Gene Signature for Liver Cancer Recurrence Found

Oct. 16 -- WEDNESDAY, Oct. 15 (HealthDay News) -- Researchers have identified a new genetic signature that may predict whether a liver tumor is likely to recur, according to a new study.

Unlike other such signatures that have been identified for other cancers, this one has something of a flourish: It is hidden not within the tumor itself, but in the normal cells that surround it -- and which, by inference, remain in the body following surgery.

The findings potentially open the door to new surveillance, treatment, and intervention strategies for liver cancer patients, both after surgery and possibly before the primary cancer ever arises, experts said.

"I think this is the start of a big step forward," said Dr. Morris Sherman of the University of Toronto, who wrote an editorial that accompanied the research, which was released online Wednesday by the New England Journal of Medicine. "It will really make a major difference in the way we monitor patients at risk for liver cancer -- potentially. I mean, there are lots of pitfalls in the way, but that's what it promises."

Dr. Todd Golub, of the Broad Institute of the Massachusetts Institute of Technology, and Dr. Josep Llovet, of Mount Sinai School of Medicine in New York City, led the study, which also involved scientific teams in Japan, Italy, Norway and Spain.

The researchers in this study faced a significant technical hurdle. Most gene-expression profiling studies use tissue samples that have been flash frozen. But tissues taken in biopsies are usually chemically fixed and embedded in wax. That method preserves the tissue, making it easier for pathologists to examine, but it also renders the nucleic acids -- especially RNA -- difficult to extract.

Golub, Llovet, and their team were able to circumvent this problem by implementing techniques for extracting nucleic acids from wax-encased tissues, some dating back 24 years, and then using those materials to probe the expression of 6,000 human genes. They then focused on which genes' expression levels correlated with a recurrence at least two years after surgery, and also with survival. From all that, they came up with a list of 186 genes as the signature for liver cancer recurrence.