February 26, 2001

Genetic counselor Amanda Walsh describes her job as part detective, part scientist, part problem-solver, and always a careful listener. Walsh joined the Division of Human Genetics at the Health Center and Connecticut Children's Medical Center in May 2000, where she counsels individuals and families about hereditary cancer risks and advises patients about delicate decisions regarding testing for cancer susceptibility genes.

Walsh says human genetics is a fast-changing field: "We are seeing amazing changes in our ability to predict cancer risk, to better understand prognoses, and to plan treatments," she says.

And while knowledge about cancer genetics is rapidly growing, Walsh stresses that many questions remain unanswered. For example, although a handful of cancer susceptibility genes have been identified, there are likely many more genes yet to be discovered.

In the meantime, Walsh uses the most up-to-date tools to help patients carefully assess their hereditary cancer risk. When appropriate, she helps patients weigh the pros and cons of genetic testing. Once testing is completed, Walsh helps patients put that information into context in their lives.

"Information can be power. Knowing an estimated risk of developing a hereditary cancer can help people make important decisions regarding lifestyle, frequency of screening tests, medications and other options," she says.

Only about five to 10 percent of cancers are hereditary, Walsh says. In these cases, an individual inherits a susceptibility gene from one parent, which dramatically increases the person's risk of developing cancer. Signs suggesting hereditary cancer include:

• two or more relatives with the same type of cancer, on the same side of the family;
  
  
• several generations affected;
  
  
• early ages of cancer diagnosis - usually under age 50;
  
  
• individuals with more than one primary cancer;
  
  
• the occurrence in one family of cancers that are known to be genetically related, such as breast and ovarian cancer or colon and uterine cancer;
  
  
• the presence of physical signs that are known to be associated with hereditary cancer, such as moles and melanoma or polyps and colon cancer.
  
  

Walsh says the most frequently asked questions are about breast and ovarian cancer. Researchers have identified two major breast and ovarian cancer susceptibility genes, BRCA1 and BRCA2. The lifetime risk for breast cancer for women with BRCA mutations is between 50 and 85 percent. The lifetime risk for ovarian cancer varies even more significantly between families, but may range between 20 and 60 percent.

The decision to participate in BRCA1 or BRCA2 testing is a difficult one, Walsh says. The presence of either of these genes does not guarantee that a woman will develop cancer, nor does the absence guarantee that she won't.

"It's important to remember that some hereditary cancers are caused by susceptibility genes that have not yet been identified," she says, "so testing for those genes is not available at this time."

She said many inquiries are also made about colorectal cancer, the second most common cause of cancer deaths in the United States. Genetic testing can determine if an individual has a colorectal cancer syndrome such as Hereditary Nonpolyposis Colorectal Cancer. Accurate identification of people with syndromes like this is important because physicians can recommend specific measures to prevent cancer, or to find it as early as possible - when treatment is most successful.

"Screening tests and early interventional tools for colorectal cancer are very effective," says Robert Greenstein, chair of the division of human genetics.

"Applying information learned from risk assessments and genetic testing to help patients prevent, detect or overcome cancers is what we strive for," Walsh adds.

Before joining the Health Center faculty, Walsh worked in genetic counseling at Columbia University and at Rhode Island Hospital. She is a graduate of the University of Massachusetts and received her graduate degree in genetics and cell biology from the University of Minnesota.

Maureen McGuire