Cancer treatments have vastly improved, so today's patients should not suffer as many future problems, specialists say.
But the research shows that those treated in the 1970s and 1980s are now facing medical, financial and emotional burdens.
"We've concentrated so much on our five and 10-year survival that we haven't paid attention to the impact of our treatments," said Dr Len Lichtenfeld, deputy medical director of the American Cancer Society.
Survival is at an all-time high. More than three out of four children are cured of cancer today, up from 58% in 1975.
"But the individuals cured currently pay a large and unacceptable price for that," said Dr Harmon Eyre, the cancer society's medical director.
Better medicines have made
cancer treatment more effective
Nearly 10 million Americans have survived cancer, including 270,000, who were diagnosed when they were 15 or younger.
Researchers around the country studied 10,397 of them, who were diagnosed and treated between 1970 and 1986, and 3034 of their siblings, who did not have cancer.
By age 45, cancer survivors were two to six times more likely than their healthy brothers and sisters to develop various health problems.
Examples include heart disease, kidney problems requiring transplants or dialysis, blindness, infertility, mental retardation, paralysis, blood clots, lung problems and even another bout of cancer.
Those who had Hodgkin's disease fared the worst, followed by those treated for brain tumours, said the lead researcher, Dr Kevin Oeffinger, of the University of Texas Southwestern Medical Centre in Dallas.
Radiation is responsible for much of the damage, and doses were much higher decades ago than they are today, he said.
Chemotherapy drugs also have taken a toll. Some, like the widely used breast cancer medication Adriamycin, are known to cause heart problems.
Less toxic drugs are needed to
fight cancer and its effects
Less toxic drugs are needed, and cancer survivors and their doctors need to watch more carefully for health problems and try to prevent them, said Dr David Johnson, a Vanderbilt-Ingram Cancer Centre doctor who is president of the oncology society.
"We want to make primary care physicians aware of these problems as well as patients," said Johnson, himself a cancer survivor, diagnosed with lymphoma 15 years ago.
The National Cancer Institute funded the study. A separate one, funded by the Lance Armstrong Foundation, found that half of survivors said their financial and emotional issues were harder to face than the physical issues, and that these needs were not met by their doctors.
"We focus predominantly on the medical issues of cancer, yet what this survey says is that the non-medical issues are as much prevalent," said Dr Steven Wolff of Meharry Medical College in Nashville.
He presented the research, which was based on an Internet survey of more than 1000 randomly selected cancer survivors. Nearly half of them said they still talked about cancer at least once a month and that their lives were affected by it "more than a little". More than half reported having to deal with chronic pain and depression.
"As cancer doctors, we are very well equipped to deal with their physical needs," said Johnson. "We aren't so well-equipped to deal with their psychological needs."