What Type of Cancer Causes Low Hemoglobin (Anemia)?

Cancer can be a cause of low hemoglobin (anemia), and is often seen with cancer types that include leukemia, breast cancer, colon cancer, and prostate cancer. Chemotherapy and radiation treatments for cancer also can lead to anemia, as can nutrition problems, internal blood loss, and certain medications like antibiotics.

Hemoglobin is a protein found in red blood cells that contains iron and helps transport oxygen around the body. Other conditions can be responsible for low hemoglobin, too, such as rheumatoid arthritis. If you have fatigue, rapid heartbeat, or other anemia symptoms, see a healthcare provider to ensure accurate diagnosis and treatment.

Cancers That Cause Anemia

Certain cancers are associated with the main causes of low hemoglobin levels: deficiencies in red blood cell production, blood loss, and higher rates than typical of red blood cell destruction in the body.

Blood and Bone Marrow Cancers

Blood and bone marrow cancers disrupt how blood cells work and how they are produced in the body. There are three main types of blood and bone marrow cancers:

• Leukemia: Arising in your blood and bone marrow (spongy tissue inside bone), leukemia is caused by the rapid production of abnormal white blood cells that normally fight infection. Leukemia hinders the bone marrow’s ability to produce red blood cells and platelets. 
• Lymphoma: The lymphatic system circulates fluid and produces white blood cells that fight infection. Lymphoma occurs when abnormal lymphocytes collect in the lymph nodes and other tissues impairing the immune system. 
• Myeloma: Plasma cells are white blood cells that produce antibodies to fight infection. Myeloma (cancer of the plasma cells) interferes with the normal production of antibodies. This weakens your immune system. 

Cancer in other parts of the body can also metastasize (spread) to bones and interfere with the production of red blood cells, leading to anemia.

Cervical Cancer

Research shows about half of all people with cervical cancer have anemia at the time of diagnosis. This is often due to bleeding tumors. It can also be due to cancer spreading to the bone marrow or malnutrition due to cancer diminishing your appetite.

Colon Cancer

Iron deficiency anemia can be one of the first symptoms of colon cancer. It is possible to have anemia at any stage of colon cancer. Studies suggest anemia is more common with cancers that affect the right side of the colon (cecum, ascending colon, parts of the transverse colon).

There are key differences between the right and left sides in the type and behavior of cancer cells, and they're treated differently, too. It's possible that anemia arises because right-sided tumors continue to bleed slowly, and over time, this will be reflected in a low blood count.

Kidney Cancer

Renal cell carcinoma and other types of kidney cancer can cause anemia, which is considered a classic sign of risk and prognosis in managing the disease. The kidneys secrete a hormone called erythropoietin, which stimulates the production of red blood cells. Kidney cancer can disrupt this process and cause anemia.

Certain medications used to treat types of renal cell carcinoma also can cause anemia as a side effect.

Breast Cancer 

Skeletal metastases are the most common location for breast cancer to spread. However, another common location for breast cancer to spread is the bone marrow. If breast cancer spreads to the bone marrow, it can affect red blood cell production.

An occult (hidden or unrecognized) breast cancer happens when there is no primary lesion in the breast and breast cancer is found elsewhere in the body. It occurs in less than 1% of breast cancer cases and is challenging to diagnose.

In one case study, a patient experienced bone marrow fibrosis due to occult breast cancer. In this case, the patient's bone marrow was replaced by scar tissue, resulting in anemia.

Prostate Cancer

One of the first symptoms of prostate cancer is sometimes anemia. Additionally, anemia occurs frequently with advanced prostate cancer.

However, while prostate cancer can spread to the bone marrow like other cancers, one of the most common causes of anemia in advanced prostate cancer is due to androgen deprivation therapy (ADT).

Lung Cancer

Anemia is common in individuals with lung cancer. When anemia occurs in patients before treatment, the prognosis is considered poorer. Anemia may be caused by cancer spreading to the bone marrow and the release of various cytokines.

Several different cytokines are involved in inflammatory processes in the body, and if there are too many of them, they can negatively affect red blood cell production. Additionally, cancer-related anemia can induce tumor hypoxia, which can make lung cancer more resistant to treatments such as chemotherapy and radiation.

Cancer Treatment and Anemia

Chemotherapy attacks all rapidly growing cells, not just cancer cells, and the cells in the bone marrow that are used to replace white blood cells, red blood cells, and platelets are some of the most rapidly dividing cells in the body.

Blood counts are usually done before each chemotherapy infusion, and if the red blood cell count is too low, chemotherapy may need to be delayed. Some people with cancer are treated with medications that stimulate the production of red blood cells so that chemotherapy can continue.

