Serum concentrations of IL-2 and TNF-α in patients with painful bone metastases: Correlation with responses to89SrCl2 therapy

We have used 89SrCl2 for the palliative treatment of painful bone metastases from various malignant diseases. We studied the correlation between serum interleukin-2 (IL-2) and tumor necrosis factor-α (TNF-α) levels and the response to 89SrCl2 therapy. Methods: Forty-two patients (24 men and 18 women) were treated intravenously with 89SrCl2 at a dose of 148 MBq (4 mCi). Results: The response rate was 33 of 42 (79%). In the control subjects, serum IL-2 concentrations were higher but TNF-α concentrations lower (P < 0.05) than in the patients with bone metastases. After treatment with 89SrCl2, IL-2 levels increased and TNF-α levels decreased, with maximal changes at the fourth month after therapy. After comparing the serum levels of IL-2 and TNF-α between responders and nonresponders, we found that these variables did not differ before 89SrCl2 therapy but differed significantly (P < 0.05) after therapy. Responders had higher IL-2 and lower TNF-α concentrations than nonresponders. A good correlation was found between IL-2 and TNF-α levels and the number of metastases and pain score. Conclusion: 89SrCl2 is effective for palliation of bone pain in patients with disseminated bone metastases. In addition to managing pain, 89SrCl2 can improve immunity and the quality of life for most patients. Further studies are needed to elucidate the roles of IL-2 and TNF-α in the response to 89SrCl2 therapy and to evaluate their usefulness as indicators of 89SrCl2 efficacy.