Treatment patterns and real world clinical outcomes in ER+/HER2- post-menopausal metastatic breast cancer patients in the United States

Table 4 Treatment discontinuation on first-line therapy with aromatase inhibitors before vs. after 5 months - from chart review

Variable	Level	Treatment discontinuation ≤ 5 months (N = 26)		Treatment discontinuation > 5 months (N = 76)		p-value
Stage at diagnosis	Early (Stage IA, IB, IIA, IIB)	5	19.2%	12	15.8%	0.4740^b
	Limited Regional (Stage IIIA)	2	7.7%	1	1.3%
	Locally Advanced (Stage IIIB)	0	0.0%	1	1.3%
	Locally Advanced (Stage IIIC)	0	0.0%	2	2.6%
	Metastatic (Stage IV)	19	73.1%	60	78.9%
ECOG performance status at the time of diagnosis of mBC ^a	0	9	34.6%	28	36.8%	0.8021
	1	13	50.0%	40	52.6%
	2	4	15.4%	8	10.5%
	3	0	0.0%	0	0.0%
De novo / relapse	De novo	19	73.1%	61	80.3%	0.5575^b
	Relapse from adjuvant	7	26.9%	14	18.4%
	Don’t know	0	0.0%	1	1.3%
Adjuvant treatment received	Yes	8	30.8%	17	22.4%	0.4328^b
	No	18	69.2%	59	77.6%
	Don’t know	0	0.0%	0	0.0%
Aromatase inhibitors received in first-line	Anastrozole	16	61.5%	46	60.5%	0.0036^b
	Exemestane	5	19.2%	1	1.3%
	Letrozole	5	19.2%	29	38.2%
Visceral disease	Yes	15	57.7%	31	40.8%	0.1349
Visceral disease	No	11	42.3%	45	59.2%	0.1349

mBC metastatic breast cancer
One patient using aromatase inhibitors in first-line was excluded due to treatment discontinuation (patient choice) at 3 months
^aDefinition of ECOG performance statuses; 0: Fully active, able to carry on all pre-disease performance without restriction; 1: Restricted in physically strenuous activity but ambulatory and able to carry out work of a light or sedentary nature, e.g. light house work, office work; 2: Ambulatory and capable of all self-care but unable to carry out any work activities. Up and about more than 50% of waking hours; 3: Capable of only limited self-care, confined to bed or chair more than 50% of walking hours
^bExact Fisher test

ISSN: 1471-2407