Comparison of Treatment Outcomes between Breast Conserving Surgery Followed by Radiotherapy and Mastectomy Alone in Patients with T1-2 Stage and 1-3 Axillary Lymph Nodes in the Era of Modern Adjuvant Systemic Treatments

<div><p>Purpose</p><p>The role of postmastectomy radiotherapy in the treatment of T1–2 primary tumor with 1–3 positive lymph nodes is controversial. We compared treatment outcomes between breast conserving surgery followed by radiotherapy (BCS+RT) and total mastectomy alone (TM) in the setting of modern adjuvant systemic treatments.</p><p>Methods</p><p>Patients with T1–2 primary breast cancer and 1–3 positive lymph nodes who were treated between 2001 and 2011 were divided into 2 groups based on the treatment approach: BCS+RT (<i>n</i> = 169) and TM (<i>n</i> = 117). All patients received adjuvant chemotherapy including taxanes. Adjuvant endocrine therapy was administered to patients with positive hormone receptors according to their menstrual status.</p><p>Results</p><p>During a median follow-up of 76.5 months, 21 patients (7.3%) experienced locoregional recurrence as the first event, including 7 patients (4.1%) in the BCS+RT group and 14 patients (12.0%) in the TM group. The 5-year cumulative incidence rate of locoregional recurrence was 2.5% for BCS+RT versus 9.5% for TM (<i>p</i> = 0.016). Competing risk regression analysis revealed that TM was associated with a relative risk for locoregional recurrence of 5.347 (<i>p</i> = 0.003). TM was also associated with a significantly lower 5-year disease-free survival rate compared with BCS+RT (hazard ratio, 2.024; 95% confidence interval, 1.090–3.759; <i>p</i> = 0.026).</p><p>Conclusion</p><p>To improve treatment outcomes for TM even after modern systemic treatments, postmastectomy radiotherapy might be required for patients with T1–2 primary breast cancer and 1–3 positive lymph nodes.</p></div

Multivariate analysis for the disease-free survival rate.

<p>Multivariate analysis for the disease-free survival rate.</p

Patient characteristics.

<p>Patient characteristics.</p

Competing risk analysis for the cumulative incidence rate of locoregional recurrence.

<p>Competing risk analysis for the cumulative incidence rate of locoregional recurrence.</p

Comparison of the 5-year cumulative incidence rate of locoregional recurrence between the breast-conserving surgery plus radiotherapy (solid line) and total mastectomy alone groups (dotted line).

<p>Comparison of the 5-year cumulative incidence rate of locoregional recurrence between the breast-conserving surgery plus radiotherapy (solid line) and total mastectomy alone groups (dotted line).</p

Comparison of the 5-year disease-free survival rate between the breast-conserving surgery plus radiotherapy (solid line) and total mastectomy groups (dotted line).

<p>Comparison of the 5-year disease-free survival rate between the breast-conserving surgery plus radiotherapy (solid line) and total mastectomy groups (dotted line).</p