Biomarkers — a silver bullet to cancer diagnosis and treatment, report

Fast-tracking biomarker research over the next five years “has the potential to transform cancer care more than anything seen over the past 50 years”, according to Professor Ian Olver, director of the University of South Australia’s Sansom Institute.

According to the institute’s latest report titled ‘Cancer Biomarkers in Australia’, the four most common cancers (prostate, breast, colorectal, lung) as well as rare but deadly pancreatic and ovarian cancers should be the focus of biomarker research. The report is based on a survey of 116 Australian oncologists and researchers.

“It’s not an exaggeration to say that biomarkers are the silver bullet that can speed up diagnosis and pinpoint the best treatment approach for the patient, maximising the response while minimising toxicities,” Olver said.

Australia, however, must streamline regulatory and reimbursement processes “to ensure bureaucratic red tape doesn’t stand in the way of matching medicines to biomarkers and seizing a new era in precision medicine”, said Professor Olver.

Australia, according to the report authors, is lagging behind other countries in making cancer medicines available that are matched to a biomarker test, with a number of medicines paired to biomarkers widely available in Canada, England and France, but not funded in Australia.

Cancer medicines matched to a biomarker test that requires a Medicare Item Number take on average twice as long to be added to the Pharmaceutical Benefits Scheme, compared to cancer medicines without a biomarker, the report suggests.

Pointing to an example of a colon cancer medicine that saves $600 million a year by being restricted to patients tested for a specific biomarker, Professor Olver said that biomarker-led treatment will save millions of dollars for the public purse.

“Research and reimbursement of biomarker-driven treatments should be a top priority for government. This is key to improving cancer survival and ensuring we get the best bang for our buck,” he said.

“Gone are the days of a ‘one size fits all’ approach where treatment decisions were based solely on tumour type or location. We can now gauge the molecular fingerprint of many cancers, allowing the right treatment to be given to the right patient, at the right time.”

Biomarker tests can inform diagnosis and prognosis, as well as predict treatment response. Existing cancer biomarkers include ALK, EGFR and PD-L1 in lung cancer, KRAS/NRAS in bowel cancer, PSA in prostate cancer, HER2 in lung, breast and gastric cancer, BRCA1 or 2 in breast cancer, BRAF in melanoma and DRG mutations in ovarian cancer.

The report calls for the federal government to approve and reimburse medicines based on the molecular characteristics of the cancer rather than where the cancer originates in the body, and to align the reimbursement of medicines with their accompanying biomarkers, ideally so this is handled by one agency. Currently, medicines are reviewed by the Pharmaceutical Benefits Committee and biomarkers are reviewed by the Medical Services Advisory Committee.

Co-author of the report Professor Doug Brooks from UniSA said strict guidelines are needed for biomarker development, validation and implementation.

Professor Brooks is involved in groundbreaking research to develop a new biomarker in prostate cancer that may replace the PSA test, which is known to give false-positive and false-negative results.

“There is a clear need to replace the PSA test, which can show elevated levels not just in men with prostate cancer but in response to benign conditions, as well as recent sexual activity or even having just ridden a bicycle,” he said.

“This leads to unnecessary biopsies and treatment in men who are well, as well as missed diagnosis in around 15% of men with prostate cancer.

“Our research has revealed that the entire cellular pathway is altered in prostate cancer with changes in more than 20 genes and proteins. This gives us a large panel of biomarkers which we hope will eventually replace PSA,” said Professor Brooks.

“The new biomarkers we are developing will enable us to not only better diagnose prostate cancer but predict how severe the disease is and guide treatment timing — a win-win for patients and the health system,” he concluded.