AVP and neoplasm: Copeptin levels at T0 were 3.85 (2.42–5.60) pmol/L and significantly increased at T1 (31.06 [10.33–57.84] pmol/L, p = 0.001) with subsequent rapid reduction; moreover, copeptin levels at T1 were significantly correlated with tumor diameter (r = 0.695, p = 0.004).