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How is ovarian cancer diagnosed?

If you have been diagnosed with ovarian cancer, you may wonder why it wasn’t found sooner and why it was never picked up in a screening test. Screening tests look for some types of cancer in people who do not have any symptoms. They are sometimes called early detection tests. At present, there is no effective  screening test for ovarian cancer.

The Cervical Screening Test (which has replaced the Pap test) looks for human papillomavirus (HPV), which causes most cases of cervical cancer but not ovarian cancer. Neither the Cervical Screening Test nor the Pap test can help find ovarian cancer.

If you do have symptoms and your doctor suspects you have ovarian cancer, you may have some of the tests below. These tests can show if there are any abnormalities that need to be checked by taking a tissue sample (biopsy).

The only way to confirm a cancer diagnosis is to take a biopsy and look at the cells under a microscope. For ovarian cancer, this is usually done during surgery which means that the diagnosis is confirmed and the cancer is treated at the same time.

Sometimes ovarian cancer is diagnosed before it causes symptoms. This is usually when abnormalities are found during tests or procedures for another health condition.

In a pelvic examination, the doctor will check for any masses or lumps by feeling your abdomen. To check your uterus and ovaries, the doctor places two fingers inside your vagina while pressing on your abdomen with their other hand. To examine inside the vagina, they may insert an instrument called a speculum that separates the vaginal walls. A pelvic examination is not painful but it may be uncomfortable. You can ask for a family member, friend or another staff member to be present during the examination if you prefer.

The doctor may also perform a digital rectal examination, placing a gloved finger into the anus and rectum. This lets the doctor feel the tissue behind the uterus where cancer cells may grow.

You may have blood tests to check for proteins produced by cancer cells. These proteins are called tumour markers. The most common tumour marker for ovarian cancer is CA125. The level of CA125 may be higher in some cases of ovarian cancer. It can also rise for reasons other than cancer, including ovulation, menstruation, irritable bowel syndrome, liver or kidney disease, endometriosis or fibroids.

The CA125 blood test is not used for screening for ovarian cancer if you do not have any symptoms. It can be used:

At diagnosis – A CA125 test is more accurate in diagnosing ovarian cancer if you have been through menopause than if you haven’t. If you have early-stage ovarian cancer, it is common to have normal CA125 levels. This is why doctors will often combine CA125 tests with an ultrasound.

During treatment – For ovarian cancer that produces CA125, the blood test may be used to check how well the treatment is working. Falling CA125 levels may mean it is working, and rising CA125 levels may mean the treatment is not working well, but the CA125 level is only one of the signs used to check your response to treatment.

After treatment – CA125 blood tests are sometimes included in follow-up tests.

Your doctor may recommend a number of imaging scans and investigations to work out how far the cancer has spread. You may also have chest x-rays to check the lungs for cancer or fluid.

Pelvic ultrasound

A pelvic ultrasound uses echoes from soundwaves to create a picture of your uterus and ovaries on a computer. A technician called a sonographer does the scan. It can be done in two ways:

Abdominal ultrasound – You will lie on an examination table while the sonographer moves a small handheld device called a transducer over your abdominal (belly) area.

Transvaginal ultrasound – The sonographer will insert a small transducer wand into your vagina. It will be covered with a disposable plastic sheath and gel to make it easier to insert. Sometimes this test may be uncomfortable, but it should not be painful. Talk to your doctor and the sonographer if you feel distressed or concerned. You can also ask for someone else to be present.

The transvaginal ultrasound is often the preferred type of ultrasound, as it provides a clearer picture of both the ovaries and uterus.

CT scan

A CT (computerised tomography) scan uses x-ray beams to take pictures of the inside of the body. It is used to look for signs that the cancer has spread, but a CT scan may not be able to detect all ovarian tumours. CT scans are usually done at a hospital or radiology clinic.

You will be asked not to eat or drink for several hours (fast) before the scan. A liquid dye (called a contrast) may be injected into a vein to help make the pictures clearer. The contrast makes your organs appear white on the scan, so anything unusual can be seen more clearly.

The contrast may make you feel hot all over and leave a bitter taste in your mouth, and you may also feel a sudden urge to pass urine. These sensations usually ease quickly, but tell the person carrying out the scan if they don’t go away.

