As a neurosurgeon regularly treating glioblastomas, Dr. Adam Sonabend followed with interest the rise of immunotherapy, a new way to help cancer patients utilize the power of their own immune systems.
But until now, not much promise has been shown for patients with glioblastomas, an aggressive type of brain tumor that has no cure.
“It’s a terrible disease,” he said.
A new study by Sonabend, a neurosurgeon, and colleagues at the Northwestern University Feinberg School of Medicine, where he is associate professor of neurosurgery, showed, however, that some patients might benefit from immunotherapy.
Sonabend was drawn to glioblastoma research out of the frustration with the limits of his job. As a surgeon, he said, “I can improve patient symptoms; I can make them feel better.” But with glioblastomas, “It always comes back.”
Glioblastoma patients can be treated with radiation and chemotherapy, but the cancer recurs, and unlike other cancers, there are no treatments available that can prolong survival upon recurrence.
About 12,000 cases of glioblastoma are diagnosed each year; symptoms can include seizures, headaches, blurred vision and confusion. It’s an aggressive type of cancer that can occur in the brain or spinal cord. It is not curable and has a median survival of about 21 months, according to the study.
Meanwhile, advances toward other cancers have found promise through immunotherapy, a type of treatment that helps the body’s immune system fight cancer. Cancer cells have learned to brake the immune system to prevent it from attacking cancer cells, allowing them to replicate. Immunotherapy treatments essentially release the brakes that cancer puts on immune cells.
Glioblastoma is the type of cancer that Sen. John McCain, Sen. Edward Kennedy and Beau Biden (son of President Joe Biden) were diagnosed with; Cary resident Lea Grover wrote a blog about her husband’s 13-year experience with the disease.
In Illinois, doctors have been using immunotherapy treatments in different ways.
Sonabend and his colleagues hope their research can help immunotherapy options become more easily available to brain tumor patients.
“That’s the exciting part of this discovery. This is really signaling which patients might benefit from this immunotherapy,” he said.
Researchers were able to identify a mutation, reported in a previous study, within some patients’ tumors that seemed to help them benefit from immunotherapy.
Right now, glioblastoma patients don’t get immunotherapy because doctors can’t tell who might benefit from it.
Previously, several clinical trials with glioblastoma patients tested for effects of immunotherapy, but didn’t show an overall extension of survival. But a subset of patients did show a robust response.
Sonabend and researchers studied this subset to see if there was something different about them.
They found a biomarker, identified as phosphorylated ERK, that could help inform which patients’ lives could be prolonged. By staining tumor pieces under a microscope, they found that when a patient had a lot of that biomarker, the immunotherapy was most effective.
The research, published in the Nature Cancer journal Nov. 29, details how immunotherapy has led to “unparalleled expansion in cancer therapy leading to long-term remissions” in other cancers like melanoma, lung cancer and renal cancer.
With glioblastoma, immunotherapy’s possibilities have so far been limited.
Next up will be a clinical trial to see if patients respond. Even though any translation to treatment would take time, and this would affect only a small percentage of glioblastoma patients, Sonabend hopes it is the start of something.
“It’s all really exciting,” he said.
