A recent study investigated the placebo response to sham surgery for benign prostatic hyperplasia (BPH), as medication trials often involve a placebo arm to equally assess the efficacy of the study drug, but BPH trials seldom include a sham surgery group due to the risks linked with simulating treatments in such patients. The study entitled “Clinically and Statistically Significant Changes Seen in Sham Surgery Arms of Randomized, Controlled Benign Prostatic Hyperplasia Surgery Trials” was published in The Journal of Urology

Randomized, controlled by placebo clinical trials are understood to be the gold standard in medical investigation and deliver first-level evidence. While such trials are common practice in medication-examination studies, they are more rarely seen in studies of actual patients under surgical procedures. In drug clinical trials, a placebo medication is easy to produce and administer, leading to an excellent setting of minimal additional risk to the participants who are given the placebo therapy. But when analyzing surgical consequences, this is more difficult, as creating a relevant placebo control group has added challenges.

Usually, most surgical procedures use some kind of anesthesia, and with surgical incisions there are higher risks associated with including a sham surgery group than with the administration of placebo treatment. The generalized disregard for the placebo effect leads to the assumption that improvements in LUTS (lower urinary tract symptoms) are attributed to the treatment while the intervention effect remains unaccounted for. But because endoscopic and intraprostatic injection BPH surgeries are not done transurethrally or percutaneously and do not require incisions in the skin, there are a few trials that do include a sham surgery group that gets objectively and subjectively examined.

This particular study sought to quantify the anticipated response to sham surgery for endoscopic procedures or intraprostatic injections for treating LUTS related to BPH. To this end, the team reviewed the available literature to find randomized, controlled trials involving endoscopic or intraprostatic injection in benign prostatic hyperplasia therapies that counted with a sham surgical arm from January 1990 to February 2015.

The results were comprehensively analysed with relevance based on study sample size. The initial search gathered 1,998 potential studies and after reviewing abstracts and full articles, 14 randomized, controlled trials were included. An average decrease from 22.3 to 16.7 (e27%) was observed in studies from AUASS (American Urological Association Symptom Score) only three months after a sham endoscopic procedure (p ¼ 0.0003) with an increase in maximum urinary flow of 1.3 ml per second (14%, p ¼ 0.001) also at the same time span. Prostate injection based studies, also at 3 months, were similar with a decrease from 21.3 to 15.7 (e26%, p < 0.001). Maximum urinary flow increased by 2.0 ml per second (23 percent, p = 0.043).

The team concluded that sham controlled endoscopic injection in benign prostatic hyperplasia interventions shows a substantial and statistically relevant change in symptom scores and maximum urinary flow, which is a response comparable to clinical drug trials. The investigators believe that future uncontrolled benign prostatic hyperplasia surgical trials should definitely take these findings into account when interpreting their own outcomes.