BACKGROUND.Active surveillance followed by selective treatment for men who have evidence of disease progression may be an option for select patients with earlyâstage prostate cancer. In this article, the authors report their experience in a contemporary cohort of men with prostate cancer who were managed with active surveillance.METHODS.All men who were managed initially with active surveillance were identified through the authors' institutional database. Selection criteria for active surveillance included: prostateâspecific antigen (PSA) <10 ng/mL, biopsy Gleason sum â€6 with no pattern 4 or 5, cancer involvement of <33% of biopsy cores, and clinical stage T1/T2a tumor. Patients were followed with PSA measurements and digital rectal examination every 3 to 6 months and with transrectal ultrasound at 6â to 12âmonth intervals. Beginning in 2003, patients also underwent repeat prostate biopsy at 12 to 24 months. The primary outcome measured was active treatment. Evidence of disease progression, defined as an increase in rebiopsy Gleason sum or significant PSA velocity changes (>0.75 ng/mL per year), was a secondary outcome. Chiâsquare and logârank tests were used to compare groups. The association between clinical characteristics and receipt of active treatment was analyzed by using Cox proportional hazards regression.RESULTS.Three hundred twentyâone men (mean age [±standard deviation]: 63.4 ± 8.5 years) selected active surveillance as their initial management. The overall median followâup was 3.6 years (range, 1â17 years). The initial mean PSA level was 6.5 ± 3.9 ng/mL. One hundred twenty men (37%) met at least 1 criterion for progression. Overall, 38% of men had higher grade on repeat biopsy, and 26% of men had a PSA velocity >0.75 ng/mL per year. Seventyâeight men (24%) received secondary treatment at a median 3 years (range, 1â17 years) after diagnosis. Approximately 13% of patients with no disease progression elected to obtain treatment. PSA density at diagnosis and rise in Gleason score on repeat biopsy were associated significantly with receipt of secondary treatment. The diseaseâspecific survival rate was 100%.CONCLUSIONS.Selected individuals with earlyâstage prostate cancer may be candidates for active surveillance. Specific criteria can be and need to be developed to select the most appropriate individuals for this form of management and to monitor disease progression. A small attrition rate can be expected because of men who are unable or unwilling to tolerate surveillance. Cancer 2008. © 2008 American Cancer Society.