EGFR Inhibition Using Weekly Erlotinib for Recurrent Malignant Gliomas

Inclusion Criteria: * Histologically confirmed intracranial malignant glioma of the following types: Glioblastoma (GBM), Gliosarcoma (GS), Anaplastic astrocytoma (AA), Anaplastic oligodendroglioma (AO), Anaplastic oligoastrocytoma (AOA, also called anaplastic mixed gliomas or AMG), High grade glioma not otherwise specified (NOS). * EGFRvIII mutation detected on pretreatment tissue from at least 1 prior surgery. * At least 15 unstained slides or at least 1 tissue blocks must be collected from at least one prior surgery. * Recovered from toxic effects of prior therapies. * Able to undergo contrast enhanced MRI scans (or CT scans for patients unable to tolerate MRI). * Shown unequivocal evidence for contrast enhancing tumor progression by MRI (or CT for patients who cannot tolerate MRI) in comparison to a prior scan. * Age \> or = 18 years. * Karnofsky Performance Status \> or = 60%. * Life expectancy of \> 8 weeks. * Normal organ and marrow function, adequate liver function and adequate renal function before starting therapy. * Women of child-bearing potential and men must agree to use adequate contraception. * Women of childbearing potential must have a negative pregnancy test documented within 7 days prior to treatment. * Women must agree not to breast feed. * Ability to understand and the willingness to sign a written informed consent document. * Ability to swallow the tablets. Cohort A (medical) specific inclusion criteria: * Fulfill all of the general inclusion criteria. * MRI/CT must demonstrate measurable enhancing tumor of at least 1cm2 in cross-sectional area to allow assessment of radiographic response, unless: measurable disease is not present because the patient underwent gross total resection as the most recent anti-tumor therapy. * At least 3 months have elapsed between any prior brain radiotherapy and initiation of study therapy. * MRI/CT must demonstrate measureable enhancing tumor at least 1cm by 1cm squared in cross-sectional area to allow assessment of radiographic response. * Stable or decreasing dose of corticosteroids for a minimum of 5 days before the baseline MRI/CT. * The baseline MRI/CT must be performed on the 14th day or less prior to initiation of study treatment. Cohort B (surgical) specific inclusion criteria: * Fulfill all of the general inclusion criteria. * An MRI/CT scan showing progression is required. Exclusion Criteria: * Received prior treatment with convection enhanced delivery, other catheter based intratumoral treatment, or carmustine (BCNU)/Gliadel wafers. * Prior therapy that included stereotactic radiosurgery during therapy for newly diagnosed or recurrent disease, or re-irradiation of any type, must have confirmation of true progressive disease rather than radiation necrosis based upon surgical documentation of recurrent/progressive disease. * Prior treatment with an EGFR inhibitor. * Received prior treatment with direct Vascular endothelial growth factor (VEGF)/Vascular Endothelial Growth Factor Receptors (VEGFR) inhibitors. * Smoking or plan to smoke tobacco or marijuana during study therapy. * Receiving any other investigational agents concurrently with study treatment. * Taking Enzyme Inducing Anti-Epileptic Drug (EIAED). If previously on an EIAED, the patient must be off of it for at least two weeks prior to study treatment. * History of allergic reactions attributed to compounds of similar chemical or biologic composition to erlotinib. * Uncontrolled intercurrent illness that would limit compliance with study requirements. * Have HIV and are receiving combination antiretroviral therapy. * Other active concurrent malignancy.