Childhood ALL survivors may develop problems later
By Anthony J. Brown, MD
NEW YORK (Reuters Health) - Among survivors of childhood acute lymphoblastic leukemia (ALL) treated in the 1970s and 1980s, approximately one in five have developed another severe chronic medical condition or have died 25 years after their cancer diagnosis, the results of a long-term study suggest. However, long-term outcomes in the future may be better.
The findings, which are reported in the medical journal Blood, indicate that the risks are greatest for patients who were treated with radiation therapy.
"Our most important finding is that children who were treated with what we would now consider successful, contemporary therapy (no relapse, no radiation) have a quality of life and health profile very similar to our control population" without ALL, senior author Dr. Joseph P. Neglia told Reuters Health. "This is important news for ALL survivors and for parents of children undergoing ALL therapy now."
ALL is the most common cancer in children, accounting for approximately 25 percent of all malignancies in this population. Due, in large part, to advances in laboratory and clinical sciences, the 5-year survival rates have climbed from less than 30 percent in the 1960s to between 80 and 86 percent currently.
Although effective in combating this blood cancer, ALL therapies, including chemotherapy and radiotherapy, have been linked to a number of serious chronic illnesses, including second cancers, heart damage, and infertility, among others.
Using data from the Childhood Cancer Survivor Study (CCSS), Neglia and colleagues examined the outcomes of childhood ALL survivors nearly three decades after their diagnosis. This study is not the first to use data from CCSS, which features the largest cohort of long-term childhood cancer survivors, but unlike some of its predecessors, it focused solely on survivors of ALL, not other malignancies.
Neglia, from the University of Minnesota in Minneapolis, and colleagues assessed the long-term survival rates in 5,760 survivors of childhood ALL. In addition, 4,151 of these subjects completed questionnaires regarding other conditions.
By 25 years after diagnosis, 13 percent of the survivors had died, most commonly from recurrent ALL or from a second cancer, the report indicates. Compared with siblings, ALL survivors were 2.8- and 3.6-times more likely to have a chronic medical condition and a severe chronic medical condition, respectively.
The 25-year rate of death or severe chronic medical condition in these patients was 21.3 percent. The mortality was higher in subjects treated with radiotherapy than in those who were not: 23.3 percent vs. 13.4 percent.
Compared with siblings, survivors reported poorer general and mental health as well as more impaired function and activity limitations. Survivors also had lower rates of marriage, college graduation, employment and health insurance.
"The practicing clinician," Neglia emphasized, "should know that the cancer-survivor population is growing and aging. In many instances, late complications of therapy will not become evident until many years (or even decades) after the child has completed therapy."
He added: "Clinicians and patients must be aware of their past history, and have follow-up that is specific to their needs. Most cancer centers now offer long-term follow-up clinics for pediatric cancer survivors. These clinics offer comprehensive summaries and risk-based follow-up recommendations that survivors and clinicians will find valuable."
SOURCE: Blood, March 31, 2008.