An observational study from UCLA's Jonsson Comprehensive Cancer comparing robotic-assisted prostate surgery to open surgery for prostate cancer found that patients who had robotic surgery had fewer instances of cancer cells at the edge of the surgical specimen, or fewer positive margins, and less need of additional cancer treatments, such as hormone therapy or radiation, than patients who had open surgery.

Led by Dr. Jim Hu, Associate Professor and Henry E. Singleton Chair in Urology and director of robotic and minimally invasive surgery, the study was published online ahead of press in the journal European Urology.

Although it is becoming more popular, robotic-assisted radical prostatectomy (RARP) - the complete removal of the prostate using a robotic apparatus - has remained controversial because there was little evidence of better cancer control over open radical prostatectomy (ORP), the traditional surgical approach, which is also less costly.

In an effort to determine whether or not robotic surgery offered an advantage, Hu and colleagues conducted a retrospective study comparing 5,556 patients who received RARP to 7,878 who received ORP during the years 2004 and 2009. Data was provided by the Surveillance, Epidemiology, and End Results (SEER)-Medicare, program of cancer registries that collect clinical and demographic information for persons with cancer.

The researchers compared the two groups by surgical margin status, which is the amount of cancer cells at the edge of the prostate specimen. A positive margin may result from cutting through the cancer and leaving some cancer behind, rather than cutting around the cancer completely. A positive margin for prostate cancer has been shown to lead to a greater risk of prostate cancer recurrence and death from the disease. Hu and colleagues also assessed the use of additional cancer therapy (androgen deprivation, or hormone therapy, and radiation) after robotic versus open surgery.

They found that RARP was associated with 5 percent fewer positive surgical margins (those that tested positive for the presence of cancer), 13.6 percent versus 18.3 percent for ORP, and this difference was greater for patients with intermediate- and high-risk prostate cancer. Patients who had robotic surgery also had a one-third reduction in likelihood of using additional cancer therapy within 24 months after robotic surgery compared to open surgery.

These findings show that despite a greater upfront cost of robotic surgery, the fewer positive surgical margins and less need for radiation therapy after robotic surgery may translate into less downstream costs and side effects of radiation and hormone therapy.