The efficacy of molecular subtyping in predicting postoperative recurrence in breast-conserving therapy: a 15-study meta-analysis

Table 1 Main characteristics of the studies enrolled in the meta-analysis

First author and publishing year	Case nationality	Dominant ethnicity	Study design	Case number	Follow-up median (m)	RT (%)	AST (%)		Types of recurrence	Source of HR	Characteristics of enrolled cases
							HT	CT
Hattangadi[30]	USA	Caucasian	R	1,223	70	100	77.0	46.0	TR	Reported	IBC, pT1-2 N0-3
Zauls[31]	USA	Caucasian	P	459	45	100	Total 62.1		LF	DE	DCIS or IBC, tumor size ≤3 cm, positive LNs ≤3
Han[32]	Canada	Caucasian	R	180	104.4	30.6	NM	NM	LR	Reported	DCIS with or without microinvasion
Millar[33]	Australia	Caucasian	P	498	64	100	49.0	38.0	LRR/IBTR/DM	DE	IBC
Moran[34]	USA	Caucasian	R	368	78	100	49.0	36.0	LR	DE	IBC, stage I-II, LN (+), margin (-)
Wong[35]	Singapore	Asian	R	541	72	100	68.0	36.0	LR/DM	Reported	IBC, LN (-)
Kim[36]	Korea	Asian	P	1,589	61	100	71.8	66.4	IBTR	Reported	IBC, tumor size ≤5 cm, age >40 years
Bantema[37]	Netherlands	Caucasian	R	752	41	100	38.7	35.4	LR/DM	Reported	IBC, stages I-III
Arvold[38]	USA	Caucasian	R	1,434	85	100	Total 91.0		LR	Reported	IBC, stage I-II
Truong[39]	Canada	Caucasian	R	5,688	71.7	100	36.6	26.7	LR/RR/LRR	Reported	IBC, pT1-2, positive LNs ≤3, M0
Sharon[40]	Canada	Caucasian	R	133	107	0.0	NM	NM	LR	Reported	DCIS, margin (-)
Roos[41]	Netherlands	Caucasian	R	39	39	51.3	0.0	NM	LR	DE	DCIS
Yau[42]	China	Asian	R	605	64.8	100	74.0	45.0	IBTR/DF	Reported	IBC, T1-2
Smith[43]	USA	Caucasian	R	8,724	60	73.0	NM	3.0	SIBC	Reported	IBC, age ≥70 years, tumor size ≤2 cm, LN (-)
Silvestrini[44]	Spain	Caucasian	R	635	72	78.1	0.0	0.0	LR	Reported	Resectable breast cancer, N0, M0

Study design is described as either prospective (P) or retrospective (R).
Radiotherapy (RT) is defined as accelerated partial breast irradiation (APBI), whole breast irradiation (WBI) or MammoSite brachytherapy (MB).
Adjuvant systemic therapy (AST) is defined as hormone/endocrine therapy (HT) only, chemotherapy (CT) only, or both.
Abbreviations: m month HR hazard ratio, NM not mentioned, TR true recurrence, LF local failure, LR local recurrence or relapse, LRR locoregional recurrence; IBTR ipsilateral breast tumor recurrence, DM distant metastasis, RR regional recurrence, DF distant failure, SIBC second ipsilateral breast cancer, DE dataextrapolated IBC invasive breast cancer, DCIS ductal carcinoma in situ, LN lymph node.