New Nanotech Helps Detect Early-Stage Cancer 18
CWmike writes "Stanford University researchers have used nanotechnology and magnetics to create a biosensor that they said should be able to detect cancer in its early stages. The sensor, which sits on a microchip, is 1,000 times more sensitive than cancer detectors used clinically today, say scientists at Stanford. The researchers announced this week that the sensors have been effective in finding early-stage tumors in mice, giving them hope that it can be equally successful in detecting elusive cancers in humans. 'In the early stage [of a cancer], the protein biomarker level in blood is very, very low, so you need ultra-sensitive technology to detect it,' said Shan Wang, professor of materials science and engineering at Stanford. 'If you can detect it early, you can have early intervention and you have a much better chance to cure that person.' Wang also noted that the biosensor could be used to determine whether chemotherapy or other cancer treatments are working after only a few days."
For anyone interested in a real description... (Score:5, Informative)
Essentially they're using magnetic nanoparticles covered with antibodies to detect the binding of some tumor biomarkers. While the idea is interesting, there's no indication (yet) that its more sensitive than other biomarker assays, although it very well may be. Fluorescence techniques can get down to the tens of molecules level of sensitivity (which is insanely impressive). If they can get even lower, I'd be extremely impressed, but I can't find any published data on their immunoassays. Their comments about capturing and sorting out cancer cells is a bit odd. If you're looking to isolate whole cells based on recognizing protein biomarkers, I can't see any advantages of their tech over standard fluorescence activated cell sorting (FACS), unless their assays are really more sensitive.
Really, the only thing of interest in this work is using the magnetic properties of their nanoparticles to detect binding. I would be really curious to see if this could supplant technologies like quartz crystal microbalances that look for changes in the vibrational modes of a crystal to detect surface binding events as being simpler and less prone to disruption by temperature fluctuations, doors opening or people walking by. The biomarker assay is interesting but by no means genuinely new technology- only the detection method is truly novel. Not bashing the work done here, the binding assay is really cool, the application looks like it was mostly thought of to get grant money.
Re:For anyone interested in a real description... (Score:5, Informative)
After reading some of the Stanford press out there on this, I've gotta say I'm really sick of 'science' journalists. Saying their test can detect cancer with 1,000 times the sensitivity and specificity has very different meanings than what they intended in diagnostics. It sounds like they're claiming 1,000-fold improvements in false negative (sensitivity) and false positive (specificity) rather than assay sensitivity based on concentrations. Their claim is also inaccurate. ELISA assays are commercially available with sensitivities as high as 1 part per 10 billion, while their claim is for a sensitivity of 1 part per 100 billion. ELISA assays have also been reported (and a couple are commercially available) with sensitivities of 1 part per 100 billion.
Re: (Score:2)
Thanks for the clarification.
On a related note, while I don't mean to discourage such research, I've been reading new line of thoughts that, as we learn more about tumor formation, early cancer detection may not be so beneficial because tumors form much more frequently and often in benign fashion than previously thought, and early detection often forces treatment that may be worse than non-treatment.
No, I'm no medical researcher.
Re: (Score:2)
What "protein biomarker" are they talking about? (Score:2, Informative)
Cancer can affect the levels of various proteins in the blood: prostate cancer can raise prostate specific antigen, carcinoembryonic antigen is associated with colon and other cancers, alpha-fetoprotein is associated with liver and other cancers... the list goes on and on.
The problem is that these proteins are produced by normal cells but cancer cells often produce them in excess. The ability to detect these proteins has never been a problem. The problem is that they often only reach a very high level when
And what level should doctors intervene? (Score:5, Insightful)
If this device is 1000x more sensitive than anything we've had before, it seems to me that we have no real data about how such a low level corresponds to actual cancer risk.
It's been well known for decades that cancer cells are commonly created in the body. Most of the time the immune system takes care of them before cancer gets a foothold. One question I have is, will this sensor be so sensitive it'll detect the normal everyday cancer that our immune system would normally fight off by itself? This could lead to un-necessary intervention, which can cause more harm than good.
Re: (Score:1, Interesting)
That's actually the argument against prostate specific antigen screening.
The detection rates (and treatment rates) are way up. However there is no evidence that the occurrence rates have actually gone up.
This seems to indicate that they are treating a lot more people than previously would have needed it.
Re: (Score:1)
Re: (Score:2)
good point!
Publication is here: doi:10.1038/nm.2032 (Score:3, Informative)
I'm part of this research and I'm pleasantly surprised someone posted it on Slashdot. To answer some questions: The device is indeed a concentration-measuring chip (not just positive / negative, which would be simpler), and in a just-posted Nature Medicine paper it shows that the signal vs. concentration curve goes 1000x farther on the low end (and the high end too, i.e. more dynamic range) before blending in with the background than the same assay (and antibodies) used on ELISA. Plus, it is a simple device that performs identically in saliva, urine, different pH and temperatures, and which is generally rugged and not too picky about the experimental conditions. This is quite helpful too.
Another point of the publication is that this device can measure small but slowly increasing tumor marker concentrations in lab mice which are known to have cancer. The key is that these tumor markers can be measured with this chip, but are too small in concentration for the traditional platforms such as ELISA. This means you can (in mice, at least) get important early cancer growth trend information (from a blood test) which you probably wouldn't have been able to obtain before.
Just published in Nature Medicine Advanced Online publications (unfortunately requires subscription):
http://www.nature.com/nm/journal/vaop/ncurrent/abs/nm.2032.html [nature.com]
Technical Report abstract
Nature Medicine
Published online: 11 October 2009 | doi:10.1038/nm.2032
Matrix-insensitive protein assays push the limits of biosensors in medicine
Re: (Score:2, Interesting)
P.S. Here is an older publication which has been open-sourced (open access) and which shows the technology:
http://www.pnas.org/content/105/52/20637.abstract [pnas.org]
this is great. (Score:2)
Soon, cancer treatment will be highly specialized and tailored to the individual and the cancer or cancers he/she has. This and other technologies can be used to dynamically adjust the patients treatments in essentially real time. If an emerging resistant strain(s) is detected or found to be emerging, then potent and thought out combination therapy can be used to control or destroy the cancer. Combination therapy will have to be engineered in such a way that it's mathematically as infeasible as possible for
Misleading (Score:1)
Re: (Score:1)
Well, from my point of view this chip is simply a very sensitive protein quantification device. You can measure a wide range of proteins (related to cardiac disease, allergies, Alzheimer's, and many more), not just "cancer biomarkers", i.e. proteins which are suspected/proven to have a link to cancer.
How reliably can one really diagnose cancer from a blood protein test? In my opinion, cancer has so many different forms (it mutates constantly) that it is harder to find a common and highly reliable diagnostic
The only conclusion... (Score:2)
after this much study and dedication to his profession is that "Wang cares".
Just don't say it too quickly.
Now if we could only... (Score:2)
Now if we could only program the nanotechnology to attack the cancer cells then lay dormant until the day comes that
the replicators have sent out the emergency activation beacon, which it would then restart and take control of the body, then we.....
um.....I think i watch too much stargate