The CT scanner is a large, doughnut-shaped machine. You will lie on a table that moves in and out of the scanner. The scan takes about 10–20 minutes, but it may take extra time to prepare and then wait for the scan. While a CT scan can be noisy, it is painless. You usually go home as soon as the CT scan is over.

PET–CT scan

A PET (positron emission tomography) scan combined with a CT scan is a specialised imaging test. It provides more detailed information about the cancer than a CT scan on its own. Only some people need this test. Medicare covers the cost of PET scans only for ovarian cancer that has returned, so they are not often used for the first diagnosis.

To prepare for a PET–CT scan, you will be asked not to eat or drink for a period of time (fast). Before the scan, you will be injected with a glucose solution containing a small amount of radioactive material. Cancer cells show up brighter on the scan because they take up more glucose than normal cells do.

You will be asked to sit quietly for 30–90 minutes as the glucose spreads through your body, then you will have the scan. The scan itself will take about 30 minutes. Let your doctor know if you are claustrophobic, as you need to be in a confined space for the scan. Any radiation will leave your body within a few hours.

MRI scan

An MRI (magnetic resonance imaging) scan uses a powerful magnet and radio waves to build up detailed, cross-sectional pictures of the inside of your body. It may be used if it is difficult to tell from the ultrasound whether a tumour is benign or may be malignant.

Let your medical team know if you have a pacemaker, as the magnet can interfere with some pacemakers. As with a CT scan, a dye might be injected into your veins before an MRI scan.

During the scan, you will lie on a bench inside a large metal tube that is open at both ends. The noisy, narrow machine makes some people feel anxious or claustrophobic. If you think you may become distressed, mention it beforehand to your medical team. You may be given a medicine to help you relax, and you will usually be offered headphones or earplugs. The MRI scan may take between 30 and 90 minutes.

Colonoscopy

In some cases, you may need to have a bowel examination (colonoscopy) to check that your symptoms are not caused by a bowel problem. The doctor will insert a thin, flexible tube with a small camera and light (colonoscope) through the anus into the bowel.

Before the test, you will have to change your diet and take prescribed laxatives to clean out your bowel completely (bowel preparation). The process varies for different people and between hospitals. Your doctor will give you specific instructions and talk to you about what to expect. On the day of the test, you will probably be given light sedation, which means you won’t be fully unconscious but you won’t feel any discomfort and may fall into a light sleep. A colonoscopy usually takes about 20–30 minutes. You will need to have someone take you home afterwards, as you may feel drowsy or weak.

Taking a biopsy

In most cases, a diagnosis of ovarian cancer will be confirmed after surgery to remove the ovary, which is also the main treatment. A sample of the tumour, known as a biopsy, will be checked under a microscope for cancer cells.

If scans show that the cancer has spread too much to be removed by surgery, a biopsy may be taken in a different way before treatment begins. This can be done with a very thin needle during a CT scan. The procedure is known as a fine-needle aspiration when the needle removes a sample of cells from the tumour, or as paracentesis when the needle removes a sample of fluid from the abdomen.

The cells in the sample will then be checked under a microscope to get more information about the cancer.

This information is reviewed by

This information was last reviewed April 2020 by the following expert content reviewers: A/Prof Sam Saidi, Senior Staff Specialist, Gynaecological Oncology, Chris O’Brien Lifehouse, NSW; A/Prof Penny Blomfield, Gynaecological Oncologist, Hobart Women’s Specialists, and Chair, Australian Society of Gynaecologic Oncologists, TAS; Dr Robyn Cheuk, Senior Radiation Oncologist, Royal Brisbane and Women’s Hospital, QLD; Kim Hobbs, Clinical Specialist Social Worker, Gynaecological Cancer, Westmead Hospital, NSW; Sonja Kingston, Consumer; Clinical A/Prof Judy Kirk, Head, Familial Cancer Service, Crown Princess Mary Cancer Centre, Westmead Hospital, and Sydney Medical School, The University of Sydney, NSW; Prof Linda Mileshkin, Medical Oncologist and Clinical Researcher, Peter MacCallum Cancer Centre, VIC; Deb Roffe, 13 11 20 Consultant, Cancer Council SA; Support Team, Ovarian Cancer Australia; Emily Stevens, Gynaecology Oncology Nurse Coordinator, Department of Obstetrics and Gynaecology, Flinders Medical Centre, SA; Dr Amy Vassallo, Fussell Family Foundation Research Fellow, Cancer Research Division, Cancer Council NSW; Merran Williams, Consumer.