This summary table contains detailed information about research studies. Summary tables offer an informative look at the science behind many breast cancer guidelines and recommendations. However, they should be viewed with some caution. In order to read and interpret research tables successfully, it is important to understand some key concepts. Learn how to read a research table.
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BRCA1 and BRCA2 mutations and risk of breast and ovarian cancer
Women who carry a BRCA1 or BRCA2 gene mutation are at an increased risk of both breast and ovarian cancer. These women have a 60 to 80 percent chance of getting breast cancer by age 70 and a 10 to 70 percent chance of getting ovarian cancer by age 70. In comparison, the average woman in the United States has, by age 70, an eight percent chance of getting breast cancer and a 1½ percent chance of getting ovarian cancer [1,2].
Prevalence of BRCA1 and BRCA2 mutations
The prevalence of BRCA1 gene mutations in the general population is quite small (only about one in 800 women) [3]. However, women of Ashkenazi Jewish descent are more likely to carry a BRCA1 or BRCA2 mutation, (about one in 40 have either a BRCA1 or BRCA2 mutation) [3,4].
BRCA1 and BRCA2 mutations and risk of other types of cancer
BRCA1 and BRCA2 carriers may also have an excess risk of colon cancer, prostate cancer (in male carriers) and some second primary cancers (new cancers that develop after a first breast cancer). However, these data are limited.
International Breast Cancer Linkage Consortium
Much of the research on genetic mutations and breast cancer risk has been done by the International Breast Cancer Linkage Consortium. This group has collected data on over 200 families worldwide. Each family has at least four family members with breast cancer.
Study selection criteria: For family-based studies: Studies with more than 200 families that have four or more members with breast cancer. For population-based studies: Studies with at least 100 cancer cases. For pooled analyses: Studies with at least 400 families.
Table note: BRCA1 carriers seem to have slightly different cancer risks than BRCA2 carriers. However, the two groups are sometimes combined in the table below since there are so few data on either group alone.
Study
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Study Characteristics
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Study Population
(number of participants)
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Cumulative Risk of Different Types of Cancer
by age 70 (95% CI)
|
| |
Second Cancers in Women with Breast Cancer
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Breast Cancer
|
Ovarian
Cancer
|
Other
Cancers
|
Breast Cancer (other side)
|
Ovarian Cancer
|
Family-based studies
|
BRCA1
|
German Consortium for Hereditary Breast and Ovarian Cancer [5]
|
BRCA1 mutation carrier families
|
645 families
|
|
|
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30.4%
(24-27%)*,†
|
|
Breast Cancer Linkage Consortium [6-8]
|
BRCA1 mutation carrier families
|
237 families that have 4 or more members with breast cancer
|
87%
(72-95%)
|
63%
|
Colon cancer:
Highly increased risk
|
64%
|
44%
(28-56%)
|
Evans et al. [9]
|
BRCA1 mutation carrier families
|
223 families
|
68%
(65-71%)
|
60%
|
|
|
|
BRCA2
|
German Consortium for Hereditary Breast and Ovarian Cancer [5]
|
BRCA2 mutation carrier families
|
333 families
|
|
|
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20.1%
(12-28%)*
|
|
Breast Cancer Linkage Consortium [10-12]
|
BRCA2 mutation carrier families
|
237 families that have 4 or more members with breast cancer
|
84%
(43-95%)
|
27%
(0-47%)
|
Prostate cancer (men):
Highly increased risk
|
52%
(42-61%)
|
|
Population-based studies
|
Struewing et al. [13]
|
Jewish residents of Washington, DC area
|
5,318
|
56%
(40-73%)
|
16%
(6-28%)
|
