Neurocognitive and behavioral outcomes in Latino childhood cancer survivors

Survival rates for childhood cancer now exceed 80%.1 However, the survivors are at increased risk for chronic health conditions due to treatment-related toxicities and one-third of the long-term survivors experience severe or disabling health conditions,2 and also are at risk for adverse behavioral outcomes. Research has documented deficits among survivors in core neurocognitive processes that underlie developmentally appropriate learning, such as attention, executive functioning, memory, and processing speed.3 Such deficits in core functions interfere with age-appropriate acquisition of knowledge so that declines may emerge over time in IQ and academic achievement scores.3 Literature also supports select social and behavioral sequalae, including poor peer acceptance, fewer friendships, and greater social sensitivity-isolation.4 Central nervous system (CNS)-directed therapy (cranial irradiation and intrathecal chemotherapy) is primarily responsible for the adverse neurocognitive and behavioral outcomes. It is for this reason that adverse neurobehavioral outcomes are most frequently observed in children with brain tumor (cranial irradiation, brain surgery), acute lymphoblastic leukemia (cranial irradiation and/or intrathecal chemotherapy) and to a lesser extent acute myeloid leukemia (intrathecal chemotherapy). Younger age at exposure to these agents and female gender serve as key modifiers of the risk.3 Additional socio-demographic factors such as ethnicity and parental education are also thought to influence the long-term outcomes in this group.3 Very few studies, however, have examined neurocognitive or behavioral outcomes in childhood cancer survivors from ethnic/racially underrepresented populations despite speculation that socio-demographic factors may increase vulnerability for adverse neurobehavioral outcomes. The few studies that have examined this issue are limited by either extremely small sample size5 or by the consideration of all ethnic/racial minority populations as a single group6 without acknowledgement of the inherent heterogeneity between the ethnic/racial minority populations. Detailed characterization of homogeneous ethnic populations is needed as the life experiences and values impacting neurobehavioral outcomes are not equal across ethnicities. Importantly, detailed socio-demographic information is necessary to disentangle the effects of ethnicity from the effects of socioeconomic status, thus taking into account the variability within ethnic groups based on education, income, immigrant status, and acculturation, in order to identify the vulnerable subgroups in need of intervention. We addressed these issues by evaluating neurocognitive and behavioral outcomes among childhood cancer survivors with CNS-directed treatments in Latino families drawn from the Los Angeles region, which comprises mostly immigrants of Mexican origin. The literature on engaging ethnic minorities in research, however, suggests recruitment may be complicated by language, cultural, and socioeconomic differences, decreased access to health-care services, and lack of trust and experience with the research enterprise.7 In particular, Latinos have the lowest educational attainment in the U.S.8 and a significant proportion may experience language barriers in interacting with community establishments such as the health care and school systems.9–10 With this background in mind, specific culturally-relevant recruitment strategies were employed to enhance participation, and the data collection was intentionally designed to minimize participant burden. In particular, we utilized a parent-report assessment of neurocognitive functioning in the pediatric survivors since performance-based, direct assessment would have required the parent to transport the child to the clinic. We aimed to 1) describe neurocognitive and behavioral outcomes in a cohort of Latino survivors; 2) examine the clinical and sociodemographic factors associated with adverse outcomes; and 3) evaluate the impact of neurocognitive impairment on health-related quality of life (HRQL). We hypothesized that sociodemographic factors such as age at diagnosis, gender, acculturation status, income, and parental education would have significant impact on the neurobehavioral outcomes in this cohort.