{"id":410748,"date":"2026-04-21T22:37:08","date_gmt":"2026-04-21T22:37:08","guid":{"rendered":"https:\/\/www.newsbeep.com\/ie\/410748\/"},"modified":"2026-04-21T22:37:08","modified_gmt":"2026-04-21T22:37:08","slug":"are-cancer-screening-blood-tests-close-to-prime-time","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ie\/410748\/","title":{"rendered":"Are cancer-screening blood tests close to prime time?"},"content":{"rendered":"

The vision of a single blood test that could screen for dozens of different cancers has tantalized oncologists for more than a decade<\/a>. <\/p>\n

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The science has advanced at a rapid clip: What began by analyzing levels of proteins in the blood has progressed to scrutinizing tiny amounts of DNA and feeding the data into algorithms that can highlight changes suggestive of cancer.<\/p>\n

It\u2019s led to a number of eye-catching developments. In one study<\/a>, a blood test called Mercury was able to correctly identify 13 cancers with an average of 87% accuracy, including 77% of stage 1 cancers. <\/p>\n

\u201cIt\u2019s amazing we can even do this,\u201d says Dr. Aadel Chaudhuri, a radiation oncologist at the Mayo Clinic in Rochester, Minnesota, who himself is researching multi-cancer blood tests. \u201cIf you had asked me 10 years ago, my answer would have been \u2018It\u2019s not feasible.\u2019 If we\u2019re thinking of DNA shed from a small tumor, it\u2019s like being on the beltway in D.C. and you\u2019re looking for one Volkswagen.\u201d<\/p>\n

The ultimate hope is a test that would be able to accurately detect a range of cancers at an early enough stage where they are still curable. That would translate into lives saved. <\/p>\n

But in February came disappointing news: The largest trial to date on cancer blood tests failed to achieve its primary objective. The trial was run by Grail, a biotechnology company that manufactures a test called Galleri that, it says, can detect more than 50 different types of cancer through measuring DNA fragments in the blood.<\/p>\n

But the trial results, released by the company<\/a>, saw no significant reduction in advanced cancer diagnoses in people who received the Galleri test compared with those who had not.<\/p>\n

More on advances in cancer treatment<\/p>\n

\u201cIt\u2019s hard to argue that it wasn\u2019t a setback,\u201d Chaudhuri said, who wasn\u2019t involved with the trial. Still, it\u2019s premature to dismiss the trial as a total failure, he said. The full results have not yet been published and it did appear that, in some cancer types, the test had helped detect more cancers at the earliest stages, while the numbers of stage 4 diagnoses \u2014 cancers which have spread to distant organs and are considered incurable \u2014 decreased. \u201cClinically, what I truly care about is a decrease in stage 4 cancers,\u201d Chaudhuri said.<\/p>\n

Survival data<\/p>\n

Dr. Deb Schrag, a medical oncologist at Memorial Sloan Kettering Cancer Center in New York City, said that for multi-cancer blood tests like Galleri to be seen as a paradigm shift by the medical profession, they will need to demonstrate that they can help save lives. Grail will continue to follow patients from its trial for up to eight years after they got their first test to monitor if there has been any reduction in deaths. <\/p>\n

Schrag said this data will be crucial because one possibility for why certain cancers might be releasing detectable amounts of DNA into the bloodstream is that they\u2019re highly aggressive. This might mean that even if a test was able to detect these tumors sooner, it\u2019s not necessarily guaranteed that they will be any more treatable.<\/p>\n

\u201cIf it can\u2019t be cured or there\u2019s nothing to do, then it\u2019s not clear that you\u2019ve helped,\u201d Schrag said. <\/p>\n

The challenge for Grail and other developers is that with people with advanced cancer living longer<\/a> than ever before because of improved treatments, it could take many years to truly know whether their tests can actually make a difference to patient survival.<\/p>\n

