Table 2. Demographic and clinical characteristics of study participants according to metastatic status.

Variables	Overall (n = 17)	Oligometastatic (n = 12)	Multimetastatic (n = 5)
Sex, n (%)
Female	16 (94)	11 (92)	5 (100)
Male	1 (6)	1 (8)	0 (0)
Age at diagnosis (years), median (range)	50 (26-72)	50 (26-72)	58 (34-60)
Race, n (%)
Caucasian	17 (100)	12 (100)	5 (100)
Tumour size, n (%)
≤5 cm (T1 and T2)	10 (59)	8 (67)	2 (40)
>5 cm (T3 and T4)	7 (41)	4 (33)	3 (60)
Nodal involvement, n (%)
N0	4 (24)	4 (33)	0 (0)
N1-N3	13 (76)	8 (67)	5 (100)
HER2 overexpression, n (%)
Yes	6 (35)	3 (25)	3 (60)
No	11 (65)	9 (75)	2 (40)
Oestrogen receptor, n (%)
Positive ≥1%	11 (65)	9 (75)	2 (40)
Negative <1%	6 (35)	3 (25)	3 (60)
Progesterone receptor, n (%)
Positive ≥1%	10 (59)	8 (67)	2 (40)
Negative <1%	7 (41)	4 (33)	3 (60)
Ki-67 expression, n (%)
High (>20%)	13 (76)	8 (67)	4 (80)
Low (≤20%)	4 (24)	4 (33)	1 (20)