Long-Term Neurological Outcome of Childhood Brain Tumors Treated by Surgery Only

Authors: Sonderkaer S, et al.
Source:JCO, 21(7), 2003, pg 1347-1351

Background

• Intracranial tumors are common in pediatric patients, relative to other childhood malignancies
• The results have improved in the treatment of these tumors, with more patients therefore experiencing late toxicity from treatment
• The focus of treatment-related late effects has been on chemotherapy and radiation, with little attention paid to patients treated with surgery alone
• This study was done with the population being children who had surgery alone (hence benign disease or low grade tumors) to evaluate the effect of surgery on the long term functioning of these patients

Materials and Methods

• The study group consisted of 65 patients, diagnosed and treated before the age of 15
• Evaluation included chart review, physical examination, and neurological examination by two physicians
• Scoring of function was: I-no disability, II-mild disability, not interfering with everyday functioning, III-disability that interfered with everyday functioning, IV-severe disability with limited or no self-care
• 51 patients had low grade astrocytomas, 3 patients had craniopharyngiomas, and the rest had benign tumors
• 50% of the tumors were located in the posterior fossa, 33% were located in the cerebral hemispheres, and 14% were midline tumors
• 50 patients had complete resections, 12 had partial resections, and 3 had biopsies only
• A total of 13 patients had 2 separate craniotomies
• Median follow up was 10.7 years

Results

• Ataxia was the most common symptom noted on follow up examination, with a total of 22 patients exhibiting some ataxia. This is a fair number, though 31 patients actually had problems with ataxia (presumably from the tumor itself) preoperatively. Seventeen of the 22 patients who had ataxia at follow up had ataxia initially. Hence, 5 patients developed this symptom independent of the tumor presentation itself.
• Eight patients had seizure problems at follow up, compared to 18 patients who had seizures at diagnosis. Three patients with seizures at follow up had no problems initially.
• Cranial nerve palsies were much more common at follow up, with only eight patients with palsies at diagnosis, compared to 18 at follow up.
• Hemiparesis was also more common at follow up when compared to preoperatively. However, the numbers of patients are small
• Visual disturbances (including blindness) was the most common symptom caused by surgery.
• At follow up, only 20 patients (31%) had no deficits (score I). However, this is compared to only two patients who had no symptoms preoperatively
• Only one patient had a score of IV
• For an unknown reason, the score was related to sex, as female patients had worse scores, most pronounced in the 10-14 age range

Authors' Conclusions

• Only 31% of patients who undergo surgical resection alone for a brain tumor are free of neurological deficits at follow up
• Most of the patients who had deficits had the same deficits preoperatively, though surgery was obviously not without consequence
• The most common symptoms that seemed to be induced by treatment were cranial nerve palsies and visual disturbances

Scientific Implications

This is a very important study that reports on the long-term toxicity of a brain tumor in the pediatric population. Specifically, these patients did not have radiation or chemotherapy. These two modalities, especially radiation therapy, are usually blamed for the long-term problems that pediatric patients experience. This reports shows that treatment with surgical resection alone has long-lasting implications. Further, it is also shown that the tumor itself is responsible for the majority of problems-presumably by mass effect inflicted on the normal tissues prior to treatment. The authors should be commended for performing this study, as any quality of life or subjective type long-term study is fraught with chances for error and bias. It points out that simply having a brain tumor is detrimental to a child's long-term health-even if cure is achieved. It should be kept in mind that this included physical and neurological toxicities only, and no attempt was made to investigate cognitive or psychological well-being, which could also very easily have been affected by this extremely stressful life event.