Pallor in cancer patients is commonly due to anemia, which is a deficiency of red blood cells. Cancer patients can develop anemia from several cancer-related factors, including:
Bone marrow suppression due to chemotherapy or the cancer itself. Chronic bleeding associated with certain types of cancers, such as gastrointestinal cancers. Nutritional deficiencies resulting from poor appetite or malabsorption. Increased destruction of red blood cells, a condition known as hemolysis.