Novel low-cost gene test could improve treatment of breast cancer

The PROSPER-2 genomic test could become a quick, low-cost and hospital-delivered alternative to commercially available genomic testing of breast cancer, which is often unaffordable for patients.

A project to test the accuracy of PROSPER-2 compared to other prognostic tools has received a grant from Sydney Health Partners, using money from the Medical Research Future Fund.

Lead investigator Dr Dinny Graham, from Sydney Health Partners member, the Westmead Institute for Medical Research, said that by measuring the molecular expression of a small handful of genes, the test predicts which tumours are more aggressive and less likely to respond to conventional treatments.

“Current diagnostic methods for predicting whether a patient is likely to respond well to standard treatments return an ambiguous result in up to one third of cases and the ideal treatment path for these patients is not 100% clear,” said Dr Graham.

“Despite multiple studies now demonstrating the advantages of adding multi-gene tests to traditional prognostic tools when evaluating breast cancer cases, the uptake in Australia has been limited,” said Dr Graham.

“Almost no-one gets these tests because they cost several thousand dollars, there is no Medicare subsidy and for some tests the tumour sample has to be sent interstate or overseas to be tested.”

“We believe the PROSPER-2 test will cost less than $100 dollars, can be done in a clinical setting and will be at least, if not more, accurate than the current tests.”

For the majority of women diagnosed with breast cancer, the standard treatment is with endocrine agents, which are highly effective, generally well tolerated and lack the damaging side effects of cytotoxic chemotherapies.

In a proportion of cases, however, clinical pathology evaluation of the cancer tissue suggests that the patient is at an elevated risk of relapsing after the tumour is removed. These patients usually receive chemotherapy in an effort to reduce that risk. Current methods to identify these patients are not perfect, meaning that some patients may receive unnecessary chemotherapy.

Dr Graham’s team of researchers identified the gene signature that would provide the best prediction of a breast cancer’s relapse risk by analysing bioinformatics data gathered during a previous, much more extensive, genetic testing project.

They will now use the novel technique to test a large bank of breast cancer tissue gathered from patients over many years.

The project is a cross-disciplinary investigation involving genomic research, clinical pathology, surgery and oncology.

“The use of PROSPER-2 testing for these equivocal cases will add confidence to treatment decisions and provide firm data on which to make a recommendation to patients about whether to stay on endocrine treatment or escalate to chemotherapy,” said Dr Graham.

“The result should be improved treatment outcomes, longer patient survival, improved productivity and the economic benefits to the public health system that will flow as a result from those gains.”

“This is potentially highly translational and we hope that what we are finding will bring low cost molecular testing into clinical practice for the treatment of breast cancer patients in the Australian public health environment.”

PROSPER-2 was one of 13 competitive grants awarded by SHP in January this year, supporting projects across the Sydney, Northern and Western Local Health Districts.

Sydney Health Partners is a Commonwealth Government-accredited Advanced Heath Research and Translation Centre, tasked with delivering the benefits of research and innovation faster and more consistently.