1: N Engl J Med. 2008 Nov 6;359(19):1995-2004. Epub 2008 Oct 15.Click here to read Links
Comment in:
J Hepatol. 2009 May;50(5):1062-4.
N Engl J Med. 2008 Nov 6;359(19):2045-7.

Gene expression in fixed tissues and outcome in hepatocellular carcinoma.

Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02142, USA.

BACKGROUND: It is a challenge to identify patients who, after undergoing potentially curative treatment for hepatocellular carcinoma, are at greatest risk for recurrence. Such high-risk patients could receive novel interventional measures. An obstacle to the development of genome-based predictors of outcome in patients with hepatocellular carcinoma has been the lack of a means to carry out genomewide expression profiling of fixed, as opposed to frozen, tissue. METHODS: We aimed to demonstrate the feasibility of gene-expression profiling of more than 6000 human genes in formalin-fixed, paraffin-embedded tissues. We applied the method to tissues from 307 patients with hepatocellular carcinoma, from four series of patients, to discover and validate a gene-expression signature associated with survival. RESULTS: The expression-profiling method for formalin-fixed, paraffin-embedded tissue was highly effective: samples from 90% of the patients yielded data of high quality, including samples that had been archived for more than 24 years. Gene-expression profiles of tumor tissue failed to yield a significant association with survival. In contrast, profiles of the surrounding nontumoral liver tissue were highly correlated with survival in a training set of tissue samples from 82 Japanese patients, and the signature was validated in tissues from an independent group of 225 patients from the United States and Europe (P=0.04). CONCLUSIONS: We have demonstrated the feasibility of genomewide expression profiling of formalin-fixed, paraffin-embedded tissues and have shown that a reproducible gene-expression signature correlated with survival is present in liver tissue adjacent to the tumor in patients with hepatocellular carcinoma. Copyright 2008 Massachusetts Medical Society.

PMID: 18923165 [PubMed - indexed for MEDLINE]