Focal Therapy for Prostate Cancer

Overview

Focal therapies are treatments for localized prostate cancer that specifically target the tumor within the prostate. These therapies are applicable when the tumor is confined to the prostate, typically on one side, without spreading to surrounding tissues or organs. Each type of focal therapy employs an energy source, such as heat, cold, or electric shock, to destroy the tumor cells.

The aim of focal therapy is to eliminate cancerous cells while preserving as much healthy tissue as possible, thereby reducing side effects and complications. This approach offers an alternative to surgery or radiation, which treat the entire prostate, and to active surveillance, which involves regular monitoring and testing of the tumor for signs of spreading. For patients with favorable intermediate-risk prostate cancer (PSA levels between 10 and 20, grade 2 or 3, and less than 50% of biopsies positive), focal therapy provides a balanced option between active surveillance and more extensive treatments like surgery or radiation.

Types of focal therapy for prostate cancer

• Cryotherapy: Using cold gasses, a doctor freezes the tumor.
• Focal Laser Ablation (FLA): Tumor cells are destroyed by the heat from a laser.
• High-Intensity Focused Ultrasound (HIFU): Tumor cells are destroyed by the heat produced by high-frequency sound waves.
• Irreversible Electroporation (IRE): An electric shock is applied to the tumor using electrodes surrounding it, causing destruction to the tumor cells.
• Transurethral Ultrasound Ablation of the Prostate (TULSA): Tumor cells are destroyed by the heat generated by sound waves.

Reasons for undergoing the procedure

Focal therapy is used to treat prostate cancer that is fully contained (localized) within the organ and has little chance of spreading. Additionally, it is ideal for the tumor to be away from your urethra—the tube that empties your bladder—and your urinary sphincter, which is the muscle that regulates when urine is discharged from your bladder.

Focal therapy is most appropriate for patients with prostate cancer that is intermediate-risk. Active surveillance is a superior way to manage low-risk cancers, whereas whole-gland therapies (such as radiation or surgery) are a better way to treat high-risk cancers.

Risks

The following are potential risks of focal therapy:

• Not all malignant cells may be eradicated (recurrence risk is higher with focal therapy).
• You may require more treatments if the cancer reappears.
• Not everyone is an ideal candidate.
• Although the risk is lower, sexual and urinary side effects can still occur.
• Many of these treatments are relatively new, so their effectiveness compared to surgery, radiation, or active surveillance may not be fully known.
• Following treatment, focal therapies frequently call for more extensive monitoring, including prostate biopsies and MRIs.

Before the procedure

You might require a number of tests and imaging investigations before to focused therapy in order to assess your course of treatment. Among these are:

• Magnetic Resonance Imagining (MRI)
• MRI-guided prostate biopsy (either transperineal or transrectal biopsy).
• Mapping biopsy: In a mapping biopsy, your healthcare provider collects multiple tissue samples from your prostate to delineate the tumor’s margins.
• PSMA PET (positron emission tomography) scan: This imaging test identifies prostate-specific membrane antigen (PSMA) in your body, helping to detect if the cancer has metastasized to other areas.

During the procedure

Every focal therapy operates somewhat differently. Whatever kind of focal therapy you require will determine what your healthcare provider tells you to expect. Typically, a provider will:

• Administer anesthesia so you won’t experience discomfort and can sleep through the process.
• Place the device into your prostate either through your rectum, urethra, or with a needle through your skin.
• Use an energy source that damages and destroys cells to target the tumor.

Outcome

Following focal therapy, you will be closely monitored by your doctor for several months or even years. Testing and searching for indications of cancer include:

• Cancer that was absent from prior imaging or tests.
• Cancer that wasn’t completely destroyed by the focal therapy.
• Recurrent cancer.
• Cancer that has metastasized or spread.

If tests reveal that there is still cancer in your prostate, you may require further treatment, such as radiation or surgery.

The success rate of focal therapy varies widely, ranging from about 30% to 96%. However, the quality of the studies varies, making these numbers not entirely comparable. Research defines efficacy according to several metrics, including:

• The proportion of patients whose biopsies are negative after focal therapy.
• Whether the cancer has remained stable and not spread over a predetermined period (often 10 years).
• Decreases in PSA levels.

Different outcomes can depend on:

• The type of focal therapy used.
• The location of the tumor.
• The likelihood of the cancer spreading.

Focal therapies tend to be less effective than whole-gland treatments like surgery and radiation. Consult your provider to learn about the effectiveness, benefits, and risks of different focal therapies to find the option that suits you best.