If a SNB is positive after neoadjuvant chemo and mastectomy, should an axillary dissection be performed or xrt given to all?

Just to clarify, the Alliance 011202 study takes patients with involved axillary nodes before induction chemotherapy who fail to convert to node-negativity post-induction, and randomizes them to axillary dissection vs not. Everyone on the trial gets comprehensive regional RT. There are options for intra-op vs post-op sentinel LN evaluation followed by registration and randomization. Note that in patients randomized to ax dissection, the contouring guidelines exclude the the dissected volume from RT (ie this area has been "addressed" by the dissection). The trial fundamentally asks the question of whether an ax dissection contributes to breast cancer control, or whether comprehensive RT alone is sufficient.

The NSABP-B51/RTOG1304 trial take...

All patients with persistent node positive disease after neoadjuvant systemic therapy should receive post mastectomy radiation or following lumpectomy whole breast and regional nodal RT. Ideally if the sentinel node is positive they would go on the alliance trial. Off trial axillary dissection at time of surgery if the node is positive is a reasonable standard at this time with the radiation fields tailored to the nodal findings-typically to the undissected level 2 3 Supraclav and internal mammary chain. If no nodal dissection is done the full axilla should be included in the radiation fields

The current standard of care is axillary dissection and that is practiced in our hospital. That being said we do end up treating some patients with RT instead of surgery for multiple reasons, with one of them being the patients declining dissection.

ALLIANCE is conducting a study where these patients are randomized between dissection followed by tailored RT vs. comprehensive radiation.