Table 1.

List of candidate serum markers for pediatric osteosarcoma and their possible clinical utility.

Serum marker	Observation for pediatric osteosarcoma	Assessed clinical utility for pediatric osteosarcoma	References
Free polyamines	POS development is accompanied by disorders of polyamine metabolism spurring their intensive release from cells into biological fluids	Informative indicator of a malignant process in POS	Ladanyi et al [35]
IGF-1 and IGFBP-3	IGF-1/IGFBP-3 levels correlate with the presence of metastatic disease, histologic response, event-free survival	Promising predictive factor of development or clinical characteristics of POS	Rodriguez-Galindo et al [36]
anti-ki57 antibody	Increased levels anti-ki57 antibody associated with extent of biological activity of tumor and clinical course of POS	Prognostic factor for POS progression	Petrosyan et al [37]
TNF-β and sTNF-R	In high-grade POS, high levels of TNF-β correlated with bad response to neoadjuvant chemotherapy	Marker for monitoring of response to neoadjuvant chemotherapy in POS	Holzer et al [38]
ANG	Expression of ANG correlates with an increase in local density of blood vessels in tumor tissue, with development of pulmonary metastasis and poor prognosis	Diagnostic and prognostic factor of primary POS	Kushlinskii et al [52]
Bone formation/resorption	Decreased production of PICP, OC, ICTP associated with bone metabolism in POS	Risk factor for pathologic bone fractures in POS	Gajewska et al [40]
T3	Increased levels T3 associated with poor/good disease-free survival	Marker of good and poor POS prognosis	Sidorenko et al [42]
CD44	No significant difference was observed between serum CD44 levels of children with sarcoma and healthy children	Serum CD44 levels were not found to be of value in diagnosis or prognosis for POS	Kebudi et al [43]
VEGF	Increased VEGF levels correlates with tumor stage and disease-free survival	Prognostic factor in POS	Koznetsova et al [85]
SAA	Increased SAA levels associated with type of tumor and high-risk POS development	Differentiates malignant bone cancer from benign bone tumors and detects POS in high-risk children	Krizkova et al [44]
BALP	Increased BALP levels associated with development of POS	Marker for late detecting, monitoring, and assessment of the efficacy of therapy in POS	Ambroszkiewicz et al [17]
CXC chemokines	Increased CXCL4, CXCL6, and CXCL12 levels associated with poor disease-free survival	Prognostic factor for POS outcomes	Li et al [50]
IL-2, IL-4, IL-8, IFN-γ, TNF-α	Analysis of cytokine concentration showed large statistically significant differences between POS and control group for IL-4 and IL-8	Markers for individual reaction of organism to the development of POS	Markiewicz et al [24]