A new study has reported that women with a first degree relative (mother, sister or daughter) with breast cancer have a 73% higher risk of triple negative (ER-/PR-/HER2-) breast cancer than women generally. However, such women also have a 62% higher risk of ER+ breast cancer and a 56% higher risk of hormone receptor negative/HER2 overexpressing (ER-/PR-/HER2+) breast cancer.
Triple negative breast cancer accounts for fewer than 20% of breast cancers overall, but it is the predominant subtype among BRCA1 mutation carriers. However, few studies have examined the association between family history of breast cancer and risk of triple negative breast cancer.
The authors examined data from 2,599,946 mammograms on 1,054,466 women aged 40 to 84 years collected by the Breast Cancer Surveillance Consortium. Fifteen percent of these women reported a first degree family history of breast cancer.
A total of 705 women were found to have triple negative disease, 10,026 had ER+ disease, and 308 had ER-/PR-/HER2+ breast cancer. First degree family history was found to similarly increase the risk of all three subtypes. Risk was highest among women with at least two first degree relatives with breast cancer.
Compared to women with no affected first degree relatives, those with at least two affected first degree relatives had 2.66 times the risk of triple negative breast cancer, 2.05 times the risk of ER+ breast cancer, and 2.25 times the risk of ER-/PR-/HER2+ breast cancer.
Selected breast cancer studies
Physical activity and the risk of breast cancer in BRCA1/2 mutation carriers in the Netherlands.
Pijpe A, Manders P, van Leeuwen F, Rookus M. Physical activity and the risk of breast cancer in BRCA1/2 mutation carriers in the Netherlands.. Poster Discussion Abstracts. American Association for Cancer Research; 2009; 10.1158/0008-5472.sabcs-505
Phenocopies in BRCA1 and BRCA2 families: evidence for modifier genes and implications for screening
Smith A, Moran A, Boyd MC, Bulman M, Shenton A, Smith L, et al. Phenocopies in BRCA1 and BRCA2 families: evidence for modifier genes and implications for screening. Journal of Medical Genetics. BMJ; 2006; 44:10-15 10.1136/jmg.2006.043091
Some characteristics of familial breast cancer
Anderson DE. Some characteristics of familial breast cancer. Cancer. Wiley; 1971; 28:1500-1504 10.1002/1097-0142(197112)28:6<1500::aid-cncr2820280623>3.0.co;2-d
Breast and Ovarian Cancer in Relatives of Cancer Patients, with and without BRCA Mutations
Lee JS, John EM, McGuire V, Felberg A, Ostrow KL, DiCioccio RA, et al. Breast and Ovarian Cancer in Relatives of Cancer Patients, with and without BRCA Mutations. Cancer Epidemiology Biomarkers & Prevention. American Association for Cancer Research (AACR); 2006; 15:359-363 10.1158/1055-9965.epi-05-0687