Gene tests on ‘don’t do’ list
Medical experts have taken aim at ‘direct to consumer’ genetic testing services amid concerns that they are causing unnecessary expense and alarm.
Medical experts have warned that patients should not initiate genetic tests on their own, particularly for coeliac disease and for the genes MTHFR and APOE, which are, respectively, associated with levels of folate and susceptibility to Alzheimer’s disease.
The Gastroenterological Society of Australia has recommended against genetic tests for coeliac disease because the relevant gene is present in about a third of the population and “a positive result does not make coeliac disease a certainty”.
Similarly, Human Genetics Society of Australasia Clinical Professor Jack Goldblatt said variants of the MTHFR gene were “very common in the general population [and] having a variant in the gene does not generally cause health problems”.
Additionally, Professor Goldblatt said that although the APOE gene was considered a risk factor for Alzheimer’s, “having a test only shows a probability, so people undertaking [the test] can also risk being falsely reassured”.
“Unnecessary genetic testing can lead to further unnecessary investigations, worry, ethical, social and legal issues,” he said. “In particular, we caution people to not initiate testing on their own. Genetic tests are best performed in a clinical setting with the provision of personalised genetic counselling and professional interpretation of test results.”
The recommendations are among 20 made by the Gastroenterological Society of Australia (GESA), the Royal Australian and New Zealand College of Radiologists (RANZCR), the Human Genetics Society of Australasia and the Australasian Chapter of Sexual Health Medicine, as part of program being coordinating by the Choosing Wisely Australia campaign to improve the use of medical tests and treatments.
The advice includes cautioning women against self-medicating for thrush, improved use of radiation therapy to treat cancer, and careful use of colonoscopies.
Professor Anne Duggan from GESA said colonoscopies had a “small but not insignificant risk of complications”, and those undertaken for surveillance placed “a significant burden on endoscopy services”.
Professor Duggan said surveillance colonoscopies should be targeted “at those most likely to benefit, at the minimum frequency required to provide adequate protection against the development of cancer”.
The RANZCR said radiation treatment was “a powerful weapon” in the treatment of cancer, and half of those diagnosed with the disease would undergo radiation therapy.
But the College advised that such treatment should be provided within clinical decision-making guidelines, “where they exist”.
In particular, it has recommended sparing use of radiation to treat prostate cancer.
Dean of the College’s Faculty of Radiation Oncology, Dr Dion Forstner, radiation oncology might not be immediately required where prostate cancer is diagnosed.
“Patients with prostate cancer have options including radiation therapy and surgery, as well as monitoring without therapy in some cases,” Dr Forstner said.
The College also advised that while whole-breast radiation therapy decreased the local recurrence of breast cancer and improved survival rates, recent research had shown that shorter four-week courses of therapy could be equally effective “in specific patient populations”. It said patients and doctors should review such options.
The Chapter of Sexual Health Medicine made several recommendations, including advising against tests including herpes serology and ureaplasma in asymptomatic patients, and the use of serological tests to screen for chlamydia, because of frequent inaccuracy and the possibility of false-positive results.
In addition, it flagged concerns about the treatment of thrush.
Chapter President Dr Graham Neilsen said it was concerning that many women with recurrent and persistent yeast infections self-administered treatment, or were prescribed topical and oral anti-fungal treatments.
Dr Neilsen said it was important that patients had “good conversations” with clinicians about appropriate care.
“It is important to rule out other causes…such as genital herpes or bacterial vaginosis, so that other infection are not left untreated,” he said. “As well as the importance of ruling out other causes before commencing anti-fungal agents, inappropriate use of antifungal drugs can lead to increased fungal resistance.”
The 20 recommendations are the latest instalment in an ongoing program, coordinated by Choosing Wisely, in which 23 medical colleges and societies are working to improve the use of tests and treatments based on the latest evidence.
The process is separate from the Federal Government’s MBS Review, which is examining all 5000 items on the Medicare Benefits Schedule.
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