What does radiation therapy after breast-sparing surgery involve?

Radiation therapy is usually performed as an outpatient procedure over a period of at least 5 weeks. Some women are not able to make that commitment. Some women live far from radiation facilities or can't afford to take the time for daily treatments. Others may have health conditions such as pregnancy, lupus, or heart disease, that prevent them from undergoing radiation. Since radiation therapy lowers the risk of recurrence for women who choose breast-sparing surgery, patients and their doctors must consider the requirements for radiation therapy before deciding which surgical option is best for them.

Why do I need radiation therapy if the tumor is removed with clear margins?

Women who have radiation therapy after breast-sparing surgery are less likely to have cancer come back in the same breast than women who have breast-sparing surgery without radiation.

What are the chances of the cancer coming back if I have breast-sparing surgery with radiation? If I decide on a breast-sparing surgery with radiation, how can you be sure there are no other "spots" in the breast?

Most women who have breast-sparing surgery followed by radiation will not have cancer recur in the same breast. In studies, recurrence rates within 10 years of breast-sparing surgery followed by radiation range from 4 percent to 20 percent. This might seem like a big range. But keep in mind that cancer that recurs in the same breast can be treated and does not affect chances of a healthy recovery compared to mastectomy. Another thing to keep in mind is that doctors suggest breast-sparing surgery only if they feel it offers a very good chance of removing all of the cancer. Obtaining a clear margin is one way the surgeon can lower the risk of recurrence. Radiation also lowers the risk of the cancer recurring in the same breast.