Anemia Symptoms

When you don't have enough hemoglobin, you have a reduced capacity for delivering oxygen to the tissues in your body. This can lead to symptoms such as fatigue, shortness of breath, and lightheadedness.

Untreated and severe anemia can lead to complications, including depression, heart problems such as arrhythmia and enlarged heart, and increased risk of infection.

Anemia might be accompanied by symptoms that reflect your body's deficit of red blood cells, including:

• Numbness and tingling of hands and feet 
• Dizziness
• Fatigue
• Feeling weak or tired all of the time
• Headache
• Increased susceptibility to infection
  
• Pallor (most easy to see in the mucous membranes)
• Pica (feeling the need to eat items that are not meant as food, such as dirt)
• Rapid heartbeat
• Shortness of breath (not related to a history of asthma or a cardiac condition)

However, it's important to note that not everyone with anemia notices symptoms.

Diagnosis

Anemia is diagnosed on a complete blood count in which a low red blood cell count or low hemoglobin levels are noted:

• Red blood cell count: A normal red blood cell count is 4.32 to 5.72 trillion cells per liter (L) in men and 3.90 to 5.03 trillion cells/L in women.
• Hemoglobin: A hemoglobin level less than 13.5 grams per 100 milliliters (ml) in men or 12.0 grams/100 ml in women is considered low.
• Hematocrit: A normal hematocrit level is 42% to 54% in men and 38% to 46% in women.

In addition to the levels, healthcare providers look at other lab tests to learn more about the potential causes of anemia. Some of these include:

• Mean corpuscular volume (MCV): MCV gives information about the size of red blood cells, whether normal, small (such as in iron deficiency), or large (such as in folate and B12 deficiency).
• Red cell distribution width (RDW): RDW gives further information on the size of red blood cells and whether there are two different populations, which can point toward different causes.
• Mean corpuscular hemoglobin concentration (MCHC): MCHC gives further information about the shape of red blood cells.

Diagnosing Cancer

When the cause of anemia is not known in someone without cancer, tests to rule out cancer may be considered. Types of tests used to diagnose cancer include: 

• Biopsy to test tissue samples, bone marrow, or body fluids
• Blood tests to check for tumor markers
• Endoscopic tests, including colonoscopy, bronchoscopy, or cystoscopy
• Imaging studies such as bone scans, computed tomography (CT) scans, and magnetic resonance imaging (MRI)

However, keep in mind that anemia may have several causes besides cancer and is a fairly common condition.

Treatment

The treatment of anemia in people with cancer includes two primary steps. The first is treating the underlying cause of the anemia, which can sometimes eliminate the anemia. The anemia itself may require specific treatment that may include:

• Diet: If your anemia is mild, simply eating iron-rich foods may suffice. It takes some time (on the order of months) to restore your red blood cell count through this method alone. Iron-rich foods that may make good choices include liver (chicken or beef), red meat, iron-fortified cereals, and legumes.
• Iron supplements: Iron supplements may be prescribed, but only take these under the advice of your healthcare provider. Studies suggest intravenous iron can be very helpful for some people with anemia due to cancer. This can be constipating, so your healthcare provider may recommend a stool softener as well.
• Blood transfusion: A blood transfusion is a way to rapidly increase your red blood cell count and is usually used if your anemia is causing significant symptoms.
• Medications: These stimulate the production of red blood cells in your bone marrow. The drugs Procrit, Epogen (epoetin alfa), or Aranesp (darbepoetin alfa) are similar to compounds made by the body to stimulate red blood cell production.
• Steroids: Steroids are sometimes used for the treatment of hemolytic anemia with lymphomas.

Coping

Anemia can be difficult to cope with, especially the resultant fatigue. While fatigue is not dangerous on its own, many people find cancer fatigue to be one of the most debilitating symptoms of cancer and cancer treatments.

Some simple measures can help as your anemia is being evaluated and treated. Standing up or sitting up slowly can help to avoid orthostatic hypotension, the decrease in blood pressure that can lead to lightheadedness or blacking out when going from lying down to a standing position too rapidly.

Pacing yourself throughout the day and prioritizing activities is also helpful, as is learning to ask for help. Eating well and making sure you are hydrated are important both for anemia as well as coping with cancer itself.

Summary

Blood, bone, colon, and other cancers are associated with anemia. Cancers can cause low hemoglobin (anemia) either directly or as a consequence of treatment. Internal bleeding from tumors, altered hemoglobin production, and chemotherapy, can each contribute to anemia's development. If anemia has no established cause, further testing is often indicated.

Cancer is diagnosed using multiple means, including imaging, endoscopic testing, and biopsies. Treatment of both cancer and anemia is dependent on the condition diagnosed.