The present invention concerns the use of interleukin-8 (IL-8) as a biomarker for predicting the outcome of the treatment with aflibercept, or ziv-aflibercept of a patient suspected to suffer from a cancer.本發明涉及使用白介素-8(IL-8)作為生物標記用於預測使用阿柏西普或ziv-阿柏西普(ziv-aflibercept)治療疑似患有癌症的患者的結果。