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Toshiba device tests cancer types from a drop of blood

japantimes.co.jp

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Re: Toshiba device tests cancer types from a drop of blood

#61

Post by ska »

BiteCode_dev wrote: post #14
pkaye wrote: post #3

Elsewhere it was mentioned it was 90% sensitivity and 95% selectivity which is not that good enough for something serious as cancer. Hopefully they can improve on it.

If it's very cheap, fast and convenient, then it's enough for at least screen the population regularly. Catching only part of the cancers is quite nice already.

Screening techniques are a real problem if their false positive rate is high. Any significant increase in the work up rate will be a real burden on the health system (so you had better see a corresponding benefit). Worse, gold standard for follow up is going to vary by disease and location, but if it is say a biopsy and you are screening a large population you are often going to start killing people without the disease. Not many, of course, but you have to balance that against the putative improvements.

Re: Toshiba device tests cancer types from a drop of blood

#62

Post by hliyan »

dannykwells wrote: post #40

Not even in trials yet. GRAIL is running a 100K person trial, to read out next year. Also, not one paper showing this kind of prediction in the clinic, which GRAIL, freenome, Guardant etc all have. No meaningful papers published + huge claims +single drop of blood = TheranosII

This is part of the damage Theranos has done. Even when a legitimate advance comes along in the same field, people are reluctant to believe it because of the hype that Theranos created.

Re: Toshiba device tests cancer types from a drop of blood

#64

Post by JackeJR »

hliyan wrote: post #62
dannykwells wrote: post #40

Not even in trials yet. GRAIL is running a 100K person trial, to read out next year. Also, not one paper showing this kind of prediction in the clinic, which GRAIL, freenome, Guardant etc all have. No meaningful papers published + huge claims +single drop of blood = TheranosII

This is part of the damage Theranos has done. Even when a legitimate advance comes along in the same field, people are reluctant to believe it because of the hype that Theranos created.

Not exactly. What Theranos has done is to make clear in its aftermath why the problem of making a diagnosis from a single drop of blood is difficult. In short, the sample size is too small and may not contain biomarkers of the diseases of interest even if they are present in the body. Unless this advancement in its application can show how and why this is not a problem, there will be resistance towards accepting what is being put out without further substantiating evidence.

Re: Toshiba device tests cancer types from a drop of blood

#65

Post by jobigoud »

jolmg wrote: post #15
pkaye wrote: post #3

Elsewhere it was mentioned it was 90% sensitivity and 95% selectivity which is not that good enough for something serious as cancer. Hopefully they can improve on it.

Does that translate to 5-10% chance of false-negative? Can't that be improved simply by having multiple tests with a few more drops of blood?

90% sensitivity = 10% false negatives. When the patient has the condition, it is detected 90/100 of the time.

95% specificity = 5% false positives. When the patient doesn't have the condition, it is correctly not detected 95/100 of the time.

Re: Toshiba device tests cancer types from a drop of blood

#67

Post by frickinLasers »

pkaye wrote: post #3

Elsewhere it was mentioned it was 90% sensitivity and 95% selectivity which is not that good enough for something serious as cancer. Hopefully they can improve on it.

Medical tests are always going to be messy, because biology is messy. It's ultimately up to the physician to order tests and interpret the results. Here's a list of tests for diagnosing breast cancer, none of which approach the numbers you are hoping for (a needle biopsy is only performed once a mass is found)

http://www.getthediagnosis.org/diagnosis/Breast_Cancer.htm

I just stumbled across this site, but you can browse by diagnosis for more numbers.

http://www.getthediagnosis.org/browse.php?mode=dx

Re: Toshiba device tests cancer types from a drop of blood

#68

Post by hermitdev »

zxcmx wrote: post #51
nugget wrote: post #46

Earlier quoted context omitted.

What follow on test for suspected lung cancer would risk the life of a not insignificant number of people? An MRI without contrast has no impact. An MRI with contrast has relatively little impact. A biopsy would only be done if the MRI with contrast lit up areas of concern. At the point a PET is ordered, you have narrowed the false positive pool substantially and probably want the scan no matter what.

Just telling millions of people per year they might have cancer... say the MRI is booked for 2 weeks out... which they are then going to majorly stress about the whole time regardless of how low you tell them the risk is - is going to have some crazy societal impact.

I typically have several MRIs per year. I'm not claustrophobic and don't stress about them, but sometimes MRIs cause me physical discomfort, even without contrast. With contrast, its slightly worse, it seems.

I think its related to a genetic disorder that causes me to retain high levels of iron, but I have nothing to back this up.

This discomfort in the MRI comes in the form of waves of warmth I feel throughout my abdomen. Its mostly annoying/distracting and not painful. The loudness of the MRI is far worse than the slight warming I feel. Less annoying than the pee your pants feel of a CT with contrast.

Re: Toshiba device tests cancer types from a drop of blood

#69

Post by robbiep »

nugget wrote: post #46
refurb wrote: post #34

Earlier quoted context omitted.

Yup. And some of those follow on tests could be quite invasive and risky in their own right. With that kind of false positive rate, you'd be risking the life of a not insignificant number of people. Either that or driving up healthcare costs significantly as those 5000 people are going to need an MRI or CAT scan or something else to rule out cancer.

What follow on test for suspected lung cancer would risk the life of a not insignificant number of people? An MRI without contrast has no impact. An MRI with contrast has relatively little impact. A biopsy would only be done if the MRI with contrast lit up areas of concern. At the point a PET is ordered, you have narrowed the false positive pool substantially and probably want the scan no matter what.

Quite rare to jump straight to an MRI - a chest MRI is a half hour deal. More common to do a CT Chest which has a 1:500 risk of causing cancer

Re: Toshiba device tests cancer types from a drop of blood

#70

Post by hermitdev »

projektfu wrote: post #8
kasabali wrote: post #7

Earlier quoted context omitted.

That's a good start. If they'd be able to do 13 tests from a drop of blood from each of my fingers that'd be 130 tests!

Ouch. Give me a needle please.

Finger pricks aren't that bad. Ive been hospitalized several times with cyclical vomiting. It throws my entire body chemistry way off and often looks like I'm diabetic (I'm not). So, I typically get several finger pricks for blood sugar tests daily when I'm admitted. The finger pricks are nearly painless. I dont typically even notice them. Really only gets bad if they use the same finger repeatedly and bruising starts occuring. Its really not bad at all if you rotate fingers.

The IV is far more painful, of course, it is also a fairly large gauge needle. I still have a track mark from my last hospital stay in my arm due to an intubated IV (a blow out) 3 months ago. It also took about 3 weeks for the swelling in my forearm to go down after that.

I also get weekly allergy shots. Slightly more painful than a finger prick, but far less than a typical vaccination.

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