Menopause and Endometriosis

In endometriosis, cells similar to the lining of the uterus grows in other places, like it does inside the uterus the tissue builds up and sheds each month. However, the tissue outside the uterus is unable to exit through the vagina and gets trapped in the body leading to the formation of scar tissue, inflammation, and pain.

Estrogen stimulates the growth of endometriosis lesions, so it seems logical that after menopause, endometriosis becomes less active as your ovaries produce less estrogen. However, as the body still makes some estrogen, it means that endo symptoms can continue even in menopause.

Can endometriosis develop after menopause?

Endometriosis can also develop after menopause but it is rare and could be associated with the use of:¹

• Hormone replacement therapy (HRT)
• Phytoestrogens (plant-based estrogens that mimic estrogen)
• Tamoxifen (a selective estrogen receptor modulator often used to treat breast cancer)

However, it is unclear whether the growth of lesions is independent to estrogen, or if there is a sensitivity to estrogen, or production of estrogen, comes from the lesion itself.²

It should be noted there is limited data on the effects of hormone therapy and endometriosis. It is believed that even after surgery involving a total hysterectomy, estrogen therapy was found to initiate endometriosis symptoms. Additionally estrogen therapy increases the risk of cancer, whereas other types of hormone therapy may not cause symptoms post-surgery.³

Another theory is that genetic changes or epigenetics are involved the development of endometriosis in menopause, which means there is a modification of the way genes are expressed. A case study of several postmenopausal women identified that all cases of endometriosis lesions were either ovarian cysts or deep infiltrating endometriosis, which is where lesions are found in other places such as the bowel and bladder.²

It’s believed that the lesions in cystic and deep infiltrating endometriosis have an ability to grow despite the lower levels of estrogen that occur after menopause, and instead start to proliferate because of genetic or epigenetic events.²

Treatments of endometriosis post-menopause

Treatments of endometriosis in menopause is primarily surgical. The use of GnRH analogues or agonists (such as Lupron, Synarel, Depot, or Zoladex) are not effective post menopause.³

The bottom line

Symptoms of endometriosis after menopause are not common, but it can happen. Endometriosis can also develop after menopause, but it is rare.

It is not known why endometriosis could develop after menopause, but some factors include increased circulation of estrogens (taken through synthetic hormones or from foods high in phytoestrogens), a change in sensitivity to estrogen, or increased localized production of estrogen. In cases where symptoms commence abruptly after menopause, it is thought that a genetic or epigenetic change may have occurred.²

A note on phytoestrogens

It should be noted that the link between phytoestrogen intake from the diet and endometriosis is not fully understood. And when it comes to human studies, the evidence is mixed:

• A population-based study found an increased risk of endometriosis in women who were fed soy-based formulas as infants.⁴
• In contrast, two other studies have found no evidence that soy intake was associated with endometriosis and may even be linked with a lowered risk.^5,6

Soy products contain very high levels of phytoestrogens. You can read more about soy and endometriosis in this article.