Major breakthrough in breast and ovarian cancer screening
A Free State medical scientist in genetics and a PhD candidate have, in a collaborative project with a research group from Stellenbosch University, come up with new cost-effective genetic testing for breast and ovarian cancer.
This means that, once implemented and operational, women with these types of cancers in their families can be quickly, easily and cheaply screened in a method that can identify risks early.
The development is thanks to researcher Dr Nerina van der Merwe, principal scientist within the University of the Free State’s division of human genetics and the National Health Laboratory Service, and her colleague, Jaco Oosthuizen, who have been working with Prof Maritha Kotze’s research group in Stellenbosch.
By using new technology based on rapid point-of-care (POC) testing, they have implemented a new diagnostic test for familial breast and ovarian cancer that “will reach more communities and hopefully contribute to saving more lives”.
“We were approached by Prof Kotze, who is also passionate about cancer research. She and her team, together with a company in the UK, have been working on designing a POC assay for this new technology, based on our research results,” Van der Merwe said.
Her unit is the state referral centre for familial breast and ovarian cancer in the country, where they have screened more than 3,000 patients diagnostically.
“With the use of our research results and access to positive controls, we are in a position to assist with the validation and potential implementation of this technology in the future,” she said, pleased with the development that comes after nearly 30 years of SA-specific genetic research on familial breast and ovarian cancer.
Van der Merwe said the new technology — once validated as a diagnostic genetic test — is the future of familial breast and ovarian cancer testing in SA, when performed in conjunction with genetic counselling.
She believes it is a user-friendly practical method and therefore suitable for use in rural clinics, with the need for expensive laboratory equipment eliminated.
“By performing the test at a community clinic, patients no longer have to be transported to tertiary hospitals for genetic testing, and more patients and related family members, who are unaware that they have inherited a disease-causing change in highrisk cancer genes such as BRCA1 or BRCA2, will be reached,” she said.
Dr Van der Merwe was appointed to determine the range and contribution of genetic changes in the two BRCA genes. Her work, in collaboration with Prof Lizette van Rensburg from the University of Pretoria, identified the first SA-specific variants, which proved to represent SA-unique recurrent, or founder variants found in African and Afrikaner populations.
As her research grew, the number of founder variants grew to six — the number she says is “ideal for the implementation of rapid POC testing, as these variants are common in affected patients and justify being screened first, before moving to more expensive diagnostic testing”.
Van der Merwe is particularly excited about the progress in her field because it will not only benefit cancer patients but will be of huge value to their at-risk family members.
The test, done through saliva taken via an inner cheek or buccal swab, is less invasive than a blood test, and the results are available in 90 minutes.
“By performing genetic counselling while the test is running, patients and family members will have the opportunity to ask questions about genetic testing and cancer, which will simultaneously increase community awareness. By face-to-face consultation, the counsellor can make sure the patient and related family members understand the value of the test,” Van de Merwe said, adding the aim was to eventually increase the low uptake of genetic testing in related at-risk family members, as this cancer type is inherited.
She said most patients who test for cancer are already affected.
“We, however, need to screen the related family members to identify who is at an increased risk, but this is not happening. So, by taking the test to the patients, that is where the benefit will be, because patients are often accompanied to the clinics by family members. This will provide an opportunity to inform them, because we have seen that patients often do not discuss their diagnosis and test results with family members who are also at risk of inheriting the disease.”
Van der Merwe and her team have since broadened their founder testing regime from screening for BRCA1 and BRCA2 only, to multi-gene panel testing using next-generation-sequencing to include other genes causing these two and other specific cancer types.
Their work has been welcomed by the Cancer Alliance, a collective group of 29 cancer-control NGOs and advocates.
“This is good news — the ultimate question is what associated cost will be, mainly for the public sector, as this is where the majority of women access health services.
For this type of test to be included as standard care for the early diagnosis of women with breast and ovarian cancer, affordability will play a major role,” said the alliance’s CEO, Salomé Meyer.
“This is also where appropriate health technology assessment could assist to determine the long-term savings of genetic testing where applicable against the actual costs of treatment and the overall economic benefits.
“Any effort to save lives will have a meaningful impact. We can only hope that this work will be presented to the appropriate decisionmakers that influence policy at the national department of health, as well as the various medical schemes,” she said.