The chances of cancer reoccurring depend on the form of cancer. Many cancer survivors endure long-term health effects, including infertility, osteoporosis and even post-traumatic stress disorder as a result of some cancer therapies. Some may also experience secondary cancers as a result of some types of treatments.
"These effects manifest themselves unrelated to their cancer," said Diller. "The people who provide primary care in this country will need to know more about how to care wholly for cancer survivors."
Many larger medical centers, especially specialized cancer centers, are doing just that. Messages poured in to ABC News' Medical Unit from more than 25 medical and cancer specialty centers across the nation, describing comprehensive survivorship programs. The programs work with health care providers from various subspecialties who help assess a survivor's medical and mental health needs after treatment.
"It's important to understand the cancer you had and the risk of recurrence or other health concerns," said Diller.
Unlike support groups, many of these programs offer individualized after-treatment plans for survivors. The University of Chicago Medical Center runs a sexual medicine clinic to help women who have survived breast or gynecological cancer regain their sexual independence.
Cedars-Sinai Medical Center in Los Angeles conducts a program that helps survivors overcome "chemobrain," a term used to describe adjustment disorders, and cognitive and learning disabilities, which can be side effects of extensive chemotherapy.
"I think there is hope for many. Despite diagnosis, people are surviving because of treatment options and supportive and follow-up care," said Jacobs.
Pardi said he was surprised to hear the number of survivors was so high -- especially since he recalled that his aunt, who had lung cancer, did not survive -- but was glad to hear there were more like him.
"Ever since I've been in remission, I haven't felt like cancer is a part of my life," said Pardi, who said he continues to receive routine screenings and annual follow-up care for his childhood leukemia.
Pardi said he'd kept his baseball cards and, with help from his oncologist, traded in the cancer.
"I really think the real definition of cancer survivor," said Pardi, "is someone who can almost 100 percent put the cancer behind them and move on to live just as full a life."