Prostate cancer (men):
16%
(4-30%) |
|
|
Lubinski et al. [14]
|
Women with a BRCA1 mutation
|
1,477
(130 breast cancer cases)
|
Women in North America:
76%‡
Women in Poland:
58%‡
|
|
|
|
|
Begg et al. [15]
|
Women with breast cancer diagnosed before age 55
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1,394
|
36%
(21-58%)
(BRCA1)
47%
(25-100%)
(BRCA2)§
|
|
|
48%
(30-67%)
(BRCA1)
59%
(30-84%)
(BRCA2)||
|
|
King et al. [16]
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Ashkenazi Jewish women with breast cancer
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1,008
|
69%
(BRCA1)
74%
(BRCA2)
|
46%
(BRCA1)
12%
(BRCA2)
|
|
|
|
Niell et al. [17]
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Ashkenazi Jews
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1,002 colon cancer cases
|
|
|
Colon cancer:
No excess risk
|
|
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Leongamornlert et al. [18]
|
British men with prostate cancer
|
913 prostate cancer cases
|
|
|
Prostate cancer:
8.6%¶
(BRCA1) |
|
|
Tryggvadottir et al. [19]
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Icelandic women with breast cancer and their first-degree relatives
|
847 women with breast cancer and 2,836 first degree relatives
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46.3% (BRCA2)
|
|
|
|
|
Thorlacius et al. [20]
|
Icelandic women with breast cancer
|
575
|
37%
(22-54%)
(BRCA2)
|
|
|
|
|
Warner et al. [21]
|
Jewish women with breast cancer
|
457
|
60% (BRCA1)
28% (BRCA2)
|
|
|
|
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Rafner et al. [22]
|
Icelandic women with ovarian cancer
|
235 cases
|
|
Highly increased risk (BRCA2)
|
|
|
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Kirchhoff et al. [23]
|
Ashkenazi Jewish men with prostate cancer
|
251
|
|
|
Prostate cancer (men): Increased risk (BRCA2)
No excess risk (BRCA1)
|
|
|
Pooled analyses
|
Antoniou et al. [24]
|
22 studies
|
429 families
|
46-59% (BRCA1)
39-51% (BRCA2)
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33-36%
(BRCA1)
11-12%
(BRCA2)
|
Prostate cancer (men): Increased risk
Pancreatic cancer: Increased risk
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* Cumulative risk for age 75.
† For women who had their first breast cancer at age 40 or younger, the risk of contralateral (opposite side) breast cancer was higher. Twenty-five years after their first breast cancer, 63% of women diagnosed at age 40 or younger developed a contralateral breast cancer compared to 20% of women first diagnosed after age 50.
‡ For women who did not have an oophorectomy (surgical removal of the ovaries) to lower their cancer risk.
§ By age 80, cumulative risk of breast cancer increased to 58% (30-80%) for BRCA1 carriers and 58% (38-81%) for BRCA2 carriers.
|| By age 80, cumulative risk of a second breast cancer in the opposite breast increased to 47% (25-100%) for BRCA1 carriers and 60% (34-92%) for BRCA2 carriers.
¶ Cumulative risk for age 65.
References
- American Cancer Society. Breast Cancer Facts & Figures 2009-2010. American Cancer Society, 2009.
- American Cancer Society. Detailed guide on ovarian cancer. Do we know what causes ovarian cancer? American Cancer Society, 2010.
- Ford D, Easton DF, Peto J. Estimates of the gene frequency of BRCA1 and its contribution to breast and ovarian cancer incidence. Am J Hum Genet. 57(6):1457-1462, 1995.
- Hartge P, Struewing JP, Wacholder S, et al. The prevalence of common BRCA1 and BRCA2 mutations among Ashkenazi Jews. Am J Hum Genet. 64(4):963-970, 1999.
- Graeser MK, Engel C, Rhiem K, et al. Contralateral breast cancer risk in BRCA1 and BRCA2 mutation carriers. J Clin Oncol. 27(35):5887-92, 2009.
- Easton DF, Bishop DT, Ford D, Crockford GP. Genetic linkage analysis in familial breast and ovarian cancer: results from 214 families. The Breast Cancer Linkage Consortium. Am J Hum Genet. 52(4):678-701, 1993.
