Last updated January 1st 2017
Prostate cancer is the most common cancer in men, with roughly 40,000 new cases diagnosed in the UK every year, according to the National Health Service. Current treatments, such as radiotherapy and surgery, regularly cause lifelong incontinence. In addition, 90 percent of men who undergo such treatments struggle with erectile problems.
Using lasers and a drug made from deep-sea bacteria, Israeli scientists have now developed a non-surgical method to treat men in the early stages of prostate cancer, drastically improving their chances of completely eliminating the disease without the need to remove the gland.
The novel approach, which has already been tested across Europe, eliminates tumors with minimal side effects. In the treatment, doctors inject a light-sensitive drug derived from deep-sea bacteria into a patient’s bloodstream, killing cancer cells without destroying healthy tissue.
“Excellent news for men”
The treatment, called vascular-targeted photodynamic therapy or VTP, was developed by Prof. Avigdor Scherz and Prof. Yoram Salomon of Israel’s Weizmann Institute of Science, in collaboration with the privately-owned company STEBA Biotech, and additional researchers from Europe.
Results of a clinical trial in 413 patients at 47 hospitals in 10 countries across Europe, most of which were performing VTP for the first time, showed that the drug, which is activated with a laser to destroy tumor tissue in the prostate, was so effective that 49 percent of patients go into complete remission, compared to 13.5 percent in the control group. That’s almost four times more effective.
“These results are excellent news for men with early localized prostate cancer, offering a treatment that can kill cancer without removing or destroying the prostate,” Mark Emberton, a University College London urologist who led the trial, said in a statement. “This is truly a huge leap forward.”
With successful trials already completed, and the results published in academic journal The Lancet, the scientists hope that this new treatment could be offered to patients within just a few years.
From the bottom of the ocean
As reported in the published study, WST11, the light-sensitive drug used, is derived from bacteria found at the bottom of the ocean. To survive with very little sunlight, they have evolved to convert light into energy with incredible efficiency. The Weizmann scientists exploited this feature to develop WST11, a compound that releases free radicals to kill surrounding cells when activated by laser light.
No significant side effects
Men with low-risk prostate cancer are currently put under active surveillance, where the disease is monitored and only treated when it becomes more severe. Radical therapy, which involves surgically removing or irradiating the whole prostate, has significant long-term side effects, so it is only used to treat high-risk cancers.
While radical therapy causes lifelong erectile problems and incontinence, VTP only caused short-term urinary and erectile problems which resolved within three months, the researchers said. No significant side-effects remained after two years.
In the trial, only 6 percent of patients treated with VTP needed radical therapy, compared with 30 percent of patients in the control group.
“The fact that the treatment was performed so successfully by non-specialist centers in various health systems is really remarkable,” Emberton said in a statement.
Hope for the future
The VTP treatment is now being reviewed by the European Medicines Agency (EMA) for a possible license, but it likely to be several years before it can be offered to patients more widely. If the trials continue to be successful, the treatment should be applied to other cancers, including breast and liver cancer, according to the research team.
Photos and video: Weizmann Institute of Science, Darryl Leja – NHGRI, NIH