Prognostic significance of multiple genetic lesions on chromosomes 19, 10, and 17 in oligodendrogliomas

: Patients diagnosed with oligodendrogliomas/oligoastrocytomas and with somatic loss of genes on chromosome 19q13.2-q13.3 survived for >5-6 years, a survival period typical of the tumors of oligodendroglial origin. One patient with oligoastrocytoma, harboring allelic loss on chromosome 10p in the tumor DNA, had a recurrence five years later with progression to anaplastic astrocytoma. However, another patient with oligoastrocytoma, whose tumor suffered multiple genetic lesions on chromosomes 19q13.2-13.3, 10q22-24, and 17p13.1 (a point mutation in the p53 gene), had two subsequent recurrences as anaplastic astrocytomas and a survival period of 29 months. Our data suggest that in tumors of oligodendroglial origin the inactivation of a tumor suppressor gene on chromosome 10, especially in conjunction with other genetic aberrations, is indicative of aggressive clinical course.