April 21, 2010 (Barcelona, Spain) — Prostate cancer patients who are otherwise candidates for a robotic-assisted laparoscopic prostatectomy (RALP) should not be denied the procedure because of a high body mass index (BMI), researchers reported here at the European Association of Urology 25th Annual Congress.
The advice comes from a team at Mount Sinai Medical Center in New York City, who found similar outcomes with RALP in patients with a low BMI (<30 kg/m2) and in those with a high BMI (≥30 kg/m2).
“Data on the impact of obesity on outcomes after RALP have been conflicting, and we felt that it was important to provide a more definitive answer,” David Samadi, MD, chief of the Division of Robotics and Minimally Invasive Surgery at Mount Sinai, told Medscape Urology. “What’s more, the availability of such information is becoming increasingly important, given that the number of RALP procedures performed annually is increasing exponentially and, regrettably, the incidence of obesity is also increasing.”
The study examined 1112 men who underwent RALP performed by a single surgeon. Overall, 870 patients had a low BMI and 242 patients had a high BMI.
“Obesity may impose constraints for surgeons that can lead to increased rates of surgical complications and worse outcomes,” Dr. Samadi pointed out.
“While outcomes are uniformly worse for obese patients undergoing open radical perineal prostatectomy, data on RALP in obese patients have been contradictory,” he added. “Some studies have found that obese patients are more likely to have a larger blood loss, longer operative time, and positive surgical margins; other studies have shown minimal differences in outcome between obese and nonobese patients after RALP.”
The Mount Sinai study found that obese patients undergoing RALP had perioperative, pathologic, and functional outcomes similar to those of their nonobese counterparts. Among the measures assessed were perioperative times, bilateral nerve-sparing, positive margins, surgical complications, and biochemical recurrence at 12-month follow-up.
Functional outcomes were similar in nonobese and obese patients at all 3 assessments. Thus, at the 3-month assessment point, 77% of nonobese and 79% of obese patients were continent, which meant that they required 1 or fewer pads per day. At 6 months, continence rates were 89% and 85% in the 2 groups, respectively, which increased to 93% and 97% at 12 months.
At 3 months, 67% of nonobese and 62% of obese patients were potent. By 6 months, potency was reported in 76% and 74% of the 2 groups, respectively, which increased to 85% and 83% at 12 months. Potency was defined as a Sexual Health Inventory for Men (SHIM) score of more than 16 in men who were potent preoperatively. The SHIM scale is a widely validated tool for assessing the presence and severity of erectile dysfunction.
“Overall, our results demonstrate that RALP is an effective and safe option in patients with a high BMI, Dr. Samadi said. “What’s more, since obese patients have been shown to have worse outcomes in multiple open prostatectomy series, RALP may be a better option for patients with a high BMI.”
Finally, Dr. Samadi, who has training in open urologic, oncology, and laparoscopic prostatectomy, in addition to robotic surgery, emphasized that volume and consistency are critical components for a successful RALP procedure. “For example, a high-volume surgeon will know how to place robotic ports correctly, which will reduce the likelihood of a decrease in the movement of robotic arms in the obese patient,” he said.
He also noted that he always works with the same surgical team, which contributes to good surgical outcomes.
“This was a very good and timely study,” Michael Chehval, MD, chief of urology at Saint Louis University School of Medicine in St. Louis, Missouri, told Medscape Urology.
“While there is an increased incidence of prostate cancer in men with high BMI, the study indicates that high BMI does not portend a worse prognosis, and that outcomes are just as good for this group as for those with low BMI in terms of curability, impotence, or incontinence,” he asserted.
The study, Dr. Chehval said, shows that concern about an increased risk for complications in men with a high BMI is unfounded.
Dr. Samadi and Dr. Chehval have disclosed no relevant financial relationships.
European Association of Urology (EAU) 25th Annual Congress: Abstract 916. Presented on April 19, 2010.
By Jill SteinOncology