Surviving childhood cancer is not the end of the battle. As adults, the risk of a second cancer or other serious illness remains high, according to a multicenter cohort study published in the Oct. 12 edition of The New England Journal of Medicine. The Childhood Cancer Survivor Study, which involved 27 institutions, including the Hutchinson Center, gathered data on almost 10,400 adults who were diagnosed between 1970 and 1986.
The authors concluded that as a group, childhood-cancer survivors were eight times as likely as their siblings to have severe or life-threatening chronic health conditions such as a second cancer, heart attack, congestive-heart failure, kidney dysfunction, severe musculoskeletal problems and disorders of the endocrine system. Three groups of former patients were at highest risk: survivors of bone tumors, central nervous-system tumors and Hodgkin's disease. The mean age of survivors in the study was 26.6 years (survivors ranged in age from 18 to 48).
In the study, survivors and 3,000 siblings, who served as a comparison group, were given a detailed health questionnaire. A severity score of 1 through 4 was assigned to their reported health conditions. About 400 patients were treated on Hutchinson Center research protocols.
More than 60 percent of the survivors reported at least one chronic condition and 28 percent said they had a severe or life-threatening condition. About 40 percent reported having two conditions and about 25 percent said they had three.
After adjusting for factors such as age, sex and race or ethnic group, survivors were more than three times as likely as their siblings to have a chronic health condition of any grade, the study found.
Lessening late effects
The apparent cause behind these chronic health problems is chemotherapy and radiation treatment, the authors concluded, and such secondary illnesses may not become apparent for many years. Five treatment combinations were associated with a tenfold-increased risk of severe or life-threatening conditions; four of the combinations included chest, abdominal or pelvic radiation.
"I was surprised by the magnitude of the findings," said Dr. Debra Friedman, a co-author of the paper and affiliate investigator in the Clinical Research Division.
Friedman noted that due to the knowledge researchers have gained about adverse health-related outcomes for cancer survivors, therapies have since been modified to decrease risk of late effects, while maintaining and, in many cases, improving efficacy. "It is only through continued research using cohorts like the CCSS that we will be able to ascertain whether the changes we have made will indeed result in fewer and less severe late effects," she said.
Importance of follow-up
For example, Friedman has an ongoing, National Cancer Institute-funded study of Hodgkin's lymphoma survivors treated from 1987 to 2001 that is studying late effects and chronic health conditions in survivors treated with more contemporary therapy. She will compare the Hodgkin's findings with those from the CCSS.
The message for physicians and other caregivers is to be aware of potential long-term complications from chemotherapy and radiation that may not manifest for a long time, Friedman said. "Most physicians don't see a lot of post-treatment complications early on and they can get lulled into a false sense of security that they won't see late effects of therapy."
For survivors, "it's important that they take note of the study's data and advocate for themselves," she said. "They need to be sure to have regular annual follow-up exams by a physician who has knowledge of late effects of cancer treatment. Many of the health conditions identified in the study can be detected early and mitigated by early intervention. For example, coronary artery disease is not usually seen in people in their 30s."
However, less than 20 percent of adult survivors of childhood cancer are followed at a cancer center or by an oncologist, the report said. "The monitoring of survivors is an important part of their overall health care," the authors said.
The findings highlight the need for survivorship programs such as the one recently opened by the Hutchinson Center at the Seattle Cancer Care Alliance. Friedman is co-director, with Dr. Karen Syrjala, of the Fred Hutchinson Cancer Research Center Survivorship Program. It is a resource where survivors can be monitored for post-treatment risks and advised of treatment. A portable health record is produced so patients can take the information to any physician regardless of the location. Culling data from old medical records can be difficult for physicians' offices, but the survivorship program has staff dedicated to providing this service.
The Hutchinson Center serves as the statistical arm for the National Institutes of Health-funded study. Dr. Wendy Leisenring is the lead biostatistician for the study and a co-author on the NEJM paper. Dr. John Potter, director of the Public Health Sciences Division, was one of the founding investigators of the CCSS.