Tests for ovarian cancer

Pelvic examination

In a pelvic examination, the doctor will press gently on the outside of your abdomen (belly) to feel for any masses or lumps. To check your uterus and ovaries, the doctor will place 2 gloved fingers into your vagina while pressing on your abdomen with their other hand.

You may also have a vaginal examination using an instrument called a speculum that gently separates the walls of the vagina.

A pelvic examination should not be painful but it can sometimes be uncomfortable. You can ask for a staff member, family member or friend to be present during the examination.

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

Blood tests

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, some infections such as pneumonia or appendicitis, liver or kidney disease, endometriosis or fibroids.

The CA125 blood test is not used to screen 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. If you have early-stage ovarian cancer, CA125 levels are often normal. 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 one way to check how well treatment is working. Falling CA125 levels may mean the treatment is working, and rising CA125 levels may mean the treatment is not working well.

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

Imaging scans

Your doctor may recommend you have some imaging scans to look for a pelvic mass or lump, and to see how big it is. You will need further tests to diagnose any mass as cancer.

Pelvic ultrasound

A pelvic ultrasound uses soundwaves to create a picture of your uterus and ovaries. The soundwaves echo when they meet something dense, such as an organ or tumour. A computer creates a picture from the echoes. A technician called a sonographer does the scan. A pelvic ultrasound appointment usually takes 15–30 minutes.

A pelvic ultrasound can be done in 2 ways:

Abdominal ultrasound – To get clear pictures of the uterus and ovaries, the bladder needs to be full, so you will be asked to drink water before the appointment. You will lie on an examination table while the sonographer moves a small handheld device called a transducer over your abdomen.

Transvaginal ultrasound – The sonographer inserts a small transducer wand into your vagina. The wand will be covered with a disposable plastic cover and gel to make it easier to insert. You may find a transvaginal ultrasound uncomfortable, but it should not be painful. If you feel embarrassed or concerned about having this procedure, you can ask for a female sonographer or to have someone in the room with you (e.g. your partner, a friend or a relative).

The transvaginal ultrasound is often the preferred method of ultrasound because it provides a clearer picture of both the ovaries and uterus.

CT scan

A CT (computerised tomography) scan uses x-rays to create a detailed picture of the inside of the body. A CT scan can be used to check your abdomen, chest and pelvic area, look for signs the cancer has spread, and assist in guiding the needle if doing a biopsy.

The CT scanner is a large, doughnut-shaped machine. You will lie on a table that moves in and out of the scanner. CT scans are usually done at a hospital or radiology clinic.

You will be asked to fast (not eat or drink) before the scan. You may need to have an injection of a special dye, called contrast, which makes your organs appear white in the pictures so anything unusual can be seen more clearly.

A CT scan is noisy but painless. The contrast will be injected into a vein. It may make you feel hot all over, have a sudden urge to pass urine, and leave a bitter taste in your mouth. These sensations usually pass quickly, but tell the person carrying out the scan if they don’t.

The scan takes about 10–20 minutes, but it may take extra time to prepare. You usually go home as soon as the CT scan is over.

MRI scan

An MRI (magnetic resonance imaging) scan uses a powerful magnet and radio waves to build up detailed pictures of the inside of your body. While not used often to diagnose ovarian cancer, an MRI may help if it is difficult to tell from the ultrasound whether an ovarian tumour is likely to be cancerous. A contrast may also be used 
with an MRI.

If you have a pacemaker, let the medical team know before having an MRI. The magnet can interfere with some pacemakers.

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. The MRI scan may take between 30 and 90 minutes.

PET–CT scan

A PET (positron emission tomography) scan combined with a CT scan is a specialised imaging test. It provides more information about the cancer than a CT scan on its own.

Only some people will have a PET–CT scan. Medicare covers the cost only for ovarian cancer that has returned, so these scans are not often used to look for ovarian cancer in the first instance. If you are having chemotherapy before surgery, you may have this scan beforehand.

To prepare for a PET–CT scan, you will be asked to fast (not eat or drink) for a period of time. 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 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. Any radiation will leave your body within a few hours.

Taking a biopsy

The only way to confirm a diagnosis of ovarian cancer is to remove a sample of tissue from the tumour, or to drain fluid from the abdomen or chest if fluid is present. This is sent to a specialist called a pathologist who checks it under a microscope for cancer cells.

Depending on the characteristics of the cancer, your treatment team will recommend the best way to collect the sample, such as:

• surgical biopsy – samples are taken during surgery to remove the mass 
• image-guided biopsy – involves removing tissue using a fine needle. The doctor will use a CT scan to guide the needle through skin which has been numbed by a local anaesthetic, into the mass
• fluid sample – fluid, called ascites, is collected in a similar way as an image-guided biopsy, using a fine needle that is guided through the skin during a CT scan. This is a cytology test.

Genomic testing on the sample

If ovarian cancer is found, the biopsy sample (tissue removed during surgery) will usually have more tests. These are called genomic tests. They look for gene changes (mutations) and other features in the cancer cells. This information can help predict how the cancer might respond to targeted therapy.

These gene changes are similar to those passed through families, however, for some people with ovarian cancer, the fault is only in the cancer cells. Genomic testing is recommended for most people diagnosed with high-grade ovarian cancer.

Genomic testing may include HRD (homologous recombination deficiency) testing. This looks for a feature in some cancer cells that makes it harder for them to repair damaged DNA. Testing your samples for HRD can help work out if targeted therapy is recommended as part of your treatment.

Your treatment team will use the results of genomic testing to help them work out what treatment may work best for you, and what treatment may not be as effective. Medicare subsidies are available for some testing. Your doctor can explain your options and refer you to a familial cancer clinic or high-risk genetics clinic for counselling and more information.