
Endometriosis vs. Cancer: How to Tell The Symptoms Apart
How to tell overlapping symptoms apart—and choose the right specialist when it matters

How to Tell the Difference
Ovarian cancer and endometriosis are two conditions that can affect a woman’s reproductive system. Understanding how they may be related and how they differ is important. Ovarian cancer is relatively uncommon, with approximately 20,000 new cases found annually in the United States and a lifetime risk of 1 in 78. At the same time, millions of women live with endometriosis, affecting up to 1 in 10. Because some symptoms overlap, recognizing the differences is essential for accurate diagnosis and proper treatment. This article explains how to tell the difference between ovarian cancer and endometriosis.
What Is Endometriosis?
Endometriosis occurs when tissue similar to the lining inside the uterus grows outside the uterus, including on the ovaries, fallopian tubes, and other organs in the pelvis and beyond. It can cause pain, infertility, and a range of other problems. Diagnosis can be suspected based on symptoms, blood tests, and various scans, but surgery is the only way to determine accurately whether endometriosis is present.
Symptoms of endometriosis can include painful periods, pain during sex, chronic pelvic pain, bloating and pain after eating, fatigue, and infertility.
What Is Ovarian Cancer?
Ovarian cancer is a type of cancer that begins in the ovaries and Fallopian tubes. It is often called the “silent killer” because it is difficult to detect in its early, more curable stages. As with endometriosis, a diagnosis can be suspected using scans and blood tests, but confirmation requires a biopsy, which is usually performed during surgery.
Symptoms of ovarian cancer can include bloating; pelvic pain or pressure; abdominal pain that is initially vague; difficulty eating or feeling full quickly; and urinary symptoms such as urgency or frequency.
The symptoms of these conditions are similar, but there are subtle distinctions and some clear differences in findings and presentation. When it comes to pain, both can cause pelvic and abdominal discomfort, but endometriosis-related pain often follows a cyclical pattern around the menstrual cycle, whereas pain from ovarian cancer tends to be more constant and dull, though endometriosis pain can be variable. With bloating, endometriosis may cause symptoms that come and go, often related to intestinal gas from inflammation and associated conditions such as small intestinal bacterial overgrowth (SIBO), while ovarian cancer can cause bloating due to gas and the accumulation of a fluid called ascites; this type of bloating typically worsens and does not fluctuate. Considering age, endometriosis is typically diagnosed during the reproductive years, whereas the most common type of ovarian cancer is usually found in women over 50, although endometriosis can persist into menopause and symptoms can even begin after menopause. Regarding family history, a family history of ovarian cancer increases risk and there are genetic links that can be tested for; endometriosis does not have a clear genetic link but does run in families. In terms of how symptoms unfold, endometriosis typically develops gradually over years, while ovarian cancer symptoms may appear more suddenly over weeks to months, with bloating that can be more pronounced and unremitting.
In general, ovarian cancer presents an immediate threat to life, while endometriosis presents a lifelong threat to quality of life, potentially spanning decades. The two can overlap because the risk of developing ovarian cancer in women with endometriosis is elevated by 1.5- to 3-fold. Although that increase is worrisome, it still represents a tiny percentage; however, even a fraction of one percent of millions of women translates to thousands or tens of thousands who may be affected. Expert opinion from a specialist and possibly genetic testing can help determine your risk. Research is underway to identify gene-driven biomarkers that could enable more accurate diagnosis.
It is important to remember that both endometriosis and ovarian cancer can share symptoms, and some women may have both conditions at the same time. If you are experiencing any of the symptoms described, speak with your healthcare provider. Many other conditions can cause similar symptoms, but if they persist and do not resolve, it is better to be cautious. For example, most people can have a bout of stomach flu with bloating, nausea, and painful diarrhea that typically passes within a few days to a week; symptoms lasting longer than that should be evaluated.
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Schedule Your VisitNavigating Specialist Care: Choosing the Right Expert for Endometriosis or Ovarian Cancer Concerns
Endometriosis and ovarian cancer are distinct conditions that affect the female reproductive system. While they share similarities such as pelvic pain, their differences can guide appropriate evaluation and treatment. Understanding these distinctions helps you and your doctor pursue the right diagnosis and care plan.
Getting an expert opinion from a specialist can be critical to getting on the right path for diagnosis and treatment. In most cases, a general gynecologist can point you in the right direction. If concerns are not addressed and endometriosis seems most likely, an endometriosis specialist may be the best next step. If both endometriosis and ovarian cancer are concerns due to your symptoms, age, or family history, consulting a gynecologic oncologist may be more appropriate or serve as an additional opinion. There are a few gynecologic oncologists who truly specialize in both endometriosis and ovarian cancer.
References
Bulun SE, Wan Y, Matei D. Epithelial Mutations in Endometriosis: Link to Ovarian Cancer. Endocrinology. 2019 Mar 1;160(3):626-638. doi: 10.1210/en.2018-00794. PMID: 30657901; PMCID: PMC6382454.
Quick Answers
Why do I have painful urination and pelvic cramping between periods?
Painful urination with pelvic cramping between periods can happen when the bladder, ureters, uterus, pelvic floor, or nerves are being irritated—sometimes in a way that still follows a subtle cycle pattern even if you’re not actively bleeding. Endometriosis can contribute by affecting the bladder wall or tissues around the bladder and ureters, and symptoms don’t have to include visible blood in the urine. Importantly, urinary tract endometriosis isn’t always “obviously urinary,” and ureter involvement can be quiet while still significant, which is why we take these symptoms seriously.
