Endometriosis does not cause cancer. However, research suggests that people with endometriosis may be at an increased risk of developing some cancers, including ovarian cancer.

Endometriosis is a condition where tissue similar to the tissue that grows inside the uterus instead grows outside the uterus — usually on organs such as the ovaries, fallopian tubes, bowels, and bladder.

According to the American College of Obstetricians and Gynecologists (ACOG), endometriosis affects 1 in 10 females in the United States. Many people receive a diagnosis between the ages of 30–40 years.

Some research suggests that endometriosis may increase a person’s risk of some cancers.

This article examines the link between endometriosis and cancer risk, including symptoms, causes, and treatments.

A person thinking about endometriosis and cancer.Share on Pinterest
Thomas Barwick/Getty Images

Endometriosis is a disease of the female reproductive system. It occurs when endometrial tissues grow outside the uterus, invading healthy tissues.

Despite growing in areas outside the uterus, endometrial lesions can thicken during the menstrual cycle and bleed during periods.

While there are concerns about how endometriosis impacts cancer, it is not a cancerous condition. Abnormal tissues growing outside the uterine lining are not cancerous. However, endometriosis can cause several complications that can increase a person’s risk of cancer.

The Office on Women’s Health (OASH) notes that endometrial implants may continue to expand and cause problems, including:

Research from 2017 suggests that endometriosis shares common pathological features with cancer. Cancer is a broad term for a group of conditions that impairs cellular functions by invading healthy cells, causing them to divide uncontrollably.

While endometriosis is not life threatening, some individuals with the condition may experience excessive pain that prevents them from doing daily activities.

Learn more

Learn about endometriosis, cancer, and more.

Evidence published in the Asian Pacific Journal of Cancer Prevention suggests that people with endometriosis may have a slightly greater chance of developing ovarian cancer.

The authors note that this may be due to a combination of factors, including:

  • high estrogen concentration, which can cause an increase in cancerous cysts
  • mutations in the ARID1A gene, a gene that helps the body suppress cancer
  • loss of the BAF250a gene expression, which can make it harder for the body to suppress tumors
  • oxidative stress, leading to genetic mutations and the formation of ovarian cysts

Additional evidence from 2017 indicates that endometriosis in the ovaries may give rise to malignant ovarian tumors, known as endometriosis-associated ovarian carcinoma (EAOC).

It may also increase a person’s risk of other types of ovarian carcinomas.

Women with endometriosis have two to three times the risk of developing ovarian cancer. The authors note that certain mutations may cause endometriosis to progress into carcinomas.

There is no evidence that endometriosis itself actually causes ovarian cancer.

Research from 2019 indicates a connection between cervical endometriosis and cervical clear cell carcinoma (CCC). It suggests that women with endometriosis may have a low risk of cervical cancer.

There is no evidence that cervical endometriosis causes cervical cancer.

A 2018 meta-analysis that examined the risk of gynecological cancers in women with endometriosis found that people with endometriosis have a low risk of cervical cancer.

Endometrial cancer occurs when cancerous, malignant cells form in the tissues of the endometrium. They can grow out of control and spread to other parts of the body.

Endometrial cancer can have similar symptoms to endometriosis, such as unusual vaginal bleeding or pelvic pain. However, it is not related to endometriosis.

Postmenopausal uterine bleeding can be a sign of endometrial cancer.

Some symptoms of endometriosis may be similar to those of cancer. However, they are two separate, distinct conditions.

Endometriosis symptoms

Endometriosis typically affects people who are actively menstruating.

However, on rare occasions, people can have endometriosis following menopause and after a hysterectomy. Symptoms can range from asymptomatic or mild to severe.

Symptoms include:

Cancer symptoms

Cancer symptoms may vary depending on the location, type, and progression of the disease.

Some common, general symptoms of cancer include:

Some of these symptoms, such as blood in the urine or stool, bloating, and fatigue, can also be symptoms of endometriosis.

A person should contact a doctor if they are worried about any symptoms.

Learn more

Learn more about the symptoms of cancer.

This section looks at possible causes of endometriosis and cancer.

Causes of endometriosis

Scientists do not know exactly what causes endometriosis.

However, some possible causes may include:

  • genetics
  • problems with the immune system
  • problems with menstrual periods
  • elevated hormone levels
  • previous surgery in the abdominal area

Causes of cancer

According to the World Health Organization (WHO), a combination of external factors can interact with a person’s genes to transform healthy cells into tumor cells.

This includes:

  • physical carcinogens such as ultraviolet and ionizing radiation
  • biological carcinogens from infections
  • chemical carcinogens from tobacco smoke, alcohol, food, and water contaminants

This section looks at some risk factors for both cancer and endometriosis.

Risk factors for endometriosis

Certain risk factors can increase a person’s chances of endometriosis.

