This study examined whether positive surgical margins in prostate cancer patients are more likely to be found following open, laproscopic, or robotic radical prostatectomy.

The standard treatment for prostate cancer is radical prostatectomy, or the surgical removal of the prostate. Radical prostatectomy can be performed in one of three ways. The most invasive is open radical prostatectomy, where one large incision is made in the lower abdomen. A less invasive laproscopic prostatectomy involves several small incisions in the abdomen through which long instruments are inserted to remove the prostate. Robotic prostatectomy is the final option, where the surgeon performs the laproscopic surgery by controlling a robotic arm from a computer.

Following each procedure the surgical margins (edges of the removed tissue) are tested for the presence of cancer cells. If cancer cells are found, it is referred to as a positive surgical margin, and can indicate that too little tissue was removed, leaving some cancer cells in the prostate bed (area that the prostate occupied before it was removed). This leaves the patient at a higher risk for biochemical recurrence (three consecutive elevations in prostate-specific antigen levels).

 Few studies have compared the rate of positive surgical margins among the three types of surgery, and those that have report conflicting results. The current study compared the rates of positive surgical margins in a large number of patients undergoing radical prostatectomy.

A total of 22,393 radical prostatectomy surgeries occurring over 11 years at 14 different medical centers were included in this analysis. Of these, 9,778 were open surgery, 4,918 were laproscopic, and 7,697 were robotic.

Positive surgical margins were noted in 22.8% of open surgical patients, 16.3% of laproscopic patients, and 13.8% of robotic patients. Both of the minimally invasive groups fared better than the open group by a relative factor of 25%.

 However, positive surgical margins were more likely to be seen following laproscopic or robotic surgeries in medical centers that did not perform many of these types of surgeries, compared to medical centers where they occurred more often. 

This study concluded that rates of positive surgical margins are higher following open radical prostatectomy compared to the less invasive laproscopic or robotic techniques.

This was a retrospective study (it looks back at patients who have been treated in the past). These studies are known to have lower statistical power than studies directly testing a hypothesis.