Genetics of Duodenal Cancer

Last Modified: March 20, 2009

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Question

Dear OncoLink "Ask The Experts,"

My 28 year-old triplet daughter found out she has duodenum cancer. She had surgery last month. She has an identical sister who [the] doctors want tested. They did a CT scan and ran blood work and she appears to be cancer free. How often should the unaffected sister be tested? Should the girls’ triplet brother be tested also? I also have two other older daughters. Should they be tested also? We were told this is a genetic cancer and usually affects people in their 60's.

Answer

Jill Stopfer, MS, CGC, Certified Genetic Counselor, responds:

Duodenal cancers can be associated with Familial Adenomatous Polyposis (FAP), which is a genetic condition that does run in families. People with FAP tend to have many, many polyps, so it would be interesting to know if she ever had a colonoscopy done, and if so, if she had any polyps.

Knowing which gene or which condition your daughter with duodenal cancer has that might have made her more vulnerable to develop this cancer would be helpful to her siblings and other family members. Your daughter (and both siblings) could certainly benefit from being seen by a genetic counselor at a GI Genetics Program. You can find a local program here: http://www.nsgc.org/resourcelink.cfm

It is important to be seen by a counselor and not just have genetic testing. If not, people are left with test results and not a clear understanding of what they mean for them & their family. But a visit to a counselor does not in any way mean you must have testing. The counselor will review what can be learned, what the results will and won’t mean, and then the person can make an educated decision whether to be tested or not.

Unless someone can sort out the type of genetic risk that led to the duodenal cancer, testing the person who had the duodenal cancer will not be informative for the other family members. So basically the person with the cancer must be tested first in order to determine what abnormality to look for in the others.

In general, the screening for duodenal cancer is upper endoscopy, but if the duodenal cancer is part of FAP, then additional screening is warranted, too (annual colonoscopy). If the duodenal cancer is part of a different hereditary cancer syndrome, then similarly there may be additional screening recommendation for other cancers as well.