C-reactive protein is a strong predictor for anaemia in renal cell carcinoma: role of IL-6 in overall survival

Authors


  • Both C.E.F. and M.T. contributed equally to this work

Claudia Falkensammer, Department of Urology, Innsbruck Medical University, Anichstrasse 35, 6020 Innsbruck, Austria – Europe. e-mail: claudia.falkensammer@i-med.ac.at

Abstract

Study Type – Prognostic (case series)

Level of Evidence 4

What’s known on the subject? and What does the study add?

The incidence of renal cell carcinoma (RCC)-associated anaemia has been linked with more aggressive tumours. Metastatic RCC patients with elevated IL-6 levels have significantly decreased haemoglobin concentrations.

We elucidate the association of progression of advanced RCC with anaemia and different factors influencing tumour-associated anaemia. Interleukin-6 emerges as a possible target to treat cancer-related anaemia in metastatic RCC.

OBJECTIVE

• To elucidate the association of progression of advanced renal cell carcinoma with anaemia and investigate factors influencing tumor-associated anaemia.

PATIENTS AND METHODS

• We analyzed different clinical variables to study associations with anaemia in 86 metastatic renal cell carcinoma patients.

• 45 (52%) of patients had already developed anaemia prior to therapy.

RESULTS

• Anaemic patients had an increase in the serum markers C-reactive protein (CRP), IL-6 and erythropoietin (EPO). In addition we observed substantial correlation between IL-6 and CRP serum levels (R = 0.639, P < 0.0001).

• Univariate logistic regression analysis revealed that patients with IL-6 >10 pg/mL had a considerable increase in risk for anaemia (odds ratio 3.86, P= 0.003).

• In addition, patients with CRP >0.7 mg/dL had a very strong increase in risk for anaemia (OR = 14.08, P < 0.0001).

• Stepwise multivariate logistic regression analysis confirmed CRP >0.7 mg/mL as the only independent predictor for anaemia. Cox-regression modeling selected serum IL-6 as the strongest independent prognostic indicator (hazard ratio 3.58, P < 0.0001).

CONCLUSION

• Anaemia depends on serum IL-6, which is a strong inductor of CRP and regulator of the iron-transport. Serum IL-6 may be considered as a target to treat cancer-related anaemia.

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