Approximately 7% of women with breast cancer are diagnosed before the age of 40 years, and this disease accounts for more than 40% of all cancer in women in this age group. Survival rates are worse when compared to those in older women, and multivariate analysis has shown younger age to be an independent predictor of adverse outcome. Inherited syndromes, specifically BRCA1 and BRCA2, must be considered when developing treatment algorithms for younger women. Chemotherapy, endocrine, and local therapies have the potential to significantly impact both the physiologic health -including future fertility, premature menopause, and bone health-and the psychological health of young women as they face a diagnosis of breast cancer.Although a diagnosis of breast cancer is distressing at any age, this occurrence in young women is fraught with several unique challenges. This article reviews the distinct epidemiology, etiology, clinicopathologic characteristics, biology, treatment strategies, outcomes, and psychosocial challenges of breast cancer before 40 years of age. Also included in this review are issues of familial breast cancer, fertility, premature menopause, breast cancer during pregnancy, and bone health. The US Surveillance, Epidemiology and End Results (SEER) database was the source of data for the tables and graphs presented here. 1
EpidemiologyThe American Cancer Society (ACS) estimates that 182,460 women in the United States were diagnosed with breast cancer in 2008 and that 40,480 women died of the disease during the year. 2 The incidence of breast cancer appears to have a sigmoid function in women less than 55 years of age (Figure 1, lower panel), with 6.6% of all cases diagnosed before age 40, 2.4% diagnosed before age 35, and 1% diagnosed before age 30 (Figure 2, inset). The individual average risk of a woman developing breast cancer was 1 in 173 by the age of 40 and approximately 1 in 1,500 by the age of 30 (Table 1). Of all cancers diagnosed among women, more than 40% is breast cancer by the age of 40, 20% by the age of 30, and slightly more than 2% by 20 years of age (Figure 1, upper panel).