Table 3.

Predictors of overall survival from initiation of first-line metastatic therapy to death or last follow-up for all patients in cohort.

Variable	n	Deaths	Univariate		Multivariate^c
Variable	n	Deaths	Median OS (95% CI)^a	p^b	Hazard ratio (95% CI)	p
Overall	113	90	3.5 (3.0–4.4)
Era of initial diagnosis
<1999	57	50	4.2 (3.1–5.2)	0.47
≥1999	56	40	3.1 (1.9–4.2)
Age at first recurrence
<50 years	62	51	4.1 (2.9–4.6)	0.39
≥50 years	51	39	3.2 (2.6–4.6)
ER and/or PR status
Positive	64	55	4.2 (3.1–5.0)	0.39
Negative	49	35	3.0 (1.7–4.1)
Site(s) of initial recurrence
Any CNS	9	8	1.9 (0.1–5.9)	0.05	2.1 (0.7–6.0)	0.18
Any liver/lung but no CNS	66	57	3.2 (2.5–4.2)		1.4 (0.7–2.9)	0.34
Any other site but no CNS liver or lung	16	12	4.6 (2.7–8.0)		0.9 (0.4–2.3)	0.91
Local/regional only	22	13	4.6 (2.7–8.4)		Reference
Number of distant metastases at diagnosis of recurrent disease
0	22	13	4.6 (2.7–8.4)	0.01	Reference^d
1	42	33	4.1 (3.2–6.0)
≥2	49	44	2.6 (2.0–3.3)		1.5 (0.9–2.7)	0.14
Disease-free interval^e
<2 years	41	33	3.0 (1.6–3.9)	0.03
≥2 years	72	57	4.4 (3.1–5.5)
Exposure to adjuvant trastuzumab
Yes	11	10	2.0 (1.0–4.6)	0.10
No	102	80	3.9 (3.1–4.4)
Exposure to adjuvant hormonal therapy
Yes	50	39	3.9 (2.6–5.5)	0.74
No	63	51	3.5 (2.7–4.4)
Exposure to adjuvant or neoadjuvant chemotherapy
Yes	93	73	3.5 (2.6–4.4)	0.88
No	20	17	4.1 (2.7–5.5)
Trastuzumab administered in the first-line metastatic setting
Yes	73	58	3.1 (2.4–4.2)	0.18
No	40	32	4.6 (3.1–5.9)

Abbreviations: CI, confidence interval; ER, estrogen receptor; PR, progesterone receptor; CNS, central nervous system.

Survival times were evaluated using Kaplan–Meier methods.

Group comparisons in the univariate analysis were based on long-rank test.

Hazard ratios and 95% CI were obtained using a Cox proportional hazard model. Adjustments in model included era of initial diagnosis, age at first recurrence, year of initiation of first-line therapy, ER and/or PR status, and disease-free interval.

Reference value for the multivariate analysis was 0–1 sites of distant metastatic disease at initial diagnosis compared to ≥2 site of distant metastatic disease.

As defined from date of initial diagnosis to diagnosis of recurrent disease.