An experimental treatment for prostate cancer tumors using high-intensity focused ultrasound (HIFU) shows promise as an effective treatment with fewer side effects than existing therapies.
The idea behind the new procedure is similar to lumpectomy in breast cancer patients, in which doctors remove only the tumors instead of the entire breast. Using HIFU, doctors can focus on treating only the cancer cells on the prostate while causing minimal damage to the surrounding tissue. Unlike more common and invasive treatments such as radiotherapy and surgical removal of the prostate gland, HIFU may be able to avoid side effects like urine leakage and impotence.
The new study, designed as a proof-of-concept study, involved just 41 men. Doctors used MRI and mapping biopsies to locate the cancerous tissues. They then focused high-energy sound waves on the affected area, causing the cancer cells to heat up to around 80°C, which kills the cells. None of the patients reported urinary incontinence a year after treatment, and only 1 in 10 suffered from poor erections. Overall, about 95% of the men were cancer-free after a full year following the trial.
“The signal from this study is quite strong,” study author Hashim Ahmed, a urologist at the University College London, told Bloomberg. “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.”
The men in the study were aged 45 to 80 with medium- to high-risk cancer, and would likely have undergone surgery or radiotherapy down the line. Men who had already received chemotherapy, hormone treatment or radiation therapy were excluded from the study. The procedure was carried out under general anesthesia and most of the patients had hospital stays of less than 24 hours after the treatment.
“Focal therapy of individual prostate-cancer lesions, regardless of whether they are multifocal or unifocal, leads to a low rate of genitourinary side-effects and an encouraging rate of early freedom from clinically significant prostate cancer,” the authors concluded in the study.
Prostate cancer is the most common cancer among men. The National Cancer Institute estimates 241,740 new cases of prostate cancer this year in the U.S. and 28,170 deaths.
Ahmed told Bloomberg that HIFU may also be cheaper than other standard treatments, noting that the cost of the MRI and mapping was an estimated $2,400, plus about $1,600 for HIFU; in comparison, removing the prostate costs about $7,100. Fewer side effects would also lower other health care costs, he said.
The researchers are now recruiting more patients and seeking funding for larger studies. While the initial results were promising, they need to be replicated; HIFU also needs to be studied long-term and compared with other therapies. If the technology holds up, it could also work for other cell-based cancers like breast, thyroid, pancreas and liver, Ahmed said.
The study was published Tuesday in the journal The Lancet Oncology.
This was too simplistic and drew unsatisfactory grades on 8 out of 9 applicable criteria. Read details below.
This particular week is a busy week in prostate cancer news: a JAMA paper on IMRT vs. proton beam therapy and Fox News promoting robotic surgery over the Cyberknife…and then this story. Readers need clear, contextual, evidence-based analysis to help them sort through all of the claims swirling around them.
The story quoted another news source quoting the researcher, who claimed “that HIFU may also be cheaper than other standard treatments, noting that the cost of the MRI and mapping was an estimated $2,400, plus about $1,600 for HIFU; in comparison, removing the prostate costs about $7,100. Fewer side effects would also lower other health care costs, he said.”
But that quote from the researcher may have been an incomplete assessment of costs.
It’s unknown if cancers are more likely to recur following HIFU. If they were, then ultimate costs would be higher. In fact, the Lancet article noted that 4 men required retreatment within one year. Additionally, 39 of 41 men had repeat MRI/biopsy after 6 months. While that may have been just part of the research protocol, the extent to which repeat MRI/biopsy are part of clinical practice would also contribute to costs.
We’re told that “Overall, about 95% of the men were cancer-free after a full year following the trial.” But, again, that may have been an incomplete picture.
The Lancet article indicates that this includes 4 men who required retreatment. “Cancer-free” is based on MRI results. Most men were also biopsied after 6 months to determine whether there was microscopic evidence of cancer and 9 of 39 did have evidence.
The story stated that “None of the patients reported urinary incontinence a year after treatment, and only 1 in 10 suffered from poor erections.” Again, this was not the whole story. 17% of men developed urinary tract infections after the procedure and men required catheters for an average of 8 days.
The story states that:
While the initial results were promising, they need to be replicated; HIFU also needs to be studied long-term and compared with other therapies. If the technology holds up, it could also work for other cell-based cancers like breast, thyroid, pancreas and liver, Ahmed said.
But, given that this was a proof of concept study in just 41 men, the emphasis should have been greater that this was very preliminary data. It was also an uncontrolled trial (no control group for comparison), yet the story allowed the researcher to get away with making claims about a better chance of “the perfect outcome” from this approach.
Then, letting him get away with this comment at this early stage was a bit over the top: “If the technology holds up, it could also work for other cell-based cancers like breast, thyroid, pancreas and liver.”
The Lancet article appropriately noted that one-year followup is far too short to fully evaluate cancer outcomes.
No disease mongering.
No independent sources were quoted – only the lead researcher.
As noted in the “Evidence” criterion above, we feel the story allowed the researcher to get away with making comparative claims of superiority after a very preliminary study in just 41 men.
Among the other therapies to be mentioned would be active surveillance (deferring any active treatment until/unless there is evidence of cancer progression), which is an appropriate strategy for men with low-risk cancers (27% of the study group according to the Lancet article).
The story was about a British study. There was no mention of the availability of HIFU in the US.
The story made no reference to any past research on HIFU for prostate cancer. This isn’t the first research in this area – yet the story may suggest that to readers.
The story appears to be based on someone else’s story – Bloomberg’s.
The intent of this criterion is to promote independent vetting of claims.
We’re not sure that happened any more with this approach than it would with copying from a news release.
We’ll rule it Not Applicable because we certainly can’t give this a Satisfactory score.