These include:

  • starting menstruation early
  • having a short menstrual cycle of fewer than 27 days
  • having heavy menstrual periods
  • having a family history of endometriosis

Risk factors for cancer

According to the National Cancer Institute (NCI), certain factors may increase a person’s risk of developing cancer.

These include:

  • being older
  • having exposure to carcinogens
  • having obesity
  • drinking alcohol
  • smoking tobacco
  • taking immunosuppressive medications

This section looks at how doctors may diagnose endometriosis and cancer.

Diagnosing endometriosis

To diagnose endometriosis, an obstetrician-gynecologist or OB-GYN will take a thorough medical history and conduct a physical exam, including a pelvic exam.

They will also ask questions about a person’s symptoms and try to rule out other possible causes.

The doctor can order some additional tests, including:

  • imaging studies, such as an ultrasound
  • laparoscopy, which is a surgical procedure to view the endometrium
Learn more

Learn more about diagnosing endometriosis.

Diagnosing cancer

It can be difficult to diagnose cancer accurately. This is because some cancer-specific signs may be absent.

If a doctor suspects cancer, they can order one or more of the following:

  • Lab tests: The doctor will check for specific biomarkers in a person’s blood, urine, and bodily fluid to detect an anomaly.
  • Biopsy: A biopsy is a procedure in which the doctor removes a tissue sample. A pathologist looks at the tissue under a microscope and runs other tests to see if the tissue contains cancer cells.

Treatments are different for endometriosis and cancer.

Treatment for endometriosis

The doctor will consider the severity of a person’s symptoms and the condition’s progression to determine the best treatment.

A treatment plan may include:

  • pain relief medication, such as nonsteroidal anti-inflammatory drugs (NSAIDs)
  • hormonal treatments such as the contraceptive pill
  • surgery to remove endometrial tissue or affected organ
  • complementary and alternative therapies such as acupuncture and chiropractic care
  • lifestyle changes such as doing regular exercise, quitting smoking, and avoiding alcohol
  • diet changes
Learn more

Learn more about endometriosis treatment and management.

Treatment for cancer

If a person has cancer, the type of cancer they have and the progression of the disease will determine their treatment.

A doctor may recommend the following:

  • Chemotherapy: For chemotherapy, the doctor will administer medications into a person’s body to shrink tumor cells. Most often, a person will have chemotherapy with other cancer treatments.
  • Radiation therapy: Radiation therapy uses high frequency radiation to kill cancer cells and shrink tumors. It can cure cancer growth and prevent it from coming back.
  • Surgery: The doctor will administer anesthesia and remove a cancerous growth from a person’s body with the aid of surgical instruments.

However, if a person has both conditions, the doctor will evaluate their symptoms and determine the best treatment plan.

The outlook for a person will be different depending on whether they have endometriosis or cancer, and the severity of the condition.

Outlook for endometriosis

Research from 2017 indicates that a combined approach of surgery and medical treatments can offer the best long-term outcomes. It can also prevent a recurrence of symptoms.

Endometriosis is not fatal, and a person can live a long and healthy life.

It is possible to treat and manage symptoms through medication, diet, exercise, and therapy.

Outlook for cancer

The stage at which a person receives a cancer diagnosis can help indicate their chances of survival. Those who receive an early cancer diagnosis have the highest chance of surviving the disease.

However, a person with cancer should talk with a doctor about the outlook for their specific case.

Surgery, chemotherapy, and other medical therapies may help to treat cancer. This can lengthen a person’s life expectancy or make a person’s life more comfortable.

Early forms of endometriosis or cancer may be asymptomatic. This means a person may not have any noticeable symptoms at the onset of the condition.

Several warning signs can be nonspecific, and symptoms of both endometriosis and cancer can be similar.

If a person notices symptoms of endometriosis or cancer, they should see a doctor immediately. Early diagnosis can lead to early, more effective treatment.

People should speak with a doctor if they notice any new symptoms or if existing symptoms worsen. This is especially important for those with a family history of cancer or endometriosis.

People should seek urgent medical attention if symptoms affect their daily lives.

This section answers some frequently asked questions about endometriosis and cancer.

How often does endometriosis turn into cancer?

It is rare for endometriosis to turn into cancer.

Research from 2018 indicates that the risk of endometriosis-related cancer is low.

What will happen if endometriosis is left untreated?

Without treatment, endometriosis can progress and become severe, causing chronic pain and infertility.

Is endometriosis precancerous?

Endometriosis is not a precancerous condition. Although it can increase a person’s chances of some types of cancer, the risk is generally low.

Endometriosis happens when cells similar to the uterine lining grow outside the uterus. It does not cause cancer.

Common symptoms may include chronic pain and infertility.

While research suggests that people with endometriosis may develop cancer in the cervix and ovaries, the risk is low.

If a person suspects either endometriosis or cancer, they should speak with a doctor. The doctor will assess their symptoms and determine the best treatment plan.