Focal Therapy May Reduce Side Effects, Improve Quality of Life in Prostate Cancer

Limited treatment to a specific area with focal therapy is an “emerging area for treatment for prostate cancer,” with the potential to reduce side effects and have a major impact on quality of life in patients with prostate cancer, an expert said. 

At the recent CURE® Educated Patient® Prostate Cancer Summit, Dr. Kara L. Watts, associate professor of urology at Montefiore Einstein in the Bronx, New York, discussed how focal therapy — particularly high-intensity focused ultrasound (HIFU) — can be used in the treatment of prostate cancer.

In particular, HIFU is a newer treatment option in this space for patients with prostate cancer, which involves the targeted delivery of ablative energy to a portion of the prostate with cancer. With this approach, care teams intend on causing cell death while minimizing harm by not treating the entire prostate, Watts explained.

“Rather than the traditional radiation to the entire prostate or radical prostatectomy to remove the entire prostate, focal therapy is really aimed at finding the prostate cancer with imaging, treating just that area, but not treating the rest of the prostate that doesn't have cancer, or has cancer that doesn't need to be treated right now.”

Reasoning Behind Focal Therapy

Focal therapy is considered organ-preserving therapy and is an approach often used for other cancer types, but Watts said the use of focal therapy in prostate cancer has lagged for a while. She attributed this lag to the ability to find and localize prostate cancer and because prostate cancer can spread in different parts of the prostate.

“Now that we have really, really great technology with MRI and using guided biopsies to identify the cancers where they are, the world of focal therapy has really become a promising and a growing option for a lot of men,” Watts added.

The main goal of focal therapy is to preserve quality of life, as it aims to minimize side effects associated with whole-gland treatment like radiation or radical prostatectomy. The most common side effects associated with these two treatment options include difficulty with erections and urinary incontinence.

Watts discussed some real-world findings during her presentation regarding the prevalence of side effects after whole gland radiation or radical prostatectomy. For example, a study published in the journal JAMA Surgery in 2021 found that after radical prostatectomy, 74% of patients reported that they were able to control their urine one year after the procedure, meaning that 26% of patients were having difficulty with urine control.

“This is a real concern for people and a real outcome that patients consider,” Watts said.

Regarding erectile dysfunction, in a study published in the journal JAMA in 2020, researchers found that its occurrence ranged between 30% and 70% in patients with prostate cancer who underwent whole-gland treatment with radiation or surgery.

Patient regret of their treatment decision may also play a factor in prostate cancer. Watts noted that there are several published papers that assess patient-reported regret after undergoing radiation or radical prostatectomy for their treatment.

“What you find is with focal therapy, the goal really is striking a balance between controlling cancer in a way that is effective, but also preserving function and quality of life,” Watts added.

She explained that there are several options related to focal therapy modalities, including cryotherapy, which she said was essentially killing cancer cells by freezing. Irreversible electroporation, or IRE, is a needle-based therapy where needles are placed around the area that needs to be ablated through the perineum, and the needles deliver an electric current through a controlled setting to promote cell death.

High-Intensity Focused Ultrasound

With HIFU, Watts explained that this is a different application of ultrasound than what it is traditionally used for to see organs like the kidney, bladder or spleen, among others.

“It's an ultrasound probe that gets inserted into the bottom, similar to how we see the prostate during a biopsy, although this is a different type of probe,” Watts said. “And the way that I describe this to patients is … you have a magnifying glass with a leaf. If you take a magnifying glass and you hold it over a leaf on a sunny day. And it's very far away and not focused, nothing happens. But if you hold that magnifying glass the right angle and distance away from the leaf, it will burn a hole, because it is focusing, in a beam, those rays of sunlight into a very precise, pinpoint spot on the leaf to cause it to burn.”

Through this approach, which was approved by the Food and Drug Administration in 2015, the focused beams of ultrasound energy can heat the affected area to burn in a very controlled manner within the prostate.

The treatment involves an ultrasound probe to see the prostate, Watts explained, for which patients would receive an enema before the procedure so nothing impedes the ultrasound’s ability to deliver energy to the prostate. Patients are put under general anesthesia for this procedure, which is typically performed in a hospital operating room or ambulatory surgery center and takes approximately two to three hours. Patients are able to return home the same day, so HIFU does not require an overnight hospital admission.

After the procedure, patients often go home with a catheter for a few days, which depends on how much tissue is treated during the procedure.

“[The catheter is] usually in place for about three to five days to allow some swelling from the procedure to settle down,” Watts said. “It's very often just minimal or mild symptoms post-procedure.”

A week after the procedure, patients may undergo an MRI to see whether the affected area was treated completely. Patients are then monitored by repeating PSA and getting another MRI within the first year after the procedure.

“The timing may depend on who's doing the treatment,” Watts explained. “And most people doing this treatment will also do a follow-up biopsy, usually at about six or 12 months, to confirm that the area has been completely treated and there isn't anything else developing.”

When Can HIFU Be a Treatment Option

Watts said that HIFU is often a treatment option for patients with localized prostate cancer without metastasis (no disease spread).

“It's typically best for a low volume of prostate cancer,” Watts added. “So, if you have a really large tumor, this is probably not the best option for that. It is given in both initial or primary treatment, so sort of as your first treatment. And it can also be given for certain cases of recurrence after radiation treatment. So men who have had a recurrence of prostate cancer in the prostate after prior radiation, you can potentially be treated with HIFU.”

The most common disease type treated with HIFU in the U.S. is intermediate-risk prostate cancer, Watts said.

Even with its advantages, HIFU does have some potential risks for side effects, Watts said. The risk for urinary incontinence is approximately 1%, and nearly 15% of patients reported erectile dysfunction after the procedure. There is also a low risk for the development of urethral strictures or fistulas. Watts also noted the potential need for retreatment, which is “the most important [risk] that I really counsel men on.” She noted that this can occur in 20% to 40% of patients in five years.

“What that can mean is, you could have a recurrence in the area that's treated, or you could have a new cancer develop in another part of the prostate,” Watts said. “One of the benefits of focal therapy, especially with HIFU, is typically, all options still remain open to you, should that be needed. But this is one of the reasons it's very important to continue to be monitored after, really, any form of focal therapy for prostate cancer.”

Several studies have analyzed outcomes after focal therapy in patients with prostate cancer. In one study comparing radical prostatectomy with focal therapy, Watts said that the rate of failure-free survival — or needing to progress onto additional treatment — was similar in both groups at up to seven years. Findings from another study demonstrated that at five years after treatment, approximately 83% of men with intermediate-risk disease did not need to progress onto additional treatment.

Watts urged patients to discuss this treatment option with their care teams, although it may not be suitable for every patient.

“This is not an option for every patient,” she said. “It's something to discuss with the urologist to find out if you may be a candidate, and that's the most important feature of this talk.”

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