Multivariable analyses and propensity score matching were performed to consider other clinical factors.<h4>Results</h4>A <i>CDKN2A/B</i> hemizygous deletion was identified in 24/215 patients, including 22/116 with astrocytoma and 2/99 with oligodendroglioma. This evidence concerns the gene CDKN2A and astrocytoma (excluding glioblastoma).