Breast-Conserving Surgery and Whole-Breast Radiation Therapy With or Without Additional Radiation Therapy to the Tumor in Treating Women With Ductal Carcinoma in Situ (BONBIS)

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)