The Risks of Cancer Screening
With More Cancer Screening and Earlier Testing, Overtreatment on the Rise
Biopsy Harm continued...
But now you have a new problem. You anxiously wait for the next call, the one that will tell you whether there really are cancer-like cells in your body.
If it's not cancer, you may breathe a sigh of relief. If it is cancer, you might think the test saved your life. But maybe not.
The vast majority of screening-triggered, cancer-positive biopsies detect cells in the very earliest stages of becoming cancers.
That's good, isn't it? Early-stage cancers usually are curable. But there's a catch, Kramer says.
"Unfortunately, right now we are diagnosing a large number of people without precise enough knowledge to spare those who don't need to be treated from treatment," Kramer says. "We treat them, but we have to accept the possibility that there is overtreatment."
Not All Cancers Kill
In 1924, a Johns Hopkins doctor named Joseph Bloodgood noted that the earlier a cancer was detected, the longer patients survived. In a famous New York Times editorial, he predicted that future cancer screening tests would virtually eliminate cancer by detecting lesions at their earliest stage.
Bloodgood was right that better screening tests would come along. And he was right that earlier diagnosis increases survival, although not always in the way he predicted. Earlier diagnosis may increase the time a person lives with cancer without necessarily letting him or her live longer.
But Bloodgood was wrong about eliminating cancer. Cancer rates have fallen since routine screening began, but they haven't dropped off a cliff. Over 1975 to 2007, the U.S. cancer death rate dropped from 200 to 178 deaths per 100,000 people.
Doctors are screening for some of the biggest cancer killers on earth. Screening is routine for cancers of the breast, prostate, colon, and cervix. Smokers get screened for lung cancer. Cure rates are up. Death rates are down -- but not as much as cure rates would predict.
Why? As Brawley notes, many of the cancers we're detecting and curing would never have killed. Some cancers are, or become, benign. Some "spontaneously remit," meaning they go away. Some -- doctors call them "indolent" -- grow so slowly that a person would die of something else.
"Overtreatment is treatment that was not necessary at all because the tumor did not need to be treated," Kramer says. "There is more and more evidence that there is an increasing pool of these tumors."