TABLE 1.

The baseline characteristics of the included studies

Study	Country	Cancer type	Tumor stage/size (cm)	Cases	Age	Study period	Sample type	Compliance to remark
(12)	Finland	BC	I‐III	180	Median 57	January 1987 ‐ December 1990	FFPE	Fulfilled all items
(14)	Japan	BC	T1‐3	67	Median 49	January 1991 ‐ December 1991	FFPE	Lacked item no. 5
(16)	Japan/UK	BC	I‐III	173/184	Median 51/56	1991 ‐ 1993	FFPE	Fulfilled all items
(15)	China	BC	I‐IV	544	65	‐	RSSM	Lacked items no. 1& 3
(20)	China	NSCLC	N1‐2, T1‐3	82	55	January 1995 ‐ November 2004	FFPE	Fulfilled all items
(17)	Korea	NSCLC	I‐II	40	62.8	2007 ‐ 2009	FFPE	Lacked item no. 5
(19)	Japan	LC	I‐IV	58	71.3	October 2008 ‐ March 2011	Serum	Lacked item no. 3
(18)	Poland	NSCLC	I‐IIIA	140	62	2000 ‐ 2010	FFPE	Lacked item no. 3
(21)	Germany	Melanoma	II‐V a	37	53.8, 54.9	‐	FFPE	Lacked item no. 1
(22)	Germany	CBM	T1d‐T3d	20	69	January 1995 ‐ May 2007	FFPE	Fulfilled all items
(23)	Germany	CM	pT1a‐pT2b	109	65	1986 ‐ 2007	FFPE	Fulfilled all items
(24)	Germany	CM	pT1a‐pT2c	60	65, 64, 66	1986 ‐ 2005	FFPE	Lacked item no. 5
(27)	Finland	HNSCC	I‐III	97	Median 66	March 1989 ‐ March 1995	FFPE	Fulfilled all items
(26)	China	OTSCC	I‐IV	50	53.5	2000 ‐ 2007	FFPE	Fulfilled all items
(25)	China	OSCC	I‐IV	128	Median 60	Jan 2004 ‐ Oct 2008	FFPE	Fulfilled all items
(28)	Japan	HCC	4.2 (0.8‐17)	173	63	December 1993 ‐ May 2007	FFPE	Lacked item no. 3
(29)	UK /India	OC	I‐IV	108	Median 63	1990 ‐ 1998	FFPE	Lacked item no. 3
(30)	China	EC	I‐III	102	Median 52.9	January 1997 ‐ July 2002	FFPE	Lacked item no. 3

Abbreviations: BC, breast cancer; CBM, ciliary body melanomas; CM, conjunctival melanoma; EC, endometrial carcinoma; FFPE, formalin‐fixed paraffin‐embedded; HCC, human hepatocellular carcinoma; HNSCC, head and neck squamous cell carcinoma; LC, lung cancer; NSCLC, non–small cell lung cancer; OC, ovarian carcinoma; OSCC, oral squamous cell carcinoma; OTSCC, oral tongue squamous cell carcinoma; RSSM, risk score staging model.

^a Clark level of invasion.