If you or someone you care about has endometriosis, it’s understandable to ask: “can endometriosis cause cancer?” Navigating pain and fertility concerns is hard enough – adding uncertainty around cancer risk can feel overwhelming.
Here’s the honest, evidence-based takeaway: endometriosis is not itself a cancer, and most people with it will never develop cancer. But in certain cases, particularly depending on the severity of the case, there is a modestly increased risk of specific cancers.
In this article, we’ll explore how uterine changes, such as hyperplasia, interplay with hormonal balance, and how endometriosis and its treatments factor into fertility planning. We’ll also touch on the best age to get pregnant with endometriosis and how to improve chances of success when undergoing IVF treatment.
Our goal here is to empower you to understand the evidence (not fear it), and to make informed decisions alongside your care team.
Endometriosis occurs when tissue similar to the lining of the uterus grows outside the uterus, on ovaries, fallopian tubes, the pelvic lining, or other organs. These growths respond to menstrual cycles, causing inflammation, pain, and scarring.
Certain aspects of endometriosis have overlap with known cancer-promoting processes:
Given those overlaps, it’s no surprise that the question frequently comes up: can endometriosis cause cancer? The data suggests that while endometriosis doesn’t cause cancer directly, it may increase risk under certain conditions.
The most consistent link research has found is between endometriosis and ovarian cancer, particularly clear cell ovarian cancer and endometrioid subtypes.
In a large study from Utah, researchers compared nearly 79,000 women with endometriosis to five times as many without the condition. They found that women with endometriosis were about four times more likely to develop ovarian cancer. For women with more serious forms of endometriosis, the risk was about ten times greater than for those without it.
Another common question is whether endometriosis is linked to endometrial hyperplasia and endometrial cancer.
What causes a thick uterus lining in conditions like hyperplasia is usually a hormone imbalance – most often too much estrogen without enough of other balancing hormones. Because hormones also play a role in endometriosis, it’s important to keep an eye on both together.
In summary: the strongest, most consistent risk is for ovarian cancer (particularly clear cell ovarian cancer) in more severe cases of endometriosis. Risks for uterine or other cancers are less certain. It’s important to note that even in people with severe endometriosis, it is rare for these cancers to develop.
Several mechanisms of the body have been proposed that link endometriosis and cancer risk:
Endometriosis is an estrogen-sensitive condition. When estrogen is not balanced with sufficient progesterone, tissue growth can get out of control.
This dynamic helps explain both what can cause a thick uterus lining, as well as hyperplasia in the endometrium. Progesterone (or progestins) counteract estrogen’s tissue growth effects—hence the potential benefits of progesterone pills for some people are especially relevant in this context.
When endometriosis lesions form, they create an environment in the body that is full of inflammation and highly reactive molecules, known as “oxidative stress.”
Over time, this consistent irritation can damage DNA in the surrounding cells. If enough damage builds up, it can cause mutations, which may increase the risk of cancer.
In rare cases, doctors have found a form of endometriosis where the cells look unusual (“atypical”), which might represent a middle step between endometriosis and cancer. But this doesn’t happen often, and most cases of endometriosis never turn into cancer.
Overall, these findings suggest that it’s biologically possible for endometriosis to play a role in cancer development, but there’s no proof that endometriosis directly causes cancer.
Not everyone with endometriosis has the same level of cancer risk. Certain factors can make the risk a little higher:
For people with more severe disease or these added risk factors, doctors may recommend close monitoring – especially when planning for fertility or future health.
Fertility often declines more quickly for people with endometriosis and treatment options may become more limited with age. Many fertility specialists advise discussing family-building goals earlier – often in the early 30s rather than later.
Further, while no randomized trials definitively tie early pregnancy to reduced cancer risk, combining fertility planning with risk awareness is sensible in many cases.
Some endometriosis patients may also want to consider egg freezing earlier as a precautionary strategy if immediate pregnancy isn’t feasible.
For patients with endometriosis who are undergoing IVF treatment, it can be helpful to know your personal window of implantation (WOI). One reason embryo implantations fail is due to a displaced WOI – endometrial receptivity tests help identify a patient’s personal WOI and adjust the embryo transfer timing accordingly.
Because the risk is modest and variable, screening must be individualized.
So, can endometriosis cause cancer? The short answer is: no, it does not inherently cause cancer. However, in women with certain subtypes (particularly ovarian endometriomas or deep infiltrating disease) the risk of clear cell ovarian cancer and other type I ovarian cancers is a bit higher.
Uterine factors also matter: atypical hyperplasia in the endometrium due to hormone imbalance is a known precursor to cancer. Monitoring via tools like an endometrial thickness chart, combined with judicious use of progesterone pills, offers a potentially protective strategy. Keep in mind that everyone’s circumstances are different – your doctor is the best person to recommend a course of action
For those with endometriosis who are planning to have children, the best age to get pregnant with endometriosis tends to be earlier, balancing fertility and risk. But again, this must always be personalized. Luckily, there are many tools and strategies in modern healthcare to help support a successful fertility journey, even in the face of challenges.
