Outcomes of Localized Prostate Cancer Following Conservative Management

Abstract

Most newly diagnosed prostate cancers are clinically localized, and major treatment options include surgery, radiation, or conservative management. Although conservative management can be a reasonable choice, there is little contemporary prostate-specific antigen (PSA)-era data on outcomes with this approach. To evaluate the outcomes of clinically localized prostate cancer managed without initial attempted curative therapy in the PSA era. A population-based cohort study of men aged 65 years or older when they were diagnosed (1992-2002) with stage T1 or T2 prostate cancer and whose cases were managed without surgery or radiation for 6 months after diagnosis. Living in areas covered by the Surveillance, Epidemiology, and End Results (SEER) program, the men were followed up for a median of 8.3 years (through December 31, 2007). Competing risk analyses were performed to assess outcomes. Ten-year overall survival, cancer-specific survival, and major cancer related interventions. Among men who were a median age of 78 years at cancer diagnosis, 10-year prostate cancer-specific mortality was 8.3% (95% confidence interval [CI], 4.2%-12.8%) for men with well-differentiated tumors; 9.1% (95% CI, 8.3%-10.1%) for those with moderately differentiated tumors, and 25.6% (95% CI, 23.7%-28.3%) for those with poorly differentiated tumors. The corresponding 10-year risks of dying of competing causes were 59.8% (95% CI, 53.2%-67.8%), 57.2% (95% CI, 52.6%-63.9%), and 56.5% (95% CI, 53.6%-58.8%), respectively. Ten-year disease-specific mortality for men aged 66 to 74 years diagnosed with moderately differentiated disease was 60% to 74% lower than earlier studies: 6% (95% CI, 4%-8%) in the contemporary PSA era (1992-2002) compared with results of previous studies (15%-23%) in earlier eras (1949-1992). Improved survival was also observed in poorly differentiated disease. The use of chemotherapy (1.6%) or major interventions for spinal cord compression (0.9%) was uncommon. Results following conservative management of clinically localized prostate cancer diagnosed from 1992 through 2002 are better than outcomes among patients diagnosed in the 1970s and 1980s. This may be due, in part, to additional lead time, overdiagnosis related to PSA testing, grade migration, or advances in medical care.