Blood test spots recurrent breast cancer

Researchers say they have developed a new type of blood test which can spot recurrent advanced breast cancers.

According to scientists at the Johns Hopkins Kimmel Cancer Centre, the cMethDNA assay test spotted the presence of cancer DNA in the blood of metastatic breast cancer patients with a high degree of accuracy. Indeed, the test correctly recognised the cancer up to 95 per cent of the time in the laboratory studies they have conducted.

It is always difficult to effectively monitor cancer patients to prepare for every outcome, but at the moment there is no lab test whatsoever to monitor those who have early stage breast cancer and are responding well, but who are at risk of a recurrence.

Dr Saraswati Sukumar, co-director of the Breast Cancer Programme at the Johns Hopkins Kimmel Cancer Centre and Barbara B. Rubenstein professor of oncology, says that standard blood tests and radiologic scans are only indicated if a patient complains of symptoms. These can include anything from bone ache to shortness of breath.

In other circumstances, normal blood tests and scans do not identify the problem, meaning patients often find themselves undergoing extra tests and biopsies which are not believed to make any difference to survival outcomes.

“The goal is to develop a test that could be administered routinely to alert the physician and patient as soon as possible of a return of the original cancer in a distant spot. With the development of cMethDNA, we've taken a first big step toward achieving this goal,” explains Dr Sukumar.

This new cMethDNA test seeks out hypermethylation, a chemical tag which is found in breast cancer-specific genes which are found in tumour DNA. It prevents other genes from controlling cell growth, meaning this can become out of control and contribute to the growth of tumours.

Hypermethylation is usually present and detectable in the blood stream, and when it appears in the DNA of genes which are related to breast cancer it usually indicates that the cancer has returned or spread to another part of the body.