Adenoid cystic/basal cell carcinoma of the prostate strongly expresses HER-2/neu
- 1Pathology and Laboratory Medicine Service, Veterans Administration Medical Center, Gainesville, Florida; Department of Pathology, Immunology, and Laboratory Medicine of The University of Florida, Florida, USA
- 2United Hospitals, School of Medicine, Polytechnic University of the Marche Region, Ancona, Italy
- Correspondence to: Dr K A Iczkowski Pathology and Laboratory Medicine Service (113), Veterans Administration Medical Center, 1601 SW Archer Road, Gainesville, FL 32608-1197, USA;iczkoka{at}pathology.ufl.edu
- Accepted 27 January 2006
Abstract
Adenoid cystic/basal cell carcinoma (ACBCC) is a rare neoplasm in the prostate. Definitive treatment is warranted, as among 19 patients previously reported by us, 5 had extraprostatic extension and 4 were metastatic. The HER-2/neu (c-erbB-2) gene has been reportedly overexpressed in adenoid cystic carcinomas in other organs, but its status in prostatic ACBCC was uncertain. Immunohistochemical staining and in situ hybridisation were carried out in 13 patients with ACBCC (11 from transurethral resection, 2 prostatectomy). One patient had metastasis to the lung. Citrate buffer and steam heat were used for antigen retrieval. Ten acinar adenocarcinomas of varying grades were also immunostained as controls. Protein and mRNA expression were 2+ to 3+ (of 3+) in all patients with ACBCC, compared to a breast cancer control with strong reactivity, whereas protein expression was noted in only one acinar carcinoma and mRNA expression was absent in all acinar carcinomas. Benign acini expressed HER-2/neu only in the basal layer. The finding of strong, consistent HER-2/neu expression in ACBCC suggests that treatment with Herceptin (trastuzumab) may be effective in patients with this rare tumour.
Footnotes
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Competing interests: None declared.
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Presented as a poster at the 94th Annual Meeting of the United States and Canadian Academy of Pathology, San Antonio, Texas, February 2005.
