Breast cancer in adolescents and young women.

Breast cancer is very rare in adolescents and very young women. Less than 1% of all breast cancer cases occur before the age of 30 years (Natl Cancer Inst Monogr 16 (1994) 69). Invasive breast cancer occurring in women before the age of 35 years has a more aggressive biological behaviour and is associated with a worse prognosis than in older premenopausal women. Breast cancers in these young women are more frequently poorly differentiated, oestrogen-receptor (ER)-negative, have lymphovascular invasion and high proliferating fractions. Breast-conserving surgery in women <35 years old is associated with a higher risk of local recurrence than in older women. All young women should be considered at moderate-high risk by virtue of their age alone and offered adjuvant therapy. The long-term toxicity of adjuvant therapies is a particular concern when treating these women. The implications of possible fertility impairment and premature menopause require consideration when discussing adjuvant chemotherapy and endocrine therapy. Adolescents and young women are particularly vulnerable to emotional distress and psychosocial problems and should be provided with appropriate support. Young women who are at a potential high-risk of developing breast cancer such as those with germline mutations of BRCA1, BRCA2, TP53, PTEN or who have previously received mantle irradiation for Hodgkin's disease need close follow-up and are candidates for screening from a young age.