How blood donations help people with cancer

Estimated reading time: 3 minutes

By Mayo Clinic staff

Regular blood drives are held in schools, churches, senior centers and businesses in many communities. People need blood products for a wide variety of reasons. They could have a chronic health condition, like kidney failure or anemia, or need a blood transfusion during surgery or after a traumatic accident.

It may come as a surprise to learn that about 25% of the U.S. blood supply is given to patients during cancer treatments. You may know people with cancer but not if they've received blood transfusions. When patients with cancer don't get the blood products they need, it can delay their treatments or make them feel sick.

In this Q&A, learn how donated blood products are used when a person has cancer:

Why do people with cancer need blood products?

Cancer patients need a lot of blood for many different reasons. Some types of cancer cause blood loss. For example, people can bleed internally if they have colon or stomach cancer. They need blood replacement for their bodies to function and help them feel well.

People who have a blood cancer, such as leukemia, lymphoma or multiple myeloma, require blood products during treatment. As these diseases progress, their bone marrow gets crowded out by cancer cells, and they can't produce enough blood themselves. Donated blood products keep their organs functioning, provide strength and help them feel better.

Finally, other cancers can suppress the production of blood or bone. Kidney cancer can change a person's hormone levels, which decreases blood production. These patients benefit from getting blood transfusions during treatment.

Why can't blood be manufactured like other medicines or treatments?

People with cancer get many manufactured products, medicines and fluids as part of their treatment plans. Yet, unfortunately, blood can't be created in a lab.

Donated blood products provide proteins and clotting factors different from anything manufactured in a lab or designed in a pharmacy. Blood products are lifesaving and life-changing. The health care system relies on community members donating blood for patients in need.

How do platelets help patients with cancer?

Platelets, which prevent or stop active bleeding, are critical to the health of patients with cancer. They prevent or stop active bleeding. Chemotherapy and radiation often suppress the bone marrow, so these patients can't produce enough blood or platelets. Often, patients with cancer are weak, fragile and at risk of falling. Additional platelets can help stop bleeding and decrease the risk of bleeding after a fall.

How many units of blood does a cancer patient need?

It depends on the type of cancer and if treatment requires blood. People with chronic blood disorders may indefinitely require two or three units a week. Patients with colon cancer may only need one or two blood transfusions over a short period of time. Some people with cancer need bone marrow stem cell transplants, which replace bone marrow entirely. These patients require many units of blood during their treatments.

The important thing to remember is that many people with cancer require blood products at some point during their treatment, and the community often underestimates the need for these products.

I get calls all the time to donate blood. Is there really a shortage?

The appeals for blood donations may seem unrelenting. But the need for blood products doesn't stop. Every two seconds, someone in the U.S. needs blood products. Yet less than 3% of eligible U.S. adults donate blood each year. That's a problem because the need for blood products remains every day.

Donated blood products have a limited shelf life. Red cells can be safely stored for 42 days, whereas platelets can be stored for just five days.

The good news is that it's quick and easy to donate blood. When you do so regularly, you support your family, friends and community during a time of need. Anna Jones, M.D., is a Mayo Clinic oncologist and hematologist.

A version of this article was originally published on the Mayo Clinic Health System blog.