Cancer Immunology, Immunotherapy

, Volume 39, Issue 5, pp 286–290

Circulating concentrations of interleukin-6 in cancer patients and their pathogenic role in tumor-induced hypercalcemia

  • B. Vanderschueren
  • J. C. Dumon
  • V. Oleffe
  • C. Heymans
  • J. Gérain
  • J. J. Body
Original Articles Cytokines, Interleukin-6, Cancer, Bone Metastases, Hypercalcemia

DOI: 10.1007/BF01519980

Cite this article as:
Vanderschueren, B., Dumon, J.C., Oleffe, V. et al. Cancer Immunol Immunother (1994) 39: 286. doi:10.1007/BF01519980

Abstract

Circulating interleukin-6 (IL-6) concentrations correlate with disease activity in severe inflammatory conditions, in sepsis and in some hematological malignancies. On the other hand, IL-6 is a potent stimulator of osteoclastogenesis and has been implicated as a contributory factor in the genesis of osteopenic conditions. We measured circulating IL-6 levels by a sensitive (detection limit of 10 U/ml) and specific bioassay in 103 patients with advanced cancer, including 41 with tumor-induced hypercalcemia before any specific hypocalcemic therapy. We related IL-6 concentrations to clinical features and to biochemical parameters of bone metabolism, including blood Ca, Ca2+, Pi, intact parathyroid hormone, parathyroid hormone-related protein, osteocalcin, 1,25-(OH)2-vitamin D and, as markers of bone resorption, the fasting urinary excretion of calcium (Ca/creatinine) and hydroxyproline. IL-6 levels were increased, i.e. detectable, in 23% of the patients, 8/41 (20%) hypercalcemic and 16/62 (26%) normocalcemic patients (NS); the distribution of the values was similar in the two groups. The presence of increased IL-6 concentrations was not related to any clinical characteristic, notably not to the survival nor to the existence of bone metastases, whether in hypercalcemic or normocalcemic patients; e.g., only 3/12 (25%) hypercalcemic subjects without bone metastases had elevated IL-6 levels. We found no significant correlations between IL-6 concentrations and any of the biochemical parameters studied. Hypercalcemic subjects with increased IL-6 had higher urinary Ca/creatinine levels than patients with normal IL-6 levels (P<0.005) but this was not the case in normocalcemic subjects. Mean concentrations of inflammatory or other bone metabolism markers were not significantly different between patients with normal or with elevated IL-6 levels. In summary, circulating IL-6 levels were increased in 23% of 103 patients with advanced cancer, but the frequency of increased IL-6 concentrations was not related to the presence of hypercalcemia or to any marker of calcium metabolism or bone turnover. The pathogenic importance of circulating IL-6 in patients with solid tumors remains to be demonstrated and our data indicate that increased circulating levels of IL-6, possibly reflecting the activation of the immune system, only contribute in a minor way to the osteolytic process in patients with tumor-induced hypercalcemia.

Key words

CytokinesInterleukin-6CancerBone metastasesHypercalcemia

Copyright information

© Springer-Verlag 1994

Authors and Affiliations

  • B. Vanderschueren
    • 1
  • J. C. Dumon
    • 1
  • V. Oleffe
    • 1
  • C. Heymans
    • 1
  • J. Gérain
    • 1
  • J. J. Body
    • 1
  1. 1.Bone Metabolism Unit and Infectious Diseases Unit, Institut Jules BordetUniversité Libre de BruxellesBrusselsBelgium