Cerebrospinal Fluid Levels of Erlotinib in Patients Receiving Erlotinib For Stage III Non-Small Cell Lung Cancer

DISEASE CHARACTERISTICS:

Patients must be enrolled in the trial: "A Phase I/II Trial of Neoadjuvant Paclitaxel, Carboplatin and OSI-774 (Tarceva) with Concurrent Accelerated Hyperfractionation Radiation Followed by Maintenance Therapy with OSI-774 for Stage III Non-Small Cell Lung Cancer," Principal Investigator: T. Mekhail, M.D.

Patient must be in maintenance therapy phase of the study and have received erlotinib for ≥ 1 week
No known CNS primary or metastatic cancer at any time prior to time of enrollment
No MRI evidence of pathological enhancement at the time of study entry

PATIENT CHARACTERISTICS:

Patients must use adequate birth control measures while in the study
No significant side effects to erlotinib that require dose reduction or interruption

None of the following medical issues which could make a lumbar puncture unsafe:

Platelets < 100,000/mm³
INR > 1.1
Known bleeding dyscrasia
Absolute neutrophil count < 1,500/mm³
Ongoing systemic bacterial infection

PRIOR CONCURRENT THERAPY:

Patients on modest or anti-epileptic therapy must be on nonenzyme-inducing drug only, including any of the following:

Neurontin
Lamictal
Depakote, Depakene
Felbatol
Keppra
Gabitril
Topimax
Zonegran
No concurrent enzyme-inducing anti-epileptic drugs such as phenytoin, carbamazepine, or phenobarbital
No concurrent other drug known to affect the metabolism of erlotinib
No concurrent anticoagulant therapy