NCCN Guidelines for Patients
Breast Cancer - Early-Stage
(STAGES I AND II)
, Version 1.2016
Treatment options after mastectomy
lists options for radiation therapy after
having a mastectomy. If your axillary lymph nodes are
cancer-free, radiation therapy is advised based on
the chances of the cancer returning after treatment.
Breast cancer is more likely to return the larger a
breast tumor is and the smaller a cancer-free surgical
margin is. Despite cancer-free nodes, your doctor
may advise radiation therapy if the surgical margin is
smaller than 1 mm, the breast tumor is larger than 5
cm, or there’s cancer in the surgical margin. Possible
radiation sites are shown in
When cancer is found in 1 to 3 axillary lymph nodes,
you may receive radiation therapy to multiple sites.
These sites include the chest wall; supraclavicular,
infraclavicular, and axillary areas; and the internal
mammary lymph nodes.
If cancer is in 4 or more axillary lymph nodes, the
breast cancer is upstaged to stage III. Radiation
therapy is advised. Radiation sites include the chest
wall; supraclavicular, infraclavicular, and axillary
areas; and the internal mammary lymph nodes.
Figure 5.2 Radiation after mastectomy
Radiation therapy after mastectomy is based on how likely the cancer will return. The
chest wall behind the removed breast may be radiated. Other sites include areas near
the collarbone and armpit as well as lymph nodes along the breastbone.