Breast cancer staging for patients with “low‐risk” disease: Are they all the same?

ABSTRACT Background Contemporary breast cancer staging incorporates anatomic and biologic factors. Although a low ( 25. Median follow up was 58.9 months. Most with RS < 11 were PPS IA (94.2%), yet OS declined with higher stage ( p < .001). Adjusted analyses showed worse OS for higher stages within RS < 11 (IB: HR 1.66 95% CI, 1.34–2.05; IIA: HR 2.29 1.44–3.65; IIB: HR 2.48 1.03–5.95). In the RS 11–17 group, 90.8% were PPS IA. Five‐year OS varied (IA: 97.8%, IB: 95.8%, IIA: 95.2%, IIB: 93.7%, IIIA: 100%; p < .001). Adjusted OS differences persisted (IB: HR 1.51 1.32–1.73; IIA: HR 1.32 1.01–1.72; IIB: HR 1.58 0.95–2.63; IIIA: HR 1.44 (0.21–9.95]). Conclusions Prognostic stage significantly influences survival among patients with low RS. RS < 11 alone should not automatically downstage patients to PPS IA; anatomic and other nongenomic factors remain important for prognosis.