Before the advent of precision medicine, patients underwent chemotherapies based on a one-size-fits-all approach, which didn’t always offer the “perfect fit” in terms of “best” treatment.
Now, with precision medicine, physicians use molecular diagnostic tests to determine which treatment will work best for the patient.
By combining data from such tests, the individual’s medical history, and monitoring relapses and anticipating resistances, healthcare providers can develop more effective targeted therapies and prevention plans.
Traditionally, anti-cancer drugs were agents that killed both cancer cells and healthy cells. However, more targeted therapies have now been developed that can be directed to kill cancer cells only, while sparing healthy cells.
Usually, a biomarker is used to see how well the body responds to a treatment for a disease or condition.
“The biomarkers actually don’t explain why the patient is relapsing and don’t offer any solutions.
“This is where we can help,” says Dr Jean-Francois Laes, chief technological officer of OncoDNA, a Belgian company specialising in precision medicine for the treatment of cancer.
Dr Jean-Francois Laes, chief technological officer of OncoDNA, a Belgian company specialising in precision medicine for the treatment of cancer. Photo: The Star/Ong Soon Hin
The company provides a comprehensive cancer tumour molecular profiling (OncoDeep) and liquid biopsy monitoring of treatment and further mutations without biopsy (OncoTrace), hence providing oncologists with therapy recommendations and drug response monitoring from chemotherapy, targeted treatments and immunotherapy.
“OncoDeep was designed to be used in adults with metastatic cancers, on all types of solid tumours. It’s the first test of its kind, which analyses both a solid biopsy (tumour) and a liquid biopsy (blood) in parallel,” says Dr Laes.
The biopsy is converted into a tumour block and sent to Belgium for analysis. Results are ready within seven to 10 days, and sent to the oncologist.
He adds: “Every tumour cell is affected by a modification of its DNA, and these modifications are different for each tumour. There could be one cell that may not respond to the treatment suggested. For that cell, we give different options.
“More and more oncologists are opting for this method when they see they have no solutions for their patients,” says Dr Laes.
“For about 20% of the patients, this is timely. Usually, when you’re at the third line of treatment, you’ve been through a few rounds of chemotherapy, and the cancer has already metastasised.”
OncoTrace, which is the next step, aims to sequence the circulating tumour DNA – the genetic material which escapes from the tumour and which is present in the blood. This test is done on a blood sample, so the patient doesn’t have to undergo another biopsy, which is often invasive.
With OncoTrace, the oncologists can identify any resistance and recurrence earlier than with imaging technologies.
- Once the tumour cells are analysed, results are revealed within seven to 10 days. Photos: OncoDNA
- The biopsy is converted into a tumour block and sent to Belgium for analysis.
Delivering the right treatment, at the right time, to the right patient, is crucial so a personalised strategy offers better outcomes and fewer deaths compared to non-personalised therapies.
Though targeted therapy has been around for the past decade, personalised treatment is a relatively new field in Malaysia, says consultant clinical oncologist and radiotherapist Dr Matin Mellor Abdullah.
So, patient A with breast cancer and patient B with breast cancer may not receive the same treatment because their molecular “signatures” may be different.
“In targeted treatment, you assume that mutation is the one that drives the cancer. If you block the ‘driver’, you’re stunting its growth.
“When cancer grows, it requires blood supply, so cancer produces some substances that migrate to the normal cells and blood vessels, which then generate blood flow to the cancer cells. This drives the nutrients necessary for new blood vessels to grow, called angiogenesis.”
Theoretically, if you use anti-angiogenesis therapy, you should be able to block the lifeline and stunt the growth of the cancer cells.
“But it doesn’t always work, and is certainly not a curative treatment. In some cancers, angiogenesis happens to be one of the main drivers, but not in others. You block the main driver, but cancer cells may decide to make that pathway redundant and find a new way to grow.
“That’s why it’s not easy to treat because cancer is very robust and adaptive. At that point in time, we do checks on the mutation and try other drugs.
“However, there are also a significant number of mutations, which develop resistance not through that particular pathway,” explains Dr Matin, who is also president of the Malaysian Oncology Society.
Dr Matin Mellor Abdullah, consultant clinical oncologist and radiotherapist. Photo: The Star/Raymond Ooi
This is when multi-platform genetic tests come in. It can tell you the types of mutation at that point in time so intervention may be different at that point.
Dr Matin says: “For example, in pancreatic cancer, chemotherapy is usually used, but if you do mutation testing, you’ll find that tyrosine kinase inhibitor drugs can also be used. But, the difficulty we have in mutation testing is the cost and lack of available data locally.”
When patients come to the second or third line of treatment, there are no more standards of care.
“So essentially, the drugs are based on clinical studies or we innovate – take the drugs and target the mutation. The fourth line of treatment doesn’t mean the patient is unwell. They may have stage four cancer, but physically, they’re still able. For those patients, if you don’t treat them, you’re allowing them to die.”
But, Dr Matin points out that intervening doesn’t mean they will live longer.
For patients opting for the tests, he advises them to think if they’re going to pursue treatment further once the results are revealed. It’s a question of affordability and availability. It cannot cure, but it may expand boundaries.
“The real question is how much money will I save if I die now or if I don’t get treatment. There are no easy answers. At the end of the day, common sense and good ideas don’t always translate to good outcomes in cancer.
“You might do the test and find that there are mutations you cannot treat. It’s an experiment with everyone’s eyes open. At that twilight zone, it’s difficult to say what’s the best thing to do,” says Dr Matin.
http://www.star2.com/health/wellness/2016/04/03/hitting-the-bullseye-in-cancer-therapy-2/