Methods

Altogether, 72 patients with bone sarcomas without distant metastases before treatment (26 osteosarcomas-36%, 23 chondrosarcomas-32%, 13 Ewing's sarcomas/PNET-18%, 10 giant-cell tumors-14%), 22 patients with benign non-inflammatory bone tumors and 50 age-matched healthy controls were included into this prospective study.

Results

Median serum levels of 9/11 cytokines, with the exception of sIL-2Rα and G-CSF, were significantly higher in sarcoma patients than in controls. Median serum levels of IL-6, IL-8, IL-1ra, TNF RI, and M-CSF were significantly higher in patients with bone sarcoma as compared to patients with benign bone tumors. In 45.9% of sarcoma patients, six or more cytokines and cytokine receptors, including those that are involved in bone destruction (eg, IL-6 and IL-8) and bone formation (eg, IL-1ra and TNFRI and TNFRII), were elevated in parallel. Serum levels of IL-6, IL-8, TNF RI, TNF RII, and VEGF correlated significantly with tumor size (< 10 cm vs.≥ 10 cm in diameter) and serum levels of IL-6, IL-8, TNF RI, and IL-1ra correlated significantly with local tumor extent (E2/4 vs. E5/6 according to the classification proposed by Spanier et al. 46). Moreover, serum levels of IL-1ra and IL-6 were significantly higher in patients with small tumors (< 5 cm in diameter) infiltrating structures adjacent to the periosteum (E5/6) than in large tumors (> 10 cm in diameter) but confined to the bone and periosteum (E< 4). The lowest median serum levels of 8/11 cytokines/cytokine receptors were found in patients with giant-cell tumors. In an univariate analysis, increased serum levels of IL-1ra, IL-6, IL-8, IL-10, sIL-2Rα, M-CSF, TNF RI, and TNF RII, the number of cytokines elevated, higher tumor grade, larger tumor size, greater local extent (E) and patients' age> 35 years correlated with poor overall survival (OS)(P< 0.05). Similarly, high serum levels of IL-1ra, IL-6, TNF RI and TNF RII, tumor grade, tumor size, and tumor local extent (E)(P< 0.05) affected disease free survival (DFS) in univariate analysis. Multivariate analysis using Cox's proportional hazards model showed that high serum levels of IL-1ra (P= 0.039) and TNF RI (P= 0.048), the number of serum cytokines above normal cut-off values (0–1 vs. 2–5 vs.≥ 6; P= 0.029), greater tumor local extent E (E2/4 vs. E5/6; P= 0.02) correlated significantly with shorter OS. Only E was found as an independent prognostic factor for DFS (P= 0.04).

Conclusions

These findings indicate that cytokines and soluble cytokine receptors, both physiologically involved in bone destruction and bone formation, have an essential role in the progression of malignant bone tumors. J. Surg. Oncol. 2003; 84: 151–159.© 2003 Wiley-Liss, Inc.