Association between serum levels of C-reactive protein and response to treatment of chemotherapy-induced anemia in patients with solid tumors: a multicenter, prospective, observational study.

Our objective was to determine the association between C-reactive protein (CRP) levels at initiation of anemia treatment and response in solid tumor patients with chemotherapy (CT)-induced anemia. This was a multicenter, prospective, observational study which included adult patients with solid tumor initiating treatment for CT-induced anemia. Data were collected up to 16 weeks, or until premature discontinuation. We included 98 patients (median age 62.5 years, 64 % males, 57 % with ECOG 0-1, 85.7 % at stages III-IV and 54.1 % undergoing palliative CT). Mean (SD) Hb levels at baseline were 10.3 (0.9) g/dL (85.7 % < 11 g/dL) and median (Q1; Q3) CRP was 16.4 mg/L (3.9; 77.8) (68 % ≥ 5 mg/L). A total of 96 % of patients initiated erythropoiesis-stimulating agents (ESA) and iron supplementation; 4 % initiated iron monotherapy. After a median of 85 days, 65 % of patients had Hb ≥ 11 g/dL (in absence of transfusion) (mean change: +0.86 g/dL, 95 % confidence interval (CI) 0.53-1.19). A total of 8 patients required transfusion. A significant correlation (r = -0.39, p = 0.003) was observed between baseline CRP and final Hb levels. In the multivariate linear regression analysis, the independent predictors of higher final Hb levels were a high baseline Hb (adjusted ß = +0.69 g/dL for each g/dL of baseline Hb, 95 % CI 0.17-1.21) and a low log baseline CRP (-0.62 for each log mg/L, 95 %CI -1.22 to -0.02). Our results suggest that, in patients with solid tumors and CT-induced anemia, high CRP levels at treatment initiation predict a poor response to treatment with ESA and iron, independently from anemia severity at therapy initiation and from other patient and disease characteristics.