High-intensity focused ultrasound may offer prostate cancer patients a treatment option with fewer side effects by targeting tumors better, according to a study published in the medical journal The Lancet Oncology.
The technology enables doctors to preserve the prostate by aiming only at the cancerous area in contrast to standard treatment, such as irradiation or surgical removal of the gland, which may cause impotence and leakage of urine or feces, researchers in London said in the study published today. The technique, also called HIFU, may provide men with an alternative similar to the lumpectomy, in which doctors remove tumors rather than the whole organ in breast-cancer patients, they said.
“The signal from this study is quite strong,” Hashim Ahmed, a urologist at the University College London who was the report’s lead author, said in a phone interview. “When you look at the current standard of care, there’s a 1-in-3, or 1-in-2 chance of having the perfect outcome. In this study, after 12 months, it’s a 9-in-10 chance.”
None of the 41 men in the trial reported urine incontinence and only one in 10 suffered from poor erections 12 months after the treatment, the researchers said. About 95 percent of the men were cancer-free after a year, meaning most had a “perfect outcome” in terms of disease progression and side effects, the authors said.
The study was carried out in London and funded by the U.K. Medical Research Council, the Pelican Cancer Foundation and St. Peter’s Trust for Kidney, Bladder & Prostate Research. Ahmed said he’s recruiting patients for a larger trial in the U.K. and is looking for funding.
HIFU is a narrow, focused beam of high-energy sound waves directed at a cancerous area the size of a grain of rice. Doctors using magnetic resonance imaging and mapping biopsies to identify targets and aim the sound waves at affected tissue, causing it to vibrate and heat to about 80 degrees Celsius (176 degrees Fahrenheit) to kill cells, according to the study.
The procedure was performed in the hospital under general anesthesia and most patients were home within 24 hours, the researchers said.
The men in the study were all medium- to high-risk patients whose cancer was likely to spread within a few years and who would have faced surgery or radiotherapy and side effects, Ahmed said. Men who had already received chemotherapy, hormone treatment or radiation therapy were excluded from the trial.
The technology is “very good for smaller tumors, and it preserves nerves and blood vessels, which is important for sexual function,” said Malcolm Mason, a spokesman on prostate cancer for Cancer Research UK and head of oncology and palliative medicine at Cardiff University.
HIFU may offer better quality of life for low-risk patients who, while not needing surgery or radiation, may be anxious about their condition, Mason said. In these cases, standard treatment isn’t given unless there’s a change in test results such as levels of prostate-specific antigen, or PSA. Low-risk patients may not see their cancer spread for many years.
“Certainly within the prostate field it’s a very encouraging step,” Mason said. “It doesn’t mean that HIFU is better and that men should demand HIFU over any other treatment.”
Cause of Death
Prostate cancer is the sixth most-common cause of cancer death in men worldwide, according to Cancer Research UK. Other treatments being used include cryotherapy, where prostate cancer cells are frozen and destroyed, as well as hormone therapy and chemotherapy.
HIFU may be cheaper than the standard treatment, Ahmed said. The cost of the MRI and mapping was an estimated 1,500 pounds ($2,400) and the HIFU procedure totaled 1,000 pounds, he said. That compares with about 4,500 pounds to remove the prostate, he said. Fewer side effects would also cost the health system less, Ahmed said.
The technology may also be applied to other cell-based cancers such as breast, thyroid, pancreas and liver, Ahmed said.