This study will examine patients with non-small cell lung cancer metastasis, that is, the distant spreading of tumors to the brain, and compare them with patients without brain metastasis. The molecular and genetic events that permit tumor metastasis are not well understood. There is intense investigation going on into the process in which tumor cells escape the primary local tumor, spread to distant places in the body, and find and create conditions that promote growth in those tissues. Metastasis of tumors such as lung cancer to the brain is a common problem. Tumor cells will be analyzed with the use of microarrays. A microarray is a tool for analyzing gene expression, consisting of a small membrane or glass slide containing samples of many genes arranged in a regular pattern. The goal is to identify a potential molecular signature. It is hoped that there will be discovery of why some patients are more likely than others to develop a brain metastasis, which can have a major negative effect on the quality of life and survival.

Patients 18 years of age with known or evidence by radiology of a non-small cell lung cancer metastatic to the brain, either squamous cells or adenocarcinoma tumors, or those who have had a removal of a brain tumor for diagnosis or treatment may be eligible for this study.

Participants will undergo the following procedures and tests:

• Craniotomy, that is, surgical opening of the skull, and removal of the brain tumor.
• Blood specimens taken from a central vein or artery before the operation, throughout as needed, and for several days afterward, to measure blood chemistries, blood count, and so forth.
• Physical examination and imaging of the central nervous system before and after surgery.
• Urine or serum, or both, pregnancy test of women of childbearing potential.

Patients will also undergo blood tests at 3-month intervals after surgery for up to 5 years. The purpose is to determine if there are tumor cells in the blood, which may explain how they reached the brain.