This analysis included data from 1,455 New Zealand women diagnosed with stage 2–3 breast cancer, all of whom satisfied the “strong recommendation” criteria for postmastectomy radiotherapy (RT) in current New Zealand National Guidelines. A total of 1,195 women (82%) underwent postmastectomy RT. In logistic regression analyses, the following factors lowered the likelihood of receiving postmastectomy RT; increasing age, residing in a rural area or a more deprived neighbourhood, being of Māori or Pacific ethnicity, having comorbidities, receiving primary cancer care in a public facility, and being diagnosed with stage 3 cancer. When analyses factored in data from only the 1,325 patients with stage disease and the 422 women diagnosed since 2010, after the current guidelines were published in 2009, the findings did not differ much from those for the entire study population.
