RATIONALE: Radiation therapy uses high-energy x-rays to damage tumor cells. It is not yet known which regimen of radiation therapy is more effective following surgery for breast cancer.

PURPOSE: Randomized phase III trial to compare the effectiveness of two regimens of radiation therapy following surgery in treating women who have 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 2 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 week for 3 weeks for a total dose of 40 Gy.

A breast boost is recommended in both 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.

Patients are followed annually for up to 20 years.

Peer Reviewed and Funded or Endorsed by Cancer Research UK

PROJECTED ACCRUAL: A total of 1840 patients (920 per arm) will be accrued for this study.

• START Trialists' Group; Bentzen SM, Agrawal RK, Aird EG, Barrett JM, Barrett-Lee PJ, Bentzen SM, Bliss JM, Brown J, Dewar JA, Dobbs HJ, Haviland JS, Hoskin PJ, Hopwood P, Lawton PA, Magee BJ, Mills J, Morgan DA, Owen JR, Simmons S, Sumo G, Sydenham MA, Venables K, Yarnold JR. The UK Standardisation of Breast Radiotherapy (START) Trial B of radiotherapy hypofractionation for treatment of early breast cancer: a randomised trial. Lancet. 2008 Mar 29;371(9618):1098-107. Epub 2008 Mar 19.
• Hopwood P, Haviland J, Mills J, Sumo G, M Bliss J. The impact of age and clinical factors on quality of life in early breast cancer: An analysis of 2208 women recruited to the UK START Trial (Standardisation of Breast Radiotherapy Trial). Breast. 2007 Jan 18; [Epub ahead of print]
• Venables K, Miles EA, Aird EG, Hoskin PJ; START Trial Management Group. The use of in vivo thermoluminescent dosimeters in the quality assurance programme for the START breast fractionation trial. Radiother Oncol. 2004 Jun;71(3):303-10.

DISEASE CHARACTERISTICS:

• Histologically confirmed invasive unilateral breast cancer

  • T1-3, N0-1, M0 at presentation
• Complete macroscopic excision of tumor by breast conserving surgery or mastectomy
• No immediate breast reconstruction
• No requirement for axillary radiotherapy after greater than a Level 1 axillary dissection or after greater than 10 lymph nodes have been removed
• Not enrolled on SECRAB or OSCAR trials

• Hormone receptor status:

  • Not specified

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Sex:

• Female

Menopausal status:

• Not specified

Performance status:

• Not specified

Life expectancy:

• Not specified

Hematopoietic:

• Not specified

Hepatic:

• Not specified

Renal:

• Not specified

PRIOR CONCURRENT THERAPY:

• Prior neoadjuvant, or primary medical, therapy is allowed provided subsequent surgery confirms complete macroscopic excision of residual primary tumor

Biologic therapy:

• Not specified

Chemotherapy:

• At least 2 weeks since prior cytotoxic agents
• No concurrent chemotherapy

Endocrine therapy:

• Not specified

Radiotherapy:

• See Disease Characteristics

Surgery:

• See Disease Characteristics