This figure illustrates the course of prostate cancer from initiation (A), to diagnosis by screening, (B), to diagnosis based upon clincial symptoms (C), to clinically detectable metastatic disease (D), and finally to death from prostate cancer (E). The “sojourn” time is the time between cancer initiation (A) and clinical detection (C). Survival is the time between cancer diagnosis (C) and death form the disease (E).