Staging prostate cancer--1997: current methods and limitations.

Clinical and pathologic staging of prostate cancer involves determination of the anatomic extent and burden of tumor based on the best available data. The TNM system [primary tumor (T), regional lymph node (N), and metastases (M)] is the most widely used system for prostate cancer staging. It stratifies patients according to the method of tumor detection, separating nonpalpable 'incidental' prostate cancers detected during transurethral resection for clinically benign prostatic hyperplasia and palpable cancers detected by digital rectal examination. This staging system also recognizes nonpalpable cancer detected by an elevated serum prostate-specific antigen level or an abnormal transrectal ultrasound image (stage T1c). Current staging is limited by a significant level of clinical understaging (up to 59% in our experience) and overstaging (up to 5%) based on comparison with pathologic examination of resected specimens. Proposed improvements in staging include preoperative systematic biopsies to assess tumor volume, the use of a volume-based prognostic index, and a multiple prognostic index. Currently, staging of prostate cancer falls short of meeting some of these goals, creating controversy and uncertainty about the comparative efficacy of various forms of therapy and expected outcomes for patients. In this report, we evaluate the current aspects of clinical and pathologic staging of prostate cancer with emphasis on the early stages in which there is the greatest chance of cure. Recent international agreement on the pathologic staging of prostate cancer should allow valid comparisons of surgical treatment from different institutions.