The SPCG-4 study (Scandinavian Prostate Cancer Group 4) began in 1999 with 695 men from across Europe diagnosed with localized prostate cancer. The men were randomly assigned to either a radical prostatectomy or watchful waiting group. Investigators have followed men in the two groups since that time, and the latest data comes after 29 years of follow up.
At this point, 80% of the men in the study have died, thus the researchers were able to assess the survival benefit of having a radical prostatectomy for localized prostate cancer. The data coming out of this study is important because few studies have such long-term follow-up, especially randomized studies that allow for valuable statistical comparison.
The newly reported data indicated that men with localized prostate cancer and a long life expectancy saw a benefit from having surgery. These men lived a mean average of 2.9 years longer than men in the watchful waiting group.
Among men in the surgery group, those with a higher Gleason score and evidence of the disease spreading outside the prostate were more likely to die of the disease. Specifically, men with a Gleason score higher than 7 were associated with a risk of prostate cancer death 10 times higher than men with a Gleason score of 6 or lower. This is not surprising, as the higher the Gleason score, the more aggressive the disease. Extracapsular tumor extension, in which the disease has escaped outside the prostate at the time of surgery, was associated with a risk of prostate cancer death 5 times higher than men without the condition.
In the surgery group, men younger than 65 saw a greater benefit than older men. After long-term follow-up, the younger men had 15% lower rate of overall death and death from prostate cancer. In addition, they had an 18.6% lower risk of developing metastatic disease.
The authors also noted that since their study began, new diagnostic procedures are available including the use multiparametric MRI with targeted biopsies, which increases sensitivity to detect high-grade and clinically-significant cancers.
All these results underscore the importance of monitoring for the early detection of prostate cancer, and for continued vigilance for men who elect active surveillance of watchful waiting.
N Engl J Med. 2018 Dec 13;379(24):2319-2329. doi: 10.1056/NEJMoa1807801.