Researchers at University College London have developed a new technique to treat early prostate cancer: Vascular-targeted photodynamic therapy.
Vascular-targeted photodynamic therapy involves injecting a light sensitive drug into a patient’s bloodstream and activating the drug using a laser. The drug then destroys cancerous cells. The technique is highly targeted and has potential to radically improve the treatment of prostate cancer.
The drug is derived from deep-ocean living bacteria. The bacteria are able to convert light into energy with incredible efficiency. Researchers have used the bacteria to develop a drug called WST11, which releases free radicals to kill surrounding cells when the compound is activated by laser light.
Typically, patients who are diagnosed in the early stages of the disease are monitored and then only treated when the cancer has become severe enough to require surgery. Standard treatments for prostate cancer involve radical radiotherapy to destroy the cancer cells or surgical removal of the prostate.
Unfortunately, there are often serious side effects to current prostate cancer treatments. Patients often suffer urinary incontinence and erectile dysfunction. Both can cause considerable distress and can have a major impact on quality of life. One in five patients experience urinary incontinence as a result of prostate cancer treatment.
Vascular-targeted photodynamic therapy on the other hand only causes short term side effects. A clinical trial showed that while urinary incontinence and erectile dysfunction occurred, the issues were short-lived and only lasted up to around three months. Patients experienced no significant side effects two years after surgery was performed. The technique is also highly effective. 49% of patients who had vascular-targeted photodynamic therapy to treat prostate cancer went into complete remission (Control group 13.5%).
Only 6% of patients who had vascular-targeted photodynamic therapy later required radical therapy, compared to 30% of the control group. The time to progression of the disease doubled from 14 months to 28 months following treatment and the probability of the cancer progressing to a more dangerous stage was three times lower in patients that had vascular-targeted photodynamic therapy performed.
The technique is also relatively easy to perform. The trial took place at 47 different sites and in the majority of cases most of the sites were performing the treatment for the first time.
Emberton said the success of the trial shows that “the treatment protocol is safe, efficient and relatively easy to scale up.” He also said the treatment would be “far more precise if we repeated it today, as technology has come a long way since the study began in 2011.”
According to Professor Mark Emberton, Dean of UCL Medical Sciences and consultant urologist at UCLH, who was lead researcher on the study, “These results are excellent news for men with early localized prostate cancer.” He went on to say “This is truly a huge leap forward for prostate cancer treatment.”
Patients can receive the treatment and return home the next day. Typically, side effects only last for a few weeks. It is hoped that in addition to treating prostate cancer, the technique can be used to treat other cancerous tumors.
The results of the clinical trial have recently been published in the Lancet Oncology Journal.