The incidence of breast cancer among African-American women under 40 is higher than that of White women under 40, according to the results of an analysis published in the Journal of the National Cancer Institute.
Breast cancer is the second leading cause of cancer death in women in the United States, with approximately 180,000 cases diagnosed each year. Progress in the areas of screening and treatment has allowed for earlier detection and higher cure rates. Researchers continue to study the incidence rates and patterns of this disease with the hopes of further improving screening, prevention, and treatment.
The incidence of postmenopausal breast cancer has been on the rise, which may be largely attributable to more successful screening for the disease, as well as the use of menopausal hormones. However, the incidence rates of breast cancer in younger women have received less attention. Researchers at the National Cancer Institute recently used the Institute’s Surveillance, Epidemiology, End Results (SEER) Database to analyze trends in breast cancer incidence during the period of 1992-2004.
The researchers analyzed over 300,000 cases of breast cancer based on age at diagnosis, year of diagnosis, racial and ethnic categories, and pathologic features of the cancer. They found that although white women had higher incidence rates than black women after age 40, the reverse was true for younger women. In women under 40, the incidence rate per 100,000 woman-years was approximately 17 for black women, compared with approximately 15 for white women. The discrepancy was even higher for women under age 30.
Furthermore, they found that younger women were more likely than older women to have tumors with poor prognostic features (larger than 2 cm, positive lymph node status, and higher stage). Younger women also had higher incidence rates for inflammatory breast cancers and estrogen-receptor positive tumors.
The researchers concluded that based on this data, it is important to continue to monitor the trends in breast cancer incidence among younger women. Mammography is not recommended in younger women because high breast tissue density makes it less sensitive. However, if the incidence of breast cancer in younger women continues to trend upward, it will be important to identify preventive approaches, including the identification of early risk factors and biomarkers.