A Blood Test That Screens For Cancer

sciencehabit writes "People usually find out that they have cancer after developing symptoms or through a screening test such as a mammogram—signs that may appear only after the cancer has grown or spread so much that it can't be cured. But what if you could find out from a simple, highly accurate blood test that you had an incipient tumor? By sequencing the abnormal DNA that a tumor releases into a person's bloodstream, researchers are now one step closer to a universal cancer test. Although the technique is now only sensitive enough to detect advanced cancers, that may be a matter of money: As sequencing costs decrease, the developers of the method say the test could eventually pick up early tumors as well."

Comments

Nobel prize

[mmHg760]

If it works with early forms of cancer, this is nobel prize material.

Re:Nobel prize

[paiute]

Hold the phone, there, Alfred. You have to think about how early you want to be able to find mutating cells. There is a sweet spot of detection - when the cancer is not yet so advanced that it can be treated - below which you may want to think twice about going. If this research results in the ability to detect cells as soon as they mutate, you and the media may think this is a great advance, but the body's immune system is able to sense and kill the vast majority of mutating cells before they grow into a tumor. At a certain detection level, the test is going to give positive results for "cancer" for most people. Then what do you do? You go to the doctor and the doctor tells you that you have malignant cells in your body. Are you going to not worry or are you going to demand treatment?

Re:Every cancer is different

[phayes]

I'm not sure that scanning for genetic changes will turn out to be useful.

Not every genetic change results in cancer as many will result in the cells dying off or being innocuous. Working on bringing the detection threshold down to low enough values to detect small tumours may just end up detecting many small cancers.

In addition, recent work shows that many small cancers are not as problematic as as long been thought. We now know that the body naturally wipes out many cancers without help. Detecting the small cancers that need treatment is much harder than it appears.