Explaining the B-RST BRCA Questions
On this page we seek to clarify each of the B-RST BRCA Test FAQs by explaining each question and its significance to the assessment.
Does the woman have a medical history of any breast cancer or of ductal carcinoma in situ (DCIS) or lobular carcinoma in situ (LCIS) or has she received previous radiation therapy to the chest for treatment of Hodgkin lymphoma?
The tool is not for use by women who have a diagnosis of breast cancer. In addition, a medical history of ductal carcinoma in situ (DCIS) or lobular carcinoma in situ (LCIS) increases the risk of developing invasive breast cancer. The method used by the Breast Cancer Risk Assessment Tool to calculate the risk of invasive breast cancer is not accurate for women with a history of DCIS or LCIS. In addition, the tool cannot accurately predict the risk of another breast cancer for women who have a medical history of breast cancer.
Further, the tool is not appropriate for women who have had previous radiation therapy to the chest for treatment of Hodgkin lymphoma. There may be more appropriate tools for these women. See the "About the Gail Model" section.
Although the tool has been used with success in clinics for women with strong family histories of breast cancer, more specific methods of estimating risk are appropriate for women known to have breast cancer-producing mutations in the BRCA1 or BRCA2 genes. Similarly, there are several hereditary conditions, such as Li-Fraumeni Syndrome, that increase a woman’s risk for breast cancer. This tool will not appropriately estimate breast cancer risk for such women. There may be more appropriate tools for these women. See the "About the Gail Model" section.
The risk of developing breast cancer increases with age. The great majority of breast cancer cases occur in women older than age 50. Most cancers develop slowly over time. For this reason, breast cancer is more common among older women.
Note: This tool only calculates risk for women 35 years of age or older.
Women who had their first menstrual period before age 12 have a slightly increased risk of breast cancer. The levels of the female hormone estrogen change with the menstrual cycle. Women who start menstruating at a very young age have a slight increase in breast cancer risk that may be linked to their longer lifetime exposure to estrogen.
Risk depends on many factors, including age at first live birth and family history of breast cancer. The relationship of these two factors in white women is shown in the following table of relative risks.
Relative Risk of Developing Breast Cancer*
Age at first
|# of affected relatives|
|0||1||2 or more|
|20 or younger||1||2.6||6.8|
|25-29 or no child||1.5||2.8||4.9|
|30 or older||1.9||2.8||4.2|
For women with 0 or 1 affected relative, risks increase with age at first live birth. For women with 2 or more first degree relatives, risks decrease with age at first live birth.
* Adapted from Table 1, Gail MH, Brinton LA, Byar DP, Corle DK, Green SB, Shairer C, Mulvihill JJ: Projecting individualized probabilities of developing breast cancer for white females who are being examined annually. J Natl Cancer Inst 81(24):1879-86, 1989. [PubMed Abstract]
Having one or more first-degree relatives (mother, sisters, daughters) who have had breast cancer increases a woman's chances of developing this disease.
Has the woman ever had a breast biopsy?
7a: How many previous breast biopsies (positive or negative) has the woman had?
7b: Has the woman had at least one breast biopsy with atypical hyperplasia?
Women who have had breast biopsies have an increased risk of breast cancer, especially if their biopsy specimens showed atypical hyperplasia. Women who have a history of breast biopsies are at increased risk because of whatever breast changes prompted the biopsies. Breast biopsies themselves do not cause cancer.
The original Breast Cancer Risk Assessment Tool was based on data from white women. But race/ethnicity can influence the calculation of breast cancer risk. Over the years, as additional data became available, researchers at the NCI updated the tool to more accurately estimate risk for African American, and Asian and Pacific Islander women. (see references 5 and 6). For Hispanic women, part of the model is derived from white women who participated in the Breast Cancer Detection Demonstration Project and from SEER data. The risk estimates for Hispanic women are therefore subject to greater uncertainty than those for white women. Calculations for American Indian and Alaskan Native women are based entirely on data for white women and may not be accurate. Recent immigrants from rural China and certain other parts of Asia probably have lower risk than predicted by the model. Researchers are conducting additional studies, including studies with minority populations, to gather more data and to increase the accuracy of the tool.
Note: If the woman's race/ethnicity is unknown, the tool will use data for white females to estimate the predicted risk.
To calculate breast cancer risk using Asian-American as the race/ethnicity, the sub race/ethnicity needs to be known. If the sub-category of race/ethnicity is not known, then “Unknown” should be selected in Question 7, rather than Asian-American. The “Other Asian American” category includes women of Asian Indian/Pakistani, Korean, Vietnamese, Laotian, and Kampuchean descent. The “Other Pacific Islander” category includes women of Guamanian, Samoan, and Tongan descent.
For further clarification on the B-RST BRCA test questions, give us a call at 914.242.7640 to schedule an appointment with our genetic counselor.