Breast cancer is the leading cause of cancer deaths in women ages 15 to 54. Although less common among younger women, breast cancer is more likely to be diagnosed at a later stage, more likely to be associated with genetic risk factors and have lower survival rates.
Background
Breast cancer usually occurs in older women. According to the American Cancer Society, or ACS, the median age for diagnosis is 61 years of age. The National Cancer Institute, or NCI, reports 95 percent of new cases and 97 percent of breast cancer deaths occur in women ages 40 and older.
However rare--only one in 2,500 women develop breast cancer by age 30--when breast cancer occurs in young women it tends to be diagnosed at a later stage and is more likely to be associated with genetic risk factors.
Diagnosis
Diagnosis in young women is more difficult because of their denser breast tissue. In addition, young women and their physicians often discount breast cancer risk. These factors translate into diagnoses at later stages and a poorer prognosis. Breast cancers among younger women also tend to be more aggressive. According to the NCI, survival is lower for women 15 to 29 years of age than for older women, regardless of the cell type of the cancer and stage.
Risk Factors
There is no single cause of breast cancer, and research on factors particular to young women is ongoing. Broadly, women with a family history, those who smoke, those who consume more than a glass of alcohol per day and those who are obese are at higher risk.
Estrogens are associated with risk, which is why early menstruation, age at first pregnancy, late menopause and birth control pills are all risk factors.
Family history is a strong risk factor. According to the ACI, having a first-degree such as a mother or sister with breast cancer doubles your risk. Having two triples it.
Certain genetic mutations increase both risk and prognosis. Radiation therapy also increases the risk.
Genetics
According to the National Institute of Medicine, although only 5 percent of women with breast cancer have BRCA1 and BRCA2 mutations, young women with breast cancer are more likely to have these genes. In fact, according to the Fred Hutchinson Cancer Research Center, or FHCRC, 16 percent of women diagnosed before age 35 have a BRCA mutation.
In addition, FHCRC notes that young women with the BRCA1 or BRCA2 genes are four times more likely to develop cancer in the breast opposite to their initial tumor than those without these genetic defects.
Exposure to Radiation
A history of radiation therapy is risk factor. Radiation therapy for young women with Hodgkin's lymphoma, for example, significantly increases the risk of early onset breast cancer, although the relative risk varies on the age at diagnosis and treatment for Hodgkin's and the type and dose of radiation.
Outlook
Breast cancer in younger women is often more aggressive and less responsive to hormone treatments. However, according to the NCI, more than 80 percent of young women diagnosed with breast cancer survive at least five years.
References
- American Cancer Society: Breast Cancer Facts & Figures: 2009-2010.
- National Cancer Institute: SEER Stat Fact Sheets: Breast.
- American Cancer Society: Causes, Risk Factors and Prevention: Breast Cancer.
- JAMA: Breast Cancer Following Radiotherapy and Chemotherapy Among Young Women with Hodgkin Disease: 2003.
- Fred Hutchinson Cancer Research Center: Breast Cancer Patients with BRCA Gene Mutations Are Four Times More Likely to Get Cancer in Opposite Breast: 2010.
