An ultrasound technique for killing cancer tumors without harming healthy tissue could transform the treatment of prostate cancer. Research presented at a meeting suggest the treatment is as effective as surgery or radiotherapy, but with fewer side effects.
There is a need for more focused treatments for prostate cancer that reduce the risk of damaging nerves that supply the penis, urine control muscles and the rectum.
The study – on the effectiveness of high-intensity focused ultrasound (HIFU) to treat men with localized prostate cancer – featured at the European Association of Urology Congress (EAU16) in Munich, Germany, March 11-15, 2016.
Led by University College Hospital (UCH) in London, UK, the study followed 625 men between 2004-2015, who were treated in the UK and who had localized, non-metastatic tumors; the tumors were in one part of the prostate and had not spread beyond the gland.
Hashim Ahmed, a consultant urological surgeon at UCH, told the meeting that 93% of patients who underwent HIFU alone to remove their prostate tumor were still cancer-free and did not need any surgery or radiotherapy 5 years after treatment.
The results follow those of an earlier study by Ahmed and colleagues published in The Lancet Oncology in 2012, where, of 41 men who underwent HIFU, 95% were free of cancer after 12 months. Not one of the patients developed incontinence, and only 1 in 10 suffered erectile dysfunction.
In the new, larger study, which reports medium-term results, only 1-2% of the HIFU patients experienced long-term incontinence, and just 15% suffered erectile dysfunction. These figures compare favorably with men who have surgery, where around 30-60% experience these distressing side effects.
More focused approach, fewer side effects
Conventional treatments such as surgery and radiotherapy treat the whole prostate and risk damaging nerves that supply the penis, urine control muscles and the rectum. Damage to these nerves leads to incontinence and erectile dysfunction.
More focused treatments are desperately needed to reduce the large proportion of men who experience these distressing side effects that affect everyday life, work and relationships.
HIFU devices exist, and one was approved recently by the federal regulators in the US for use in prostate cancer, but there is a need for more independent studies with longer follow-up periods to verify their safety and accuracy.
HIFU focuses ultrasound waves to millimeter accuracy, causing targeted tissue to heat up to 80-100°C, which kills cells instantaneously. The procedure does not affect healthy tissue. Another advantage of the treatment is that patients can leave hospital on the same day.
The technique can thus be used to remove small lumps of affected tissue instead of the whole prostate in men with localized prostate cancer; in this respect, it has been likened to the “lumpectomy” alternative to a full mastectomy in breast cancer.
Study coauthor Tim Dudderidge, a consultant urological surgeon at Southampton General Hospital, is one of a small group of doctors in the UK that is using HIFU to treat prostate cancer. He says the study results are “impressive and have the potential to transform prostate cancer treatment,” and concludes:
“It is extremely exciting technology and these results show that in men diagnosed early by prostate-specific antigen (PSA) blood testing, this targeted therapy could be as effective as surgery to remove the whole prostate gland or radiotherapy and cause far fewer side effects.”
Prostate cancer normally affects men over the age of 50. It is the second most common cancer in men worldwide. More than 1.1 million cases of prostate cancer were recorded in 2012, accounting for around 8% of all new cancer cases and 15% in men. Two thirds of cases are diagnosed in more developed regions of the world.
In the US, estimates suggest that during 2016, there will be around 180,890 new cases of prostate cancer and about 26,120 deaths from the disease. In the UK, where the study was conducted, 37,000 new cases are diagnosed every year.
Meanwhile, Medical News Today learned from a German study presented at the same conference that testing for non-coding RNA molecules in urine may be a more reliable and accurate way to detect prostate cancer than using the current PSA and PCA3 biomarker tests.
Written by Catharine Paddock PhD