. 2014 Aug 27;16:427. doi: 10.1186/s13058-014-0427-5

Table 1.

Recent large studies investigating the impact of age on breast cancer prognosis

	Young age, years (n)	Control age, years (n)	Outcome definition	Impact of young age on outcome^a		Factors controlled in multivariate model
	Young age, years (n)	Control age, years (n)	Outcome definition	Hazard ratio	95% CI	Factors controlled in multivariate model
Gnerlich et al. 2009 [5]	<40 (15,548)	≥40 (227,464)	BC-specific survival	1.39	1.34-1.45	T, N, grade, race, marital status, ER, PgR, local therapy
Fredholm et al. 2009 [6]	<35 (378)	50-69 (13,486)	BC-specific survival	1.76	1.36-2.28	T, N, grade, ER, multifocality, local and systemic therapy
Cancello et al. 2010 [7]	<35 (315)	35-50 (2,650)	BC-related event	1.7	1.33-2.18	T, N, grade, histology, ER, HER2, PgR, ki67 vascular invasion
Han et al. 2010 [8]	<35 (1,443)	40-50 (6,354)	Overall survival	30-34 years: 1.43 26–29 years: 1.97	1.18-1.74 1.48-2.62	T, N, ER, systemic therapy
Azim et al. 2012 [9]	≤40 (339)	>40 (2,562)	Relapse-free survival	1.34	1.10-1.63	T, N, grade, BC molecular subtype, systemic therapy

^aIn multivariate models. BC, breast cancer; CI, confidence interval; ER, estrogen receptor; n, number; N, nodal involvement; PgR, progesterone receptor; T, tumor size.