DCIS: This study is evaluating different radiation doses and schedules in people with non-low risk ductal carcinoma in situ (DCIS) of the breastA Randomised Phase III Study of Radiation Doses and Fractionation Schedules in Non-low Risk Ductal Carcinoma In Situ (DCIS) of the Breast

Inclusion

Patients must fulfill all of the following criteria for admission to study:

• Women ≥ 18 years.
• Histologically proven DCIS of the breast without an invasive component.
• Bilateral mammograms performed within 6 months prior to randomization.
• Clinically node-negative.
• Treated by breast conserving surgery (primary excision or re-excision) with complete microscopic excision and clear radial margins of ≥1 mm* (*Patients with superficial or deep resection margin of <1 mm are eligible if surgery has removed all of the intervening breast tissue from the subcutaneous tissue to the pectoralis fascia).

• Women who are at high risk of local recurrence due to:

  • Age < 50 years; OR

  • Age ≥ 50 years plus at least one of the following:

    • Symptomatic presentation
    • Palpable tumour
    • Multifocal disease
    • Microscopic tumour size ≥ 1.5 cm in maximum dimension
    • Intermediate or high nuclear grade
    • Central necrosis
    • Comedo histology
    • Radial* surgical resection margin < 10 mm. (*Patients with superficial or deep resection margin of < 10 mm are eligible if surgery has not removed all of the intervening breast tissue from the subcutaneous tissue to the pectoralis fascia.)
• Assessed by surgeon and radiation oncologist to be suitable for breast conserving therapy including whole breast RT.
• Ability to tolerate protocol treatment.
• Protocol RT should preferably commence within 8 weeks but must commence no later than 12 weeks from the last surgical procedure.
• ECOG performance status 0, 1 or 2.
• Patient's life expectancy > 5 years.
• Availability for long-term follow-up.
• Written informed consent.