Detecting Malignant Brain Tumor Cells in the Bloodstream During Surgery to Remove the Tumor

Overview

Glioblastomas, the most frequent malignant brain tumor in adults, are widespread in the brain, despite their discrete appearance on computed tomography (CT) or magnetic resonance imaging (MRI). While this tumor tends to spread widely in the brain, unlike other tumors of the body, it rarely metastasizes, or spreads, to other organs. Approximately 10 percent of patients with glioblastoma develop metastatic disease after radiation or brain surgery. In the absence of radiation or brain surgery, few patients have developed disease spread outside the brain. During surgery to remove tumors of other organs of the body, such as the lung, prostate, kidney, or ovary, cells from these tumors are routinely found in the bloodstream. These cells are believed to be the reason for the spread of these tumors. In the case of malignant brain tumors, this process of glioma (tumor) cells shedding into circulation has not yet been investigated. This study will determine whether glioma cells can be detected in the bloodstream of patients undergoing surgery. If glioma cells are absent, it may mean they are unable to penetrate the blood-brain barrier. If they are present, they presumably can penetrate into blood vessels but they may be recognized and eliminated by the immune system, or they may escape detection yet not be able to take hold in the new microenvironment. The results of the study will add to the knowledge of the biology of these highly malignant tumors. Study participants will be admitted to the hospital for 8 to 10 days. They will undergo a complete physical and neurological exam and blood and urine tests. An electrocardiogram will be performed, and x-rays may be taken. On the morning of surgery, the patient will receive sedation intravenously. A tiny plastic tube called a catheter will be introduced into a vein in the groin through needles. The catheter will be passed through to the jugular bulb, right above the jugular vein, on the same side as the tumor. The patient will then be taken to the operating room for surgery. During surgery, not more than one quarter of a unit of blood will be removed through the catheter. The catheter will be removed before the patient enters the intensive care unit. Another MRI will be taken after surgery. The study will enroll participants for 2 years. Patients will be followed at 3 months and 6 months after the surgery to make sure the postoperative period is uneventful.

Glioblastomas are the most frequent malignant brain tumor in adults and are widespread in the brain despite their discrete appearance on CT or MRI. While locally aggressive, metastasis of glioblastoma to extracranial organs is considered rare. Approximately 10% of patients with glioblastoma develop metastatic disease after radiation or craniotomy. Few patients have developed extracranial metastatic disease in the absence of surgical resection or radiation. Unlike tumors of other organs such as lung, colon and prostate, the presence of glioma cells in the circulation of patients undergoing surgical resection has not been established. If found absent, glioma cells may be unable to intravasate through the blood brain barrier. If present, these tumor cells presumably can intravasate but may be recognized and eliminated by an immunological process, or they may escape detection yet not be able to take hold in the new microenvironment. The information provided will add to the knowledge of the biology of these highly malignant tumors.