The natural history of prostate cancer.

Predicting the long-term outcome of patients who choose watchful waiting as initial therapy for prostate cancer is difficult. The wide variation in disease progression, the impact of competing medical hazards, and the potential impact of early hormonal therapy that is characteristic of contemporary patients all conspire to compromise survival estimates dating from the pre-PSA era. The survival analysis figure developed by Albertsen et al (Fig. 1) estimates a 15-year survival rate based on patient age and Gleason score at diagnosis from patients diagnosed in the pre-PSA era. Although no effort was made to adjustfor competing medical hazards, patients and clinicians can adjust a patient's chronological age to match his "physiological" age. The advent of widespread PSA testing appears to have advanced the date of diagnosis by approximately 5 years and the onset of secondary treatment by at least as many years. Therefore, the figure describing the natural history of prostate cancer most likely underestimates rather than overestimates survival among men with newly diagnosed, localized prostate cancer who select watchful waiting as their treatment choice. As contemporary databases of men with localized prostate cancer mature, more data on the natural history of this disease will become available. Only time will tell how the use of PSA has altered the precision of historic case-series data.