Successful external validation of a model to predict other cause mortality in localized prostate cancer.
Prostate cancer is the most commonly diagnosed (non-skin) cancer among men in the United States, with 179 000 new cases and 37 000 deaths expected in 1999 (1). Although $5 billion is spent annually for the care of those diagnosed with prostate cancer (2), a systematic evaluation of practice patterns and the impact of treatments on health-related quality of life (HRQOL) on a national scale has yet to be conducted. In 1994, the National Cancer Institute (NCI) initiated the Prostate Cancer Outcomes Study (PCOS) to investigate variations in the initial treatment of prostate cancer and to describe HRQOL outcomes in a large, heterogeneous cohort of newly diagnosed prostate cancer patients treated in community medical practices. The study is the most comprehensive population-based outcomes study focusing on prostate cancer ever conducted and complements the national prostate cancer research agenda. The main purpose of this commentary is to provide the rationale and objectives for the PCOS and to describe how the study fills a critical gap in the understanding of men’s experiences with prostate cancer. Better knowledge of treatment outcomes is desired by thousands of patients, families, and clinicians who deal with prostate cancer every day. The PCOS was initiated to obtain more comprehensive and generalizable information about the effects of treatments on HRQOL outcomes. Information about HRQOL is also important, from a cancer surveillance perspective, for providing a broader perspective for interpreting recent trends in prostate cancer incidence and mortality. Given the uncertainty about the efficacy of selected interventions, it is essential to document the complete burden of the disease in order to characterize the extent to which progress is being made. A second purpose of this commentary is to describe the design, methods, and limitations of the PCOS in order to enhance the understanding and interpretation of numerous ongoing and planned research projects using the data collected.