These symptoms can also come from conditions that overlap with (or mimic) endometriosis, such as bladder pain syndrome/interstitial cystitis, pelvic floor overactivity, adenomyosis-related uterine cramping, or other pelvic pain drivers. In our evaluation process, we focus on your full flare pattern—what triggers it, how it relates to your cycle, and whether urine tests have been repeatedly negative—then use targeted exam and the right imaging (often expertly interpreted ultrasound and/or MRI) to map what’s actually going on.
If you’re noticing recurring burning with urination, pressure, cramping, or symptoms that predictably flare mid-cycle or before your period, that pattern is useful diagnostic information—not something to dismiss. You can explore our urinary symptom and diagnostic evaluation resources to see how we approach “UTI-like” symptoms with negative cultures, and you’re welcome to reach out to schedule a consultation so our team can help you sort out whether this is bladder/ureter endometriosis, a look-alike condition, or a combination.
Why does ovarian cyst pain keep coming back?
Ovarian cyst pain can feel “recurrent” for a few different reasons. Some cysts are functional (they form with ovulation and then resolve), so the pain returns in a similar spot month after month even though it’s not the exact same cyst. In other cases, the cyst itself can come back or persist—especially if it’s an endometrioma (an ovarian cyst caused by endometriosis), which can behave differently than a simple cyst and may be associated with deeper pelvic disease.
Another common reason is that the cyst isn’t the whole story: endometriosis on the pelvic sidewall, uterosacral ligaments, bowel, bladder, or around the ovary can irritate the same nerves and tissues and make it feel like “my cyst is back” when the driver is actually inflammatory disease nearby. Adhesions (scar-like bands) can also tether the ovary and cause recurring pulling or sharp pain, even when imaging doesn’t show a large cyst. If your pain cycles, escalates, returns quickly after a “normal” ultrasound, or keeps recurring despite prior treatment, our team can help you map the pattern, interpret imaging with an endometriosis lens, and decide whether targeted evaluation and—when appropriate—excision surgery is the next best step.
Why do I get low back and leg pain during my period?
Low back and leg pain that predictably flares with your period can happen when pelvic inflammation irritates pain pathways that “refer” into the back, hips, buttocks, and down the leg. In some patients, endometriosis can be part of that story—either indirectly (pelvic inflammation and scarring increasing pressure and sensitivity around nearby nerves) or more directly if disease is affecting areas close to major nerves.
When period-related leg pain resembles sciatica—deep buttock pain, tingling, burning, or pain radiating down the back of the thigh—it raises the possibility of endometriosis-related sciatic irritation or pelvic floor involvement (often described as piriformis-type pressure on the nerve). These symptoms may start before bleeding, peak during the period, and linger afterward, and in more significant cases can be associated with weakness or changes in walking.
Because back and leg pain can also come from the spine, hips, or muscles, the key is the pattern and the full symptom “constellation,” including pelvic pain, bowel/bladder symptoms, or pain with sex. Our team can help you sort out whether your pain fits an endometriosis/adenomyosis pattern and, if needed, plan next-step evaluation such as targeted imaging and a strategy focused on lasting relief rather than temporary suppression.
Can endometriosis cause infertility and pelvic pain in your 20s?
Yes. Endometriosis can absolutely show up in your late 20s and it can be a driver of both chronic pelvic pain and fertility challenges. Pain can include severe or worsening period cramps, pain with sex, bowel or bladder pain, and “flare” patterns that track with your cycle—although symptom severity doesn’t always match how much disease is present.
Endometriosis can affect fertility in several ways, including adhesions that distort tubo‑ovarian anatomy, inflammation and immune signaling that interferes with fertilization or embryo development, and ovarian factors—especially when endometriomas are involved. For some patients, the uterine environment also matters, particularly when adenomyosis is present alongside endometriosis. In our practice, we focus on listening to your full symptom and fertility story and then building an evaluation that looks for endometriosis while also checking for common look‑alikes or coexisting issues, so we can tailor a plan to your goals—whether that’s pain relief, preserving fertility, or both.
Why do I have chronic fatigue and pelvic pain?
Chronic fatigue plus pelvic pain often feels “unexplainable” because it’s rarely caused by just one issue—and many of the most common drivers don’t show up on routine labs or a quick ultrasound. Endometriosis and adenomyosis can cause persistent pelvic pain, painful periods, bowel/bladder symptoms, and deep fatigue through inflammation, disrupted sleep, heavy bleeding (and possible iron deficiency), and the sheer energy cost of living with ongoing pain. It’s also common for more than one gynecologic condition to coexist—like fibroids, polyps, or benign cysts—so a single label may not fully match what you’re experiencing.
Another reason symptoms can persist is that the nervous system can become more pain-sensitive over time (often called central sensitization), meaning pain can spread, linger outside your cycle, or feel disproportionate to what imaging shows. In those cases, symptom relief alone can miss the bigger picture: we think in terms of both treating disease (for example, addressing endometriosis lesions or uterine drivers like adenomyosis/fibroids) and building a personalized pain-management plan so your body can “turn down the volume” on pain signals.
If your fatigue and pelvic pain have been brushed off or left without a clear plan, our team can help you sort through the likely contributors, including endometriosis/adenomyosis and common coexisting conditions, and map next steps that fit your goals. You can explore our educational resources on fatigue, chronic pelvic pain, and comprehensive treatment approaches, and reach out to schedule a consultation when you’re ready.


