A study from Swedish researchers appearing in the New England Journal of Medicine suggest that for younger men with low-risk prostate cancer, complete removal of the prostate gland (radical prostatectomy) led to higher survival rates than “watchful waiting.” The study, an update of a 2008 report with an additional three years of data, found 38 percent fewer prostate cancer deaths among men randomly assigned to the surgery group versus those in the watchful waiting group. The survival benefits were restricted to men under 65. For this group, surgery saved one life for every seven men who had prostatectomies.
Below are comments from Otis W. Brawley, M.D., chief medical officer in response to the news.
“In this report, Swedish scientists report longer-term data from a study that was the first to show that radical prostatectomy saves lives. At that time the ‘number needed to treat’ ( NNT) was 19 men treated to save one life over nine years. This study includes a median of 13 years of follow-up, and the NNT is now 15 to save one life overall and just seven needed to treat to save one life in men younger than 65 years. In fact, the study found almost no survival advantage for radical prostatectomy over age 65.
“This update showing a benefit for men with low risk disease and that nearly all the survival benefit occurs in men under the age of 65 is an important finding. But its relevance to men in the U.S. may be limited. This Swedish population is a group that had few PSA detected cancers; only 5.2%. That means that the results (in the number needed to treat to save one life) really do not apply to most Americans, who in fact are diagnosed with localized disease by PSA. In a PSA screened (earlier detected) cohort like in the U.S., one would predict the NNT to be higher than in this study, perhaps even four to five times higher. That would put it close to the 48 men needed to treat to save one life that the European screening trial suggested.
“Another important point of the Swedish study is that even though surgery decreased risk of prostate death by about 25 to 30%, 55 of 347 men treated with surgery for prostate cancer died of prostate cancer anyway. Also, nearly half the men in the surgery arm of the study (166 out of the 347) died in the 13 years of follow-up, mostly from causes other than prostate cancer. In other words, while the headline is true, that prostatectomy saves lives, we need to remember that a good proportion of the men with ‘early’ cancer still died from the disease.”