Table 1. Clinical characteristics of Study participants from the discovery and replication sets.

Study	Number of breast cancer deaths	Total number of Breast cancer patients	Estrogen Receptor (ER) status- Negative (%)	Average age at Diagnosis (±SD)	Follow-up time in years (±SD)	N-stage	M-stage	T-stage
POSH stage-1 (Discovery)	236	536	370 (69.2%)	35.7 (3.8)	4.1 (2.0)	N0–248N1–262NA-26	M0–481M1–50NA-5	T1–227 T2–207 T3–20 T4–31 NA-51
HEBCS (Discovery)	301	805	230 (30.0%) NA-39	56.8 (12.4)	7.2 (2.9)	N0–338N1–446NA-21	M0–740M1–57NA-8	T1–390 T2–304 T3–50 T4–47 NA-14
POSH stage-2 (Replication)	221	1415	362 (23.7%)	35.8 (3.5)	5.2 (1.7)	N0–705N1–810NA-8	M0–1506M1–18NA-1	T1–692 T2–494 T3–49 T4–34 NA-254

HEBCS: Helsinki Breast Cancer Study; NA = not available, HER2 = Human Epidermal Growth Factor Receptor 2, N-stage = metastasis to lymph node, M-stage = metastasis.