Standardization of Breast Radiotherapy: Trial A - A Randomized Comparison of Fractionation Regimens After Local Excision or Mastectomy in Women With Early Stage Breast Cancer

OBJECTIVES:

• Determine the benefits of radiotherapy schedules using fraction sizes larger than 2.0 Gy in terms of normal tissue responses, local-regional tumor control, quality of life, and economic consequences in women prescribed postoperative radiotherapy for early stage breast cancer.

OUTLINE: This is a randomized, multicenter study. Patients are stratified according to center, type of surgery (mastectomy vs local excision), and breast boost (yes vs no). Patients are randomized to 1 of 3 treatment arms.

• Arm I: Patients receive radiotherapy 5 times a week for 5 weeks for a total dose of 50 Gy.
• Arm II: Patients receive radiotherapy 5 times a fortnight (i.e., Monday/Wednesday/Friday/Tuesday/Thursday/Monday, etc.) for 13 fractions over 5 weeks for a total dose of 41.6 Gy.
• Arm III: Patients receive radiotherapy as in arm II for a total dose of 39 Gy. A breast boost is recommended in all arms for patients with microscopic evidence of invasive or in situ cancer at, or within 1 mm of, a resection margin. These patients receive radiotherapy for 5 fractions in 1 week for a total boost dose of 10 Gy.

Quality of life is assessed at baseline and then at 6, 12, 24, and 60 months.