Cancer is a major worldwide public health concern and is the second leading cause of death in the world with colorectal and breast cancer being among the most common cancers in the world (Siegel et al. 2019). Breast cancer is the most common type of cancer and the leading cause of cancer related deaths in women while colorectal cancer is the third most common cancer among women and men in Turkey (TC Ministry of Health Turkey Cancer Statistics 2018).Capecitabine is used orally in the treatment of breast, colorectal and gastric cancer. Capecitabine is a precursor and converted to 5-fluorouracil (5-FU) (which is a cytotoxic agent) in the tumor. 5-FU is one of the oldest and the most widely used antimetabolite and cytotoxic agents (Reigner et al. 2001).