Predictors of next-generation sequencing panel selection using a shared decision-making approach

Exploring Stakeholders' Perspectives on Implementing Universal Germline Testing for Colorectal Cancer: Findings From a Clinical Practice Survey

PURPOSE

New guidelines recommend considering germline genetic testing for all patients with colorectal cancer (CRC). However, there is a lack of data on stakeholders' perspectives on the advantages and barriers of implementing universal germline testing (UGT). This study assessed the perspectives of members of the Collaborative Group of the Americas on Inherited Gastrointestinal Cancer (CGA-IGC) regarding the implementation of UGT for patients with CRC, including readiness, logistics, and barriers.

METHODS

A cross-sectional survey was sent to 317 active members of CGA-IGC. The survey included sections on demographics, clinical practice specialty, established institutional practices for testing, and questions pertaining to support of and barriers to implementing UGT for patients with CRC.

RESULTS

Eighty CGA-IGC members (25%) participated, including 42 genetic counselors (53%) and 14 gastroenterologists (18%). Forty-seven (59%) reported an academic medical center as their primary work setting, and most participants (56%) had more than 10 years of clinical practice. Although most participants (73%) supported UGT, 54% indicated that changes in practice would be required before adopting UGT, and 39% indicated that these changes would be challenging to implement. There was support for both genetics and nongenetics providers to order genetic testing, and a majority (57%) supported a standardized multigene panel rather than a customized gene panel. Key barriers to UGT implementation included limited genetics knowledge among nongenetics providers, time-consuming processes for obtaining consent, ordering tests, disclosing results, and lack of insurance coverage.

CONCLUSION

This study demonstrates wide support among hereditary GI cancer experts for implementation of UGT for patients with CRC. However, alternative service delivery models using nongenetics providers should be considered to address the logistical barriers to UGT implementation, particularly the growing demand for genetic testing.

Understanding cancer predisposition in Singapore: What's next

Knowledge of an underlying genetic predisposition to cancer allows the use of personalised prognostic, preventive and therapeutic strategies for the patient and carries clinical implications for family members. Despite great progress, we identified six challenging areas in the management of patients with hereditary cancer predisposition syndromes and suggest recommendations to aid in their resolution. These include the potential for finding unexpected germline variants through somatic tumour testing, optimal risk management of patients with hereditary conditions involving moderate-penetrance genes, role of polygenic risk score in an under-represented Asian population, management of variants of uncertain significance, clinical trials in patients with germline pathogenic variants and technology in genetic counselling. Addressing these barriers will aid the next step forward in precision medicine in Singapore. All stakeholders in healthcare should be empowered with genetic knowledge to fully leverage the potential of novel genomic insights and implement them to provide better care for our patients.

Pharmacogenes that demonstrate high association evidence according to CPIC, DPWG, and PharmGKB

BACKGROUND

Different levels of evidence related to the variable responses of individuals to drug treatment have been reported in various pharmacogenomic (PGx) databases. Identification of gene-drug pairs with strong association evidence can be helpful in prioritizing the implementation of PGx guidelines and focusing on a gene panel. This study aimed to determine the pharmacogenes with the highest evidence-based association and to indicate their involvement in drug-gene interactions.

METHODOLOGY

The publicly available datasets CPIC, DPWG, and PharmGKB were selected to determine the pharmacogenes with the highest drug outcome associations. The upper two levels of evidence rated by the three scoring methods were specified (levels A-B in CPIC, 3-4 in DPWG, or 1-2 levels in PharmGKB). The identified pharmacogenes were further ranked in this study based on the number of medications they interacted with.

RESULTS

Fifty pharmacogenes, with high to moderately high evidence of associations with drug response alterations, with potential influence on the therapeutic and/or toxicity outcomes of 152 drugs were identified. CYP2D6, CYP2C9, CYP2C19, G6PD, HLA-B, SLCO1B1, CACNA1S, RYR1, MT-RNR1, and IFNL4 are the top 10 pharmacogenes, where each is predicted to impact patients' responses to ≥5 drugs.

CONCLUSION

This study identified the most important pharmacogenes based on the highest-ranked association evidence and their frequency of involvement in affecting multiple drugs. The obtained data is useful for customizing a gene panel for PGx testing. Identifying the strength of scientific evidence supporting drug-gene interactions aids drug prescribers in making the best clinical decision.

Current scenario of the genetic testing for rare neurological disorders exploiting next generation sequencing

Next generation sequencing is currently a cornerstone of genetic testing in routine diagnostics, allowing for the detection of sequence variants with so far unprecedented large scale, mainly in genetically heterogenous diseases, such as neurological disorders. It is a fast-moving field, where new wet enrichment protocols and bioinformatics tools are constantly being developed to overcome initial limitations. Despite the as yet undiscussed advantages, however, there are still some challenges in data analysis and the interpretation of variants. In this review, we address the current state of next generation sequencing diagnostic testing for inherited human disorders, particularly giving an overview of the available high-throughput sequencing approaches; including targeted, whole-exome and whole-genome sequencing; and discussing the main critical aspects of the bioinformatic process, from raw data analysis to molecular diagnosis.

