Exploring the Link Between Cancer and Autoimmune Diseases

The immune system is responsible for defending against infections and diseases. However, for some people, the immune system does not function like it should. For example, in those with an autoimmune disease, the body mistakenly attacks normal cells.

Prevalence of Autoimmune Diseases in the U.S.

An autoimmune disease may arise due to genetics and environmental factors. There are more than 100 types of autoimmune diseases, according to reports from the American Autoimmune Related Diseases Association. In the United States alone, about 24 million people have a form of autoimmune disease.

Some of the most common types include:

  • Type 1 diabetes
  • Rheumatoid arthritis
  • Pernicious anemia
  • Multiple sclerosis
  • Lupus (also called systemic lupus erythematosus)
  • Inflammatory bowel disease
  • Autoimmune thyroid disease

Cancer and Autoimmune Disease Connection

People diagnosed with an autoimmune disease have a high risk of cancer, according to multiple medical studies. It varies depending on the type of autoimmune disease someone has and the medications they use to manage their condition.

“The risk is very particular to the specific autoimmune disease diagnosis, and usually the risk is for a specific type or types of cancer,” explains Dr. Timothy Niewold, a professor of rheumatology and pathology and director of the Colton Center for Autoimmunity at NYU Langone Health. “This suggests that there is something in common in the causal factors between certain autoimmune diseases and specific types of cancer.”

Moreover, the treatments and medications used for certain autoimmune diseases may contribute to a higher cancer risk. It is challenging for most scientists to assess cancer risk in patients with autoimmune diseases due to the many factors that presumably connect them together, says Dr. Rosalind Ramsey-Goldman, a research professor at the Feinberg School of Medicine, Northwestern University in Chicago and medical-scientific advisory council member at the Lupus Foundation of America.

A Closer Look at the Link Between Autoimmune Diseases and Cancer

Here are some examples exhibiting the connection between cancer and autoimmune diseases.

  1. Rheumatoid arthritis and Lung Cancer

Rheumatoid arthritis is a form of inflammatory disease. Painful swelling of the joints is its most common symptom. However, rheumatoid arthritis can also manifest itself through heart and breathing problems. People with this autoimmune disease have a slightly higher risk for certain cancers, including lung cancer, reveals Dr. Anne R. Bass, a rheumatologist at the Hospital for Special Surgery in New York.

Those who suffer from rheumatoid arthritis and smoke cigarettes have a 40 percent increased risk of developing lung cancer in comparison to those who smoke but do not have the disease, warns the Arthritis Foundation. This increased risk could be the result of chronic inflammation, a well-known cancer risk factor, which occurs in people who have rheumatoid arthritis.

Currently “healthy” individuals who smoke or use tobacco products have a higher risk of both rheumatoid arthritis and lung cancer because of the environmental association between arthritis and lung cancer, along with the genetic factors that may play a role.

  1. Sjögren’s Syndrome and Lymphoma

Sjögren’s syndrome is an autoimmune disease mainly associated with dry eyes and dry mouth. A patient can have Sjögren’s alone or have it secondary to another form of autoimmune disease, such as rheumatoid arthritis or lupus. Similar to arthritis and many other autoimmune diseases, Sjögren’s syndrome is not limited to the eyes and mouth, meaning it can affect other areas of the body, including the lungs and kidneys.

People diagnosed with Sjögren’s are at a 7-fold to 19-fold elevated risk for lymphoma, a form of malignancy that affects the lymph nodes. The lymph nodes help filter harmful substances out of the body. The lymphoma that develops when someone has Sjögren’s syndrome is more likely to take place in the salivary glands. The good news, however, is that the lymphoma that arises due to Sjögren’s is often treatable, according to the Sjögren’s Syndrome Foundation.

  1. Vasculitis and Bladder Cancer

Vasculitis describes a number of rare autoimmune conditions associated with inflamed blood vessels. In severe cases of vasculitis, a doctor may prescribe a drug called cyclophosphamide (Cytoxan), says Niewold. Unfortunately, the drug has been linked to a higher risk of bladder cancer and other malignant disorders. Cyclophosphamide is an immunosuppressant, which means it works by “dampening” the response of the immune system. As such, although people with severe cases of vasculitis using Cytoxan may survive, they may develop lymphoma or bladder cancer later on in life, according to the Johns Hopkins Vasculitis Center.

This elevated risk depends on how long a patient uses the drug and at what dosage. The risk of bladder cancer is also greater when a patient takes cyclophosphamide orally and daily. A study involving 145 participants with Wegener’s granulomatosis (a form of vasculitis) supported these findings. In patients treated daily with cyclophosphamide, 6 percent developed bladder cancer. Among patients who followed for up to 15 years, the projected incidence of cancer in the bladder was as high as 16 percent.

Other Notable Connections

Several other autoimmune diseases carry a potentially higher risk of cancer development, either because of the disease itself or due to the medications used. Some examples include:

  • Rheumatoid arthritis is also linked to a higher risk of lymphoma.
  • Scleroderma, a cluster of diseases chronically affecting the skin and connective tissue, is associated with an increased risk of lung cancer.
  • Dermatomyositis, an autoimmune disease that causes muscle weakness and a rash, is linked to an increased risk of many different cancers, including of the ovaries, lung, breast, and intestines.
  • People with psoriasis, a skin condition affecting about 7.5 million Americans, may have a higher risk of non-melanoma skin cancers and other types of malignancies.

Monitoring for Cancer Risk

Undergoing age-appropriate cancer screenings recommended by healthcare professionals is the best way for people with autoimmune diseases to monitor their cancer risk. For some diseases, such as psoriasis, additional monitoring for skin cancer is advisable. This often includes regular visits to a licensed dermatologist.

Cancer Treatment and Autoimmune Diseases

If you have an autoimmune disease, a newer treatment called immunotherapy can offer more promise compared to conventional methods like chemotherapy and surgery. Immunotherapy stimulates your own immune system to recognize and attack cancer cells. It is relatively safer and less harmful than traditional treatments.

To find out whether immunotherapy is right for you, contact us today to schedule your consultation.

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