CCTG MA.39/Tailor RT (Breast Cancer) - Clinical Trial

We are doing this study to find out if women with a type of low risk breast cancer need to receive regional radiation therapy.

Biomarker low risk node positive breast cancer

-Adults, 40 years or older
-Have had breast conserving surgery or mastectomy

If you choose to join this study, you will:
- Be randomized (like flipping a coin) into Group 1 or Group 2:
--Group 1 will go as follows:
----If you had surgery to remove part of the breast, you will get radiation aimed at the breast only
----If you had surgery to remove the whole breast you will receive no radiation
therapy

--Group 2 will go as follows:
----If you had surgery to remove part of the breast, you will receive radiation aimed at the breast only and additional radiation aimed at the surrounding lymph glands
----If you had surgery to remove the whole breast you will receive radiation aimed at the chest area and the surrounding lymph glands