Expert Discusses Outcomes With Radiation Therapy in Locally Advanced Prostate Cancer

Stanley Liauw, MD

Recent outcomes with radiation therapy (RT) in patients with locally advanced prostate cancer have been highly encouraging, according to Stanley Liauw, MD.

“It has been really a big change recently,” says Liauw of how he has seen radiation therapy impact his patients. “We are seeing better control rates and less individuals who have PSA failures. We are seeing better quality of life of the men who have to undergo treatment.”

Liauw discussed the outcomes of radiation therapy in patients with locally advanced disease during the OncLive State of the Science Summit on GU and Prostate Cancer.

In an interview with OncLive during the meeting, Liauw, an associate professor at the University of Chicago Medicine, discussed the evolving role of radiation therapy in locally advanced prostate cancer—and how it compares with surgical procedures.

OncLive: What is the current role of radiation therapy in locally advanced prostrate cancer?

Liauw: The role of radiation for locally advanced prostate cancer has been defined by several randomized trials that have happened over the last couple of decades. The current standard of care has now evolved to include radiation with long-term hormonal therapy for men that are defined as high-risk patients.

There is also some debate, from the surgical side, as to whether or not surgery is preferable to radiation therapy.

What are some experts in the field unaware of regarding radiation therapy?

Many individuals do not really have a good sense of what gets done behind the scenes. They send patients to us, then they get treated, and then they come out. However, this therapy also requires an understanding of the different technologies that are available and why they might be used to treat patients with prostate cancer.

What are some of the advances that have come about over the years in radiation oncology, tying in with prostate cancer?

There have been several innovations with prostate cancer in the last 20 years or so. Many of them have come about as a means of improvement with hardware and software.

Twenty-plus years ago, there were really different ways to deliver radiation. Radiation therapists would take physical blocks—7-centimeter—thick lead blocks—and they would affix them to the heads of linear accelerators.

There was a major leap with technology when computer-generated leads could serve the purpose of those blocks. Then, in place of having a big block, one could actually reshape fields and have multiple field shapes through each beam angle. Basically, it became possible to deliver a much more sophisticated radiation treatment plan, and that plan could lead to better long-term outcomes in terms of disease control and adverse effects of therapy.

What role do you envision radiation therapy continuing to have?

Similar to the role of surgery, radiation has been increasingly used for patients who have higher-risk diseases. The role is sort of shifting into this higher-risk spectrum and moving away from a low-risk spectrum, where men with low-risk prostate cancer are generally followed on active surveillance rather than treated with local therapy.

RT is also being used more often after surgery, so men who have radical prostatectomy and have a PSA recurrence will ultimately receive radiation therapy to try to cure any kind of recurrence. This is becoming more of a mainstay in the treatment of men right now.

What have been some of the hotly debated topics in this part of the field over the last couple years?

One of the big debates right now is the role of radiation compared with the role of surgery. In the last 5 years, there have been 10 or more studies that compared long-term outcomes for men who get surgery with outcomes for men who receive radiation. The vast majority of these results have shown improvements for men who get surgery in terms of whether they are likely to die from prostate cancer.

That is certainly an area of debate, and radiation oncologists need to acknowledge that the information is out there so they can try to find ways to improve treatment or understand whether those studies are flawed in any way. Personally, I think that there are opportunities to make radiation outcomes better, and one of them may be to integrate the use of higher doses with brachytherapy.

What are some key questions in this area that ongoing clinical trials are attempting to answer?

Some of the big questions ask, “What happens for men who have metastatic disease? Is there any role for local therapy with either surgery or radiation therapy?” There are some trials that are being designed right now to test the role of local therapy in men who have very advanced metastatic disease. It will actually be very interesting to see if this therapy can help prolong lives for men who, ordinarily, would not receive this treatment.

Other than that, an important goal is to always try to find ways to make radiation outcomes better. We talk about the concept of the therapeutic ratio. As radiation oncologists, we want to get the best chance for disease control. However, it is also important to limit the chances of adverse effects, and there are a number of ways to do that—sometimes with technology, patient selection, radiation sensitizers, or hormonal therapy. There are trials that are ongoing to try to improve disease outcomes, and those are always exciting.

How do you decide if a patient should receive radiation therapy or surgery?

Generally, most men are candidates to get radiation, but a lot of men are actually candidates to get either radiation or surgery. So, that can be a pretty involved decision-making process. When I see men who are candidates for both, I usually talk to them about the nuanced differences that may exist in disease outcome and in the quality of life after treatments.

We also cover what patients can expect in terms of the actual procedure, then the long-term follow-up plan, and then how adverse effects might be different.

For some men, there may be reason to think that they would do better with surgery. For example, patients who have larger prostates with obstructive symptoms—younger, fitter men—are better candidates for surgery. Other men may be better candidates for radiation if they have some comorbidities, if they are older, are not good operative candidates, or if they want to avoid any invasive procedures.

What will radiation therapy look like in the next 5 to 10 years?

I don’t really see any major leaps in the next 5 years, but you never know. What drives this field a lot is the technology and, sometimes, it can be difficult to get a good sense of when the next big technology will hit. We are making steady progress in trying to improve upon the therapeutic ratio of treatment, and we are trying to continue to improve disease outcomes and lower the adverse effects of therapy through those gains of technology and new medicines.