Table 1.

Features of 12 articles included in this meta-analysis

REF	First author	Year	Cases	Gender (M/F)	Median age	Inclusion period	Method	ki-67 cut-off	Ethnicity	NOS score
1	Wang et al.	2018	50	28/22	24.15	2015–2017	IHC	A1*B1 > 3	Asian	8
2	Fu et al.	2017	20	9/11	11.27	2008–2012	IHC	A1 ≥ 1	Asian	8
3	Li et al.	2017	21	11/10	24.33	2011–2013	IHC	A1 ≥ 1	Asian	8
4	Lin et al.	2014	55	31/24	17.42	2004–2011	IHC	A1*B2 > 3	Asian	7
5	Li et al.	2014	94	59/35	–	2006–2010	IHC	B3 ≥ 2	Asian	7
6	Matsumoto et al.	2013	29	19/10	19.00	1978–2007	IHC	A1 ≥ 1	Asian	8
7	Junior et al	2003	25	13/12	29.00	1958–2001	IHC	A1 ≥ 1	Asian	8
8	Xu et al.	2003	30	16/14	19.83	–	IHC	A3 ≥ 2	Asian	7
9	Zhang et al.	2003	30	16/14	–	1994–1999	IHC	A3 ≥ 2	Asian	7
10	Peng et al.	2002	62	–	17.00	1995–2001	IHC	A1 ≥ 1	Asian	8
11	Zhang et al.	2001	45	28/17	17.60	1993–1998	IHC	A1 ≥ 1	Asian	8
12	Liao et al.	1998	39	26/13	20.10	1992–1995	IHC	A1 ≥ 1	Asian	7

A: Positive cell percentage: A1: scored 0 (< 5%), 1 (6–25%), 2 (26–50%), 3 (> 50%); A2: scored 1 (< 25%), 2 (26–50%), 3 (51–75%), 4 (> 75%); A3: scored 0 (< 5%), 1 (5–20%), 2 (> 20%)

B: Staining intensity: B1: scored 0 (light yellow), 1 (brownish yellow), 2 (brown); B2: scored 0 (absence of staining), 1 (weak staining), 2 (middle staining), 3 (strong staining); B3: scored 0 (absence of staining), 1 (light yellow), 2 (brownish yellow), 3 (brown)