\u201cSo we\u2019re the victims of our own success in some sense,\u201d Schrag said. \u201cAs patients are living longer, these trials are getting harder to do.\u201d<\/p>\n

There\u2019s another reason why survival data is important. It may prove crucial for multi-cancer blood tests to get wider reimbursement from insurers.<\/p>\n

So far, none of these tests have been approved by the Food and Drug Administration, although Grail has been able to use a regulatory loophole to market and sell the Galleri test without review. But with very few insurers willing to cover it, it\u2019s predominantly sold through high-end clinics and medical concierge services to people willing to pay for it out of pocket.<\/p>\n

Cancers with no screening methods<\/p>\n

Even without survival data, there may be other ways in which the tests can demonstrate their value in the short term. Nickolas Papadopoulos, a professor of oncology at Johns Hopkins School of Medicine, said he\u2019s interested to see if trials show that they\u2019re capable of detecting cancers where there\u2019s currently no approved method of screening. <\/p>\n

While screenings for breast, lung, colon, prostate and cervical cancers effectively catch early cases and reduce cancer deaths, these five cancers represent less than a third of all annual cancer diagnoses in the U.S. <\/p>\n

\u201cExisting screening leaves a lot of important cancer types behind,\u201d Schrag said. \u201cThat includes one of the deadliest of all cancers, pancreatic cancer<\/a>, but many other important cancers.\u201d<\/p>\n

Papadopoulos said he\u2019s awaiting the full breakdown of the Galleri trial data before judging whether it\u2019s been a success.<\/p>\n

\u201cI would like to know what they found,\u201d said Papadopoulos, who led a session on cancer blood tests Tuesday at the American Association of Cancer Research annual conference in San Diego. \u201cDid they find cancers that are not part of standard of care screening?\u201d <\/p>\n

Oncologists are also keen to assess how the accuracy of the Galleri test varied between cancer types in the trial. So far, one major limitation of multi-cancer blood tests is that their performance tends to vary greatly between different forms of cancers. One study<\/a> of a test called CancerSEEK, for example, found that it detected 98% of ovarian cancers but just 33% of breast cancers.<\/p>\n

According to Chaudhuri, this is because tumor types vary in the amount of DNA they release into the blood, with kidney, thyroid and early-stage prostate and breast cancers being \u201clow shedders,\u201d while head and neck and pancreatic tumors tend to be more detectable.<\/p>\n

But in time, there may be other ways of detecting even the lower shedders. Chaudhuri said there\u2019s considerable optimism that newer tests could be developed which are even better at picking up signs of early-stage cancers through integrating multiple sources of data collected from a person\u2019s blood, from protein levels to the sizes of DNA fragments and using AI to look for abnormalities.<\/p>\n

While it may take a number of years to gather the evidence that blood tests can make a difference to the lives of patients, Schrag said that she\u2019s still incredibly excited about the potential of the technology and believes that we\u2019re on the \u201ccusp of breakthrough.\u201d<\/p>\n

However, she said, it may ultimately be too optimistic to have a single test which can screen for many dozens of cancers. Instead, she said, the likely future is that there could ultimately be a basket of blood tests which screen for different families of cancers.<\/p>\n

\u201cThe dream is that you would go to the doctor and get one blood test that would identify 75 different types of cancer, from the common ones to the rarest of the rare,\u201d she said. \u201cWe may not get there. It may be that there\u2019s one blood test that looks for cancers of that pulmonary tract, another that looks for blood cancers, another for digestive cancers and so on.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"The vision of a single blood test that could screen for dozens of different cancers has tantalized oncologists…\n","protected":false},"author":2,"featured_media":410749,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[103,61,60],"class_list":{"0":"post-410748","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-health","8":"tag-health","9":"tag-ie","10":"tag-ireland"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/410748","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/comments?post=410748"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/410748\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media\/410749"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media?parent=410748"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/categories?post=410748"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/tags?post=410748"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}