Multiple randomized trials have demonstrated that breast-conserving therapy with partial mastectomy and radiotherapy provides survival equivalent to that seen with mastectomy for patients with early-stage breast cancer. Breast-conserving therapy has been associated with better quality of life relative to mastectomy and has become the standard of care for patients with early-stage breast cancer. Young age has been identified as a risk factor for recurrence and death from breast cancer. Some studies have suggested that young women (less than 35 or 40 years of age) have inferior outcomes with breast-conserving therapy, implying that such women may be better served by mastectomy. On review of the available literature, there is no definitive evidence that mastectomy provides a consistent, unequivocal recurrence-free or overall survival benefit over breast-conserving therapy. However, available meta-analyses have not compared outcomes in young women specifically, and such analyses should be performed. In the interim, breast-conserving therapy is not contraindicated in young women (less than 40 years of age) and can be used cautiously; however, such women should be advised of the lack of unequivocal data proving that survival is equivalent to that with mastectomy in their age group.

Breast/chest wall irradiation (RT) increases risk of cardiovascular death. International Quantitative Analysis of Normal Tissue Effects in the Clinic (QUANTEC) guidelines state for partial heart irradiation a "V25Gy <10% will be associated with a <1% probability of cardiac mortality" in long-term follow-up after RT. We assessed whether women treated with breast/chest wall RT 10-years ago who died of cardiovascular disease (CVD) violated QUANTEC guidelines. A population-based database identified all cardiovascular deaths in women with early-stage breast cancer <80 years, treated with adjuvant breast/chest wall RT from 2002 to 2006. Ten-year rate of cardiovascular death was calculated using a Kaplan-Meier method. Patients were matched on a 2:1 basis with controls that did not die of CVD. For left-sided cases, the heart and left anterior descending (LAD) artery were retrospectively delineated. Dose-volume histograms were calculated, and heart V25Gy compared to QUANTEC guidelines. 5249 eligible patients received breast/chest wall RT from 2002 to 2006: 76 (1.4% at 10-years) died of CVD by June 2015. Forty-two patients received left-sided RT (1.7% CVD death at 10-years), 34 right-sided RT (1.3% at 10-years). Heart V25Gy did not exceed 10% in any left-sided cases. No cardiac dosimetry parameter distinguished left-sided cases from controls. QUANTEC guidelines were not violated in any patient that died of CVD after left-sided RT. The risk of radiation induced cardiac death at 10-years appears to be very low if MHD is <3.3 Gy and maximum LAD dose (EQD23 Gy) is <45.4 Gy. Further studies are needed to evaluate heart and LAD constraints in the CT-planning era.