Immunohistochemical expression of gonadotropin releasing hormone receptor in human breast carcinoma

• Published in: Pathology international 2001-05, Vol.51 (5), p.333-337
• Main Authors: Moriya, Takuya, Suzuki, Takashi, Pilichowska, Monika, Ariga, Naohiro, Kimura, Noriko, Ouchi, Noriaki, Nagura, Hiroshi, Sasano, Hironobu
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; breast carcinoma; Breast Neoplasms - chemistry; Breast Neoplasms - metabolism; Breast Neoplasms - pathology; Carcinoma, Ductal, Breast - chemistry; Carcinoma, Ductal, Breast - metabolism; Carcinoma, Ductal, Breast - secondary; Female; gonadotropin releasing hormone (GnRH); Humans; Immunohistochemistry; Ki-67 Antigen - chemistry; Lymph Nodes - pathology; Menopause; Middle Aged; Neoplasm Staging; receptor; Receptors, Estrogen - analysis; Receptors, Estrogen - metabolism; Receptors, LHRH - analysis; Receptors, LHRH - metabolism; Receptors, Progesterone - analysis; Receptors, Progesterone - metabolism
• ISSN: 1320-5463; 1440-1827
• DOI: 10.1046/j.1440-1827.2001.01210.x

Gonadotropin releasing hormone (GnRH) analogs can cause regression of hormone‐dependent breast carcinomas via the specific GnRH receptor (GnRH‐R). In an attempt to obtain a better understanding of GnRH actions in human breast carcinoma, the expression of GnRH‐R was examined immunohistochemically in 58 invasive ductal carcinomas and correlated with various clinicopathological parameters. GnRH‐R was immunolocalized in the cytoplasm of carcinoma cells in 37 of 58 invasive ductal carcinoma cases (64%). Immunoreactivity for GnRH‐R was also detected focally in the cytoplasm of morphologically normal glandular epithelia adjacent to the carcinoma. A significant correlation was observed between the immunohistochemical expression of GnRH‐R and estrogen receptor labeling index (LI; P= 0.030) or progesterone receptor LI (P= 0.0074). There was a significant inverse correlation between GnRH‐R immunoreactivity and Ki‐67 LI (P= 0.012). No significant correlations were detected between GnRH‐R and other clinicopathological parameters, including patient age, menopausal status, stage, tumor size, lymph node status, histological grade and prognosis. This study indicates that GnRH‐R is widely distributed in human breast carcinoma cells and regulates GnRH actions locally. Breast carcinomas positive for GnRH‐R maintain some hormonal regulatory mechanisms, and GnRH actions may lead to a low proliferative rate in human breast carcinoma.