How ovarian cancer is diagnosed

Because there’s no routine screening test for ovarian cancer, most diagnoses begin the same way: a woman notices persistent symptoms, or a doctor feels something during an exam, and testing begins. Only about 20% of ovarian cancers are found early — 70–80% of women already have stage III or IV disease at their first consultation. Knowing how the diagnostic process works helps you move through it faster and ask better questions at every step.

The exam that starts it

Pelvic exam. Your doctor feels the uterus, ovaries, vagina, bladder, and rectum, checking for anything unusual in size or shape — an enlarged ovary, or fluid in the abdomen. It’s an essential first step, but a small, early cancer can escape detection by touch alone, which is why abnormal findings (or persistent symptoms with a normal exam) lead to imaging.

Imaging tests

• Transvaginal ultrasound. A small probe placed in the vagina gives a close-up view of the ovaries and uterus. It’s often the first imaging test, and it’s recommended for women at elevated risk or with abnormal pelvic findings.
• CT scan. Cross-sectional X-ray images that help show whether cancer has spread to other organs.
• MRI. Detailed cross-sectional images made without X-ray radiation.
• PET scan. Used when your team needs to clarify whether something seen on a CT or MRI is likely to be cancer.

The CA-125 blood test

CA-125 is a protein that ovarian and fallopian tube cancers often shed into the blood, and a simple blood test measures it. It sounds like the screening test everyone wishes existed — but it isn’t, for two reasons. Non-cancerous conditions like endometriosis and pelvic inflammatory disease can push CA-125 up, and some ovarian cancers don’t make enough of it to register at all. That’s why CA-125 should not be used as a screening test for women at average risk.

Where it earns its keep: establishing a baseline for high-risk women, tracking whether treatment is working, and watching for recurrence. We’ve written a full guide to the CA125 test and the cancers it can miss.

Biopsy: the definitive answer

Exams, imaging, and blood tests can raise suspicion, but a biopsy is the only way to definitively diagnose ovarian cancer. A sample of tissue or fluid is removed and examined by a pathologist, who confirms whether cancer is present and what type it is.

If a test comes back abnormal

Ask for a referral to a gynecologic oncologist — a surgeon who specializes in cancers of the reproductive system. Research consistently shows women do better when a gynecologic oncologist leads their care. They’ll review your results, order any further testing, and, if it is cancer, plan treatment with you.

Two questions we hear a lot

“My Pap smear was normal — doesn’t that rule this out?” No. A Pap smear screens for cervical cancer. It does not detect ovarian cancer.

“How long should I wait on symptoms before pushing for tests?” If symptoms persist beyond two weeks despite the simple fixes — rest, diet changes, laxatives — contact your doctor for an evaluation. Persistent is the key word; you’re not overreacting.