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    Study tracks long-term challenges facing survivors of childhood CNS tumors

    Greg Armstrong

    The most comprehensive study yet of long-term survivors of childhood central nervous system (CNS) tumors details risks some survivors face decades after their diagnosis, prompting a renewed call for improved follow-up care.

    The risks include the return of or spread of the original cancer, the diagnosis of a second cancer as well as the elevated incidence of other problems, some related to hearing, hormones and concentration.

    The findings were published in the July 1 issue of the Journal of the National Cancer Institute. The work is part of the ongoing Childhood Cancer Survivor Study (CCSS), a collaborative effort of 30 institutions in the U.S. and Canada. St. Jude is the central coordinating institution.

    Greg Armstrong, MD, Epidemiology and Cancer Control, said the results highlight the continuing health care needs of childhood cancer survivors.

    “This is a population who needs high-quality, long-term follow-up, preferably by a cancer center such as we have here at St. Jude,” said Armstrong, the paper’s lead author and CCSS project director. CNS tumors vary widely and include several that are low-grade, which are generally slower to grow and spread. “This pattern of late recurrence suggests a need for continued surveillance of disease well beyond the first five years,” the investigators wrote.

    The study focused on five-year survivors of CNS tumors whose cancers were diagnosed between 1970 and 1986. All were age 20 or younger when they became patients. They underwent treatment for a variety of cancers, including medulloblastomas, astrocytomas and ependymomas.

    In this study, about 7 percent of survivors who received high-dose radiation therapy as children developed second CNS tumors within 25 years. Such tumors were reported in just 1 percent of survivors whose treatment did not include radiation.

    “What is surprising is the continued high rate of late mortality, even 30 years later, and the increasing rate of second cancers among survivors,” Armstrong said.

    In this study, about 25 percent of long-term survivors died within 30 years of their original diagnosis. About 60 percent of the deaths were linked to the return or spread of that cancer.

    Overall, researchers reported that the death rate among long-term survivors of childhood CNS cancer was 13 times higher than for other Americans of the same age and sex. Mortality was 17 times greater among survivors of medulloblastomas and primitive neuroectodermal tumors (PNETs).

    CNS tumor survivors whose cancer was treated with high-dose radiation of the frontal and temporal lobes of the brain were also less likely than the siblings of survivors to marry or to be employed. Those brain regions are important in planning, reasoning, emotional control and memory. Investigators also linked higher radiation doses with an increased risk for long-term problems in such skills as memory, attention and organization.

    Researchers noted that today’s young CNS patients may face quite different futures. Treatment has changed substantially, in part due to earlier studies of the long-term impact of childhood cancer and its treatment. “There has been a reduction in radiotherapy doses for lower risk patients, increased use of chemotherapy, including high-dose chemotherapy, and adoption of improved surgical and radiotherapy delivery techniques,” the researchers wrote.

    In an effort to track the impact of such changes, the CCSS is expanding to include long-term cancer survivors whose diseases were diagnosed between 1987 and 1999.

    Death rates in this study were based on data from 2,821 individuals who were treated for CNS tumors. Information on second cancers, disability, education, employment and other issues came from 1,877 survivors who since 1994 completed at least two CCSS questionnaires. Nearly 4,000 siblings served as the comparison group.

    Each year new CNS tumors are diagnosed in about 2,200 Americans age 20 and younger. The tumors account for about 21 percent of all new childhood cancers. With current therapies, 74 percent of patients are still alive five years later.

    The CCSS was launched in 1994 with funding from the National Cancer Institute (NCI). As the number of childhood cancer survivors continues to climb, CCSS investigators have provided survivors, their families and their health providers a clearer picture of what survivorship means.

    Other authors on this paper are Sujuan Huang, Kirsten Ness, PhD, and Kevin R. Krull, PhD; all of Epidemiology and Cancer Control; Les Robison, PhD, Epidemiology and Cancer Control chair; and Melissa Hudson, MD, director, Cancer Survivorship Division.

    This research was supported by the NCI and ALSAC.

    July 2009