A Blood Test That Screens For Cancer 71
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."
Nobel prize (Score:5, Insightful)
If it works with early forms of cancer, this is nobel prize material.
Every cancer is different (Score:5, Insightful)
It would be nice but I can't see any one test being able to identify all possibilities any time soon. As the article says, it's a step.
Your headline is too true (Score:5, Insightful)
Your headline is more true than you realize... although you don't realize it.
Something like 2/3rds of the population that we would consider to die of "old age" (generally defined as dying of a condition that predominately kills the elderly, and doing so at around, or greater, than the average lifespan for a developed country), have been discovered, upon death, to have cancer of some sort, but cancer that did NOT contribute to their death. IIRC, the most "popular" are Prostate, Breast, and Brain tumors. Some of those tumors may have been decades old, but slow-growing and non-aggressive enough to simply not be an issue.
Not all cancer is worth detecting if it's almost inevitable that you'll die from simply "wearing out" first.
Re:Every cancer is different (Score:4, Insightful)
I really think you guys are worried about the wrong end of this. It is highly unlikely that this test is going to be too sensitive any time soon...quite the opposite, the key will be making it sensitive enough to be useful. One or a few cells aren't going to make enough DNA that you would have any reasonable chance of picking it up in a random blood sample. There would have to be some critical mass there already, and who knows, but I would guess that the amount of DNA released into the blood by even an in situ is going to be too small to detect.
It is true that cells mutate fairly frequently, but most of these are not "cancer". Cancer implies that it grows invasively. These sequencing tests would be looking for certain genes known to be linked with cancer. Perhaps over time they will develop heuristics that will allow for detection of mutations not previously characterized but initially it would probably be limited to cancer genes already understood. But my initial concern is whether early cancers dump enough genetic material into the blood for this to be useful for early detection. I'll bet that it is only after it becomes invasive that it releases enough DNA to detect.