Increased screening, effective treatments, and overall decline in the community incidence of regional-distant prostate cancer

Abstract

Despite the increased incidence in organ-confined disease and the decline in regional-distant prostate cancer at initial diagnosis, local or metastatic prostate cancer may still occur at a later time. The purpose of this study was to investigate trends in the community incidence of regional-distant stage prostate cancer over the entire course of illness. All Olmsted County, Minnesota, residents who had prostate cancer initially diagnosed from 1964 through 2000 were identified using the resources of the Rochester Epidemiology Project. Their community medical records were examined for evidence of locally advanced (T3/4 or N+ disease) or metastatic prostate cancer first detected at any time between 1980 and 2000, based on pathology report at radical prostatectomy or pelvic lymphadenectomy at diagnosis (pathologic staging) and on all clinical and radiological findings at diagnosis and during follow-up. With priority given to pathologic staging, 407 men were identified with regional-distant disease; the age-adjusted incidence per 100,000 men increased from 47.4 (in 1980–1986) to 65.8 (in 1987–1993), and then declined to 33.3 (in 1994–2000) (P < 0.001). The proportion with regional-distant disease based on information from the pathology report increased (27.5, 51.1, and 49.1% for the three time periods, respectively; P = 0.003) and mean number of prostate specific antigen determinations increased (0, 1.4, and 2.4, respectively; P < 0.0001). Incidence rates of regional-distant disease based on clinical criteria over the entire course of illness (n = 268 men) were lower: 42.3, 41.2, and 18.1 (P < 0.001) in the three time periods, respectively. These rates were 27%, 32%, and 47% higher for the three time periods, respectively, compared with rates based only on clinical criteria at initial diagnosis. The incidence of regional-distant prostate cancer over the entire course of disease has declined in recent years, due in part to increased use of curative treatments and early detection by screening. Estimates based only on stage at initial diagnosis, however, underestimate the true burden of regional-distant disease in the community.