Pandora's Lab: Seven Stories of Science Gone Wrong

by Paul A. Offit

During the past 50 years, doctors and scientists have proven that some cancers can be prevented. Sunblock can prevent skin cancer. The hepatitis B virus vaccine can prevent the most common cause of liver cancer. The human papillomavirus vaccine can prevent the only known cause of cervical cancer. And cessation of cigarette smoking can prevent a common cause of lung cancer. The results of these four strategies are clear. The definition of cancer, however, is changing—and not for the better. Medical textbooks 20 years ago defined cancer as a “disease the natural course of which is fatal.” No longer. Now we detect cancers that aren’t fatal—the kind of cancers that you are more likely to die with than from. In the process of detecting these nonfatal cancers, we are probably doing more harm than good. Gilbert Welch, a professor at Dartmouth Medical School, offers the best analogy to our current dilemma. It’s a barnyard analogy. Imagine, writes Welch, three animals in a barn that are trying to escape: a bird, a turtle, and a rabbit. When you open the door, they will escape at different rates. The bird, which will invariably fly out before you have time to close the door, is analogous to the kind of cancer that will kill you no matter what you do. Even if you detect the cancer early, it doesn’t matter—you’ll die from it anyway. It’s just too aggressive. The turtle, which is so plodding that it will never effectively escape, is analogous to a cancer that is so slow growing, so non...