particular, there is a lack of detailed cost data related to genetic services. A detailed micro-costing of 28 possible pathways relating to breast and/or ovarian cancer and BRCA testing was carried out by defining service activities and establishing associated costs. These data were combined with patient-level data from a Royal Marsden Cancer Genetics Service audit over a 6-month period during which BRCA testing was offered to individuals at ≥10 % risk of having a mutation, in line with current NICE guidance. The average cost across all patient pathways was £2227.39 (range £376.51 to £13,553.10). The average cost per pathway for an affected person was £1897.75 compared to £2410.53 for an unaffected person. Of the women seen in the Cancer Genetics Service during the audit, 38 % were affected with breast and/or ovarian cancer, and 62 % were unaffected but concerned about their family history. The most efficient service strategy is to identify unaffected relatives from an affected individual with an identified BRCA mutation. Implementation of this strategy would require more comprehensive testing of all eligible cancer patients, which could be achieved by integrating BRCA testing into oncology services. Such integration would be also more time-efficient and deliver greater equity of access to BRCA testing than the standard service model.

Guidance for laboratories performing molecular pathology for cancer patients

Molecular testing is becoming an important part of the diagnosis of any patient with cancer. The challenge to laboratories is to meet this need, using reliable methods and processes to ensure that patients receive a timely and accurate report on which their treatment will be based. The aim of this paper is to provide minimum requirements for the management of molecular pathology laboratories. This general guidance should be augmented by the specific guidance available for different tumour types and tests. Preanalytical considerations are important, and careful consideration of the way in which specimens are obtained and reach the laboratory is necessary. Sample receipt and handling follow standard operating procedures, but some alterations may be necessary if molecular testing is to be performed, for instance to control tissue fixation. DNA and RNA extraction can be standardised and should be checked for quality and quantity of output on a regular basis. The choice of analytical method(s) depends on clinical requirements, desired turnaround time, and expertise available. Internal quality control, regular internal audit of the whole testing process, laboratory accreditation, and continual participation in external quality assessment schemes are prerequisites for delivery of a reliable service. A molecular pathology report should accurately convey the information the clinician needs to treat the patient with sufficient information to allow for correct interpretation of the result. Molecular pathology is developing rapidly, and further detailed evidence-based recommendations are required for many of the topics covered here.

Application of next-generation sequencing in clinical oncology to advance personalized treatment of cancer

With the development and improvement of new sequencing technology, next-generation sequencing (NGS) has been applied increasingly in cancer genomics research over the past decade. More recently, NGS has been adopted in clinical oncology to advance personalized treatment of cancer. NGS is used to identify novel and rare cancer mutations, detect familial cancer mutation carriers, and provide molecular rationale for appropriate targeted therapy. Compared to traditional sequencing, NGS holds many advantages, such as the ability to fully sequence all types of mutations for a large number of genes (hundreds to thousands) in a single test at a relatively low cost. However, significant challenges, particularly with respect to the requirement for simpler assays, more flexible throughput, shorter turnaround time, and most importantly, easier data analysis and interpretation, will have to be overcome to translate NGS to the bedside of cancer patients. Overall, continuous dedication to apply NGS in clinical oncology practice will enable us to be one step closer to personalized medicine.