Anemia is a common symptom for many people with cancer, and it’s sometimes the first sign of cancer or progressive disease in a patient’s cancer journey, says Dr. Diep.
Low red blood cell counts can also be caused by cancer treatments or something other than cancer.
In people with cancer, anemia is linked with a higher likelihood of poor outcomes, including death, and reduced quality of life.
There are several reasons why cancer and anemia are linked.
Cancer Cells Crowd Out Healthy Blood Cells Some cancers that affect the bone marrow, such as leukemia or lymphoma, can invade and disrupt the production of red blood cells. The bone marrow is responsible for making blood cells, including red blood cells. When cancer cells take over this space, it leads to reduced production of healthy red blood cells, which lowers hemoglobin levels.
Chronic Bleeding Certain cancers, such as colorectal cancer or stomach cancer, may cause internal bleeding, which can result in a gradual loss of red blood cells. Over time, this leads to a condition called iron-deficiency anemia, as the body runs low on the iron needed to produce new red blood cells.
Chemotherapy and Radiation Anemia can be related to the treatments a patient might receive to treat their cancer, says Diep.
Cancer treatments like chemotherapy and radiation can suppress bone marrow activity, making it harder for the body to produce red blood cells.
Chronic Inflammation Some cancers produce systemic inflammation, which can interfere with the body’s ability to produce red blood cells. This is particularly true for cancers that have spread (metastasized), as they produce signals that disrupt normal blood cell production.
It is not unusual to see multiple factors contributing to a patient’s anemia in the context of cancer, says Diep.
Anemia in cancer patients is typically classified as iron-deficiency anemia or anemia of chronic disease. Iron-deficiency anemia occurs when the body doesn’t have enough iron to make red blood cells, while anemia of chronic disease is a type of anemia caused by underlying conditions like cancer, where inflammation or bone marrow disruption prevents red blood cell production.
