New Blood Test Detects Over 50 Cancers, Raising Hopes for Earlier Diagnosis

A groundbreaking blood test that can detect more than 50 types of cancer has shown promising results, identifying cancer in nearly two-thirds of positive cases, according to a new study.

The Galleri test, developed by US biotechnology firm Grail and currently being trialled by the NHS, works by detecting DNA fragments shed by cancer cells into the bloodstream — often before symptoms appear.

The Pathfinder 2 trial followed more than 23,000 symptom-free participants in the US and Canada for at least a year. Among those whose blood samples showed a “cancer signal,” 61.6% were later confirmed to have the disease.

The test also proved highly accurate at ruling out cancer, correctly identifying 99.6% of people who did not have it. In cases where cancer was detected, Galleri pinpointed the affected organ or tissue with 92% accuracy — potentially saving time and resources on further tests.

Researchers said the findings suggest Galleri could complement existing screening programmes for cancers such as breast and bowel. An NHS trial evaluating its use for people without symptoms is expected to publish results next year.

Sir Harpal Kumar, Grail’s president of international business, said the test detected “seven times as many cancers as other screening programmes combined” and could help “transform cancer outcomes.”

Modelling indicates the test could be used annually for people over 50, when cancer risk rises sharply. Earlier research published in BMJ Open suggested such screening could lead to 49% fewer late-stage cancer diagnoses and 21% fewer deaths within five years.

Experts have praised the results but urged caution. Professor Nitzan Rosenfeld of the Barts Cancer Institute called the results “impressive,” while Professor Clare Turnbull from the Institute of Cancer Research said more evidence is needed on whether the test actually reduces cancer deaths.

Professor Anna Schuh of the University of Oxford also warned that the test still gives false positives nearly half the time, saying this is “disappointing” and only “slightly better than tossing a coin.”