GDF15 and neoplasm: A strong association between circulating levels of GDF‐15 and the histopathological grade of malignancy, tumour mass and metastatic progression has been documented for colorectal, pancreatic, prostate and oral squamous cancer in mostly small studies.9, 14, 15, 16, 25 As a consequence, GDF‐15 has been discussed as a potential biomarker for tumour diagnosis and surveillance.8 However, larger studies investigating the prognostic association of GDF‐15 in an unselected cohort of especially treatment‐naïve cancer patients have not been conducted.