Gene expression profiling predicts liver cancer survival

NEW YORK (Reuters Health) - Genomewide expression profiling is feasible in formalin-fixed hepatocellular carcinoma specimens, and can be used to predict survival, according to a report in October 15th online issue of The New England Journal of Medicine.

At present, it is difficult to identify patients who are at high risk for disease recurrence after undergoing potential curative therapy for hepatocellular carcinoma, senior author Dr. Todd R. Golub, from the Massachusetts Institute of Technology in Cambridge, and colleagues note. Being able to identify such patients, however, could have important treatment implications.

Gene expression profiling is usually performed on frozen tissues, but collection of such tissues is not routinely performed for patients with hepatocellular carcinoma. By contrast, formalin-fixed, paraffin-embedded tissues account for the vast majority of specimens taken.

In the present study, Dr. Golub's team examined the feasibility and predictive value of gene expression profiling performed on fixed tissues obtained from 307 patients with hepatocellular carcinoma. Profiling of more than 6000 genes was performed.

The profiling method developed by the team yielded high-quality data from 90% of the patients, including some cases in which the samples had been stored for over 24 years.

The gene expression profiles of the liver tumors themselves did not correlate with survival, the authors found. By contrast, the profiles of adjacent non-tumor tissue were strongly predictive of survival, both in a training set of specimens from 82 Japanese patients and in tissues from a validation cohort of 225 US and European patients.

In a related editorial, Dr. Morris Sherman, from the University of Toronto, comments that "by demonstrating an association between survival and recurrence signatures in nontumorous liver tissue, the authors bring the possibility of individualized therapy for hepatocellular carcinoma one step closer."

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