Prognostic Significance of Serum Alkaline Phosphatase Level in Osteosarcoma: A Meta-Analysis of Published Data

Table 4

Main characteristics and results of the eligible studies for evaluation of metastasis development for nonmetastatic patients.

Study; (author/year)	Country	Number of patients	Age (y)	ALP cut-off (IU/L)	Enneking stage	RR (95% CI)	Follow-up (m); Median (range)
Smeland et al., 2003 [44]	Norway	104	NA	A^†	II	1.66 (0.68–4.07)	83 (42–124)
Han et al., 2012 [37]	China	177	23.2 (5–57)	A	II	2.17 (0.97–4.84)	87 (8–144)
Kim et al., 2014 [45]	Korea	91	NA	A	IIB	2.03 (1.04–3.97)	NA

NA: not available, A: available (see the footnotes for details), RR: relative risk, y: year(s), and m: month(s).
: ALP cut-off: 2–10 y 350 IU/L; 10–13 y female 400 IU/L; 13–15 y male 500 IU/L; 20–50 y 100 IU/L; other childhood age 300 IU/L.
: ALP cut-off: >14 y 115.5 IU/L; <14 y 300 IU/L.