ELEVATED SERUM LEVELS OF P105(ERBB-2) IN PATIENTS WITH ADVANCED-STAGEPROSTATIC ADENOCARCINOMA

Expression of a truncated or extracellular form (p105(erbB-2)) of p185 (erbB-2) has been demonstrated in the sera of breast cancer patients. We examined the levels of p105(erbB-2) in, the sera of patients with v arious stages of prostatic adenocarcinoma, in patients with benign pro static hyperplasia (BPH) and in a series of control male patients hosp italized for illnesses unrelated to the prostate. p105(erbB-2) levels did not differ between the controls and BPH patients or between these groups and patients with stage A, B or C adenocarcinomas. In contrast, serum p105(erbB-2) levels of patients with stage D adenocarcinomas we re significantly elevated when compared with either control or BPH pat ients. There was no correlation between PSA and p105(erbB-2) levels am ong controls, patients with BPH or patients with prostate cancer. Pati ents with poorly differentiated tumors (combined Gleason score >7) or moderately differentiated tumors (combined Gleason scare 5-7) had high er p105(erbB-2) levels as compared to patients with well-differentiate d tumors (combined Gleason score <5), though this difference was not s tatistically significant. There was no correlation between serum p105( erbB-2) levels and p185(erbB-2) expression in malignant tissue, as det ermined by immunohistochemistry. However, patients with moderate to st rong expression of p185(erbB-2) within the adenocarcinomas were approx imately 4 times more likely to demonstrate elevated serum p105(erbB-2) levels as compared with patients with low expression of p185(erbB-2). (C) 1996 Wiley-Liss, Inc.