- Easton DF, Ford D, Bishop DT. Breast and ovarian cancer incidence in BRCA1-mutation carriers. Breast Cancer Linkage Consortium. Am J Hum Genet. 56(1):265-271, 1995.
- Ford D, Easton DF, Bishop DT, et al. Breast Cancer Linkage Consortium: Risks of cancer in BRCA1-mutation carriers. Lancet. 343(8899):692-695, 1994.
- Evans DG, Shenton A, Woodward E, Lalloo F, Howell A, Maher ER. Penetrance estimates for BRCA1 and BRCA2 based on genetic testing in a Clinical Cancer Genetics service setting: risks of breast/ovarian cancer quoted should reflect the cancer burden in the family. BMC Cancer. 8:155, 2008.
- Ford D, Easton DF, Stratton M, et al. Genetic heterogeneity and penetrance analysis of the BRCA 1 and BRCA 2 genes in breast cancer families. The Breast Cancer Linkage Consortium. Am J Hum Genet. 62(3):676-89, 1998.
- Easton DF, Steele L, Fields P, et al. Cancer risks in two large breast cancer families linked to BRCA2 on chromosome 13q12-13. Am J Hum Genet. 61(1):120-128, 1997.
- Cancer risks in BRCA2 mutation carriers. The breast cancer linkage consortium. J Natl Cancer Inst. 91(15):1310-1316, 1999.
- Struewing JP, Hartge P, Wacholder S, et al. The risk of cancer associated with specific mutations of BRCA1 and BRCA2 among Jewish Ashkenazi Jews. N Engl J Med. 336(20):1401-1408, 1997.
- Lubinski J, Huzarski T, Byrski T, et al. for the Hereditary Breast Cancer Clinical Study Group. The risk of breast cancer in women with a BRCA1 mutation from North America and Poland. Int J Cancer. 131(1):229-34, 2012.
- Begg CB, Haile RW, Borg A, et al. Variation of breast cancer risk among BRCA1/2 carriers. JAMA. 299(2):194-201, 2008.
- King MC, Marks JH, and Mandell JB. Breast and Ovarian Cancer Risks Due to Inherited Mutations in BRCA1 and BRCA2. Science. 302(5645):643-6, 2003.
- Niell BL, Rennert G, Bonner JD, et al. BRCA1 and BRCA2 Founder Mutations and the Risk of Colorectal Cancer. J Natl Cancer Inst. 96(1):15-21, 2004.
- Leongamornlert D, Mahmud N, Tymrakiewicz M, et al. Germline BRCA1 mutations increase prostate cancer risk. Br J Cancer. 106(10):1697-701, 2012.
- Tryggvadottir L, Sigvaldason H, Olafsdottir GH, et al. Population-based study of changing breast cancer risk in Icelandic BRCA2 mutation carriers, 1920-2000. J Natl Cancer Inst. 98(2):116-22, 2006.
- Thorlacius S, Struewing JP, Hartge P, et al. Population-based study of risk of breast cancer in carriers of BRCA2 mutation. Lancet. 352(9137):1337-9, 1998.
- Warner E, Foulkes W, Goodwin P, et al. Prevalence and Penetrance of BRCA1 and BRCA2 Gene Mutations in unselected Ashkenazi Jewish Women with Breast Cancer. J Natl Cancer Inst. 91(14):1241-1247, 1999.
- Rafner T, Benediksdottir KR, Eldon BJ, et al. BRCA2, but not BRCA1, mutations account for familial ovarian cancer in Iceland: a population-based study. Eur J Cancer. 40(18):2788-93, 2004.
- Kirchhoff T, Kauff ND, Mitra N, et al. BRCA mutation and risk of prostate cancer in Ashkenazi Jews. Clin Cancer Res. 10(9):2918-21, 2004.
- Antoniou AC, Cunningham AP, Peto J, et al. The BOADICEA model of genetic susceptibility to breast and ovarian cancers: updates and extensions. Br J Cancer. 98(8):1457-66, 2008.
Updated 08/13/12
