Endometriosis is a chronic disorder in which the endometrium — the tissue that ordinarily lines your uterus — develops outside your uterus. It typically involves other parts of your reproductive system such as the fallopian tubes and ovaries.

The abnormal tissue that grows from endometriosis is not cancerous, but it can cause complications such as:

According to the Endometriosis Foundation of America, endometriosis affects about 200 million women globally.

Studies have sought to determine a potential connection between endometriosis and cancer, and results are mixed.

The European Society for Human Reproduction and Embryology recommends doctors inform women that evidence does not indicate endometriosis causes cancer, though some types of cancer are more common in those experiencing endometriosis.

Endometrial cancer

Endometrial cancer, also called uterine cancer, starts in the endometrium. Exact causes are unknown, but symptoms include pelvic pain and bleeding from the vagina after menopause or between periods.

A 2015 study examined the association between endometriosis and endometrial cancer. Of the case participants, 0.7 percent of people who had been diagnosed with endometriosis developed endometrial cancer in the 10-year follow-up period. In the control group, 0.2 percent were diagnosed with endometrial cancer during that time.

The researchers suggested those experiencing endometriosis may have an increased risk of endometrial cancer later in life because of both estrogen stimulation and chronic inflammation. However, the cancer was seen in less than 1 percent of those with endometriosis.

Ovarian cancer

A 2017 review of research conducted on endometriosis and ovarian cancer showed studies have demonstrated an increased risk of epithelial ovarian cancer in people with endometriosis. One reason might be the high estrogen levels common with the condition, which can result in proliferation of malignant endometriotic cysts.

It should be noted that although ovarian cancers are more common in women experiencing endometriosis, the overall lifetime risk for developing ovarian cancer is still low.

Breast cancer

Breast cancer is the most common type of cancer in women. A 2016 review of research on the link between endometriosis and breast cancer revealed inconclusive results. Evidence that has connected the two has relied mostly on hormonal dependence and the risk factors of both conditions.

Although endometriosis has the potential to impact everyday life, it is not cancerous. While some studies have demonstrated an increase in risk of certain types of cancers in those with endometriosis, the increase in risk is not much higher than those who do not experience the condition.

If you’re experiencing symptoms of endometriosis, visit your doctor. They can provide a full diagnosis and develop a treatment plan for pain management.