The Long-term Disease-specific Mortality of Low-risk Localized Prostate Cancer: A Prospective Population-based Register Study over Two Decades

Abstract

Objective To identify prognostic factors, and to estimate the long-term disease-specific and annual disease-specific mortality rates of low-risk prostate cancer patients from the early prostate-specific antigen (PSA) era. Patients and Methods We studied data extracted from the Southeast Region Prostate Cancer Register in Sweden, on1300 patients with clinically localized low-risk tumors, T1-2, PSA level ≤10 μg/L and Gleason scores 2-6 or World Health Organization Grade 1, diagnosed 1992-2003. The Cox multivariate regression model was used to evaluate factors predicting survival. Prostate cancer death rates per 1000 person-years were estimated for 4 consecutive follow-up time periods: 0-5, 5-10, 10-15, and 15+ years after diagnosis. Results During the follow-up of overall survivors (mean 10.6 years; maximum 21.8 years), 93 patients (7%) died of prostate cancer. Cancer-specific survival was 0.98 (95% confidence interval [CI] 0.97-0.99), 0.95 (95% CI 0.93-0.96), 0.89 (95% CI 0.86-0.91), and 0.84 (95% CI 0.80-0.88), 5, 10, 15, and 20 years after diagnosis. The 5-year increases in cancer-specific mortality were statistically significant (P