Genetic test can improve cancer care and cut side effects

The National

7 hours ago

Medical researchers in the UAE are turning to genetic testing to understand more about how some patients respond to drugs so that side effects can be reduced and effectiveness improved.
Pharmacogenetics is becoming more common in the treatment of cancer, depression and cardiac disease.
More personalised prescriptions, rather than a one size fits all approach to medication, can improve patient care and cut costs for hospital and insurers, researchers said.
Genetics play a significant role in drug response, with an estimated 70–90 per cent of drug response variability having a genetic component.
More than 200 medications – including drugs for oncology, cardiology, psychiatry, pain management, and infectious diseases – come with guidelines that advise prescribing based on a person's genes.
Tests costs around Dh1,000 but that is expected to come down in price as doctors predict they will become a routine aspect of care.
Jen Blandos, 51, a Canadian, had a first breast cancer diagnosis in 2012 and two more cancer diagnoses after that.
Her latest breast cancer treatment plan has been created using knowledge gleaned by doctors from a genetic test, allowing them to improve her care and minimise debilitating side effects of regular chemotherapy.
'Compared to my first cancer diagnosis, now there's much more detailed mapping of the cancer I have, and a number of different things doctors look at to determine the best treatment,' said Ms Blandos, who lives in Dubai and has two children.
'One of the tests is getting more comprehensive mapping done on my genes. I had genetic variants where it showed I don't metabolise certain drugs. I also have a tonne of allergies, including all opiates and pain relief except paracetamol," she said. 'I'm also allergic to all antibiotics except for one, so I'm not an easy person for doctors to treat.
'When you're put on drugs for seven years after chemotherapy, you want to make sure it's going to be the right drug and it's going to work.'
Tumour test score
Her most recently discovered cancer, an invasive carcinoma, was picked up in a routine check in April. Doctors took a blood test and biopsy of her tumour to understand more about the kind of care she would most respond to.
The test is based on the activity of 21 genes in the tumour tissue and gives an indication of how likely the cancer will respond to chemotherapy, or return in the future.
It helped doctors decide on 12 courses of chemotherapy.
'Like anybody who's had cancer, universally we all worry about it returning,' said Ms Blandos.
'We try to put it to the back of our minds. I'm aware there is potential for genetic data to be misused, and there could be future problems.
'But I know the genetic testing that I need allows insurers to have access to that information, which makes me cheaper as a patient for them as they're not wasting money on treatments I don't necessarily need.'
There is particular value to genetic testing of patients with chronic health conditions who are prescribed multiple medications.
Personalised medicine is becoming more common in every-day care.
Ravi Sharma, chief pharmacy officer at Burjeel Holdings, said genetic testing could become a routine part of prescriptions.
'Medicines are one of the most common interventions in healthcare, and what's really interesting is that from the evidence, 30 to 60 per cent of patients may not always respond commonly as we predict to these medicines,' he said.
'We would like this to be a pre-test for patients getting their routine care, to enable us throughout their whole healthcare journey to prescribe optimally according to their genomic response.'
Within 20 years, more than 90 per cent of patient populations across the world will find at least one drug that has a pharmaco-genomic gene relationship, doctors said.
Treatments could be optimised in a number of fields, such as psychiatry, hypertension, endocrinology, opioid use and management, and oncology.
Hassan Jaafar, consultant in medical oncology and medical director at Burjeel Cancer Institute, said pharmaco-genomics is playing a major role in his clinical management.
'Even within the same ethnicity, there are different hereditary backgrounds which make certain drugs metabolise faster in the liver, and even in other parts of the tissue,' he said.
'It's important to identify the sensitivity and the toxicity of chemotherapeutic agents or any other drugs.
'The approach for those patients, the outcome, the prognosis can be completely different if you identify them and approach them differently to the standard treatment.'
More efficient prescribing
Genetic testing can also streamline prescribing to reduce hospital admissions with better use of medicines, allowing doctors to deliver more sustained continuity of care.
A typical test involves a blood sample processed in a lab, with the genetic information integrated into a patient's health records.
When a doctor comes to prescribe medication, they would receive an alert displaying a patient's clinical parameters and suitability for drugs.
Mohammad Fityan, chief medical officer at Burjeel Medical City, said patients currently have to pay for the Dh1000 test, but it could soon become available under health insurance.
'By doing this test, not only we will make sure that the medicine will work, but it will work safely and with fewer side effects,' he said.
'In patients with depression, we can try some medication and it takes us up to six weeks before we know whether it will work effectively or not.
'We have all these drug resources, now it's about how to use them effectively in a smart way that will serve our patients the best.'