AMACR is not applicable as a diagnostic tool in hepatocellular carcinoma
Gro Linno Willemoe1, Ben Vainer
1Department of Pathology, Rigshospitalet, Copenhagen, Denmark. gro@willemoe.dk
Abstract:
Alpha-methylacyl coenzyme A racemase (AMACR or P504S) is a mitochondrial and peroxisomal protein present in a variety of human cells. Demonstration of increased expression is used diagnostically in prostatic adenocarcinoma. AMACR is also produced by normal hepatocytes and it has been postulated that the demonstration of AMACR expression or its pattern of distribution is useful in the diagnosis of hepatocellular carcinoma (HCC) (Jiang et al., Hum Pathol 2003;34, Guzman et al., Appl Immunohistochem Mol Morphol 2006;14, Li et al., J Exp Clin Cancer Res 2008;27). The aim of the present study was to evaluate whether immunohistochemical staining for AMACR can be used in a routine histopathologic setting. Immunohistochemical staining for AMACR was performed on paraffin-embedded tissue from livers resected for HCC during 1980-2006 at Rigshospitalet, Copenhagen, Denmark (n = 44). Tumor sections as well as surrounding non-neoplastic tissues were studied. In both tumor and non-tumor tissues, intracellular localization and staining pattern were assessed and the staining intensity of AMACR was graded. The fraction of stained tumor cells was not significantly different from that of stained non-tumor cells in the same patients (p = 0.97). A significantly lower staining intensity was observed in clear cell areas (p = 0.005), but the AMACR expression did not correlate with the HCC type and could not distinguish neoplastic from non-neoplastic liver cells. AMACR is not applicable as a tool in the histopathologic diagnosis of HCC.
Insights
Alpha-methylacyl coenzyme A racemase (AMACR) is not a reliable biomarker for diagnosing hepatocellular carcinoma (HCC). Studies show AMACR expression does not effectively differentiate between cancerous and non-cancerous liver cells.
Area of Science:
- Oncology
- Pathology
- Biochemistry
Background:
- Alpha-methylacyl coenzyme A racemase (AMACR) is a protein found in human cells, including mitochondria and peroxisomes.
- Increased AMACR expression is a diagnostic marker for prostatic adenocarcinoma.
- AMACR is also present in normal hepatocytes, suggesting potential diagnostic utility in hepatocellular carcinoma (HCC).
Purpose of the Study:
- To evaluate the utility of immunohistochemical staining for AMACR in the histopathologic diagnosis of HCC.
- To determine if AMACR expression patterns can distinguish between neoplastic and non-neoplastic liver cells.
Main Methods:
- Immunohistochemical staining for AMACR was performed on paraffin-embedded liver tissues from HCC resections (n=44).
- Both tumor and surrounding non-neoplastic tissues were analyzed for intracellular localization, staining pattern, and intensity.
- The fraction and intensity of AMACR-stained cells were assessed and compared between tumor and non-tumor tissues.
Main Results:
- No significant difference was found in the fraction of stained tumor cells versus stained non-tumor cells (p = 0.97).
- A significantly lower staining intensity for AMACR was observed in clear cell areas of the tumors (p = 0.005).
- AMACR expression did not correlate with HCC type and could not differentiate neoplastic from non-neoplastic liver cells.
Conclusions:
- AMACR is not applicable as a diagnostic tool in the histopathologic diagnosis of hepatocellular carcinoma.
- The expression patterns of AMACR in liver tissue do not reliably distinguish HCC from normal liver cells.
