Survivors of childhood brain tumors

Abstract

This paper reviews the literature on the psychological adjustment and quality of life in children who survive brain tumors. A total of 31 studies were reviewed. Findings are discussed in terms of the rates of general psychological adjustment, internalizing behavior problems, externalizing behavior problems, social competence, correlates or predictors of adjustment, and quality of life among survivors. Although these survivors appear to be at risk for compromised social competence and long-term quality of life, reports in the literature on rates of psychological adjustment in this population vary widely. Limitations in the current literature are discussed including inadequate assessment techniques, lack of appropriate comparison groups, and small sample sizes. Directions for future research are offered.

Introduction

Children with tumors originating in the central nervous system (CNS) constitute approximately 17% of the pediatric oncology population, making this type of cancer second only to leukemia in incidence and cause of death among the childhood cancers (Gurney, Smith, & Bunin, 1999). Survival rates among these children have increased slightly over the past 20 years with older children evidencing better outcomes (Gurney et al., 1999). Some reports suggest that incidence rates have been rising (Gurney et al., 1997); however, such increased rates may be due in part to improved diagnostic technology (e.g., greater use of magnetic resonance imaging [MRI]) (Gurney et al., 1999). Notably, psychologists have become involved as part of neuro-oncology treatment teams in hospitals and comprehensive cancer clinics in an attempt to improve patients' long-term adjustment to their illness. However, there remains a paucity of research on adjustment and quality of life to help guide clinical interventions with these children. Although a small body of research exists seeking to understand issues related to adjustment, to date, the majority of childhood brain tumor research has focused primarily on motor/sensory functioning deficits or alterations in brain functioning and the attendant neuropsychological deficits in these children (Kennedy & Leyland, 1999).

Research has demonstrated that children treated for brain tumors with ionizing cranial radiation therapy (CRT) show decreased processing speed Mulhern et al., 1988, Packer et al., 1987, specific memory deficits (Dennis et al., 1991), and visual–motor decrements Armstrong & Mulhern, 1999, Johnson et al., 1994. Such deficits are believed to be secondary to white matter loss and microvascular changes associated with CRT Jenkin et al., 1995, Mulhern et al., 1999. Recognition of these late effects of treatment has resulted in changes in treatment protocols and CRT dosage in an attempt to reduce these deficits. However, even with changes in CRT dosage, neuropsychological late-effects are still present in this patient population (Mulhern et al., 1998). Identified risk factors for cognitive impairment include intracranial pressure (Jannoun & Bloom, 1990), a greater number of neurosurgical procedures and extracranial shunt infection (Kao et al., 1994), younger age at treatment Dennis et al., 1996, Packer et al., 1987, and greater time since diagnosis Dennis et al., 1996, Ellenberg et al., 1987.

Although it is important for health care professionals to be aware of the long-term neuropsychological deficits that children with brain tumors often experience, it is equally important for professionals to be cognizant of how the stress associated with diagnosis and treatment, as well as the late effects of therapy, can impact a child's adjustment and quality of life. To date, relatively few studies have examined psychosocial aspects of survival in children with brain tumors Mulhern et al., 1992, Ris & Noll, 1994.

Indeed, researchers investigating children with specific types of CNS-related health conditions (e.g., cerebral palsy, spina bifida, epilepsy) have found greater emotional and behavioral problems compared to both healthy children and children with non-CNS-related chronic health conditions (Nassau & Drotar, 1997). Further, epidemiological studies suggest that children with chronic neurological diseases are at significant risk for developing psychological disorders (Rutter, Graham, & Yule, 1970). Thus, these data may be interpreted to indicate that children with brain tumors also may be at risk for social, emotional, and behavioral problems.

While studies on the psychological adjustment of children with leukemia and lymphoma have generally found good overall adjustment among this survivor group Brown et al., 1992, Kupst et al., 1995, poorer adjustment has been noted among children with visible and serious side effects of treatment (Greenburg, Kazak, & Meadows, 1989). The degree of generalization of this literature to children with CNS cancer remains tentative. Children with brain tumors typically differ in a number of fundamental ways from children with non-CNS cancers. Importantly, the risk to cerebral integrity is greater among children with brain tumors not only because of the critical location of the malignancy and its impact on cerebral tissue but also because of the iatrogenic effects of neurosurgery, radiation, and chemotherapy. In addition, decline in cognitive functioning, including cognitive slowing (i.e., decreased processing speed), may subsequently impact a child's ability to adapt to the stress of their illness ultimately impacting their psychological adjustment (Mulhern et al., 1992). Nassau and Drotar (1997) have hypothesized that children with CNS-related chronic health conditions (e.g., cerebral palsy, epilepsy, spina bifida) may exhibit deficits in age-appropriate social competence and peer relations because cognitive impairments hinder the understanding of social cues and social relations. Recent research has corroborated this hypothesis relating low cognitive ability to diminished social skills (Bellanti & Bierman, 2000). Thus, children with brain tumors may be at risk for specific types of adjustment difficulties (e.g., social competency deficits) not necessarily observed among the majority of children with non-CNS cancers.

Given the apparent risks for adjustment difficulties among these children, the primary focus of this review is to examine literature on the social, emotional, and behavioral adjustment in children who are survivors of brain tumors. Although there are a limited number of studies in this area, a synthesis of the extant data can be useful in presenting directions for future research and assisting practitioners in the management of adjustment problems. Prior to this, a brief overview of the more common types of brain tumors and their treatment among children will be provided to help establish a context for the current review. A more comprehensive review is beyond the scope of this paper and the reader is encouraged to refer to Cohen and Duffner (1994).