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


METHODS
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.


RESULTS
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).


CONCLUSIONS
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.
Nishio
Yoshitaka
Y
Department of Urology, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan.
Yamada
Yoshiaki
Y
Kokubo
Hiroto
H
Nakamura
Kogenta
K
Aoki
Shigeyuki
S
Taki
Tomohiro
T
Honda
Nobuaki
N
Nakagawa
Atsuko
A
Saga
Shinsuke
S
Hara
Kazuo
K
D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000556:secondary*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011467:Prostate / Q000378:metabolism*; D011471:Prostatic Neoplasms / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D015996:Survival Rate
D018719:Erb-b2 Receptor Tyrosine Kinases