CHARACTERISTICS OF PROSTATE-CANCER FOUND WITH EARLY DETECTION REGIMENS

This article reviews the clinical and pathologic characteristics of nonpalpable (Stage T1c) prostate cancer reported in five studies published to date. Stage T1c tumors more closely resemble palpable prostate cancers (Stage T2) than they do incidental prostate cancers detected in cystoprostatectomy specimens. The mean tumor volume of Stage T1c tumors is about 50 times greater (2.0 mL vs 0.04 mL) than incidental cystoprostate cancers. Only about 20-25% of T1c tumors have a tumor volume < 0.5 mL; tumors > 0.5 mL are considered to have significant biologic potential. Furthermore, 30-50% of T1c tumors have penetrated the prostatic capsule, 20-30% demonstrate positive surgical margins, and 5-10% demonstrate seminal vesicle invasion and/or positive pelvic lymph nodes. Possible reasons for nonpalpability of T1c tumors include tumor location in the central and/or anterior zones of the prostate and increased gland volume due to benign prostatic hyperplasia, making T1c tumors more difficult to palpate. A combination of serum prostate-specific antigen (PSA) density < 0.1 and favorable needle biopsy pathology (no Gleason 4 or 5 pattern in any core, < 3 cores positive for cancer, and < 50% involvement of any single core) will identify about 75% of men with tumors < 0.5 mL who might be followed without immediate treatment. Overall, however, these data, indicate that most T1c tumors are significant cancers > 0.5 mL that warrant aggressive treatment in accordance with age and other health considerations.