Randomised Trial Testing Observation (No Radiotherapy) Against Radiotherapy In Women With Low-Risk Completely Excised ER Positive Ductal Carcinoma In Situ (DCIS) Of The Breast On Adjuvant Endocrine Therapy

Fecha de inicio: 1 de abril de 2004

DISEASE CHARACTERISTICS: * Diagnosis of unifocal ductal carcinoma in situ of the breast without an invasive component * Microinvasion (defined as 1 or more foci of invasion each \< 1 mm) allowed * Prior complete microscopic excision (within the past 6 months) with a minimum radial margin of 1 mm by specimen x-ray required * Maximum microscopic tumor diameter \< 30 mm (\< 15 mm if grade 3 tumor) * Planning to receive adjuvant tamoxifen or anastrozole for 5 years * Eligible patients may receive adjuvant endocrine therapy on ICR-IBIS-II * Hormone receptor status: * Estrogen receptor positive OR * Progesterone receptor positive * More than 10% tumor staining for receptor OR a cutpoint of ≥ 2 PATIENT CHARACTERISTICS: Sex * Female Menopausal status * Premenopausal, perimenopausal, or postmenopausal Performance status * Not specified Life expectancy * Not specified Hematopoietic * Not specified Hepatic * Not specified Renal * Not specified Cardiovascular * No prior deep vein thrombosis Pulmonary * No prior pulmonary embolus Other * No unexplained postmenopausal bleeding * No contraindication to full-dose radiotherapy to the breast * No other cancer within the past 5 years except nonmelanoma skin cancer or carcinoma in situ of the cervix PRIOR CONCURRENT THERAPY: Biologic therapy * Not specified Chemotherapy * Not specified Endocrine therapy * See Disease Characteristics * No prior tamoxifen or raloxifene use for more than 3 months in duration Radiotherapy * Not specified Surgery * See Disease Characteristics * No prior mastectomy Other * No concurrent anticoagulants