Genetic abnormalities - missing DNA or duplicate DNA - that fuel the growth of one type of cancer may actually be at work in several others, U.S. researchers said on Wednesday.

The finding, based on a large-scale study of the genetic make-up of 26 different types of cancers, suggests cancer has less to do with where in the body it occurs, and more to do with the genetic changes that cause it to grow.

“A lot of the events that cause cancer are common between cancers of different tissue types,” said Matthew Meyerson of the Dana-Farber Cancer Institute and the Broad Institute of Harvard and the Massachusetts Institute of Technology in Boston, whose study appears in the journal Nature.

“You have breast cancer, lung cancer, cancer of the kidney - many of the events that cause these cancers are going to be the same,” Meyerson said in a telephone interview.

“What that means for treatment is that many treatments may be used across many different kinds of cancers.”

The finding is based on an effort started in 2004 to systematically map the genetic changes across different types of cancers.

The team focused on specific aberrations in the genetic code known as somatic copy-number alterations, in which segments of a tumor’s genome contain extra copies of a piece of DNA or lack the segment altogether.

For the study, the team collected more than 2,500 cancer specimens representing more than 24 cancer types, including lung, prostate, breast, ovarian, colon, esophageal, liver, brain and blood cancers.

They combined this with publicly available data from another 600 tumor samples.

“What we’re seeing here is that the copy number events that are happening in some of one cancer type are happening in some of another cancer type,” Meyerson said.

Out of 17 different types of cancer, they found that most copy number changes - either extra or missing DNA - were present in more than one type.

For drug companies, Meyerson said the finding suggests that rather than developing drugs to treat a specific type of cancer, companies may need to focus on drugs that target genetic changes that drive cancer growth.

“In principle, there could be broader drugs that could be effective against many cancers,” he said.

SOURCE: Nature, February 18, 2010.