Decline in the overall incidence of regional-distant prostate cancer in Olmsted County, MN, 1980-2000

OBJECTIVE: To describe trends in the incidence of regional-distant prostate cancer over the entire course of the disease, before and after the introduction of prostate-specific antigen screening in 1987. PATIENTS AND METHODS: All residents of Olmsted County, MN, USA, with a diagnosis of prostate cancer from 1964 to 2000 were identified using the resources of the Rochester Epidemiology Project. Their community medical records were examined to identify men with documented evidence of locally advanced (T3/4 or N+ disease) or metastatic prostate cancer between 1980 and 2000. RESULTS: In all, 407 men had regional-distant prostate cancer, based on clinical or pathological staging at the time of initial diagnosis of prostate cancer and/or on radiological information over the entire course of their illness. The age-adjusted incidence per 100 000 men increased from 47.4 in 1980-86 to 65.8 in 1987-93, and declined to 33.3 in 1994-2000 (P < 0.001). Based on clinical and radiological information over the entire course of illness (268 men) the age-adjusted incidence of regional-distant disease was 42.3 in 1980-86, 41.2 in 1987-93, and declined to 18.1 in 1994-2000 (P < 0.001). These latter rates were 27%, 32% and 47% higher for the three periods, respectively, than rates based on clinical staging at initial diagnosis of prostate cancer. CONCLUSIONS: The overall incidence of regional-distant stages of prostate cancer has declined in recent years, regardless of the stage at initial diagnosis. This may be a result in part of early detection and curative treatments. These findings also indicate that assessing the incidence of regional-distant prostate cancer only at the initial diagnosis underestimates the full impact of the benefits of early detection and treatment.