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.