Researchers at the Johns Hopkins Kimmel Cancer Center in the US are developing a new liquid biopsy test that can detect cancer DNA markers in advanced breast cancer.

The Liquid Biopsy for Breast Cancer Methylation (LBx-BCM) test, which provides results in five hours, can be used to quickly help oncologists determine whether treatments are working.

Developed in collaboration with Cephied scientists, the test is now a prototype developed for research use only.

It can be integrated with the commercially available GeneXpert molecular testing platform.

Using a panel of nine genes that can detect four breast cancer subtypes, the test has the capability to identify methylation markers in one or more genes. Methylation is a chemical tag type.

These genes include COL6A2, RASSF1, HIST1H3C, TMEFF2, ZNF671, HOXB4, RASGRF2, AKR1B1 and TM6SF1.

The test process involves the collection of a blood or plasma sample from a cancer patient, which is placed in a tube containing a reagent. The contents are then placed in cartridges for the commercial system to modify the DNA chemically, before amplifying and detecting methylated genes.

Johns Hopkins University School of Medicine oncology and pathology professor Saraswati Sukumar said: “Our goal was to develop an assay that would be sophisticated yet simple to perform worldwide and could be used at the point of care to provide same-day feedback to clinicians and patients.

“If we are able to show by this cartridge assay that we are indeed successful in predicting the course of treatment, we might be able to institute changes in the way we look at chemotherapy and the way we treat patients for metastatic breast cancer.”

The LBx-BCM test was evaluated on separate days, using stored samples obtained from four patients without breast cancer and 11 with metastatic breast cancer. The results were similar for more than 90% of the cases.

The ability of the test to detect metastatic breast cancer in two sample sets, obtained from previous studies at Johns Hopkins, was also assessed.

For 85% of overall diagnostic accuracy, the LBx-BCM test was found to correctly rule out cancer 92% of the time and detect it 83% of the time.