How effective is radiotherapy for ductal carcinoma in situ?

DCIS is abnormal cells confined to a milk duct. After the area is removed with breast-conserving surgery, radiotherapy treats the remaining breast tissue around the surgical site. Its purpose is local control: it lowers the chance of DCIS or an invasive breast cancer developing in that breast later. It does not treat disease elsewhere in the body.

The decision depends on the size and grade of DCIS, whether the surgical margins are clear, breast features seen on imaging, age, and personal preferences. Some people may discuss surgery alone, while others receive radiotherapy as part of a broader plan.

Ask the breast team to explain how the pathology report changes the expected local benefit for you. Discuss whether the treatment follows breast-conserving surgery, how the area will be planned, and what short-term skin or breast changes may occur. Keep follow-up imaging appointments so the treated breast and the other breast can be monitored.

Contact the treatment team promptly for spreading redness, blistering, worsening swelling, fever, or pain that is difficult to control during or after treatment. Seek urgent help for sudden chest pain, severe breathlessness, or fainting. A new breast change outside the expected treatment reaction also deserves assessment, but it does not by itself identify the cause.

Which features of my DCIS affect the value of radiotherapy? Are my surgical margins clear? What area will be treated, and how will follow-up imaging be arranged? Which breast changes should I report, and who should I contact if they occur?