Hereditary Cancer Risk Assessment Including Breast and Ovarian Cancer
- These tests are based on your DNA sequencing analysis and some of these tests may require next generation sequencing (NGS) of your genome or exome sequencing.
- This test helps in identifying the patients and family who may be possibly at increased risk of developing certain type of cancer and also provides an opportunity to manage and understand the risk for cancer
Breast cancer is currently the second most common cancers among Indian women (19%) after cervical cancer (30%). On an average 80,000 women are diagnosed with breast cancer and approximately 40,000 deaths occur every year due to this disease (GLOBOCAN 2002). In Indian women the age of onset is almost a decade earlier than in Western populations (Saxena et al, 2006).
Approximately 5-10% of the total breast cancer cases are familial (Easton and Peto, 1990; Claus et al., 1991; 1996), with approximately 20% of the familial cases being due to mutations in the BRCA1 and BRCA2 genes (Valarmathi et al., 2004). Every woman is born with the BRCA1 (breast cancer gene 1) and BRCA2 (breast cancer gene 2) genes. When functioning normally, these genes do not pose any risk to a woman’s health. However, some women may be born with or experience mutations of the BRCA genes through their lifetime. Though researchers are still uncertain what causes changes in these genes to occur, women who have BRCA mutations are at increased risk for developing breast cancer compared with women who do not have these mutations. Over a lifetime, women with BRCA mutations have a 60% to 85% higher chance of developing breast cancer.
What are the Benefits of this Test?
- This test aids doctors in identifying patients who are at a risk for developing Breast/Ovarian cancer.
- If positive, proper steps can be taken with the advice of the doctor regarding how to detect these cancers at an early stage. This will help prevent progression of early stage cancer to late stage cancer.
- Women with breast cancer may have better responses to certain treatments that are specifically designed for BRCA positive patients.
- Women may take preventive measures (such as making changes in diet, exercising, abstaining from smoking or taking tamoxifen (Fisher et al, 2005, U.S. Preventive Services Task Force, 2002)) by consulting their doctor to help reduce their risk of breast cancer if they test positive for BRCA mutations. Such women may also learn about performing self-breast examination proactively and having annual or semi-annual clinical examinations and annual mammography.
- Women with BRCA1 mutations may also undergo Ovarian cancer screening (transvaginal ultrasonography, measurement of CA-125 serum level) (Burke et al, 1997; NIH consensus conference. Ovarian cancer, 1995),
- The USPSTF found fair evidence that prophylactic surgery (ie. mastectomy or oophorectomy after completion of childbearing) significantly decreases the incidence of Breast/Ovarian cancer respectively, in women who test positive for deleterious BRCA1 or BRCA2 mutations (NIH consensus conference. Ovarian cancer, 1995; Meijers-Heijboer et al, 2001). Preventive Oophorectomy has been shown to reduce not only the risk of Ovarian cancer among carriers but also the risk of breast cancer (Rebbeck, 2002; Kauff et al, 2002).
- Other family members may decide if they wish to be tested for BRCA mutations based on the results of a woman’s test in their family.
This test is recommended for individuals with
- Breast cancer affecting both breasts (bilateral breast cancer)
- A family history of breast cancer in two or more close relatives, such as parents, siblings and children.
- A family history of breast cancer in two or more close relatives (parents, siblings and children) or in more than one generation in the same side of the family.
- A family member who developed breast cancer before the age of 50 years on either mother’s or father’s side of the family (especially aunt or grandmother).
- One or more family member with cancer in both breasts
- A family history of Ovarian cancer
- A frequent occurrence of Ovarian cancer within your family
- A positive BRCA1 or BRCA2 genetic test in a relative
- Both Breast/Ovarian cancers