Increasing use of observation among men at low risk for prostate cancer mortality.

PURPOSE: There are growing concerns regarding the overtreatment of localized prostate cancer. It is also relatively unknown whether there has been increased uptake of observational strategies for disease management. We assessed the temporal trend in observation of clinically localized prostate cancer, particularly in men with low risk disease, who were young and healthy enough to undergo treatment.
MATERIALS AND METHODS: We performed a retrospective cohort study using the SEER-Medicare database in 66,499 men with localized prostate cancer between 2004 and 2009. The main study outcome was observation within 1 year after diagnosis. We performed multivariable analysis to develop a predictive model of observation adjusting for diagnosis year, age, risk and comorbidity.
RESULTS: Observation was performed in 12,007 men (18%) with a slight increase with time from 17% to 20%. However, there was marked increase in observation from 18% in 2004 to 29% in 2009 in men with low risk disease. Men 66 to 69 years old with low risk disease and no comorbidities had twice the odds of undergoing observation in 2009 vs 2004 (OR 2.12, 95% CI 1.73-2.59). Age, risk group, comorbidity and race were independent predictors of observation (each p <0.001), in addition to diagnosis year.
CONCLUSIONS: We identified increasing use of observation for low risk prostate cancer between 2004 and 2009 even in men young and healthy enough for treatment. This suggests growing acceptance of surveillance in this group of patients.