Table 3.

Effective features of a 5-year recurrence risk model for breast cancer with low-positive HER2 expression.

Variable	t test	P value
T stage	–6.6856792	3.16 × 10–11
N stage	–7.0331876	2.98 × 10–12
TNM staging	–7.4456521	1.57 × 10–13
Histological grade	–3.0961791	0.002
Lymphvascular invasion	5.8209306	7.05 × 10–9
ER status	–2.2399913	0.025
PR status	–3.0788973	0.002
Prognostic stage	–5.9334610	3.63 × 10–9
Ki67 index (continuous variable)	–4.7105960	2.68 × 10–6
Ki67 index (grouping variable)	–3.9762508	7.31 × 10–5
Chemotherapy	2.5179750	0.012
Neoadjuvant chemotherapy	6.2394494	5.61 × 10–10
Breast surgery	–3.7477011	1.85 × 10–4
Axillary surgery	–5.3146575	1.22 × 10–7
Endocrine therapy	–2.2796274	0.022

ER: Estrogen receptor; HER2: Human epidermal growth factor receptor 2; PR: Progesterone receptor; TNM: Tumour (T), regional lymph nodes (N), and metastatic involvement (M).