Scientists at Johns Hopkins have developed a new way to test for cancer recurrence using a blood test. To do this, researchers focused on large chunks of DNA that are rearranged in cancer cells.
DNA is the genetic material, or instruction manual, found in nearly every cell of the body. Part of DNA is made up of four chemicals. Each DNA chemical is represented by a letter. For DNA, these letters are A, C, G, T.
In the past, researchers looked for changes in just a single letter in the DNA that might signal cancer. For example, they might try to find that there is a G in a place where there should be a T. Given that there are billions of these letters in a molecule of DNA, it's like finding the "needle in the haystack."
Finding Books, Not Letters
With the new technique, researchers instead search for large chunks of DNA that have been rearranged. It turns out that large chunks of DNA often are rearranged in cancer cells, but not in normal cells. This makes these changes particularly useful for detecting cancer.
It's also easier to find large sections of DNA that are in the wrong place, than to find a single letter that's been misplaced. It's more like trying to find a book in a library, than trying to find a single letter in a long book.
Putting the Test to Use
The genetic material of cancer cells can be found in the blood of people with cancer. The new test would be a very useful way to figure out who has a cancer recurrence. The test would detect the presence of cancer much sooner than a typical scan or scope.
This test also could be used to see how people are responding to treatment. Doctors could measure the baseline level of the rearranged DNA in a patient's blood. After a few treatments, the blood would be checked again. If the levels of rearranged DNA have gone down, it would signal that the tumor is shrinking. If not, the doctor can pick a different, better treatment for that particular patient.
Check back with my blog in the future to look for updates on this promising new cancer blood test.
