Objective To explore the indications for postmastectomy radiotherapy in early breast cancer patients with 1-3 positive axillary lymph nodes.

Methods Ninety-two early breast cancer patients with 1-3 pathologically confirmed positive axillary lymph nodes after radical mastectomy were retrospectively analyzed. Of these patients, 45 received irradiation to the lateral chest wall, internal mammary chain and supraclavicular area. The prognostic index≥4 was considered as high-risk, while < 4 as the low-risk. Survival analysis was performed using the Kaplan-Meier method. The Log-rank test was used for the comparison of survival curves between different groups.

Results The 5-year survival rates of patients with and without radiotherapy were 93.5% and 86.4%(χ²=3.43, P > 0.05), the 10-year survival rates were 73.0% and 56.8%(χ²=2.82, P > 0.05), the 10-year local recurrence rates were 6.7% and 19.1%(χ²=4.66, P < 0.05). The 10-year survival rates of patients with low risk and high risk without radiotherapy were 73.0% and 56.8%(χ²=3.45, P > 0.05), while the local recurrence rates were 11.0% and 24.0%(χ²=4.64, P < 0.05). The 10-year survival rates of patients with low risk and high risk with radiotherapy were 82.0% and 72.3%(χ²=4.07, P < 0.05), while the local recurrence rates were 11.0% and 5.0%(χ²=5.64, P < 0.05).

Conclusion The early breast cancer patients with 1-3 positive axillary lymph nodes after radical mastectomy and the prognostic index suggests "high-risk" should receive irradiation to the chest wall and supraclavicular area.