Can ovarian cysts become cancerous? | Cancer Research UK
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Can ovarian cysts become cancerous?

This page tells you about ovarian cysts and whether they can become cancerous. There is information about


Ovarian cysts

Ovarian cysts are very common. They are fluid filled swellings on the surface of the ovary. You can get them both before and after the menopause, but they are more common in younger women. You can have one or more cysts on one ovary (unilateral) or on both ovaries (bilateral).

Most cysts are not cancerous (benign) and will not become cancerous. Many studies have looked at the best way to treat ovarian cysts. In the past, surgery to remove the cyst was the choice of treatment. But studies show that regular monitoring of the cyst, using ultrasound scan and blood tests, is possible for most women.


Tests to check for ovarian cancer

If you have an ovarian cyst you may have regular blood tests to check for a protein called CA125. This protein is normally found in the blood but levels can rise in women with ovarian cancer. This is not a specific test for cancer, as CA125 can rise due to other conditions, including

  • Ovarian cysts
  • Pelvic or abdominal infection
  • Endometriosis - a condition where the lining of the womb (endometrium) grows outside the body of the womb
  • Inflammation of the liver (hepatitis)
  • Pregnancy

Depending on what the cyst looks like on the ultrasound scan, women under 40 may have a blood test to check levels of lactate dehydrogenase (LDH), alpha feta protein (AFP) and human chorionic gonadotrophin (HCG). The level of these chemicals (tumour markers) in the blood are sometimes raised in types of ovarian cancer called germ cell tumours.


UK guidelines for ovarian cysts

The Royal College of Obstetricians and Gynaecologists (RCOG) have guidelines for doctors to follow when treating women who have had their menopause and who have ovarian cysts. They recommend that doctors monitor these women using the CA125 test and ultrasound scan. But this can vary depending on

  • The size of the cysts
  • What they look like on a scan and
  • Whether they change over time

The guidelines say the risk of developing cancer is very low if you have small cysts on one ovary (less than 5 cm wide). More than half these cysts will disappear on their own within 3 months. The RCOG advise a follow up ultrasound scan 4 months after the cysts have gone. 

The RCOG have guidelines about the care of pre menopausal women with an ovarian mass (lump). They say that almost all ovarian cysts in pre menopausal women are not cancerous. The most common type of cyst, the functional cyst, usually disappears without treatment within 3 months, especially if they are less than 5cm wide. They suggest that follow up for these women is not usually necessary. However women with cysts between 5cm and 7cm should have an ultrasound every year to monitor the cyst. And those with larger cysts may have an MRI scan or surgery to remove the cyst.

Doctors will usually want to do surgery to remove cysts that have not gone away or have got larger over time. To do this, your doctor will usually suggest you have a laparoscopy (keyhole surgery).

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Updated: 27 April 2016