‘Game-changing’ blood test is even better at detecting early breast cancers than a mammogram

A simple blood test that promises to be more effective at detecting early-stage breast cancer than a mammogram has been hailed as a “game changer” for women’s health.

The Trucheck test, which highlights cancer cells circulating in the blood, correctly identifies 92% of breast cancers, about five percentage points more than mammography.

But scientists say the real breakthrough is its increased ability to detect early-stage breast cancers that are so small they’re hard to detect on scans, especially in young women.

Breast cancer surgeon Professor Kefah Mokbel, who was involved in the research, predicted the blood test would lead to a ‘paradigm shift’ in breast cancer screening.

“Potentially, this test is a game-changer. It could transform breast cancer screening,” he said.

A simple blood test that promises to be more effective at detecting breast cancer early than a mammogram has been hailed as a ‘game changer’ for women’s health

Medical oncologist Dr Tim Crook, from the private hospital The London Clinic, which offers it to patients, said the test could even replace mammograms, adding: “We have a huge problem of late diagnosis of cancer in this country and it’s been hard to think of ways to improve that.

During the test, a nurse takes 5ml of blood, which is processed to identify the presence of ‘circulating tumor cells’ (CTCs). These cells are almost always produced by cancerous tumors and are a very definite sign of cancer.

In a case-control study of blood samples from 9,632 healthy women and 548 others with breast cancer, Trucheck was able to correctly detect cancer where it existed 92% of the time.

The test pinpointed advanced-stage cancer perfectly – where tumors have spread beyond the breast – identifying 100% of samples from women with stage 3 or 4 disease.

It wasn’t as accurate at spotting early-stage cancers, which produce fewer CTCs, but the results were still impressive – identifying 96% of women with stage 2 disease, where the tumors are largely confined to the breast .

For stage 1, where the cancer is small and only in the breast, the accuracy was 89%. Even for ‘ductal carcinoma in situ’, also known as stage 0, where there are precancerous lesions that may develop into disease, he identified 70% of cases.

But scientists say the real breakthrough is its increased ability to detect early-stage breast cancers that are so small they're hard to detect on scans, especially in young women.

But scientists say the real breakthrough is its increased ability to detect early-stage breast cancers that are so small they’re hard to detect on scans, especially in young women.

There have been no false positives – in which a test indicates cancer exists but none is found – although another study found a handful.

In contrast, about one in ten positive mammograms is a false alarm, leading to unnecessary treatment. Dr Crook said the blood test had other advantages over mammography, such as the absence of radiation, which increases the risk of cancer, and “the absence of the need for infrastructure” such as clinics .

Women in England are asked to have their first mammogram at age 50, then every three years until age 71. Last year, only 62% of eligible women had the x-ray, in part due to the pandemic affecting services and attendance – meaning that while 1.2 million had a mammogram, which resulted in almost 11,000 diagnosed with breast cancer, 750,000 didn’t. Late diagnosis reduces the chances of survival.

Dr Crook said if more women were diagnosed when their breast cancer was less developed, it would improve the overall results significantly.

Professor Kefah Mokbel predicted that the blood test would lead to a

Professor Kefah Mokbel predicted the blood test would lead to a ‘paradigm shift’ in breast cancer screening

When spotted in stages 1 and 2, cure rates exceed 90% “without high-tech treatment”.

The test could help women in their 40s, who are not normally offered NHS mammograms because they are relatively poor at spotting tumors in the denser breast tissue found in younger women.

More than 10,000 women under 50 – most in their 40s – are diagnosed with breast cancer in the UK every year – a fifth of all cases. Often, their cancers are not spotted until late when they have spread.

Professor Mokbel, of the London Breast Institute at Princess Grace Hospital, said the blood test results, published in the journal Cancers, “represent a crucial step towards extending the early detection of breast cancer beyond current screening age and to women not participating in current screening programs’.

The test has European approval for use in women over 40, but is still undergoing validation studies in the UK and US. The same technology, developed by the Indian firm Datar, has been validated to accurately identify glioblastoma, an aggressive brain cancer.

Dr Crook said the test could potentially be used to screen for multiple cancers each year from a single blood sample, adding: ‘If you can have a single-tube blood test that can reliably detect all tumors current solids would be fantastic. Your GP could do this.

Simon Vincent, from the charity Breast Cancer Now, said: ‘Early detection can prevent people from dying. This method could be particularly useful for diagnosing breast cancer where the detection limits of mammography are pushed back.

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