Table 2. Univariate analysis of overall survival in metastatic breast cancer using trastuzumab from 09/2017 to 08/2018 in a reference hospital in oncology in Rio de Janeiro, Brazil.

Explanatory variables		HR (univariate)	log-rank
Age at diagnosis
	20–29	-	p=0.62
	30–49	0.64 (0.25–1.61. p=0.340)
	50–69	0.80 (0.32–2.01. p=0.633)
	70–90	0.83 (0.25–2.74. p=0.762)
Skin color
	White	-	p=0.15
	Black and brown	1.36 (0.90–2.06. p=0.147)
Metastatic site
	1_bone	-	p=0.00051
	2_CNS	4.86 (1.99–11.89. p=0.001)
	3_Liver	2.42 (0.86–6.76. p=0.092)
	4_Multiple	1.92 (1.07–3.45. p=0.029)
	5_Lung	0.68 (0.22–2.07. p=0.496)
	6_Others	0.99 (0.45–2.19. p=0.978)
Hormone receptor (estrogen or progesterone)
	Negative	-	p=0.26
	Positive	0.79(0.52–1.19. p=0.259)
Prior exposure to trastuzumab
	Exposed	-	p=0.065
	Not exposed	0.69 (0.46–1.03. p=0.067)
Type of surgery
	1_None	-	p=0.0041
	2_Radical mastectomy	0.38 (0.23–0.64. p<0.001)
	3_Simple mastectomy	0.72 (0.28–1.85. p=0.491)
	4_Conservative	0.77 (0.30–1.95. p=0.577)
	5_Secondary tumors	0.36 (0.17–0.78. p=0.010)
	6_Others (vascular access support)	0.54 (0.30–0.98. p=0.044)
Histopathological degree
	G1	-	p=0.39
	G2	2.08 (0.65–6.66. p=0.217)
	G3	1.78 (0.55–5.77. p=0.337)
Body mass index
	Normal weight (18.5 to 24.9)	-	p=0.43
	Overweight (25.0 to 29.9)	0.74 (0.46–1.20. p=0.219)
	Obesity (≥30.0)	0.92 (0.56–1.52. p=0.757)
Staging
	I–III	-	p=0.36
	IV	1.20 (0.81–1.80. p=0.365)