Comparison of treatment patterns and economic outcomes in metastatic breast cancer patients initiated on trastuzumab versus lapatinib: a retrospective analysis

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Table 1 Baseline characteristics: demographics and prior therapies

Characteristics	Trastuzumab	Lapatinib	P-value
Total number of patients	N = 381	N = 262
Age at index date (mean ± SD)	56.7 ± 12.0	54.4 ± 10.2	0.020**
Region, N (%)
East	74 (19.4)	63 (24.0)	0.159
Midwest	117 (30.7)	101 (38.5)	0.039**
South	151 (39.6)	74 (28.2)	0.003**
West	39 (10.2)	24 (9.2)	0.652
Index year, N (%)
2007	101 (26.5)	98 (37.4)	0.003**
2008	131 (34.4)	78 (29.8)	0.220
2009	89 (23.4)	46 (17.6)	0.076
2010	60 (15.7)	40 (15.3)	0.869
Time from first mBC diagnosis to index date (days; mean ± SD)	185.8 ± 329.4	518.5 ± 490.6	< 0.001**
Prior cancer treatments, N (%)
Trastuzumab use, any time prior to the index date	-	171 (65.3)
Hormonal therapy, during the baseline period	104 (27.3)	61 (23.3)	0.252
Radiation therapy, during the baseline period	104 (27.3)	103 (39.3)	0.001**
Surgery (mastectomy), during the baseline period	61 (16.0)	7 (2.7)	< 0.001**
Chemotherapy or anti-angiogenic therapy, during the baseline period	114 (29.9)	154 (58.8)	< 0.001**
Chemotherapy or biological therapy, between the first mBC diagnosis and index date	118 (31.0)	188 (71.8)	< 0.001**
CCI^a (mean ± SD)	6.7 ± 1.0	6.6 ± 1.2	0.224
Physical comorbidities^b, N (%)
Other neurological diseases	22 (5.8)	28 (10.7)	0.022**
Chronic pulmonary diseases	49 (12.9)	19 (7.3)	0.023**
Iron deficiency anemia	64 (16.8)	70 (26.7)	0.002**

**Denotes statistical significance at the 5% level.
^aCCI, Charlson Comorbidity Index.
^bOnly comorbidities with at least 5% prevalence in each cohort that were statistically significantly different between lapatinib and trastuzumab patients were reported.
N, number of patients; SD, standard deviation.