Read More: Popular Science
Finding out you have cancer is a bell you can’t unring. As doctors increasingly have the tools to find cancers before they actually pose a problem, we’re going to have to start asking ourselves a tough question: is knowing always a good thing? Half of Americans say they’d want to be screened even for a type of cancer they couldn’t do anything about. But medical professionals are somewhat divided on just how much we should test people for diseases we’re not able to treat. Meanwhile, our screening tests are getting broader. A study in the journal Science this week demonstrated a solid first step toward a blood test that detects eight different kinds of cancer. Together, these eight diseases account for 60 percent of cancer deaths in the U.S., and the screen is able to not only identify cancer with reasonable accuracy, but can also sometimes indicate which organ the disease is in. It does this by testing for mutations in floating tumor DNA, and by looking for cancer-specific proteins. This combination makes the test more accurate than many prior efforts. It’s not ready to go to market anytime soon, but its very existence raises some big issues for the medical community. A significant subset thinks that earlier detection is key to preventing deaths. Another segment thinks that earlier detection isn’t always key, and that screening can actually do substantial harm. While some doctors push for broad screening, others urge caution even as diagnostic technology surges ahead. To understand why this divide exists, we have to take a step back to the basics.