Prognostic significance of immunohistochemical expression of the HER-2/neu oncoprotein in bone metastatic prostate cancer

• Published in: Urology (Ridgewood, N.J.) N.J.), 2006-07, Vol.68 (1), p.110-115
• Main Authors: Nishio, Yoshitaka, Yamada, Yoshiaki, Kokubo, Hiroto, Nakamura, Kogenta, Aoki, Shigeyuki, Taki, Tomohiro, Honda, Nobuaki, Nakagawa, Atsuko, Saga, Shinsuke, Hara, Kazuo
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Biological and medical sciences; Bone Neoplasms - secondary; Gynecology. Andrology. Obstetrics; Humans; Immunohistochemistry; Male; Male genital diseases; Medical sciences; Middle Aged; Nephrology. Urinary tract diseases; Prognosis; Prostate - metabolism; Prostatic Neoplasms - metabolism; Prostatic Neoplasms - mortality; Prostatic Neoplasms - pathology; Receptor, ErbB-2 - metabolism; Survival Rate; Tumors; Tumors of the urinary system; Urinary tract. Prostate gland
• ISSN: 0090-4295; 1527-9995
• DOI: 10.1016/j.urology.2006.01.060

To investigate the usefulness of the overexpression of the human epidermal growth factor receptor (HER-2) oncoprotein in patients with bone metastatic prostate cancer as a marker for the time to recurrence and outcome after endocrine therapy. We studied 50 patients who had been diagnosed with bone metastatic prostate cancer. HER-2 overexpression in the prostatic tissue by biopsy was evaluated by immunohistochemistry using the Hercep test. The results were scored into four levels by two pathologists; scores greater than 1+ were considered positive. The HER-2 staining score was 0, 1+, 2+, 3+, and indeterminate in 28, 4, 11, 6, and 1 case, respectively. HER-2 was overexpressed (greater than 1+) in 21 patients (42%). The cause-specific survival and nonrecurrence rates were significantly lower in the HER-2-positive group than in the negative group ( P = 0.0084 and P = 0.0485, respectively). Furthermore, the cause-specific survival rate after recurrence was significantly greater in the HER-2-negative group than in the positive group ( P = 0.0247). We consider that HER-2 overexpression, as measured by immunohistochemistry, may be useful as a marker of an unfavorable prognosis by predicting the interval until relapse and outcome after endocrine therapy in patients with bone metastatic prostate cancer.