Colon cancers that are inherited — and that's nearly one-third of them — may be more aggressive and strike people when they're younger.

Huntsman Cancer Institute researchers have led an effort to find genes involved in the formation of that familial cancer, because if you don't know you've inherited it and you follow traditional screening schedules, it may be too late.

Now those researchers believe they've found a section of chromosome 7 where a subset of familial colon cancers begins.

"We're really interested in identifying the causes of that 30 percent (of colon cancers) because those are the people who would need early and more aggressive screening," said Deb Neklason, HCI investigator and a research assistant professor at the University of Utah who led the multi-center research.

Neklason and colleagues at other cancer centers nationally studied genetic material from at least two siblings who'd had colon cancer in 83 separate families. In all, they analyzed materials from 163 individuals who had had colon cancer. They found similarities on a region of chromosome 7 (referred to as 7q31) and also noted that siblings who have that genetic region tend to develop cancer 3.8 years earlier than siblings who do not. That finding alone seems to support the theory that there's something related to the cancer happening right there.

"There's something in that region that's causing them both to have colon cancer," she said. "There are quite a few genes in that region. We need to pick it apart and find out which gene it is."

Their findings are published in the Nov. 1 issue of Cancer Research.

While they were doing their research, they received some confirmation from a study out of England that pointed to activity in a region on Chromosome 3, but also activity on 7. "And we saw a little going on on Chromosome 3, as well," she said.

The researchers looked at 1,100 genetic markers in those sibling pairs and trios diagnosed with colon cancer to hone in on this region. And the finding is potentially very important, because where genetic information is unknown, it's harder to make sure appropriate screening is done early. They hope the research not only answers questions about the cancer process, but also helps create a screening test to detect genetic colon cancers.

Next up for the researchers is a look at the genes in this region to see if they can identify the actual changes that occur. Because there is a lot of change, they're paying attention to likely cancer pathways. Examination of the cancers themselves may reveal specific genetic changes that would help understand what's going on. And they're hoping that other researchers will also have findings that bolster this one. They plan to study more sibling pairs, too.

HCI took the lead on the research, which was funded by the National Cancer Institute. Other centers involved were University of California Irvine; Karmanos Cancer Institute; Johns Hopkins University; Colorado School of Public Health; Duke University; University of North Carolina at Chapel Hill; University of Texas Southwestern Medical Center; University of Texas MD Anderson Medical Cancer Center; Cancer Therapy and Research Center and University of Texas San Antonio; University of Pennsylvania; Massachusetts General Hospital Statistical Coordinating Center; Yale Center for Informatics and the National Cancer Institute.

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