Staging of prostate cancer: a review with reference for further refinement

Staging of prostate carcinoma provides a standardized method for tumor classification which is based on involvement of the prostate gland, adjacent local structures, regional lymph nodes, and distant sites. Staging information is therefore crucial for clinicians to be able to assess risk of disease progression, to offer therapeutic choices in the individual patient, and to provide population-based prognostic information. Clinical staging, which is based on data obtained prior to first definitive treatment, relies on tumor determination by digital rectal examination, transrectal ultrasonography, other imaging techniques, and serum PSA level, while pathological staging requires histological identification of tumor extent in prostate gland and surrounding tissues. T1 tumors, denoted to clinically unapparent, not palpable or visible by imaging, are diagnosed by transurethral resection of the prostate procedure or needle biopsy. T2 tumors are confined to the organ, are subdivided by involvement in one or both lobes, and are determined by radical prostatectomy procedure. Stage T3 denotes locally advanced tumors that spread beyond the organ's boundaries, and T4 denotes invasion or fixation to the pelvic organs. Despite wide acceptance of the system as a whole, the current 2010 revision of the American Joint Committee on Cancer/Union for International Cancer Control tumor, node and metastasis (TNM 7) appears to contain some controversies, particularly T2 three-tiered subclassification. This review will cover suggested changes to further TNM editions; these changes have been accumulated in the literature in recent years and include items such as lymph node involvement quantification, "vanishing" carcinoma, Gleason score, resection margin status, pretreatment serum PSA level, as well as difficulties the pathologist may encounter in microscopic examination which may hamper accurate stage assessment.