For Your Patients: The Links Between Endometriosis and Other Diseases

If you have endometriosis, you already know that it can cause symptoms throughout the body well beyond the reproductive tract. In addition to menstrual-related pain, you may experience headaches, fatigue, back and joint pain, sexual dysfunction, and bowel and bladder difficulties.

And like other conditions involving widespread inflammation, endometriosis is sometimes associated with other major diseases, including autoimmune disorders, cardiovascular problems, and cancer.

While the chances you will develop these diseases are not greatly increased over those of individuals without endometriosis, as a patient you should make extra efforts to maintain a healthy weight, diet, and lifestyle and have the recommended regular preventive screenings. Be watchful and report any unusual symptoms to your doctor.

Here's what we know about the risks for three major non-gynecologic diseases in the presence of endometriosis.

Diseases Related to Immune System Abnormalities

Endometriosis has been long associated with autoimmune disease, in which underlying abnormalities in the body's immune system prompt it to wrongly attack healthy cells. Instead of just fighting infections, allergens, and cancers, immune cells wage war on normal tissues to the detriment of many sites from joints and skin to blood vessels. Experts think these same abnormalities, which include higher-than-normal numbers of certain immune cells and antibodies, may also be involved in endometriosis. They may prevent the immune system from clearing away the displaced endometrial tissue and instead allowing it to form lasting inflammatory implants outside of the uterus.

At present, most autoimmune disease problems are currently diagnosed after the emergence of endometriosis, except for adolescent asthma, which is usually present before the gynecologic problem appears. There is some suggestion that the presence of autoimmune disorders is associated with more severe endometriosis.

A large study from 2019 found slight increases in the risk of the following immune-related inflammatory conditions in individuals with endometriosis:

• Systemic lupus erythematosus

• Multiple sclerosis

• Inflammatory bowel disease

• Celiac disease

• Myasthenia gravis

• Behcet's syndrome (an inflammatory disease that attacks the mouth, skin, eyes and genitals)

The increased risk was greatest for the last two conditions, but remember, these disorders are still relatively uncommon in the U.S. population, so your risk as an endometriosis patient is not appreciably higher.

Cardiovascular Disease

The risk of cardiovascular and cerebrovascular disease may be somewhat greater in women with endometriosis because of the impact of the inflammatory milieu on the blood vessels and heart. But the greatest risk to the cardiovascular system comes from the early removal of the estrogen-producing ovaries in young women whose endometriosis is not controlled by medication or by excision of endometrial tissue from sites outside of the uterus.

Comparing endometriosis patients with women without endometriosis, the Nurses' Health Study II found those with confirmed disease had modest increases in risk for the following:

• 52% greater risk for heart attack

• 91% greater risk of chest pain

• 35% greater risk of having heart surgery

In research from England, endometriosis patients were seen to have a slight increase in the chance of developing cerebrovascular disease such as stroke, and of having heart failure, irregular heart beat (cardiac arrhythmia), and high blood pressure.

Needless to say, however, even young, generally healthy women with endometriosis should be sure to get assessed for their individual risk of heart disease. They should actively reduce their risk factors, particularly by avoiding tobacco and excess alcohol, following a healthy eating plan, and getting at least 30 minutes of moderate exercise daily.

Cancer

Endometriosis has been linked to a slightly higher risk of certain cancers. While the precise connection is unknown, one of the driving factors may again be widespread inflammation, as inflammation is one step in the pathway that turns normal cells into abnormal ones and then into malignant tumors.

In a large 2020 review of studies of a range of cancers, risk appeared to be very slightly increased for ovarian cancer (5% higher) and breast cancer (4% higher), although there was a somewhat larger increased risk for thyroid cancer, at 39%.

Bear in mind, however, that these increases in cancer risk are still minimal. For example, if 1.3 out of 100 women in the general female population will develop ovarian cancer in their lifetime and this percentage goes up by 2.5% in women with endometriosis, that still means that 97.5% of endometriosis patients will not develop ovarian cancer.

It's interesting to note that in this study the risk of cervical cancer decreased by 39% in the presence of endometriosis. This is probably due to (1) the regular gynecologic monitoring required for endometriosis patients detecting precancerous cells before they become malignant; and (2) the cervix being removed in some endometriosis patients who undergo hysterectomy for pain.

The potential link with other cancers such as skin and colon still needs to be determined. In the meantime, as for heart disease, endometriosis patients should be extra mindful of the need to reduce the general cancer risk factors for cancer faced by everyone. Preventive measures include avoiding smoking, maintaining a healthy weight and regular exercise patterns, and eating plenty of fresh fruits and vegetables. Keep alcohol intake to a minimum and always use sun protection such as high-SPF UV ray-blocking sunscreens, along with sun hats and sunglasses.

Read previous installments in this series:

For Your Patients: What Is Endometriosis?

For Your Patients: Will Your Doctor Diagnose Endometriosis?

For Your Patients: What to Know About Endometriosis Treatment

For Your Patients: Fertility and Pregnancy in Endometriosis

For Your Patients: Managing Endometriomas: What to Know

For Your Patients: Tips for Talking to Your Doctor About Endometriosis

For Your Patients: 10 Q&As About the Burden of Endometriosis

"Medical Journeys" is a set of clinical resources reviewed by doctors, meant for physicians and other healthcare professionals as well as the patients they serve. Each episode of this 12-part journey through a disease state contains both a physician guide and a downloadable/printable patient resource. "Medical Journeys" chart a path each step of the way for physicians and patients and provide continual resources and support, as the caregiver team navigates the course of a disease.