Blood test for 50 types of cancer could speed up diagnosis, study suggests | Hacker News Reader

Blood test for 50 types of cancer could speed up diagnosis, study suggests

theguardian.com

97 pointsbirriel16 comments

The GRAIL press release [1] has more detailed stats.

> The analysis showed strong performance of GRAIL’s MCED methylation-based platform in the symptomatic population of more than 6,000 patients and demonstrated the feasibility of using an MCED test to assist clinicians with decisions around the route of referral from primary care.

> Within the study, 368 (6.7%) of the 5,461 evaluable patients were diagnosed with cancer through standard of care. The most common cancer diagnoses were colorectal (37.2%), lung (22.0%), uterine (8.2%), oesophago-gastric (6.0%) and ovarian (3.8%).

> GRAIL’s MCED test detected a cancer signal in 323 people, 244 in whom cancer was diagnosed, resulting in a positive predictive value (PPV) of 75.5%, negative predictive value (NPV) of 97.6%, and specificity of 98.4%. The overall sensitivity of the MCED test was 66.3%, ranging from 24.2% in stage I cancers to 95.3% in stage IV, and increased with age and later cancer stage. The overall accuracy of the top CSO prediction after a positive MCED test was 85.2%. The mean age of patients in the study was 62.1 years old.

[1] https://grail.com/press-releases/grail-and-university-of-oxf...

Seems an excellent opportunity to cross post recent reporting of insurance companies reevaluating their partnership with GRAIL after more than 400 patients were incorrectly told they may have cancer. Significant benefits, but only with thoughtful implementation. https://news.ycombinator.com/item?id=36176338

How would one in the US be able to access this test?

might need regulation to prevent insurance companies from collecting this info and using it to kick people off insurance or raise their rates until they can't afford it. Perhaps further, we get rid of the need for a private middle man in the first place. 2c

this will just make people more anxious when they find out they have ten different types of cancer

Or a theranos gets pulled, and all the data is BS

Don't think Illumina would be fighting so hard to hold onto their purchase if it was BS e.g. https://qz.com/ftc-illumina-grail-acquisition-antitrust-carl...

https://arstechnica.com/health/2023/06/cancer-biotech-custom...

In this case, it seems like the sending of positive letters was erroneous, not the test itself. That is, the test takers tested negative but still got a letter stating they may have cancer.

If it's accurate, I would think that people who have ten different types of cancer probably should be a bit concerned? (Unless you're saying that most people have a bit of cancer and most of it isn't dangerous; if that's the case I'd want to verify that it's really true but then the solution is telling people that, not hiding in ignorance)

It can be a real problem though in aggregate, and is an issue that pops up with aggressive screening.

Cancer treatment isn't exactly a walk in the park and brings its own health issues with it. Further, it can be hard to impossible to give an accurate answer to "am I going to die from this or with it?". So you find out you have cancer, and now you treat it. And if it was never going to be a big deal, you're likely worse off than if you had left it alone.

At the individual level what you say is true. But at population scale it is easy to make the case that early detection causes more harm than good.

Assuming high sensitivity this is good stuff to learn - anxiety of a correct diagnosis is healthy.

The prospect of having ten different types of cancer and not knowing it is making me more anxious

I don't trust The Guardian, and it has a paywall. Here's a BBC piece :

https://www.bbc.com/news/health-65775159

It's about the Galleri Test, which looks good enough to be useful. It's a DNA fragment analysis of a blood sample with lots of false negatives, but few false positives. This study was of people already suspected to have cancer, but the test helped determine what kind and where it was. cool

The Guardian is famously one of the few news site that do NOT have a paywall.

Huh. I saw something blocking me from reading halfway down but it is not there now on my phone anyway. Still don’t trust em, but I guess it’s not paywalled.

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