What Type of Cancer Causes Low Hemoglobin?

Hearing your hemoglobin levels are low can leave you feeling unsettled, especially since low hemoglobin can be linked to cancer. But it’s important to know that the two aren’t always intertwined. Understanding the connection between cancer and low hemoglobin levels can help guide next steps and bring you peace of mind.

What it Means to Have Low Hemoglobin Levels

Hemoglobin is a protein in red blood cells that helps carry oxygen throughout the body. When levels of the protein drop, the body doesn’t get the oxygen it needs to function well. This drop is often caused by anemia, a serious blood disorder that can develop as a result of an underlying medical condition, vitamin or iron deficiencies, pregnancy, liver or kidney failure or cancer.

Most of the time, low hemoglobin levels are identified through a blood test called a complete blood count, or CBC. Results can show whether hemoglobin levels are below the normal range.

Symptoms of Low Hemoglobin

Low hemoglobin symptoms can range from mild to severe and may include:

• Brittle nails
• Cold hands or feet
• Cravings for nonfood items (called pica)
• Dizziness
• Fatigue
• Headaches
• Pale skin
• Rapid heartbeat
• Shortness of breath
• Weakness

Still, even when hemoglobin levels are low, some people have few or no symptoms.

Anemia and Cancer

Low hemoglobin doesn’t always mean cancer. But there are certain cancers that are more commonly linked to anemia and low hemoglobin levels.

When anemia is a sign of cancer, it’s usually when it develops without a clear explanation or doesn’t improve with treatment. Some cancers affect the production of red blood cells, while others cause slow blood loss or inflammation that interferes with red blood cell production.

Types of Cancer Caused by Low Hemoglobin

Several types of cancers are known to cause low hemoglobin levels. These cancers include:

• Blood and bone marrow cancers: Blood cancers are among the most common causes of cancer-related anemia. These cancers begin in the bone marrow, where blood cells are made. They include leukemia, lymphoma and multiple myeloma. In these cancers, abnormal cells crowd out healthy blood-forming cells, reducing the body’s ability to produce red blood cells. Often, anemia is one of the first symptoms people notice. Rare bone marrow disorders, such as myelodysplastic syndrome, can also lead to low hemoglobin levels because they prevent blood cells from maturing properly. Also, in some cases, inherited or rare conditions like aplastic anemia may increase the risk of developing certain blood cancers later in life.
• Breast cancer: Breast cancer can cause anemia when it spreads to the bone marrow, affecting blood cell production. Sometimes, although it’s rare, breast cancer is only discovered after an anemia diagnosis leads to further testing.
• Colon and colorectal cancer: Iron-deficiency anemia can be an early sign of colon cancer. Tumors in the colon may bleed slowly over time, leading to blood loss that isn’t always visible.
• Cervical cancer: Many people diagnosed with cervical cancer have anemia at the time of diagnosis. That’s often due to tumors that bleed, but anemia may also result from poor nutrition or cancer spreading to the bone marrow.
• Kidney cancer: The kidneys produce a hormone called erythropoietin, which tells the bone marrow to make red blood cells. Cancer in the kidneys can disrupt this process, leading to reduced red blood cell production and anemia. Some medications used to treat kidney cancer can also contribute to low hemoglobin levels.
• Lung cancer: Lung cancer is frequently associated with anemia, particularly when cancer-related inflammation interferes with red blood cell production or when cancer spreads to the bone marrow.
• Prostate cancer: Anemia is common in advanced prostate cancer and is sometimes one of its first signs. Treatments such as hormone therapy can also lower hemoglobin levels.

How Cancer Leads to Anemia

Cancer can affect red blood cells in several ways, including:

• Blood loss from tumors
• Bone marrow involvement that limits blood cell production
• Increased breakdown of red blood cells
• Inflammation that slows red blood cell formation
• Nutritional deficiencies due to reduced appetite or absorption

These factors may occur alone or together, depending on the type of cancer and stage of the disease.

Cancer Treatment and Low Hemoglobin Levels

Cancer treatments are also a very common cause of anemia. Chemotherapy, radiation therapy, immunotherapy and targeted therapies can all affect bone marrow.

Chemotherapy, in particular, targets fast-growing cells, including healthy blood-forming cells. Many people receiving chemotherapy develop anemia at some point during treatment.

When hemoglobin levels drop too low, treatment may need to be delayed or adjusted. Managing anemia helps support overall strength and allows cancer treatment to continue as safely and effectively as possible.

Compassionate Care for Blood Disorders and Cancers

At AdventHealth, our hematology oncologists specialize in diagnosing and treating conditions that affect the blood, bone marrow and lymphatic system. If you develop anemia as a result of your cancer or as a side effect of your treatment, we’ll work with you to find the root cause and create a personalized plan that supports your overall well-being.

Learn more about the hematology oncology team at AdventHealth.