Table III.

Similarities and differences of molecular subtypes between the two datasets.

Molecular subtype	Single-centerdataset (n=166)	Surveillance, Epidemiology and End Results dataset (n=15,322)	χ2	P-value
HR+/HER2−	92 (55.4)	9,222 (60.2)	4.605	0.196
HR+/HER2+	26 (15.7)	2,710 (17.7)
HR-/HER2+	21 (12.6)	1,406 (9.2)
HR-/HER2−	27 (16.3)	1,984 (12.9)

Values are expressed as n (%). HR, hormone receptor; HER2, human epidermal growth factor receptor 2. P-value pertains to comparison among all groups.