Being obese may increase the cost of surgery for men with prostate cancer - at least the more traditional forms of the procedure, a new study suggests.

Researchers found that among 629 prostate cancer patients at their center who had a radical prostatectomy - surgical removal of the prostate gland - obese men generally incurred greater costs.

The difference, the study found, came from higher costs for anesthesia and other services in the operating room.

However, while obesity was related to greater expenses from both traditional “open” surgery and minimally invasive laparoscopic, or “keyhole” surgery, it did not affect the price tag of robot-assisted laparoscopic surgery - a technique that, over the past decade, has become the predominate approach to prostate removal in U.S. hospitals.

Among patients who underwent traditional surgery, performed through a long abdominal incision, the typical cost for obese men was $4,885. That compared with $4,377 for all other men.

The pattern was similar when it came to traditional laparoscopic surgery - a less invasive procedure where the surgeon makes several small incisions to insert thin instruments, including a camera that provides a view inside the abdomen. Among study patients who had this surgery, the typical cost was $5,703 for obese men and $5,347 for their non-obese counterparts.

In contrast, weight did not appear to sway the costs of robot-assisted laparoscopic surgery, in which a surgeon sits at a computer console, controlling robotic “arms” that hold the surgical instruments.

The price tag for robotic surgery was $6,761 for obese men and $6,745 for thinner men, according to findings published in the urology medical journal BJU International.

However, while weight did not affect the costs of robotic prostate surgery, the procedure clearly is not a bargain for obese men, said Dr. Yair Lotan, the senior researcher on the study and an associate professor of urology at the University of Texas Southwestern Medical Center in Dallas.

In an interview, he pointed out that hospitals pay about $1.5 million for the robot and take on other costs - including service contracts that run in excess of $100,000 a year. And the charges for the surgery reflect that.

If one were to consider cost alone, Lotan said, “it would be very difficult to justify” choosing robot-assisted prostate surgery over open surgery for patients of any weight.

However, the researcher added, if robotic surgery is the choice anyway, the current findings suggest that a patient’s extra pounds will not lead to extra costs.

The findings are based on 629 men who underwent radical prostatectomy at the Texas center between 2003 and 2008. Of those patients, 156 had open surgery, 211 had laparoscopic surgery, and 262 had robot-assisted surgery.

In general, Lotan explained, prostate surgery is more technically difficult and time-consuming with obese patients. And with surgery in general, he added, obese patients tend to have higher risks of complications, such as wound infections and problems with anesthesia.

So it is not surprising that the costs of open surgery would be greater for obese prostate cancer patients than for their thinner counterparts, according to Lotan. But it is not clear why obesity affected the cost of standard laparoscopic surgery, but not that of the robot-assisted procedure, he said.

One possibility, Lotan noted, is that the robot maneuvers the surgical instruments more easily compared with a surgeon performing standard laparoscopy, shortening the surgical time. But he added that technical skill and speed are also very much dependent on the surgeon and his or her experience.

Indeed, Lotan and his colleagues point out, a limitation of this study is that patients were treated at a single medical center, and the findings may not be true of all institutions.

Still, Lotan said, the findings do underscore the impact that obesity can have on surgical costs. “I don’t think it’s a stretch to say that the obesity problem in the U.S. is getting worse by the day,” he said. “This study highlights the fact that there is an added cost of that.”

SOURCE: BJU International, online March 23, 2010.