Blood Test Finds Cancer Before First Symptoms Start:
From NBC News
Researchers say they have taken a big step towards developing a test that can tell people if they have cancer long before the first symptoms show up.
The blood test detected the majority of cancers in people with four of the biggest cancer killers: breast, colon, lung and ovarian cancer, the team at Johns Hopkins University said.
The test is a long way from being used to screen for cancer, but the study shows a way to get there, the team reported in the journal Science Translational Medicine.
“There is a lot of excitement about liquid biopsies, but most of that has been in late-stage cancer or in individuals where you already know what to look for,” said Dr. Victor Velculescu, professor of oncology and pathology at the Johns Hopkins University Kimmel Cancer Center.
“The surprising result is that we can find a high fraction of early-stage patients having alterations in their blood,” said Velculescu, who led the study team.
It was not a slam dunk, but the test found cancer in the blood of more than half the patients who had been diagnosed with stage 1 cancer. It was even more accurate in finding late-stage cancers, but the goal would be to catch cancer in its earliest, easiest-to-treat stage.
There were no false positives in 44 people who did not have cancer, they said. That’s important, said Dr. Wyndham Wilson of the National Cancer Institute, because there is no point detecting cancer in people if the cancer is not going to actually cause trouble.
“You don’t want to go screening people for hallmark (cancer) mutations unless you absolutely know that when you find it, that there is a tumor there and that it is a tumor that needs to be treated,” said Wyndham, who was not involved in the study.
Sometimes, early-stage tumors or precancerous growths just go away — attacked by the immune system or because they don’t thrive for other reasons.
Several different liquid biopsies are already on the market, used to help track whether cancer treatments are working. But there’s nothing yet that can detect cancer in someone who has not yet been diagnosed.