RATIONALE: Radiation therapy uses high-energy x-rays to kill tumor cells. Giving radiation therapy after surgery may kill any tumor cells that remain after surgery. It is not yet known whether whole-breast radiation therapy is more effective when given with or without additional radiation therapy to the tumor in treating patients with ductal carcinoma in situ.

PURPOSE: This randomized phase III trial is studying breast-conserving surgery followed by whole-breast radiation therapy to see how well it works when given with or without additional radiation therapy to the tumor in treating women with ductal carcinoma in situ.

OBJECTIVES:

Primary

• Estimate and compare local recurrence-free survival of women with ductal breast carcinoma in situ (DCIS) treated with breast-conserving surgery followed by whole breast irradiation with vs without a radiation tumor bed boost.

Secondary

• Compare relapse-free survival between the two arms.
• Compare overall survival.
• Compare acute and late toxicities.
• Compare cosmetic results and quality of life.
• Identify patients at risk for late toxicities using a biological test.

Tertiary

• Store blood samples at the CEPH (French Center of the Human Polymorphism Center) for polymorphism analyses.

OUTLINE: This is a multicenter study. All patients undergo breast-conserving surgery (after a single intervention or second excision) with a margin ≥ 1 mm. A superficial or deep margin is acceptable if the surgery has left the skin tissue or the fascia pectoral muscle, respectively. Twelve weeks later, patients are randomized to 1 of 2 treatment arms.

• Arm I: Patients undergo whole breast irradiation (WBI) once daily, 5 days a week for 5 weeks.
• Arm II: Patients undergo WBI as in arm I. Patients also undergo a radiation tumor bed boost once daily for 8 fractions (weekdays only) over 2 weeks.

Quality of life will be assessed.

After completion of study treatment, patients are followed up every 6 months for 5 years and then annually for 10 years.

DISEASE CHARACTERISTICS:

• Histologically confirmed ductal carcinoma in situ of the breast

  • No invasive component
  • No clinically palpable lymph node or presence of tumor cells in the sentinel lymph node (if done)
  • No local recurrence of a primary breast cancer
  • No multicentric or multifocal tumors not suitable for conservative surgery R0 with a margin ≥ 1 mm

• Has undergone bilateral mammography within 6 months before randomization

PATIENT CHARACTERISTICS:

• ECOG performance status 0-2
• Life expectancy > 5 years
• Not pregnant
• Available for long-term follow up
• No history of in situ carcinoma in the contralateral breast
• No history of another cancer except for basal cell carcinoma of the skin or carcinoma in situ of the cervix
• No uncontrolled cardiac, renal, or pulmonary disease
• No uncontrolled systemic disease (e.g., lupus erythematosus or scleroderma)
• No HIV positivity
• Affiliated with the social health system
• No psychological, familial, sociological, or geographical situations that preclude compliance with study treatment and follow up

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• No concurrent participation in another therapeutic trial (participation in epidemiologic studies is allowed)