The American Society of Clinical Oncology (ASCO), American Society for Radiation Oncology (ASTRO), and Society of Surgical Oncology (SSO) have issued a joint consensus guideline update for the use of radiotherapy following mastectomy in patients with breast cancer.1
The joint panel agrees that postmastectomy radiation therapy reduces the risks of locoregional failure, any recurrence, and breast cancer mortality for patients with T1-2 breast cancer with 1 to 3 positive axillary nodes; however, certain patients may have such a low risk of locoregional failure that the risks of postmastectomy radiotherapy outweigh the benefits.
Because the acceptable ratio of benefit to toxicity varies among patients and physicians, the panel recommends that clinicians use a great deal of clinical judgment when deciding whether to use radiotherapy following surgery.
The panel further agrees that clinicians should consider factors that may decrease the risk of locoregional failure, impact the benefit of reduced breast cancer-specific mortality, and/or increase the risk for developing radiotherapy-related complications.
According to the guidelines, when axillary lymph node dissection is omitted following a positive sentinel node biopsy, patients should receive adjuvant radiotherapy only if there is already sufficient information to justify its use without the need to know whether additional axillary nodes are involved. In addition, patients with axillary nodal involvement after the receipt of neoadjuvant systemic therapy should receive postmastectomy radiotherapy.
The panel also recommends radiation treatment generally be delivered to both the internal mammary nodes and the supraclavicular-axillary apical nodes, as well as to the chest wall or reconstructed breast.
1. Recht A, Comen EA, Fine RE, et al. Postmastectomy radiotherapy: an American Society of Clinical Oncology, American Society for Radiation Oncology, and Society of Surgical Oncology focused guideline update. J Clin Oncol. 2016 Sep 19. doi: 10.1200/JCO.2016.69.1188. [Epub ahead of print]