• Axillary recurrence rate [ Designated as safety issue: No ]
  

• Shoulder function as assessed by arm function test questionnaire at baseline, 1, 3, and 5 years after surgery [ Designated as safety issue: No ]
  
• Quality of life as measured by Quality of Life Questionnaire Core 30 Items (QLQ-C30) and QLQ-BR25 at baseline, 1, 2, 3, and 5 years after surgery [ Designated as safety issue: No ]
  
• Axillary recurrence-free survival [ Designated as safety issue: No ]
  
• Disease-free survival [ Designated as safety issue: No ]
  
• Overall survival [ Designated as safety issue: No ]
  

OBJECTIVES:

• Compare the regional control of the axilla obtained by complete axillary lymph node dissection vs axillary radiotherapy in sentinel lymph node-positive women with operable invasive breast cancer.
• Determine whether local and regional axillary control can be obtained without axillary lymph node dissection in sentinel lymph node-negative women.
• Compare the axillary 5-year recurrence-free survival of these patients treated with these regimens.
• Compare the morbidity of patients treated with these regimens.
• Compare the quality of life of these patients treated with these regimens.

OUTLINE: This is a randomized, multicenter study. Patients are stratified according to participating center and type of breast surgery (conservation vs total mastectomy). Patients are randomized to 1 of 2 treatment arms.

Patients are given an injection of a tracer and undergo lymphoscintigraphy 2-3 hours later to identify the sentinel lymph node. Within 24 hours after lymphoscintigraphy, patients undergo wide local excision of the tumor or mastectomy after the sentinel node is removed. If no sentinel node is found or metastasis is found in a nonsentinel node, patients undergo complete axillary lymph node dissection (ALND) regardless of randomization. Sentinel node-negative patients receive no further treatment. Sentinel node-positive patients continue treatment according to randomization.

• Arm I: Within 8 weeks after surgery, patients undergo complete ALND.
• Arm II: Within 8 weeks after surgery, patients undergo axillary lymph node radiotherapy daily 5 days a week for 5 weeks.

Patients in arm I may receive postoperative axillary irradiation if 4 or more nodes are positive and more than 1 axillary level is involved.

Quality of life is assessed at baseline and then at 1, 2, 3, and 5 years.

Patients are followed annually for 5 years.

PROJECTED ACCRUAL: A total of 3,485 patients (1,394 sentinel node-positive and 2,091 sentinel node-negative) will be accrued for this study within 3 years.