Prostate cancer-specific survival at 10 years is slightly lower among men with low-grade disease undergoing active surveillance compared with active treatment, according to population-based data.
“Although outcomes on [active surveillance] are excellent, these results do suggest that some men are misclassified or may miss an opportunity for cure,” Antonio Finelli, MD, of the University of Toronto, Princess Margaret Cancer Centre, in Canada and colleagues wrote in The Journal of Urology.
In the retrospective study, investigators compared long-term cancer outcomes among 21,282 men receiving active surveillance or definitive treatment with radiation or surgery in Ontario, Canada from 2002 to 2014. At 10 years, only 39% of men remained on active surveillance, the investigators reported. The 10-year prostate cancer-specific survival rates were 98.1% in the active surveillance group and 99.1% in the initial treatment group. The 10-year metastasis-free survival rates were 94.2% and 95.8%, respectively, and the 10-year overall survival rates were 88.7% and 89.9%, respectively.
In a landmark analysis, active surveillance was significantly associated with a 34% increased risk of metastasis, a 12% increased risk of all-cause mortality, and a 66% increased risk of prostate cancer-specific mortality compared with initial treatment, Dr Finelli’s team reported. In a propensity-score matched analysis, active surveillance was significantly associated with a 28%, 12%, and 87% increased risks of these outcomes, respectively, compared with initial treatment.
The investigators calculated that 125 men on active surveillance would need to receive initial treatment to prevent 1 prostate cancer death at 10 years. They cautioned that overtreatment is associated with potential urinary, bowel, and sexual-related harms.
The findings highlight “a need for a careful discussion between patient and clinician to balance treatment-related side effects and impact on quality of life vs the modest decrease in PC-specific mortality associated with intervention,” Dr Finelli’s team wrote.
Among the study’s limitations, data on prostate cancer stage and PSA levels were incomplete. Most men were diagnosed before widespread use of pre-biopsy prostate MRI.
Timilshina N, Alibhai SMH, Tomlinson G, et al. Long-term outcomes following active surveillance of low-grade prostate cancer: A population-based study using a landmark approach. J Urol. doi:10.1097/JU.0000000000003097