Here's the takeaway: the mortality rate is the number of people who die every year of a given cause in a specific number of people (often 100,000). The survival rate is how many people are still alive at a specific time after diagnosis.
Survival rates, Carroll explains, can be lengthened by preventing death, curing an illness or ... diagnosing the disease earlier.
As he explains it, suppose there were a dread disease, cancer of the thumb. No one could detect it until they felt a lump. All got chemo, but four years later, anyone who got it was dead. That's a five-year survival rate of zero.
Now suppose you had a super-duper scanner that could find that cancer of the thumb at the very first cell, say, five years before the patient would have felt a lump. The patients all get chemo. In other words, the treatments are unchanged. But the patients still all die four years after they would have felt the lump.
The five-year survival rate is close to 100 percent, but the mortality rate is unchanged.
Carroll also does a nifty comparison of breast cancer and prostate cancer in the U.S. and Great Britain. Sure, U.S. survival rates of both diseases beat the Brits. But, mortality rates? Not so much.