Health Matters Blog

Genetic Risk Assessment

By Agnes Mikijaniec, ARNP

Agnes MikijaniecLast Wednesday morning, I was performing my daily routine of packing the kids’ lunches and getting them to school. The morning news was on the TV as usual. My husband then asks me “What is wrong with Angelina Jolie? Does she have breast cancer?” Every news service in the country that morning was reporting on Angelina’s announcement in the New York Times Op Ed section. In her article she states that she has the BRCA 1 gene and elected to have a double mastectomy with reconstruction. She talks about her mother’s decade long struggle with ovarian cancer, her surgery and her motivations for undergoing such an extensive procedure. “I wanted to write this to tell other women that the decision to have a mastectomy was not easy. But it is one I am very happy that I made. My chances of developing breast cancer have dropped from 87 percent to under 5 percent. I can tell my children that they don’t need to fear they will lose me to breast cancer. “

Because of the media’s focus on breast cancer and now Angelina Jolie, more Americans are learning of the genetic links to breast and ovarian cancer. Although great strides have been made in the field of oncology, cancer is still a word that strikes fear in everyone’s hearts. Many individuals, however, are unclear on how their own personal or family history relates to a genetic risk for cancer.

About 5% of cancers are considered hereditary. Hereditary cancers develop because of a change (mutation) in certain genes that normally protect the body from cancer (tumor suppressor genes). These tumor suppressor genes encode for enzymes that help stabilize DNA during the phase of replication. If one of the pair of these genes is mutated, the risk of error in the DNA significantly increases. This in turn can cause the evolution of a cancer cell. These gene mutations can be passed from one generation to the next. Genetic cancer risk can be passed from mothers or fathers to daughters or sons. For some cancer genes the risk is linked to more than one cancer. For example, the BRCA 1 and 2 genes cause an increased risk for breast and ovarian cancer, and to a lesser extent pancreatic cancer and prostate cancer in men.

Risks of hereditary breast-ovarian cancer syndrome may include, but are not limited to:

  • Breast cancer at age 45 or younger,
  • Breast cancer in both breasts,
  • Both breast and ovarian cancer in the same woman,
  • Two or more people within a family with ovarian cancer and/or breast cancer, especially if the breast cancer was diagnosed before age 50,
  • At least one family member with breast and ovarian cancer,
  • Breast cancer in men,
  • Ashkenazi Jewish heritage and ovarian cancer at any age or breast cancer before age 60.

The two genes commonly associated with breast and ovarian cancer are BRCA 1 and BRCA 2. A female without any increased risk for breast cancer has a 12% chance of developing breast cancer during her lifetime. An individual with a BRCA 1 or BRCA 2 mutation can have a 50 to 87% lifetime risk of developing breast cancer, and a 20 to 40% lifetime risk of developing ovarian cancer. Testing for the BRCA 1 or 2 genes is performed by a blood test or oral swab. A positive test means an individual has an increased risk for developing cancer, but it does not mean the person will definitely get cancer. A negative gene test does not mean a person will never develop cancer.

If one does test positive for the BRCA gene there are a number of options for decreasing the risk of developing cancer. These options can be divided into three types of risk reducing strategies – surgery, increased screening and medications. Prophylactic surgeries remove as much of the “at-risk” tissue as possible to reduce the risk of developing cancer. A bilateral mastectomy with or without reconstruction reduces the risk of developing breast cancer by 95%. Removing the ovaries, an oophorectomy, significantly reduces the risk of ovarian cancer. This is a very important intervention because ovarian cancer typically presents at an advanced stage and screening is relatively ineffective. Increased screening includes mammography, clinical breast exams and breast MRI. With careful surveillance early breast cancer can be diagnosed early enough to be successfully treated. Medications that reduce the risk of recurrence in breast cancer have also been shown to prevent the development of breast cancer. Tamoxifen has been shown in numerous studies to reduce the risk by about 50 percent in patients with increased risk of breast cancer. High quality studies are still needed to better determine the effectiveness of these options. However, all of the above strategies are considered viable options by national oncology guidelines.

A specialist in cancer genetics – genetic counselor, geneticist, or medical provider trained in cancer risk assessment – can help guide the individual through the process of discerning cancer risk as well as the benefits and drawbacks of genetic testing.

Agnes Mikijaniec, ARNP, a City of Hope-trained genetic clinician in Brattleboro Memorial Hospital’s Comprehensive Breast Program offers cancer risk assessment for hereditary breast and ovarian cancers. The Norris Cotton Cancer Center’s Familial Cancer Program also offers genetic counseling and testing for all hereditary cancers. If you feel you have a personal or familial risk for breast or ovarian cancer, you can call the BMH Comprehensive Breast Program at 802-251-8437.

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