Many clinical trials have divided patient populations based on menopausal status, or age greater or less than 50. Virtually no published clinical trials have focused on treatment issues for the youngest women. Trials reporting results of treatments for premenopausal women largely reflect outcomes for patients in their 40s. Thus, findings from studies that consider average results for premenopausal women may not be directly applicable to very young patients.

Partly owing to inadequate screening options for young women, breast cancer tends to be larger and more often locally advanced. Consequently, young women may more likely need or benefit from preoperative systemic therapy than older women, although available data in this area are limited. Despite the large benefit that young women obtain from an irradiation boost to the tumor bed, most studies continue to indicate that young age is a risk factor for local recurrence, for both invasive and noninvasive disease (47,48,49,50,51,52,53) (Fig. 92.2). No evidence suggests, however, that mastectomy in young women improves survival compared with breast conservation, likely because these women are also at increased risk of systemic recurrence. In a population-based Danish cohort of 9,285 premenopausal women with breast cancer, the incidence of local recurrence was 15.4% after breast-conserving therapy among the 719 women under age 35 compared with 3.0% in women ages 45 to 49, although no difference was found in the risk of death between the two age groups (54 ...