Abstract
BACKGROUND: Anemia is a common manifestation in patients with cancer. Little is known about the frequency of and risk for anemia with targeted therapies used to treat solid tumors. METHODS: We performed a meta-analysis of randomized controlled trials of solid tumors by comparing targeted therapy (alone or in combination) with standard therapy alone to calculate the incidence and relative risk (RR) for anemia events associated with these agents. Overall, 24,310 patients were included in the analysis. RESULTS: The addition of targeted therapies to standard treatment (chemotherapy or placebo/best supportive care) increased the risk for all grades of anemia by 7%. The RR for all grades (incidence, 44%) and grades 1-2 (incidence, 38.9%) of anemia was higher with biological therapies alone but not when combined with chemotherapy. The risk was significant for erlotinib, trastuzumab, and sunitinib. Bevacizumab was associated with a lower risk for anemia. Anti-epidermal growth factor receptor, anti-human epidermal growth factor receptor 2, anti-vascular endothelial growth factor receptors, and tyrosine kinase inhibitors predicted RRs of 1.24, 1.20, 0.82, and 1.33, respectively, and all of these values were significant. CONCLUSION: Grade 1-2 anemia is frequently associated with biological agents. The risk is particularly associated with small-molecule tyrosine kinase inhibitors (gefitinib and erlotinib), breast cancer, and lung cancer. Erythropoiesis-stimulating agents are not labeled for use with targeted therapies (without chemotherapy) and the treatment is supportive only.