The Changing Tides in Prostate Cancer Treatment

Surgery, radiation, or observation - which is best? Two big studies published this summer will change the way doctors and patients choose between treatment options.

Prostate cancer is one of the most common cancers in men, affecting more than one in seven males. Over the past two decades, there have been big debates over the optimal treatment approach. Treatment options include surgery, external radiation, internal radiation, and close observation (often called active surveillance or monitoring). Until now, doctors have not had good data to compare these options.

Making things more complicated, a new type of surgery, called robotic surgery, has taken off in popularity, About 80% of the prostate cancer surgeries done in the U.S. now use the robot, adding about $5,000 to the cost of each surgery. Although the robotic approach has been touted as a way of reducing side effects and perhaps improving cure rates, the science to support its use has lagged behind its popularity.

Two new studies published this summer have gone a long way toward tackling these questions. They are both randomized studies, which are viewed as the strongest study design in medicine. Randomized studies assign patients to different treatments groups at random (like flipping a coin), allowing for fair comparisons between treatment options. You can read more about the importance of randomized studies here.

Prostate Surgery: Robot or Not?

The first randomized trial compared two approaches in men having surgery for prostate cancer: robotic surgery vs. open surgery. Open surgery is the traditional approach, where the surgeon makes a standard incision, almost always in the lower abdomen. Researchers in Australia enrolled 326 men aged 35-70 with prostate cancers that had not spread outside the prostate, and all men had a PSA test measured at no higher than 20. Half of the men were assigned to receive robotic surgery and half were assigned to receive open surgery. The main outcomes that the researchers wanted to examine included urinary and sexual function after treatment.

When comparing these two groups of men after treatment, those who received the robotic surgery vs. those who received the open surgery, there was no difference in urinary or sexual function at 6-weeks or 12-weeks post-surgery. The authors also looked at the rates of "positive margins", meaning that the tumor came to the edge of the surgical specimen, a finding that raises concerns that some tumor is left behind. The positive margin rates were similar in the two groups - 15% in the robotic group and 10% in the open group. The robotic approach did have some minor advantages, including less blood loss (although no one in the open group needed a transfusion), but these are considered much less important than the main outcomes.

We are awaiting the long-term data from this trial, including the outcomes at two years post-surgery. But this early data suggests that there's not a big difference between the two approaches. In the words of the authors: "In the interim, we encourage patients to choose an experienced surgeon they trust and with whom they have rapport, rather than a specific surgical approach."

Read more about picking a good surgeon.

Surgery, Radiation, or Observation?

The second trial, done in the UK, took a broader approach and compared three options for prostate cancer: surgery, external radiation, or active monitoring. Active monitoring means holding off on treatment until it becomes clear that the cancer is progressing. The trial enrolled 1643 men aged 50-69 who had prostate cancer detected by PSA testing and had not spread beyond the prostate.

The men were each assigned to one of the three groups (surgery, radiation, or active monitoring). The main purpose of the trial was to look at the rates of death from prostate cancer at 10 years, and there were no differences found. In each group, only about 1% of patients had died of prostate cancer by 10 years. And the chances of dying from anything within 10 years was also very similar in all three groups, around 10%.

The advantage of the active monitoring group is apparent: almost half of the patients in that group (45%) still didn't need any treatment 10 years later. Because they were able to delay or avoid treatment, the active monitoring group did better in many of the quality of life outcomes (such as sexual function and urinary continence). The disadvantage of the active monitoring group is that they had a higher chance of the cancer spreading elsewhere in the body, but that risk was very low, about 0.6% per year.

The Bottom Line

These two studies provide valuable information that will help patients diagnosed with prostate cancer. To me, the bottom line is this:

• Active monitoring is an excellent approach that spares many men from the side effects of treatment, and the long-term risk of death (10 years later) is no different than in men who choose to have surgery or radiation.
• For men who choose to have treatment, outcomes after surgery or radiation are very similar, so the decision between the two should come down to the patient's preference. To make sure that the patient hears all sides of the story, it is important they meet with both a surgeon and a radiation doctor before choosing treatment.
  
• For men who choose surgery, paying extra to have robotic surgery doesn't seem warranted. It's best to find a good, trustworthy surgeon who performs large numbers of prostate cancer surgeries every year, rather than finding a surgeon who takes a specific surgical approach.