According to recent results published in Clinical Cancer Research, patients with glioblastoma who were treated with a combination of vaccination and chemotherapy lived longer and had cancer progression significantly delayed compared to patients treated with either approach alone.
Approximately 17,500 people are diagnosed with primary brain cancer in the United States each year. Primary brain cancer is cancer that originates in the brain and has not spread from cancer already located elsewhere in the body. Glioblastoma is one of the most common, and fatal, types of primary brain cancer. Glioblastoma is cancer of the glial cells, which are the most abundant cells in the nervous system. Glial cells perform many functions in the brain. One important role is providing support for neurons, the cells that transmit impulses between the brain, spinal column and nerves.
Standard treatment options for glioblastoma consist of surgical removal of the cancer if possible, radiation therapy and/or chemotherapy. However, the majority of chemotherapy agents cannot penetrate the blood-brain barrier. The blood-brain barrier is a membrane that surrounds the brain and spinal cord and protects the brain and nervous system by allowing only very select molecules to pass through. Thus, even with the most aggressive treatment available, most patients will survive less than one year after diagnosis.
Because of the difficulties with chemotherapy in the treatment of brain cancers, researchers have turned to vaccines. Cancer vaccines work by mobilizing the patient’s own immune system against the tumor. Unfortunately, researchers have not found a significant clinical benefit with vaccines alone, and they are evaluating vaccines in combination with chemotherapy.
In the recent Cedars-Sinai study, a small group of patients with glioblastoma were treated with vaccine plus chemotherapy (13), vaccine alone (12), or chemotherapy alone (13).
The patients who were treated with the combination lived longer on average (26 months) than those who received vaccine alone (18 months) or chemotherapy alone (16 months). Furthermore, the patients who received the combined treatment experienced a high rate of tumor regression (>50%) that is rarely seen in brain tumors and lived longer than is commonly seen with glioblastoma; 42% of patients lived 2 years and 18% lived 3 years.
Reference: Christopher J. Wheeler, Asha Das, Gentao Liu. Clinical responsiveness of glioblastoma multiforme to chemotherapy after vaccination. Clinical Cancer Research. 2004; 10: 5316 – 5326.