Light Therapy Could Revolutionize Early Prostate Cancer Care

A new photodynamic laser therapy for low-risk prostate cancer can effectively kill cancer cells while preserving healthy tissue, according to a new study.

Researchers at University College London (UCL, United Kingdom), Skäne University Hospital (Malmö, Sweden), and 45 other European institutions conducted a study to examine the effectiveness of vascular-targeted photodynamic therapy (VTP) for treating low-risk prostate cancer. The treatment involves injecting padeliporfin, a light-sensitive compound that releases free radicals when activated by light. The drug is injected into the bloodstream, and then activated via a fiberoptic laser to destroy tumor tissue in the prostate.

For the study, the researchers randomly assigned 206 patients to VTP and 207 patients to active surveillance. The VTP patients received 4 mg/kg of padeliporfin intravenously over 10 minutes, and optical fibers were inserted into the prostate to cover the desired treatment zone. Subsequent activation was by 753 nm laser light at a fixed power of 150 mW/cm for about 22 minutes. Co-primary endpoints were treatment failure (histological progression of cancer) and absence of definite cancer at 24 months.

At the end of the follow-up period, the researchers found that 49% of patients treated with VTP had entered complete remission, compared with only 13.5% of patients who received active surveillance. Additionally, only 6% of men treated with VTP required radical therapy, compared with 30% in the control group. VTP-treated patients were also three times less likely to have their cancer progress, and VTP was found to double the average time to progression from 14 months to 28 months. The study was published on December 19, 2016, in The Lancet Oncology.

“With such an approach we should be able to achieve a significantly higher remission rate than in the trial, and send nearly all low-risk localized prostate cancers into remission,” said senior urologist author Professor Mark Emberton, MD, Dean of UCL Medical Science. “We also hope that VTP will be effective against other types of cancer - the treatment was developed for prostate cancer because of the urgent need for new therapies, but it should be translatable to other solid cancers including breast and liver cancer.”

Current standard of care for men with low-risk prostate cancer is active surveillance, which involves monitoring of prostate-specific antigen (PSA) levels, digital rectal exams, or prostate biopsies. As radical therapy, which involves surgically removing or irradiating the whole prostate, it has significant long-term side effects, including erectile dysfunction and incontinence; it is only used to treat high-risk cancers.

Related Links:
University College London
Skäne University Hospital