It kills the cancer, not the prostate
focal therapy, although not the standard of care, is emerging as a way to treat localized prostate cancer in carefully selected patients. I recently interviewed one of the leaders in this field, urologist Arvin K. George, MD, Director of Prostate Cancer Programs at the Brady Urology Institute at Johns Hopkins.
Focal therapy is just one part of George’s clinical practice, which covers the diagnosis and management of prostate and other genitourinary cancers. is a specialist surgeon who performs robotic prostatectomy and kidney surgery. His research focuses on the use of imaging and biomarkers in the diagnosis, risk stratification and management of prostate cancer.
Why is focal therapy a difficult topic? As we have discussed here and elsewhere on this site and media the bookprostate cancer is a multifocal disease: like dandelions in a field, cancer can appear in many parts of the prostate at the same time. This is why the gold standard for local disease is its treatment whole prostate through surgery or radiation.
Focal therapy—killing or removing only the known spot or spots of clinically significant cancer within the prostate—has been around for decades in various forms. The most common approaches are cryotherapy (freezing) and high-intensity focused ultrasound (HIFU), with other technologies emerging. But for years, urologists have had questions about the idea of focal therapy itself, including:
- What if you kill the cancer in one spot, but miss another tiny spot or spots of cancer?
- Urine leaves the body through the urethra, which passes right through the prostate, like a road through a tunnel. To protect him during focal treatment, doctors maintain his normal temperature with either a heating tube or cooling. What if there is cancer near the urethra that is also spared?
- What if a spot of cancer is removed, but a new one starts to grow? Can the prostate tolerate multiple cycles of the same type of focal therapy, should a different approach be used, or should the patient be switched to surgery or radiation?
Why is Johns Hopkins researching and offering focal therapy now? What changed;
First and foremost, George says, the reason is visualization. “The better the image, the better and more precise our treatments become.” Improvements in MRI have changed the game. “We can see where a lesion is, how far it extends, and apply a treatment to that exact area.” This is true, although some cancers simply do not show up on MRI, as discussed here. There is also the potential for PSMA imaging technology to play a role in the treatment of localized disease, although so far it has not been routinely used in patients considering focal therapy. PSMA-PET is more of a “big gun” when cancer is suspected to have escaped the prostate.
Risk stratification has also been greatly improved. PSA density, second-line biomarker tests such as the 4K score and the Prostate Health Index (PHI), and molecular pathology findings (from biopsy tissue) help doctors create a “profile” of the cancer, assess his potential to be aggressive or more. slow growth.
So says Mohamad Allaf, MD, Director of the Brady Urology Institute (and, incidentally, the Hopkins surgeon who removed my husband’s prostate and saved his life, thank God!), “as we understand the biology of the disease more and our ability to see cancer has improved – even though MRI and PSMA-PET are not perfect – there may be a role for focal therapy. That remains to be seen, he adds, and “Arvin is perfectly suited to do this. Doctors in the community already provide focal treatment and someone should take the lead to study it in a very rigorous way, monitoring cancer control in the long term. We see Brady as a steward of therapy and a leader in defining the role of focal therapy. The unique thing Arvin brings is the academic rigor to study and implement focal therapy and anything image-guided in prostate cancer, including the new transperineal MR fusion biopsies.”
“We certainly have some bridges to rebuild”
A major priority is improving the public’s understanding of focal therapy, says George. “We definitely have some bridges to rebuild,” because of doctors around the world over the last 20 years who weren’t as responsible or, unfortunately, as skilled as they should have been. “We didn’t know what we didn’t know. There was a learning curve in this new technology: how we implement it and how we follow the men afterwards. We have some clarity on this with updated surveillance protocols, but we still have a lot to learn!”
That said, he adds: “Some of the focal treatment practitioners out there were downright sloppy,” he says, “providing inadequate cancer coverage, exorbitant out-of-pocket costs, non-follow-up, patient learning as technology evolved, causing fistulas and other complications. We are still suffering from this hangover of offshore treatments and paying in cash.”
But focal therapy is not the same today as it was then. With close monitoring, George says, focal therapy may be a good option for some men with localized cancer. “Tens of thousands of focal ablation cases have been performed,” he says. “While we have less data than that, we have a five- to seven-year median outcome in more than 1,300 patients that has been published.” He believes focal therapy is here to stay. “It’s all about choosing the right patient.”
Right now, the “sweet spot” for focal therapy, as we’ve discussed here, is a patient with a favorable intermediate risk. “Less aggressive cancer may require no treatment at all, and more aggressive disease may require more aggressive treatment.” The ideal patient “has cancer that is visible on imaging but is not near vital structures such as the urethra, rectum, or neurovascular bundles and does not have high-risk features such as extracapsular extension or vesical invasion.”
George is the Principal Investigator of two focal therapy clinical trials. One is the PRESERVE study, which involves removing prostate tissue via irreversible electroporation (IRE). IRE is largely “thermal”. It uses neither heat nor cold. Instead, it creates an electric field in the tissues between two electrodes. The electricity creates microscopic holes in the cells, causing them to die. “Because IRE does not damage the scaffold or connective tissue, in theory, it can heal closer to the nerves.” The other study is the VAPOR 2 trial, using water vapor to destroy tissue. “This is an extremely hopeful time for men with prostate cancer.”
Additionally with BookI have written about prostate cancer on the Prostate Cancer Foundation website, pcf.org. The stories I have written are in the “Understanding Prostate Cancer” and “For Patients” categories. I firmly believe that knowledge is power. Saving your life can start with going to the doctor and knowing the right questions to ask. I hope all men put prostate cancer on their radar. Get a baseline PSA blood test in your early 40s and if you are of African descent or have a family history of prostate cancer and/or cancer, you should be screened regularly for the disease. Many doctors don’t do this, so it’s up to you to ask.
©Janet Farrar Worthington
