My professor, a practicing doctor, put it like this:
In other countries, they practice preventative medicine. People go to the doctor for free, the doctor finds a growth, does a biopsy and excision, follows it up, and it ends up as a relatively inexpensive experience. In the United States, people can't afford to go to the doctor and they put it off. When they're finally so sick that they have no choice, they go to the doctor and find out they have full blown metastasized cancer. This results in extended hospital stays, surgery, radiation treatments, and insanely expensive drug therapy. Not only does the price tag balloon into hundreds of thousands of dollars but, after all that, the odds are much higher that the patient dies, anyway.
Why?
Because some people are so worried that others might "get something for free" that they're willing to have higher costs across the board.