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How Are Young Women Affected by Breast Cancer?

While most women who develop breast cancer are older, breast cancer can occur in younger women. Approximately 11% of all invasive breast cancers are diagnosed in women under the age of 45, and breast cancer is the most frequently diagnosed cancer in young adults.1 Age is the biggest risk factor in developing breast cancer, with a woman’s risk of breast cancer increases as she ages. However, age is only one risk factor, and other factors often play a role when breast cancer is diagnosed in younger women, including genetic mutations, like BRCA1, BRCA2, and others.2

When breast cancer occurs in a young woman, it is more common for there to be a family history of breast cancer. Because of this, young women with breast cancer may want to consider getting genetic screening and can discuss testing options with their doctor.3 In one study of women under the age of 30 with breast cancer, approximately half who had family histories of breast cancer had genetic mutations in BRCA1, BRCA2, or TP53. Less than 10% of the women without a family history of breast cancer had these genetic mutations.4,5 If a woman tests positive for genetic mutations, they may also want to consider preventive measures to reduce the chance of future cancers. Preventive measures may include taking certain medications or having prophylactic (preventive) surgery.6

Risk factors

Risk factors are identified characteristics that can potentially increase a person’s likelihood of developing a disease. However, risk factors do not necessarily cause breast cancer. Young women are more likely to develop breast cancer if they have4:

  • A family history of breast cancer
  • Genetic mutations, such as BRCA1, BRCA2, and/or TP53
  • Previous radiation therapy to the chest, such as for Hodgkin lymphoma treatment
  • Started menstruating at an early age (before age 12)
  • Recently used oral contraceptives
  • Heavy alcohol consumption
  • High intake of red meat

Unique challenges of breast cancer in young women

Learning about a breast cancer diagnosis is distressing at any age. However, when breast cancer occurs in young women, there are additional challenges, including psychosocial challenges, fertility concerns, and the potential that treatment may induce premature menopause.4

More aggressive cancers and higher mortality rates in young women

Generally, breast cancers in younger women tend to be larger tumors, more aggressive cancers, and more likely to have lymph node involvement. Breast cancer tumors in young women, especially in young black women, are more likely to be “triple negative” – a type of breast cancer that is hormone receptor negative (estrogen receptor negative and progesterone receptor negative) and HER2 negative. One research study found that 56% of African American women and 42% of Caucasian women with breast cancer aged 20-34 had triple-negative breast cancer. Triple-negative breast cancers are more challenging to treat, as there are currently no targeted therapies for this type of breast cancer and hormone therapies are not effective for these cancers; however, there are other available treatments.4

Treatment for young women with breast cancer

Treatment options for young women with breast cancer are based on the individual’s type of breast cancer and the tumor’s characteristics, such as whether it is hormone receptor-positive or HER2 positive. Treatment may include3:

Some treatments, such as some forms of chemotherapy or hormone therapy, may cause a young woman to go into premature menopause. Young women should talk to their doctor about their treatment and fertility options.3,4

Written by: Emily Downward | Last reviewed: December 2018.
  1. Rosenberg SM, Newman LA, Partridge AH. Breast cancer in young women: rare disease or public health problem? JAMA Oncol. 2015;1(7):877-878. doi:10.1001/jamaoncol.2015.2112.
  2. Breast cancer risk in American women. National Cancer Institute. Available at https://www.cancer.gov/types/breast/risk-fact-sheet. Accessed 7/26/18.
  3. ESO-ESMO 3rd international consensus guidelines for breast cancer in young women (BCY3). The Breast. 2017 Oct;35:203-217. doi: https://doi.org/10.1016/j.breast.2017.07.017.
  4. Anders CK, Johnson R, Litton J, Phillips M, Bleyer A. Breast Cancer Before Age 40 Years. Seminars in oncology. 2009;36(3):237-249. doi:10.1053/j.seminoncol.2009.03.001.
  5. Lalloo F, Varley J, Moran A, Ellis D, O'dair L, Pharoah P, Antoniou A, Hartley R, Shenton A, Seal S, Bulman B, Howell A, Evans DG. BRCA1, BRCA2 and TP53 mutations in very early-onset breast cancer with associated risks to relatives. Eur J Cancer. 2006 May; 42(8):1143-50.
  6. Can I lower my risk of breast cancer? American Cancer Society. Available at https://www.cancer.org/cancer/breast-cancer/risk-and-prevention/can-i-lower-my-risk.html. Accessed 7/26/18.