Predictive Testing for Tumor Predisposition Syndromes in Pediatric Relatives: An Asian Experience

Approximately 10% of pediatric cancer patients possess germline pathogenic/likely pathogenic variants (PV/LPV) in known tumor predisposition genes. Predictive testing is the optimal approach to identify asymptomatic at-risk relatives to guide gene-directed surveillance for early cancer detection and/or risk-reducing strategies. However, the uptake rate for predictive testing remains low in Asian countries. We aim to evaluate the uptake rate of predictive testing in a pediatric population (aged under 21-years-old) in a multi-ethnic Asian cancer center. Our retrospective analysis included families with PV/LPVs identified in genes associated with pediatric tumor predisposition. Of the 83 pediatric first-degree relatives (FDRs) from 49 unrelated families, 20 FDRs (24.1%) originating from 13 families (26.6%) underwent predictive testing. Genes tested in pediatric FDRs were APC, RB1, SBDS, SDHA, SDHB, SDHD, and TP53. All pediatric FDRs of probands with PV/LPVs in RB1 and biallelic PVs in SBDS underwent predictive testing, while <45% of pediatric FDRs had predictive testing for familial PV/LPVs identified in the APC, SDHA, SDHB, SDHD, and TP53 genes. Amongst the 13 families who underwent pre-test counseling, 80% of pediatric FDRs in these families proceeded with predictive testing. Malay pediatric FDRs and siblings of probands were more likely to undergo predictive testing. We conclude that the predictive testing rate in pediatric FDRs is higher than that of adult FDRs in Asia, but still below the global average. We postulate factors that may influence predictive testing uptake in pediatric FDRs includes a lack of genetics awareness, concerns regarding insurance, and genetic discrimination.

Impact of free cancer predisposition cascade genetic testing on uptake in Singapore

Cascade testing for cancer predisposition offers a highly efficient and cost-effective method for identifying individuals at increased risk for cancer, in whom targeted interventions can often improve survival. The aim of this study was to determine the impact of free cascade testing on uptake and identify other associated factors. Demographic and clinical data were gathered prospectively for 183 probands found to have a pathogenic variant associated with cancer predisposition and their 826 first-degree relatives (FDRs). The provision of free cascade testing was significantly associated with uptake (21.6% vs 6.1%; χ ², P < 0.001). Relationship type between FDR and proband and FDR age also demonstrated significant associations, suggesting greater engagement amongst younger generations. Overall, 29.0% (53/183) of families had at least 1 FDR who underwent cascade testing. Of these families, 67.9% (36/53) had an uptake rate of at least 40.0%. Cost is a significant barrier to cascade testing uptake in Singapore. Tailored interventions targeting underrepresented groups and genetic counseling approaches supporting family communication and decision-making are necessary.

Use and Patient-Reported Outcomes of Clinical Multigene Panel Testing for Cancer Susceptibility in the Multicenter Communication of Genetic Test Results by Telephone Study

PURPOSE

Multigene panels (MGPs) are increasingly being used despite questions regarding their clinical utility and no standard approach to genetic counseling. How frequently genetic providers use MGP testing and how patient-reported outcomes (PROs) differ from targeted testing (eg, BRCA1/2 only) are unknown.

METHODS

We evaluated use of MGP testing and PROs in participants undergoing cancer genetic testing in the multicenter Communication of Genetic Test Results by Telephone study (ClinicalTrials.gov identifier: ), a randomized study of telephone versus in-person disclosure of genetic test results. PROs included genetic knowledge, general and state anxiety, depression, cancer-specific distress, uncertainty, and satisfaction. Genetic providers offered targeted or MGP testing based on clinical assessment.

RESULTS

Since the inclusion of MGP testing in 2014, 395 patients (66%) were offered MGP testing. MGP testing increased over time from 57% in 2014 to 66% in 2015 (P = .02) and varied by site (46% to 78%; P < .01). Being offered MGP testing was significantly associated with not having Ashkenazi Jewish ancestry, having a history of cancer, not having a mutation in the family, not having made a treatment decision, and study site. After demographic adjustment, patients offered MGP testing had lower general anxiety (P = .04), state anxiety (P = .03), depression (P = .04), and uncertainty (P = .05) pre-disclosure compared with patients offered targeted testing. State anxiety (P = .05) and cancer-specific distress (P = .05) were lower at disclosure in the MGP group. There was a greater increase in change in uncertainty (P = .04) among patients who underwent MGP testing.

CONCLUSION

MGP testing was more frequently offered to patients with lower anxiety, depression, and uncertainty and was associated with favorable outcomes, with the exception of a greater increase in uncertainty compared with patients who had targeted testing. Addressing uncertainty may be important as MGP testing is increasingly adopted.

The influence of Malay cultural beliefs on breast cancer screening and genetic testing: A focus group study

OBJECTIVE

Malays comprise an Asian cultural group reported to have low breast cancer screening uptake rates and poor cancer outcomes. Little is known about Malay cultural factors influencing beliefs and practice of cancer screening and genetic testing. Our study aims to explore health beliefs of Malay women around breast cancer screening and genetic testing.

METHODS

We conducted focus groups among healthy English-speaking Malay women in Singapore, aged 40 to 69 years, using a structured guide developed through literature review, expertise input and participant refinement. Thematic analysis was conducted to extract dominant themes representing key motivators and barriers to screening and genetic testing. We used grounded theory to interpret results and derive a framework of understanding, with implications for improving uptake of services.

RESULTS

Five focus groups (four to six participants per group) comprising 27 women were conducted to theme saturation. Major themes were (a) spiritual and religious beliefs act as barriers towards uptake of screening and genetic testing; (b) preference for traditional medicine competes with Western medicine recommendations; (c) family and community influence health-related decisions, complexed by differences in intergenerational beliefs creating contrasting attitudes towards screening and prevention.

CONCLUSIONS

Decisions to participate in breast cancer screening and genetic testing are influenced by cultural, traditional, spiritual/religious, and intergenerational beliefs. Strategies to increase uptake should include acknowledgement and integration of these beliefs into counseling and education and collaboration with key influential Malay stakeholders and leaders.