Decrease in motor performance in children with cancer is independent of the cumulative dose of vincristine.

BACKGROUND

Impaired performance on motor tasks in children treated for acute lymphoblastic leukemia (ALL) after completion of treatment is often attributed to vincristine (VCR). Whether motor problems persist in other children who receive different cumulative doses of VCR is to the authors' knowledge not known. The objective of the current study was to determine the extent of motor problems in children with ALL, Wilms tumor (WT), B-cell non-Hodgkin lymphoma (B-NHL), and malignant mesenchymal tumors (MMT) and whether these motor problems were related to VCR dose.

METHODS

In 128 children ages 4-12 years who completed treatment after at least 1 year, motor performance was measured using the Movement Assessment Battery for Children (m-ABC).

RESULTS

The m-ABC scores of the total study group were significantly lower than those of the normal population (P < 0.001). There were no differences in scores noted between children with ALL, WT, B-NHL, or MMT. There also were no differences noted between those children with ALL who had received pulses of VCR and steroids during maintenance therapy and those who had not. All groups demonstrated large variability in scores. Scores were not found to be significantly different between those children who had received low (< 20 mg/m(2)), intermediate (20-40 mg/m(2)), or high (> 40 mg/m(2)) cumulative doses of VCR. Cumulative doses of corticosteroids and methotrexate did not affect scores, nor did age at diagnosis and time since the completion of therapy.

CONCLUSIONS

Although motor performance was impaired in all patient groups, no correlation was found between motor performance and the cumulative dose of VCR or other drugs, age, and follow-up time. Future studies have to address several issues, including whether polymorphisms in drug metabolizing genes or drug target genes explain the significant variability noted in the long-term motor outcome of children with cancer.