During a woman’s period, tissue builds up and sheds if she doesn’t become pregnant. However, women with endometriosis develop tissue outside of the uterus, on the reproductive organs, and in the abdominal cavity. This tissue builds up and breaks down during hormonal changes, resulting in bleeding in the pelvis that leads to inflammation, swelling, and scarring of normal tissue.

This article examines whether endometriosis can increase the risk of some types of ovarian cancer, the causes, and how to treat the condition.

The Link Between Endometriosis and Cancer

Endometriosis affects approximately 2% to 10% of women in the United States. While endometriosis is considered a benign (noncancerous) disease, it has features similar to cancer, a mutation that appears the same as ovarian cancer, plus an increased risk of developing ovarian cancer.

Some studies indicate there is a link between endometriosis and ovarian endometriomas, which are conditions that cause benign (noncancerous) or malignant (cancerous) tumor growth. Large studies have demonstrated the presence of ovarian carcinoma in 5% to 10% of cases of endometriosis, while others have shown that malignant transformation through atypical endometriosis. 

However, one study indicated that the lifetime risk of ovarian cancer among women with endometriosis is fewer than two women in 100. This low-risk value can reassure women with endometriosis that their lifetime ovarian cancer risk is low.

Endometriosis Treatment

Currently there is no cure for endometriosis. However, there are several options to treat the accompanying pain and infertility issues. These include: 

• Hormone therapy: Because hormonal changes are linked to the buildup and breakdown of endometrial tissue, hormone therapy can be an optimal method to treat the pain. Hormones in either pills, injections, or nasal sprays can be used. This form of treatment stops ovulation and the production of estrogen, which helps slow the growth and buildup of the endometrium, endometrial lesions, and stops new scarring from forming.
• Pain medication: If symptoms are mild, NSAIDs or prescription pain medication may help alleviate pain and other symptoms. However, evidence of their effectiveness in relieving pain is limited. 
• Surgery: Healthcare providers may recommend surgery to treat severe pain. Surgical treatments range from laparoscopic surgery to surgery severing the pelvic nerves. Surgery as a course of treatment may provide significant, but short-term relief.

To treat infertility, your healthcare provider may suggest laparoscopic surgery to remove the tissue growth. However, in spite of studies indicating improved pregnancy rates after this type of surgery, success rates are unclear.

In vitro fertilization (IVF) is another option to treat infertility. Hormones used in IVF have proven successful in treating infertility related to endometriosis. Other issues may occur, such as hormones used during IVF don’t cure endometriosis lesions, pain may also recur after pregnancy, and not all women with endometriosis are able to conceive with IVF. Researchers are investigating other hormone treatments for infertility caused by endometriosis.

Causes of Endometriosis

It’s unclear what causes endometriosis, but researchers are examining a number of possible causes that include:

• Menstrual flow: Retrograde menstruation (when the blood flows back into the pelvis, not out of the vagina) is probably the primary cause of endometriosis.
• Genetics: Endometriosis can run in families and, therefore, may be genetically inherited.
• Weak immune system: The immune system may fail to find and destroy endometrial tissue growing outside of the uterus.
• Hormones: The hormone estrogen seems to contribute to the development of endometriosis. Researchers are examining whether endometriosis is a problem with the body's hormones.
• Surgery: During a cesarean delivery (C-section), which is delivering a baby through incisions made in the abdomen and uterus, or hysterectomy, which is the surgical removal of the uterus, endometrial tissue could be picked up and moved by mistake to the abdominal cavity.

When to See a Healthcare Provider

If you suspect you have symptoms of endometriosis, make an appointment with your healthcare provider. Discuss your symptoms to determine whether you have the condition.

Your healthcare provider will recommend a series of tests that include a pelvic exam to see if there are any large cysts and/or an imaging test to check for ovarian cysts (fluid-filled sacs). They may prescribe birth control pills to help alleviate the pain or recommend laparoscopic surgery to confirm 100% that you have endometriosis.

Summary

Endometriosis can be a painful condition when tissue builds up outside the uterus, around the reproductive organs, and inside the abdominal cavity. Some studies show a link between endometriosis and cancer, but the risk is very low.

Causes are not certain, but a number of factors may include menstrual flow issues, genetics, a weakened immune system, hormones, and more. Symptoms of endometriosis include pain, bleeding, and infertility. To treat the condition, your healthcare provider may prescribe pain medications or recommend over-the-counter NSAIDs, depending on the severity of your pain. Other options include surgery.