盐湖城— A married couple who sailed from England to America around 1630 may be the ancestors of hundreds of people alive today who are at risk for a hereditary form of 结肠癌.
研究ers from Huntsman Cancer Institute (HCI) at 犹他大学 have discovered a founder mutation—a mutation that has been traced from many individuals in the present-day population back to a common ancestor—which may contribute to a significant percentage of 结肠癌 cases in the United States.
An article reporting the finding was published in the Jan. 2, 2008 issue of Clinical Gastroenterology and Hepatology. The researchers studied two large families, 一个在犹他州，一个在纽约, that both carry a specific genetic mutation responsible for increased risk of colorectal cancer. They discovered that the two families share common ancestors—a couple who came to America from England in the 1630s, 大概是清教徒的时代.
"The fact that this mutation can be traced so far back in time suggests that it could be carried by many more families in the United States than is currently known,Deborah Neklason说, Ph.D., a University of Utah research assistant professor and leader of the study. "In fact, this founder mutation might be related to many 结肠癌 cases in the United States."
The mutation causes a condition called attenuated familial adenomatous polyposis (AFAP). 没有适当的临床护理, people with the AFAP mutation have a greater than 2 in 3 risk of 结肠癌 by age 80, compared to about 1 in 24 for the general population. Yet the cancer can be prevented with proper screening 和护理.
"Knowing one has the condition can be life-saving,内克拉森说. "Not only are affected individuals at greater risk then the general population as they grow older, but precancerous polyps are often found in mutation carriers in their late teens and 结肠癌 has been diagnosed in individuals in their 20s."
然而, 她解释说, clinical recognition of AFAP can be difficult because 结肠癌 develops on average in a person's 50s and the majority of sporadic, 在职或, 结肠癌s occur after the age of 50. About a third of people with AFAP also have just a few polyps—again similar to that for sporadic 结肠癌—and they may have a limited family history.
"People need to talk with their family, 了解他们的家族癌症病史, and share this information with their doctors. 医生需要了解AFAP, 识别有风险的人, and know the screening and treatment protocols that can prevent 结肠癌 from developing,内克拉森说.
The Utah family in this study has more than 7,000 descendants spanning nine generations recorded in the Utah Population Database (UPDB), a shared resource for genetics research housed at HCI. 研究ers use UPDB to identify and study families that have higher than normal incidence of cancer or other disease, to analyze patterns of genetic inheritance, and to identify specific genetic mutations.
Known individuals in this one family account for 0.15 percent of all colorectal cancers reported in Utah from 1966 to 1995. 基于这个百分比, researchers expected to see eight cases of 结肠癌 from this family among the over 5,000 reported between 1996 and 2003. But after previous research identified this family as affected by AFAP, aggressive education and clinical intervention resulted in only one mutation carrier in the family being diagnosed with 结肠癌 during those years.
"Preventing seven cancers may not sound like much," says Neklason. "But that's seven 结肠癌s that didn't devastate this family. And consider that $50,000 is a conservative estimate for the cost of colorectal cancer treatment. That amounts to at least $350,000, and that means a lot for any family."
Co-authors on the study included physicians and researchers that belong to several University of Utah departments, including Huntsman Cancer Institute, 肿瘤科学, 人类遗传学, 和医学. Funding for the study was provided by the National Cancer Institute, 犹他州卫生部, 犹他大学, 亨茨曼癌症研究所.
The mission of Huntsman Cancer Institute (HCI) at The University of Utah is to understand cancer from its beginnings, to use that knowledge in the creation and improvement of cancer treatments, to relieve the suffering of cancer patients, and to provide education about cancer risk, 预防, 和护理. HCI is a National Cancer Institute-designated cancer center, which means that it meets the highest national standards for cancer care and research and receives support for its scientific endeavors. HCI is also a member of the National Comprehensive Cancer Network (NCCN), a not-for-profit alliance of the world's leading cancer centers, which is dedicated to improving the quality and effectiveness of care provided to patients with cancer.