Olaparib and Temozolomide in Treating Patients With Relapsed Glioblastoma

DISEASE CHARACTERISTICS: * Histologically confirmed grade IV glioblastoma * Radiological diagnosis of recurrent or progressive disease according to Response Assessment in Neuro-Oncology Working Group (RANO) criteria, which is suitable for palliative resection * Must have an adequate amount of tumor tissue available * Previously received first-line treatment with radical radiotherapy, or chemoradiation followed by adjuvant chemotherapy * No prior chemotherapy for recurrent disease PATIENT CHARACTERISTICS: * WHO performance status 0-2 * Life expectancy \> 12 weeks * Hemoglobin ≥ 10.0 g/dL * Absolute neutrophil count ≥ 1.5 x 10\^9/L * Platelet count ≥ 100 x 10\^9/L * Serum bilirubin ≤ 1.5 times upper limit of normal (ULN) * ALT or AST ≤ 2.5 times ULN * Calculated creatinine clearance ≥ 50 mL/min OR isotope clearance measurement ≥ 50 mL/min (uncorrected) * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use one (male) or two (female) highly effective forms of contraception 4 weeks prior to, during, and for 6 months after completion of study therapy * Able to swallow and retain oral medications * Not at high medical risk due to non-malignant systemic disease, including active uncontrolled infection * No known hepatitis B, hepatitis C, or HIV seropositivity * No concurrent congestive heart failure, prior history of NYHA class III-IV cardiac disease, prior history of cardiac ischemia, or prior history of cardiac arrhythmia within the past 12 months * No grand mal seizures occurring ≥ 3 times per week over the past month * No gastrointestinal disorders likely to interfere with absorption of the study medication * No known hypersensitivity to any of the components of olaparib * No known hypersensitivity to temozolomide (TMZ) or any of its components, or to dacarbazine (DTIC) (for patients enrolled in stage 2 study only) * No known lactose intolerance (for patients enrolled in the stage 2 study only) * No metal fragments in the eyes (shrapnel or bullet injuries are excluded on the basis of their unsuitability to undergo MRI scans) * No other condition which, in the Investigator's opinion, would not make the patient a good candidate for the clinical trial EXCLUSION CRITERIA: * See Disease Characteristics * No ongoing toxic manifestations from previous treatments except for alopecia or grade 1 toxicities which, in the opinion of the Investigator and the Drug Development Office (DDO), should not exclude the patient * At least 12 weeks since prior radiotherapy, endocrine therapy, or immunotherapy * At least 6 weeks since prior major surgery * At least 4 weeks since prior chemotherapy * At least 4 weeks since prior immunizations with live vaccines (or expected to receive vaccines during the trial and up to at least 6 months after receiving last study treatment), including BCG and yellow fever vaccines * No prior PARP inhibitors, including olaparib * No prior major thoracic or abdominal surgery from which the patient has not yet recovered * No prior heart surgery * No pacemakers * No change to systemic steroids dose within 5 days prior to enrollment (i.e., must be on a stable dose at time of enrollment and remain on a stable dose throughout the treatment period) * No herbal supplements and/or ingestion of foods known to modulate CYP3A4 enzyme activity from time entered on screening period until 28 days after the last dose of study medication * No concurrent drugs known to be potent inducers of CYP3A4, including phenytoin, carbamazepine, phenobarbital, rifampicin, rifapentine, rifabutin, nevirapine, modafinil, or St. John wort (wash-out period for phenobarbital is 5 weeks, 3 weeks for all others) * No concurrent drugs known to be potent inhibitors of CYP3A4, including ketoconazole, itraconazole, ritonavir, indinavir, saquinavir, telithromycin, clarithromycin, or nelfinavir (wash-out period is 1 week) * No concurrent or planned participation in another interventional clinical study * Participation in an observational study is acceptable * No concurrent warfarin (patients requiring anticoagulation should be given subcutaneous low molecular weight heparin) * No other concurrent anticancer therapy (including radiotherapy) or investigational drugs * No blood transfusions within 4 weeks prior to study start of features suggestive of myelodysplasia or AML