From left: Prof. Andrew Kaye, Director of The Royal Melbourne Hospital
Department of Neurosurgery; Prof. Tali Siegal, Director of Hadassah’s
laboratory. Dr. Siegal and Dr. Lavon visited Royal in August.
By Dr. Elizabeth Finkel*
In warfare strategic alliances can make all the difference and what is true for the battleground is true for the fight against brain cancer. Now cancer researchers at
To translate scientific research into cures, researchers need to share their expertise and their patients. That is exactly what Kaye is up to with Professor Tali Siegal and Dr. Iris Lavon, who visited RMH last week. Siegal, a neurologist-researcher is Director of Hadassah’s Neuro-oncology centre; Lavon heads the research laboratory. The pair are paying Kaye a return visit after he and other
While many types of cancers are yielding to modern therapies, brain cancer has remained one of the most resistant. Part of the problem is that researchers do not have a sensitive way to monitor their treatments. Unlike the lung or bowel, it is extremely hard to get an accurate picture of what is going on in the brain. The mainstay technique, MRI, is a blurred lens. Not only is it unable to detect tumours less than 5 mm in size, it fails to distinguish between tumours and local inflammation. This becomes a problem in the follow-up period after chemotherapy and radiotherapy. A suspicious shadow on an MRI scan often turns out to be inflammation not cancer, meaning the patient has been put through risky surgery for no reason. “Many times we have a dilemma, we have endless arguments,” says Siegal.
A blood-based test to detect brain cancers is “the holy grail”, says Kaye. Often cancers do leave clues to their existence in the bloodstream; they shed cells, proteins or even DNA. In prostate cancer, for instance, the protein PSA is used as a marker for the cancer. But so far there is no equivalent for brain cancer. Hadassah and RMH are forging a partnership in this quest. Kaye’s laboratory has focussed its efforts on cells that can sprout into blood vessels, so-called endothelial cells. In patients with cancer, these cells are commonly found circulating through the bloodstream and might provide the hoped-for “marker” for brain cancer. On a different front, Hadassah researchers are developing a test to detect the DNA of cancer cells.
As Lavon explains, cancers not only grow more prolifically than other cells, they also die more prolifically. When cancer cells disintegrate some of the debris ends up in the bloodstream as DNA. Like a fingerprint, the DNA of a cancer cell is specific for that cancer. For instance a type of brain cancer known as oligodendroglioma tends to lose particular bits of its DNA in specific regions of chromosomes 1 and 19. Another known as glioblastoma tends to lose methyl groups from a gene called MDMT.
Over the past three years Lavon tested these DNA markers in blood samples and in brain tissue specimens of patients. She was indeed able to detect the same DNA signature in the brain tissue and the bloodstream of the patient, results that will be published shortly in the journal Neuroncology. Now the key question is: how early can these blood-borne DNA signatures be detected in the course of the disease? To answer that question as quickly as possible, the
For these combatants against brain cancer this is just the beginning of a powerful strategic alliance. “I see great synergies that can be developed; this is the first step,” says Kaye.