Prostate Cancer: Light Therapy Offers Effective Treatment for Early Stages, New Study Shows
Nearly 1 out of every 7 men in the U.S. will develop prostate cancer in their lifetime. A new study offers hope that for men with early prostate cancer a new non-invasive treatment might be an effective, nonsurgical course of treatment.
The study, published in The Lancet Oncology, showed that for men with early localized prostate cancer, light therapy - a.k.a. vascular-targeted photodynamic therapy (VTP) VTP treatment - drastically reduced their likelihood of needing radical therapy (e.g. radiation therapy or the surgical removal of the prostate and adjacent tissues). Most impressively, it also showed that 2 years after the VTP treatment, nearly 50% of patients had complete remission.
Prostate cancer is the second most prevalent cancer for men in the U.S., second only skin cancer. When the cancer is found in its early stages, it is localized to the prostate and considered “low risk.” The protocol at this stage is to closely monitor it through regular biopsies, antigen test and rectal exams. If the condition worsens, radical treatments may become necessary.
What is Vascular-Targeted Photodynamic Therapy?
So what is VTP? It is a treatment which injects WST11, a drug derived from ocean bottom bacteria, into the bloodstream. The drug is light-sensitive, and when a laser activates it, “the drug releases free radicals that destroy cancer cells in the prostate.” This technique of VTP was developed in Israel at the Weizmann Institute of Science with the partnership of STEBA Biotech.
VTP for Prostate Cancer Research
In their recently published phase III trial, Prof. Emberton and associates sought to further understand the efficacy of VTP as a treatment method for men with low risk prostate cancer. From 47 different treatment facilities across 10 European nations they found 413 patients who were under active surveillance after being diagnosed with early stage, localized prostate cancer. These men were randomly split into two groups: half received VTP while the other half acted as the control group and received no treatments but continued with active surveillance.
For the subsequent 2 years, all patients had follow-up testing every 3 months. The results were quite remarkable. After the the final 2-year follow-up, 49% of patients treated with VTP had gone into complete remission, while only 13.5% of those in the control group had. Only 6% of the patients treated with VTP came to need radical therapy compared with 30% of the patients in the control group. The researchers also reported that the men treated with VTP were three times less likely to have cancer progression and that the progression that did occur took on average twice as long.
These results are great news for men over 65--those who are most commonly stricken with prostate cancer. When needed, radical therapies can be effective, but they come with a lot more risks and frequent side effects such as urinary incontinence, bowel trouble, and erectile dysfunction. Receiving VTP in the early stages has the potential to prevent all that by obviating the need radical treatment. It also kills prostate cancer cells without damaging the healthy tissue surrounding them.
How long before this treatment option will be readily available? It’s still uncertain, but VTP is currently under review by the European Medicines Agency for treating prostate cancer. It may be a some years before VTP is widely available. In the meantime, researchers are hopeful that VTP’s miraculous effectiveness will prove equally applicable in treating other types of cancer.
Azzouzi, A., Vincendeau, S., Barret, E., Cicco, A., Kleinclauss, F., Poel, H. G., . . . Emberton, M. (2016). Padeliporfin vascular-targeted photodynamic therapy versus active surveillance in men with low-risk prostate cancer (CLIN1001 PCM301): an open-label, phase 3, randomised controlled trial. The Lancet Oncology. doi:10.1016/s1470-2045(16)30661-1