Breast cancer: new blood test can predict return, researchers say

A new “ultra-sensitive” blood test can predict whether breast cancer will return years before the disease shows up on scans, researchers say.

It detects traces of a tumor’s DNA before a complete relapse and has been shown to be 100% accurate in predicting which patients would see their cancer return.

It is hoped that the test will allow treatment to begin earlier and improve survival rates.

The British research has been described as “incredibly exciting” by experts, but it is still in its early stages.

Breast cancer is the most common form of the disease worldwide, with 2.26 million women diagnosed in 2020 and 685,000 deaths in the same year, according to Breast Cancer UK.

A team of researchers from the Institute of Cancer Research (ICR) in London carried out the trial on 78 patients with different types of early breast cancer.

The “liquid biopsy” looked for 1,800 mutations in patients’ blood, released by cancer cells.

These circulating tumor DNAs were found in 11 women, all of whom saw their cancer relapse. No other woman has had her cancer return.

On average, blood tests detected cancer 15 months before symptoms appeared or before the disease showed up on scans, according to results presented Sunday at the American Society of Clinical Oncology conference in Chicago.

The earliest detection occurred 41 months before a scan confirmed the diagnosis.

Lead researcher Dr Isaac Garcia-Murillas, from the ICR, said: “Breast cancer cells may remain in the body after surgery and other treatments, but there may be so few of these cells that they are undetectable during follow-up examinations. »

He added that the cells can cause patients to relapse several years after their initial treatment.

Dr. Garcia-Murillas said the study lays the groundwork for better post-treatment monitoring and potentially life-extending treatment.

Researchers analyzed blood samples at diagnosis and again after surgery and chemotherapy.

These tests were then repeated every three months for the following year and every six months for the following five years.

Dr Simon Vincent, director of research, support and influence at Breast Cancer Now – which part-funded the study – said: “Early detection is one of our greatest weapons against cancer breast cancer and these initial results, which suggest that new tests may be able to detect signs of breast cancer recurrence more than a year before symptoms appear, are incredibly exciting.

While acknowledging that the research was still in its early stages, he said detecting breast cancer recurrence earlier means treatment is much more likely to destroy the cancer and prevent its spread to other parts of the body and become incurable.

Dr Vincent continued: “With around 11,000 people dying each year in the UK from secondary breast cancer, advances like these are urgently needed so we can prevent people from losing their lives because of this devastating disease. »

It’s unclear when the test might be widely available.

This news follows a number of developments in cancer research over the past week.