An immunohistochemical study of chromogranin A and human epidermal growth factor-2 expression using initial prostate biopsy specimens from patients with bone metastatic prostate cancer
Article first published online: 11 OCT 2006
Volume 99, Issue 1, pages 189–195, January 2007
How to Cite
Yamada, Y., Nakamura, K., Aoki, S., Taki, T., Naruse, K., Matsubara, H., Tobiume, M., Zennami, K., Katsuda, R. and Honda, N. (2007), An immunohistochemical study of chromogranin A and human epidermal growth factor-2 expression using initial prostate biopsy specimens from patients with bone metastatic prostate cancer. BJU International, 99: 189–195. doi: 10.1111/j.1464-410X.2006.06500.x
- Issue published online: 7 NOV 2006
- Article first published online: 11 OCT 2006
- Accepted for publication 10 July 2006
- bone metastatic;
- prostate cancer;
- chromogranin A;
- neuroendocrine differentiation;
To investigate, using prostate needle-biopsy specimens at diagnosis from patients with bone metastatic prostate cancer, whether the relationship between neuroendocrine (NE) cell differentiation and human epidermal growth factor-2 (HER-2) expression is a prognostic factor for outcome.
PATIENTS AND METHODS
The study included 50 patients diagnosed as having bone metastatic prostate cancer between January 1998 and December 2001. We tested for NE cell differentiation by using immunohistochemical (IHC) staining for chromogranin A (CgA), and for HER-2, using a commercial test for IHC staining.
Eleven patients (22%) were positive for CgA; there was a significant difference in the time to recurrence (P = 0.025) but no significant differences in cause-specific survival rate or survival rate after recurrence. In all, 21 patients (42%) were positive for HER-2; the cause-specific survival rate, time to recurrence and survival rate after recurrence were all significantly more favourable in the HER-2-negative group (P = 0.008, 0.049 and 0.025, respectively). In the 49 patients for whom both factors could be determined, there was no significant correlation between CgA and HER-2 positivity.
NE cell differentiation of the primary tumour in patients with bone metastatic prostate cancer does not reflect the prognosis, whereas HER-2 overexpression is a prognostic factor for an unfavourable outcome. These results suggest that NE cell differentiation is not induced by HER-2.