Recent reports show that cancers are returning and almost one in five new cases in the U.S. now involves someone who has had the disease before.
Doctors define "second cancers" as cancer of a different tissue type or at a different site, not a recurrence or spread of the original tumor, according to San Francisco Gate.
Even by medical standards, Judith Bernstein of suburban Philadelphia is an extreme case. She has had eight types of cancers over the last two decades - all treated successfully.
"There was a while when I was getting one cancer diagnosis after another. At one point I thought I had cancer in my little finger," said Bernstein, who has fought breast, lung, esophageal, and the latest - a rare tumor of her eyelids - according to ABC News.
A recent study found that about 19 percent of cancers in the United States now are second-or-more cases. In the 1970s, second-time cancer was only at 9 percent. Since then, the number of first cancers has risen 70 percent while the number of second cancers has risen 300 percent.
The main reason for this, researchers say, is that people are surviving cancer, and living long enough to get it again because the risk of cancer increases with age.
Other reasons for second cancers are gene mutations or risk factors, like smoking. Psychologically, a second cancer can be more traumatizing than the first.
"I think it's a lot tougher for most people. The first time you're diagnosed, it's fear of the unknown. When you have your next diagnosis, it's fear of the known," said Julia Rowland, director of the Federal Office of Cancer Survivorship, according to the Daily Herald.
For doctors too, second cancers can be challenging. Treatment choices may be more limited as radiation usually isn't given to the same area of the body more than once. Some drugs also have lifetime dose limits to avoid nerve or heart damage.
"The body has a memory for the radiation or chemotherapy," and can't endure too much of the same type, said Dr. Alan Venook, a colon and liver cancer expert at the University of California, San Francisco, reports ABC News.
