If you are diagnosed with prostate cancer, your doctor will monitor the disease periodically to see if it is spreading and how well treatments are working. Prostate-specific antigen (PSA) continues to be the primary marker of how the disease is progressing or responding to treatment.
Several recent studies indicate that PSA doubling time -- the time it takes for a patient's PSA level to double -- predicts how aggressive the cancer is. The faster the PSA level doubles, the more aggressive the cancer.