15-YEAR SURVIVAL IN PROSTATE-CANCER - A PROSPECTIVE, POPULATION-BASEDSTUDY IN SWEDEN

Objective.-To describe the natural history of initially untreated earl y-stage prostate cancer. A key secondary objective was to calculate lo ng-term survival rates by stage, grade, and age at diagnosis. Design.- Prospective cohort study, Setting.-Population-based in 1 county of Swe den, without screening for prostate cancer. Patients.-A group of 642 p atients with prostate cancer of any stage, consecutively diagnosed bet ween 1977 and 1984 at a mean age of 72 years with complete follow-up t o 1994. Main Outcome Measures.-Proportion of patients who died from pr ostate cancer, and 15-year survival (with 95% confidence interval [CI] ), corrected for causes of death other than prostate cancer. Results.- In the entire cohort, prostate cancer accounted for 201 (37%) of all 5 41 deaths. Among 300 patients with a diagnosis of localized disease (T 0-T2), 33 (11%) died of prostate cancer. In this group, the corrected 15-year survival rate was similar in 223 patients with deferred treatm ent (81%; 95% CI, 72%-89%) and in 77 who received initial treatment (8 1%; 95% CI, 67%-95%). The corrected 15-year survival was 57% (95% CI, 45%-68%) in 183 patients with locally advanced cancer (T3-T4) and 6% ( 95% CI, 0%-12%) in those 159 who had distant metastases at the time of diagnosis. Conclusion.-Patients with localized prostate cancer have a favorable outlook following watchful waiting, and the number of death s potentially avoidable by radical initial treatment is limited. Witho ut reliable prognostic indicators, an aggressive approach to all patie nts with early disease would entail substantial overtreatment. In cont rast, patients with locally advanced or metastatic disease need trials of aggressive therapy to improve their poor prognosis.