Table 2.

Probability of long-term survival according to different clinical parameters (univariate logistic regression analysis)

Parameter at diagnosis	Category	Number of events (%)	Odds ratioa	95% CI	P value
Ageb	<60 years	608 (37.0)
	≥60 years	279 (22.4)	0.49	0.42-0.58	<0.001
ECOGb	0-1	306 (40.1)
	2-4	92 (17.3)	0.31	0.24-0.41	<0.001
Hormone receptor	Negative	279 (25.2)
	Positive	563 (33.8)	1.51	1.27-1.79	<0.001
HER2 receptor	Negative	342 (22.5)
	Positive	458 (42.0)	2.50	2.11-2.96	<0.001
Biological Subtype	HER2+	492 (42.2)
	Luminal-like	242 (26.9)	0.50	0.41-0.60	<0.001
	TNBC	99 (16.1)	0.26	0.24-0.33	<0.001
Number of BM	1	337 (42.7)			<0.001
	2-3	218 (31.4)	0.62	0.50-0.76	<0.001
	≥4	269 (24.0)	0.42	0.35-0.52	<0.001
pCR (ypT0)	No	218 (29.4)
	Yes	60 (42.0)	1.73	1.20-2.51	0.003
Leptomeningeal metastases	No	795 (32.5)
	Yes	92 (20.8)	0.55	0.43-0.70	<0.001
Clinical symptomsb	No	235 (36.9)
	Yes	652 (29.0)	0.70	0.58-0.84	<0.001
ECMb	No	234 (40.0)
	Yes	653 (28.3)	0.59	0.49-0.72	<0.001
Chemotherapy after diagnosis of BM	No	388 (22.0)
	Yes	499 (44.2)	2.8	2.38-3.30	<0.001
Endocrine therapy	No	649 (26.0)
	Yes	238 (60.7)	4.4	3.53-5.49	<0.001
HER2-targeted therapy	No	429 (20.4)
	Yes	458 (58.0)	5.37	4.50-6.41	<0.001

BM, brain metastases; CI, confidence interval; ECM, extracranial metastases; ECOG, Eastern Cooperative Oncology Group; pCR, pathological complete remission; TNBC, triple-negative breast cancer.

^aAn odds ratio ≥1 means to have a higher probability to be assigned to the group of long-term survivors.

^bAt diagnosis of BM.