Modern Healthcare: What is cancer?
Dr. Otis Brawley: Cancer is uncontrolled cell growth. When a cell goes from one to two mitosis, and then two to four, that's usually normal growth. If there's not a stop signal, that's when you have a cancer. The fact that people had these uncontrolled growths is talked about in the Bible and is even seen on the walls of caves in Egypt from 3,000 or 4,000 years ago.
MH: What do you think is problematic about this definition of cancer?
Brawley: We've used the biopsy a lot over the past 160 years, since the Germans gave us the microscopic definition of cancer in the 19th century. They used autopsies of people who clearly died of breast, lung, colon and prostate cancers. They were the first to do biopsies and what we now call H&E staining. They looked at biopsies under their microscopes, drew pictures of what they saw and defined what cancer looks like.
Now, 160 years later, keep in mind X-ray was invented in 1895, mammography in 1955, ultrasound in the 1960s, CT in the '70s, MRI in the '80s, and some of our biopsy techniques have just been patented in the past 10 to 15 years. Now we can see a five-millimeter tumor in a woman's breast, stick a needle into the tumor, sample it and send it to a pathologist. The pathologist uses the same H&E staining techniques that were used 160 years ago and looks at it under a 2014 version of the microscope. That pathologist says this looks just like what the Germans defined as cancer 160 years ago.
The big difference is that what the Germans saw was a tumor that clearly had spread and caused harm and killed the patient. This 5 millimeter thing may very well not be genomically or genetically programmed to grow, spread and cause harm, and that's what we call an overdiagnosed cancer. In breast cancer, with mammography screening, we believe 10% to 30% of all of our localized cancers are overdiagnosed cancers. These are women who will be treated needlessly.
In prostate cancer, some people estimate 40% to 60% of prostate cancers that we are currently diagnosing are these over-diagnosed cancers. We desperately need a 21st-century definition of cancer versus the 19th-century definition we've been using.