Inclusion Criteria:  Females with age ≥ 18 years old. Newly diagnosed breast cancer patients. Planned neoadjuvant chemotherapy.  Exclusion Criteria:  Pregnancy. Nursing mothers. Active or uncontrolled infection. Presence of another malignancies. Inadequate blood picture. Serum Creatinine more than 1.5 mg /dl. AST and ALT more than 2.5 upper limit. History of known hypersensitivity to lansoprazole.