Benefit of watchful waiting in patients with prostate cancer risk

The authors determined the long-term outcomes of active surveillance (watchful waiting) in patients with low risk of prostate cancer.  

Active surveillance is an option, often used in patients with favorable-risk prostate cancer (Stage I/II, confined to prostate with low risk of spread or growth). It involves monitoring the cancer for signs of growth without using active treatment.

Long-term studies are needed to determine the benefit of active surveillance as a treatment option in favorable-risk prostate cancer. 

The aim of this study was to determine the long-term benefit of active surveillance in patients with prostate cancer risk

Data from 993 patients were included in this study. The median (midpoint) follow-up time was 6.4 years.

The overall survival (patients who were still alive following treatment) was between 0.2 years and 20.2 years. The 10-year overall survival was 80% and 15-year overall survival was 62%. Patients over the age of 70 years had nearly 3 times increased risk of experiencing cancer death. Patients with high prostate specific antigen (PSA – protein elevated in the blood indicating the presence of prostate cancer) levels had a 52% increased risk of experiencing cancer death. Patients with a Gleason score (scoring system that compares cancer cells to healthy cells) of 6 had a 70% increased risk of experiencing cancer death.

The 10-year cause-specific survival (patients who did not die from prostate cancer) was 98.1% and 15-year cause-specific survival was 94.3%. At 5-years 75.7% of patients remained untreated. At 10-years 63.5% of patients remained untreated. At 15 to 20 years, 55% of patients remained untreated. Gleason score at 1 year and PSA values were significant predictive factors for treatment intervention. The risk of dying from prostate cancer was 9.2 times higher than from other conditions. Overall, 2.8% developed metastatic disease (cancer spread to other parts of the body). 1.5% of all patients died from metastatic prostate cancer. 

The authors concluded that active surveillance was a feasible and effective option in favorable-risk patients based on a 15-year time frame. 

Patients with Gleason scores of 6 might have had higher-grade disease than predicted from the score. So the results could have been biased.