HSP-27 HAS NO DIAGNOSTIC OR PROGNOSTIC-SIGNIFICANCE IN PROSTATE OR BLADDER CANCERS

Heat shock protein 27 (hsp-27) is a cytosol protein of unknown function that is concentrated in many estrogen-sensitive normal target organs and is expressed to a varying degree in many tumors, including ductal carcinoma of the breast, malignant fibrous histiocytoma (MFH) of the soft tissues, adenocarcinoma of the prostate, and transitional cell carcinoma (TCC) of the urinary bladder. Overexpression of hsp-27 has independent prognostic significance in patients with breast cancer and MFH, but its potential predictive value with prostate and bladder cancers has not been evaluated. Differential expression of hsp-27 may occur between invasive cancer and host tissue that could aid in diagnosis, and varying expression among invasive cancers may have potential prognostic significance that could influence the use of adjuvant therapy. To test these hypotheses, hsp-27 expression was evaluated by immunohistochemistry in archival formalin-fixed paraffin-embedded sections of primary prostate and bladder carcinomas where the outcome of the patient was known. In 36 prostate cancer specimens from patients who had undergone radical prostatectomy (Stages T1, T2; NO; MO), no normal glandular elements or invasive cancers expressed this protein. In 24 bladder cancer specimens from patients who had undergone radical cystectomy (Stages T2, T3A, T3B, T4A; NO, N1; MO), 12 (50%) cancers overexpressed this protein. Hsp-27 did not correlate with degree of histologic differentiation, T-stage, nodal status, local recurrence, metastases, or survival. From these, observations, we conclude that hsp-27 expression has neither diagnostic nor prognostic significance and will not serve as a predictive biologic marker with these important genitourinary cancers.