Improving 5-year Survival in Glioblastoma Requires more Aggressive Treatments

Glioblastoma with extreme nuclear enlargement.
Glioblastoma with extreme nuclear enlargement.

Despite improvements in median and short-term survival rates for patients with glioblastoma, also known as glioblastoma multiforme (GBM), the most common form of brain tumor in adults, the percentage of patients achieving five-year survival remains low, according to researchers at the Mayo Clinic.

This is the conclusion of a study to be published next month in Mayo Clinic Proceedings, a monthly peer-reviewed medical journal that publishes original articles and reviews dealing with clinical and laboratory medicine, clinical research, basic science research, and clinical epidemiology.

The authors of the new study noted that little has changed in terms of five-year survival ? only 5.5% of patients live for five years after diagnosis ? and calls for more aggressive treatments to be considered for all glioblastoma patients.

Malignant Primary Brain Tumors

Gliomas represent about 75% of malignant primary brain tumors, according to previous studies, and glioblastoma, grade 4 glioma, is among the most aggressive forms of cancer. The retrospective analysis evaluated 48,652 cases included in the National Cancer Database, a clinical oncology database sourced from hospital registry data that are collected in more than 1,500 Commission on Cancer (CoC)-accredited facilities which is jointly sponsored by the American College of Surgeons and the American Cancer Society.

Daniel M. Trifiletti, MD, a radiation oncologists at the Mayo Clinic in Jacksonville, Florida, specialized in the treatment of brain tumors.
Daniel M. Trifiletti, MD, a radiation oncologists at the Mayo Clinic in Jacksonville, Florida, specialized in the treatment of brain tumors.

Looking at data from January 2004 through December 2009, the researchers found that 2,249 patients survived at least five years after diagnosis.

Among those who reached five-year survival, the median length of survival was 88 months. Patients who did not survive five years had a median survival of just seven months.

Revolutionary treatment

“The introduction of chemotherapy in the treatment of glioblastoma was revolutionary, although this research suggests that chemotherapy serves more as a temporizing measure against disease recurrence and death,” noted Daniel Trifiletti, MD, a Mayo Clinic radiation oncologist and senior author of the study.

“Considerable work needs to be done to provide hope for patients with glioblastoma,” Trifiletti added.

The study involved oncology, radiation and biomedical statistics researchers from Mayo Clinic’s Florida and Minnesota campuses, and East Tennessee State University.

According to the study, factors associated with five-year survival included age, race and gender. Those who achieved five-year survival were relatively younger adults, female and nonwhite. Other factors included generally good health, higher median income, tumors that were on the left side of the brain or outside the brainstem, and treatment with radiotherapy. Contrary to previous studies, tumor size did not appear to affect the odds of long-term survival significantly.

The findings suggest that more aggressive treatments that focus on long-term survival will be needed.

“Although it is uncertain how this may be achieved, it likely will require novel and radical approaches to treatment of the disease,” Trifiletti explained.

The study recommends that nearly all patients should be offered enrollment in a clinical trial.

Trifiletti observed that there are several new studies underway testing promising new surgeries, radiation techniques and drug therapies. “To me, the most exciting area is in cellular therapy,” he says.

“In my lab, I am evaluating the possibility of using targeted cellular therapy as an agent that can synergize with existing therapies, including radiation,” he concluded.