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A Breathalyzer For Cancer
Tiger4 writes "Cancer researchers in the UK have come up with a way to sniff for lung cancer on the breath. 'From the results, the researchers identified 42 "volatile organic compounds" (VOCs) present in the breath of 83% of cancer patients but fewer than 83% of healthy volunteers. Four of the most reliable were used to develop a nine-sensor array made from tiny gold particles coated with reactive chemicals sensitive to the compounds.' Other sources have picked up the story as well. Obviously, this would be a big breakthrough for rapid screening, and early detection significantly improves outcomes."
Non-oncs generally don't understand that a whole lot of cancer is "clinically irrelevant". That is, it would never go on to kill you. Thus, as early detection gets better in most areas, you detect a greater percentage of cancer that was never going to hurt the patient. However, once you see the cancer, you are duty-bound to slash/burn/poison (Susan Love's famous chapters) to cure it. Statistically speaking, you know you are actually harming some patients, but it is a dilemma -- you hurt all the patients in order to serve a greater good for some percentage of them. A good example is the growing backlash against general PSA screening. Even just a biopsy for prostate cancer can't be 100% risk-free, but the treatment is really risky, assuming you're not enthusiastic about being impotent and/or incontinent for the rest of your life.
So don't get too excited about increased early detection of cancer. Currently, it is usually a double-edged sword that brings suffering to some percentage of patients who would have avoided it before the new test existed. An exciting development would be a detection test for distinguishing cancer that's just sitting there from cancer that's on the move and likely to kill.
Yeah... that was my first reaction. With a false-positive rate that high, this is useless as a diagnostic tool.
First of all, not all lung cancer is caused by smoking, just as not all smokers get lung cancer. Secondly, perhaps we could give the benefit of the doubt to the cancer researches and to the scientific method that they must have employed. Put another way, if you were able to think of this, you can be sure they would have realized early on that smoking might be a variable to take into account.
It depends on how quick and cheap this test is. If it's really cheap, then it would be useful in validating more accurate (and inherently more expensive) tests that would be used for initial detection or risk assessment. As a hospital manager would you rather run 83 cheap tests and 17 expensive ones to confirm or 100 expensive tests; again it depends on the cost. On the other hand, I'd be more worried about the false negatives. Not being diagnosed with cancer, when you have it, and getting early treatment is much worse than getting an extra test, at least from the patient's perspective.
the scientific method that they must have employed
Quote from FA: "Moreover, in a break from the convention in medical innovation, the researchers claim that full clinical trials may not be necessary to take this new technology to a stage where it is hospital-ready. They believe instead that they could prove the device's accuracy using a series of "artificial mixtures" of particulates that could simulate cancerous and healthy breath. "
In short: We are only in it for the money.
CC.
TaijiQuan (Huang, 5 loosenings)
"Just recently?" That's been a standard example in introductory statistics classes for many decades.
If they weren't in it for the money. This would never have been made!
Since when did research/production/innovation with the goal of making money become a bad thing? It's like it's become a taboo.. making money, it's for the exchange of goods and services!
Pay them in jelly-beans! everyone loves jelly-beans! awww look! they're doing it for jellllyyy beeaaanns
I would run whichever test had the highest profit margin.