Radiation therapy to the chest wall after mastectomy #2

This recommendation was adapted from the NICE 2018 guidelines (UK). The source recommendation is based on a systematic review of the evidence conducted to September 2017 and used wording (‘Offer’) indicative of a strong recommendation (using GRADE methods) by the source guideline authors. The source recommendation was adapted by narrowing the population to ‘patients who have undergone a mastectomy and have macrometastases in 1-3 lymph nodes’, and by changing the wording from ‘offer’ to ‘consider’ as radiation therapy is not conventionally offered to patients with a single positive node.

This recommendation is also informed by the ASCO/ASTRO/SSO focused guideline update on postmastectomy radiotherapy 2016 which notes that, although the panel unanimously agreed that available evidence shows that postmastectomy radiation therapy reduces the risks of locoregional failure (LRF), any recurrence, and breast cancer mortality for patients with T1-2 breast cancer with one to three positive axillary nodes, some subsets of these patients are likely to have such a low risk of LRF that the absolute benefit of PMRT is outweighed by its potential (lung, cardiac) toxicities. In addition, the acceptable ratio of benefit to toxicity varies among patients and physicians. Thus, the decision to recommend PMRT requires a great deal of clinical judgment.