Cancer Genes More Abundant Than Thought

Cancer genes may be more abundant than scientists
previously thought.

So say cancer gene specialists including P. Andrew Futreal, PhD, co-leader
of the Cancer Genome Project at the Wellcome Trust Sanger Institute in
Cambridge, England.

Futreal's team is researching the connection between genes and cancer.
They're combing through human DNA to look for genetic patterns associated with

As part of those efforts, Futreal and colleagues screened the DNA from 210
human cancers and from healthy human tissue. They focused on 518 genes that
make a type of protein that has been linked to various cancers.

The DNA tests had widely varying results. Of the 210 cancers, 73 had no
mutations in the studied genes, while others had "exceptionally large"
numbers of mutations, the researchers write in Nature.

Drivers and Passengers

All in all, the scientists spotted more than 1,000 gene mutations in the
cancers' DNA.

Most of those mutations apparently don't affect cancer development. The
researchers call those mutations "passenger mutations."

However, the scientists also spotted an estimated 158 "driver
mutations" that appeared to increase cancer risk. Of the 518 genes studied,
nearly 120 had driver mutations, the study shows.

"It turns out that most mutations in cancers are passengers,"
Futreal says in a Wellcome Trust Sanger Institute news release.

"However, buried amongst them are much larger numbers of driver
mutations than was previously anticipated," he continues. "This
suggests that many more genes contribute to cancer development than was

The study doesn't show that those gene mutations were the sole cause of
cancer. A mix of genetic and environmental factors is thought to affect cancer

Reviewed by Louise Chang
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