New Nanotech Helps Detect Early-Stage Cancer

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."

Comments

For anyone interested in a real description...

[toppavak]

and not a pile on nonsensical garbage, the wang group page has a good description of the project.

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...

[toppavak]

Also this may just be splitting hairs, but putting "helps detect early stage cancer" in the headline implies that they, well, actually helped detect an early stage cancer in a patient. A laboratory proof of concept for a protein biomarker assay is very, very far away from actually "help[ing to] detect early stage cancer".

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.

And what level should doctors intervene?

[Vellmont]

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.