Tragically Hip lead singer Gord Downie has been diagnosed with glioblastoma, "one of the most aggressive forms of brain cancer," James Perry, the neuro-oncologist treating him, revealed at a press conference at Sunnybrook Health Sciences Centre in Toronto on Tuesday.
What it is
Glioblastomas are the most common form of malignant brain tumours in adults, according to the Canadian Cancer Society. They are typically found in the cerebral hemispheres and they grow quickly. Every day, 27 Canadians are diagnosed with this form of cancer and the cause is unknown.
"It's amongst the deadliest of tumours that we get," D.J. Cook, a neurosurgeon at Kingston General Hospital who performed surgery on Mr. Downie, said in an interview. "It is one that we don't have a cure for."
There are two types of glioblastomas: primary, which form and start to cause symptoms rapidly, and secondary, which often start more slowly before building up.
Mr. Downie has a primary glioblastoma in the left temporal area of the brain.
Patients with a primary glioblastoma are typically diagnosed after experiencing symptoms, including seizures, neurological deficits and stroke-like symptoms. In Mr. Downie's case, his tumour was discovered after he suffered a seizure while walking down the street in Kingston last December, Dr. Perry said.
Dr. Cook was able to remove most of the tumour, allowing doctors to examine it and come up with a treatment plan.
Treatment and next steps
Many patients with glioblastomas will follow a similar treatment pattern: surgery, radiation and chemotherapy to relieve pressure in the brain, control the symptoms and prolong survival.
After surgery, Mr. Downie underwent six weeks of daily Monday-to-Friday radiation treatments combined with an oral chemotherapy drug called temozolomide.
Dr. Perry said the good news is that Mr. Downie has a type of glioblastoma that is known to respond well to treatment. He has a specific genetic marker – positive MGMT methylation status – that can translate into "significantly longer survival," the doctor said.
He said Mr. Downie's cancer should not preclude him from participating in the Tragically Hip's farewell tour slated for this summer. Mr. Downie will continue to receive maintenance chemotherapy and will undergo magnetic resonance imaging (MRI) scans to monitor the tumour, Dr. Perry said.
Dr. Cook likened this type of cancer to an anthill. The tumour mass is visible, like the sandy part of an anthill. But underground, there are countless ants crawling around far from the hill. In other words, surgery can remove most of the mass, but it can't get rid of the cancer cells that are spread to other parts of the brain. While Mr. Downie's cancer is currently at bay, eventually those cells will grow and multiply and form another tumour. At that point, the treatment plan will vary depending on the patient, the location and size of the tumour and how aggressive it is. For some patients, another round of surgery will be appropriate. Eventually, those treatment options will be no longer viable.
"At some point the benefits of doing surgery to remove additional tissue actually just will render an individual in worse condition," Dr. Cook said.
Dr. Perry was careful to avoid discussion of Mr. Downie's life expectancy, as each individual is different and many variables are involved.
For now, the disease is under control. Dr. Cook said that patients who go through treatment without complications, as Mr. Downie has, "can enjoy a good quality of life for a period of time."
He said Mr. Downie is "in great condition and great spirits and is doing extremely well."
Numerous research institutes around the world are conducting trials to improve survival and search for better treatments, but at this point, there is no cure. According to the American Brain Tumor Association, the median survival for patients – meaning the time at which the number of patients who have died is equal to the number that have survived – with a glioblastoma and undergoing his treatment regimen is 14.6 months. The two-year survival rate is 30 per cent.
The MD Anderson Cancer Center in Texas says the recurrence rate for glioblastomas is close to 100 per cent, with the average recurrence time being about six or seven months.
Despite the grim prognosis, Dr. Cook says understanding of this form of brain cancer has "come a long way" in the past two decades. Better treatments are giving patients more time and researchers are focused on finding a cure.
"Every university centre, essentially, has a lab that's studying its pathology and aspects of it," Dr. Cook said. "As with any cancer, it is inherently difficult to treat because it is a disease process that adapts and changes and works around the therapies that you build against it."