Table 3: Main characteristics and results of the eligible studies for evaluation of presence of metastasis at diagnosis.

CountryNumber of patientsAge (y)ALP cut-off (IU/L)Enneking stageRR (95% CI)

Bacci et al., 1993 [43]Italy549NAAII-III5.53 (2.85–10.74)
Wu et al., 2009 [33]Taiwan ROC9120.2 (5–84)AII-III16.5 (1.05–260.27)
Hung et al., 2015 [40]Taiwan ROC7613.5 (3.8–17.7)150II-III18.6 (1.17–294.97)

NA: not available, A: available (see the footnotes for details), RR: relative risk, and CI: confidence interval.
: 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.