Montreal researchers develop new tool to fight the ‘Terminator’

Montreal researchers have developed a new tool to fight glioblastoma, a brain cancer so ruthless that some call it the ‘Terminator’.

Modern medicine is essentially powerless against glioblastoma, and patients’ life expectancy is only a year or two after diagnosis.

The goal of the new tool, called Sentry, is to improve this statistic by helping surgeons remove as many cancer cells as possible before they can regenerate.

“Glioblastoma is a very aggressive cancer. The prognosis for patients depends largely on the amount of tumor that remains after surgery,” explained Dr. Kevin Petrecca, head of neurology at the McGill University Health Centre (MUHC).

“Radiation and chemotherapy are not curative. But if we can reduce the number of cancer cells to a very small number, it is possible to achieve very good long-term survival rates, and that is what motivated the development of this device.”

The problem with this surgery is that “the tumor has no margin; it is a type of cancer without margins,” he added. Therefore, when the surgeon tries to remove the tumor, it is difficult to distinguish between cancerous tissue and normal brain tissue. And obviously, when it comes to normal brain cells, “it is not desirable to remove them because of the deficits that this would cause for patients,” said Dr. Petrecca.

Sentry looks like a pencil that the surgeon uses to touch tissue of uncertain nature. Sentry sends out lasers that are modified by the nature of the tissue, which tells the surgeon what it is.

Sentry uses artificial intelligence to compare the tissues it comes into contact with to thousands of samples. This allows it to distinguish cancer cells from healthy cells with great accuracy, helping the surgeon remove more diseased cells while leaving the rest of the brain intact.

“We trained the tool for several years for glioblastomas,” said Professor Frédéric Leblond of Polytechnique Montréal. “But in the last year, we have found that the AI we developed for glioblastomas can be generalized to all brain tumors.”

Researchers have also been able, added Leblond, to “demonstrate, through clinical studies, that it is useful for other diseases.” For example, the tool could identify breast cancer, lung cancer, prostate cancer, and colorectal cancer.

When Dr. Petrecca tested the tool on about 20 patients, he achieved a success rate of nearly 100 per cent with glioblastoma and glioma (a less aggressive form of brain cancer), a result that exceeded the researchers’ expectations.

“For us, there has been something of a paradigm shift in recent months,” said Professor Leblond.

A patient who undergoes surgery for glioblastoma can expect to survive between 12 and 18 months if the surgeon is unable to remove all of the cancer. If the surgeon is able to completely remove the visible part of the tumor, life expectancy increases to two or three years, said Dr. Petrecca.

But it is possible to go even further and perform what doctors call a “supratotal resection,” or “super total resection,” in which the surgeon removes brain cells that appear healthy but have likely been infiltrated by cancer.

Life expectancy then increases to five or six years, and about a quarter of patients who undergo supratotal resection can expect complete remission.

“I think we can improve that and get it up to 40 per cent,” concluded Dr. Petrecca. “(Sentry) gives us hope for long-term survival. Ten years ago, glioblastoma was nicknamed ‘Terminator’, and we are trying to change that to achieve very good results, even cures, for nearly 40 per cent of the population. That’s huge. There aren’t many other technologies, devices, or drugs that can achieve such results for such an aggressive form of cancer.”

Researchers are currently working to obtain all the necessary regulatory approvals so that Sentry can be used to combat the Terminator in operating rooms around the world as quickly as possible. The powerful U.S. Food and Drug Administration is reportedly planning to grant it priority review status.

–This report by La Presse Canadienne was translated by CityNews