by Jeanette Yuen, Shao Tzu Li, Eliza Courtney and Joanne Ngeow
Cancer Genetics Service, Division of Medical Oncology, National Cancer Centre Singapore
Cancer is the leading cause of mortality in Singapore [1,2], a similar pattern is observed in other Asian countries and the world. Cancer is the uncontrolled proliferation of cells that arises due to the accumulation of mutations in genes that regulate the cell cycle. Identifying the factors that cause or drive mutations is often the focus of much cancer research and the findings of which help inform public health campaigns to reduce cancer risk in the general community. A small proportion of all cancer patients (~5-10%) are born with a heritable mutation in genes important for cell cycle regulation, increasing their risk of cancers. The introduction of genetic testing into clinical practice has been useful in identifying these individuals, who are then offered early interventions, such as intensified cancer screening or risk-reducing surgeries, to better manage their increased risk of cancer(s).
Genetic testing for individuals who are suspected of having a hereditary cancer syndrome is usually delivered within specialist cancer genetics services. It is within these settings that formally trained clinical geneticists and genetic counsellors provide individualised cancer risk assessments, clinical genetic testing, result interpretation and personalised risk management recommendations for individuals and families. Strong multidisciplinary relationships with other cancer specialists, including surgeons, medical oncologists and radiation oncologists, help promote high quality care as genetic test results are increasingly used to guide treatment plans. At the National Cancer Centre Singapore (NCCS), we provide comprehensive clinical cancer genetics services across all tumour types.
The field of cancer genetics has been witness to a dramatically changing landscape over the years, particularly with respect to the rapid advances in genomic technologies and increases in service demand resulting from greater public awareness. Twenty years ago, testing of a single gene took several years and cost thousands of dollars. Nowadays, the rapid expansion in the availability of testing laboratories and the high throughput nature of current technology has meant that multiple cancer predisposition genes can be interrogated in a matter of weeks for a fraction of the cost.
Despite the growing accessibility of clinical genetic testing in Singapore, previous  and recent reports [4-6] from Asia continue to report low uptake of genetic testing in the population identified at risk of hereditary cancer syndromes. Reasons cited as barriers to uptake are high costs of genetic testing for patients and exclusion of clinical genetic testing services from national healthcare systems, with the consequent a lack of government subsidies. Testing costs are now included under healthcare insurance policy coverage and/or government subsidies in Western societies, having demonstrated meaningful clinical benefits in a cost-effective manner [7-9]. More importantly, the use of genetic testing could spare non-mutation carriers from unnecessary and invasive risk management, targeting valuable medical resources towards those identified as mutation carriers.
Despite the growing body of literature pointing to the cost-effectiveness of identifying those individuals with hereditary cancer syndromes, genetic testing still remains unsubsidised by Singapore’s public healthcare funding scheme and is borne entirely by the patient. In the absence of financial assistance for patients who are unable to cover the cost of testing, it is not only the individual, but also the healthcare system that would be deprived of the benefits that cancer genetic testing has to offer.
Over the past two years, NCCS was fortunate to receive philanthropic donations from the Lee Foundation that allowed for the provision of various subsidy schemes for patients with financial hardships. To study the impact of different subsidy schemes on the uptake of genetic testing, our team compared uptake data for 445 patients who were offered genetic testing based on established criteria [10,11] through Cancer Genetics Service (CGS) between January 2014 and May 2016. The three subsidies offered during this time were either blanket (100%) cover; no cover; and varied cover. The latter covered 50-100% of the cost and was determined based on the patient’s inclusion in certain pre-existing nationwide social support schemes.
While our study reveals that cost is not the main barrier to a patient’s willingness to test, subsidised patients still represent at least half of the patients who were recommended to have genetic testing. Therefore, there is concern that removing the availability of subsidies could potentially diminish the uptake rate of genetic testing in those who need it. Furthermore, our data revealed that the genetic testing uptake rate was higher under the varied subsidy verses the blanket subsidy, suggesting that testing uptake rate may not necessarily be associated with a more lenient or generous subsidy policy. This was also reflected in the consistent mutation detection rate of 20% amongst patients who received genetic testing across all 3 subsidy schemes.
Unfortunately, the subsidies offered at the CGS are not easy to sustain, as philanthropic donations are limited and will eventually deplete. Because of this, we decided to model the overall costs in the pipeline involving subsequent costs of diagnosis and treatment of cancer. This demonstrates that the savings gained through reduction in subsidies of downstream services will surpass the subsidies spent on the genetic testing and ensuring the sustainability of genetic testing subsidies.
With growing public awareness on the usefulness of cancer genetic assessments, the services must always continue to review and refine their delivery of care. The study has revealed room for improvement in the areas of increasing the referral and predictive testing rate for at-risk relatives of our patients who are identified as mutation carriers in our service. Our current predictive testing rates of about 15% in first-degree relatives fall short of the 40-60% needed to optimize the cost-savings at the health system level. Efforts to understand the barriers for predictive testing in the patients’ relatives are critically needed.
In summary, efforts targeted at increasing predictive testing rates, coupled with the implementation of a formal subsidy program will significantly impact the health of individuals, their families and society as a whole.
About the Author
Dr Ngeow Yuen Yie Joanne
BMedSci, MBBS, MRCP, FAMS
Dr Joanne Ngeow, MBBS, MRCP, is a Senior Consultant in the Division of Medical Oncology at the National Cancer Centre Singapore. She currently leads the Cancer Genetics Service at the National Cancer Centre Singapore with an academic interest in hereditary cancer syndromes and translational clinical cancer genomics. Her current clinical focus and research revolves around understanding cancer predisposition by studying cancers clustering in families, young adults and in families with multiple / rare cancer presentations.
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