To the Editor: Viral hepatitis is a major public health conc worldwide, and hepatitis B virus (HBV), with which two billion people infected globally, has been commonly reported to undergo reactivation during chemotherapy for malignancies.[1,2] Some literatures have reported hepatitis C virus (HCV) reactivation in hematological malignancies.[1,3] Breast cancer, the most common cancer in female, is increasing rapidly globally. Hence, oncologists would undoubtedly deal with breast cancer patients with asymptomatic HCV carrier who are prone to HCV reactivation.[3] HCVreactivation is defined as a minimum 3?fold increase in alanine transaminase (ALT) level in a patient with the absence of liver metastasis with careful exclusion of HCV reactivation from other causes.[1] An increase in HCV viral load of more than 1 × 103 U/L could be a sign of HCV reactivation.