Discussion
Consistent with previous studies, the present findings highlight social difficulties among pediatric brain tumor survivors. Peer relationships (i.e., friendship quality, acceptance by peers) emerged as an area of particular concern. Significantly more survivors were rated as having difficulties with peer relations relative to normative expectation, with a sizable portion of pediatric brain tumor survivors (~25%) experiencing social exclusion (e.g., not being invited to play, selected last for team games). These findings broadly correspond with previous research highlighting survivor vulnerability to peer exclusion and isolation. 31,32 Further, a relatively small but remarkable number of survivors (~10%) were rated by caregivers as having no friendships. These results are similar to previous findings,3,33 although Hocking and colleagues reported a greater proportion of survivors (38%) who were unable to name a friend.
The proportion of survivors experiencing problems with social skills also significantly differed between survivors and normative expectations, which is consistent with previous findings documenting social skill deficits among pediatric brain tumor survivors2,32. Specific prosocial skills, such as complimenting others and offering to help, emerged as areas of difficulty on individual item review in the present study. Ultimately, the results encourage continued efforts to better understand and support survivor social functioning.
In examining associations between social and cognitive outcomes, the current findings identify several cognitive variables as potentially influential for peer relations and social skills among pediatric brain tumor survivors. Processing speed, an area in which survivors consistently demonstrate impairment, 34-36significantly correlated with both peer relationships and social skills. Executive functioning and verbal memory also correlated significantly with peer relations. However, no cognitive variables significantly predicted social skills, and only verbal memory approached significance as a unique predictor of peer relations in the context of other cognitive and treatment variables in the regression model. The fact that verbal memory approached significance as a unique predictor of peer relations is not surprising given the role of verbal memory in language processing and social communication, facilitating the retrieval of previously learned verbal information and incorporation of such information with conversational demands. 37 However, while verbal memory correlates with social problem solving and caregiver-reported social skills in other medical populations (e.g., traumatic brain injury38), the relationship between verbal memory and social outcomes has not been closely examined in the pediatric brain tumor population. As verbal memory is known to be at risk in brain tumor survivors, likely as a result of disease and treatment-related damage to temporal structures and cortical connectivity underlying memory function,39 this relationship warrants further investigation.
It is notable that survivor social outcomes did not differ based on RT modality, although significant differences in cognitive outcomes between survivors treated with XRT versus PRT extend previous studies suggesting a potential neuroprotective benefit of PRT for cognitive skills.24-27 Given previous associations of cognitive impairment with poor social outcomes,12 it was expected that the XRT group would have significantly lower social outcomes than the PRT group as a function of lower cognitive performance. Indeed, Gross and colleagues26 identified significant differences between radiation groups on a measure of adaptive social functioning, suggesting that survivors treated with PRT have more favorable social outcomes relatives to those treated with XRT. However, the present findings suggest that RT modality may be a less important driver of long-term social outcomes than other treatment variables. Longer time since RT and shunt placement were significant correlates of survivor peer relation difficulties, and tumor diameter emerged as a significant predictor of social skills in the multiple linear regression model. These results echo early findings of worse parent-rated social skills for survivors with greater time since diagnosis40 and suggest that disease factors and illness complications (e.g., tumor size, hydrocephalus) are impactful for long-term social outcomes, potentially more so than RT modality. Further investigations will benefit from consideration of specific treatment factors as well as broader aspects of brain tumor diagnosis and treatment (e.g., school absences, internalizing and externalizing symptoms associated with medical trauma, changes in family dynamics) as potentially meaningful influencers of survivor social outcomes.
The present study has several clinical implications. First, the social challenges observed in the present sample were documented at long-term follow-up, indicating that late effects of brain tumor diagnosis and treatment likely include social deficits that occur well into survivorship. Further, the finding of social difficulties among survivors in both RT groups supports the need for careful monitoring of social adjustment regardless of radiation modality. Models and guidelines for the neuropsychological care of survivors41 should therefore emphasize continued surveillance and monitoring of social functioning, even in light of potential neurocognitive sparing associated with PRT. The recent social limitations and isolation resulting from COVID-19 precautions likely place survivors at even greater risk for social adjustment challenges. Additionally, results suggest that survivors with cognitive impairments at follow-up, particularly in verbal memory, may be at heightened risk for social difficulties. It is also notable that peer relations, not social skills, emerged as the greater area of concern for survivors. This encourages careful consideration of assessment methods, with measures that directly inquire about friendships and social acceptance potentially capturing a broader picture of survivor social functioning than those evaluating social skills. Direct questions regarding survivor friendships in an interview format, such as the approach utilized by Hocking and colleagues, 3 may also provide opportunities to offer clarification and thereby identify a greater number of survivors with social difficulties compared to parent rating measures alone.