SALT LAKE CITYFor people with a family history of adenomas (colon polyps that lead to colon cancer), up to 10 percent of colorectal cancers could be missed when current national screening guidelines are followed. Colorectal cancer is the third most common cancer in the United States and the second deadliest.
In the largest population-based study to date, researchers from Huntsman Cancer Institute (HCI) at the University of Utah made this finding based on nearly 127,000 individuals who underwent colonoscopy in Utah between 1995 and 2009. The results appear online in "Early View" of the journal Cancer.
Family history of colon cancer is widely accepted as a factor that increases risk for the disease. This study quantified the increased risk to first-degree relatives (parents, siblings, children) of patients with adenomas or advanced adenomas at 35 to 70 percent higher than in relatives of patients without these conditions. The study also detected smaller percentages of elevated risk in more distant second- (aunts and uncles, grandparents) and third-degree relatives (cousins, nieces and nephews, great-grandparents).
"We expected to see increased risk in first-degree relatives, but we weren't sure the risk would also be higher for more distant relatives in multiple generations," said N. Jewel Samadder, MD, MSc, principal investigator of the study and an HCI investigator. "The biggest surprise was the percentage of missed cancers under the current guidelines. We figured there would be a few percent, but 10 percent is a large number," he added.
For the general population, current national colon cancer screening guidelines recommend colonoscopy every 10 years starting at age 50. For first-degree relatives of people diagnosed with colorectal cancer or advanced adenomas before they were 60 years old, increased screening is recommendedcolonoscopies every five years starting at age 40. The screening recommendations for more dist
|Contact: Linda Aagard|
University of Utah Health Sciences