Can ovarian cysts be cancerous?

You may have noticed there have been a few stories in the news about ovarian cancer being misdiagnosed as ovarian cysts recently. Ovarian cysts are common and are usually non-cancerous. We spoke to Dr Brooke Vandermolen, an Obstetrics and Gynaecology doctor, to find out more.

Ovarian cysts are common and are usually non-cancerous. However, in some cases, they can be cancerous. There are different types of ovarian cysts, and each has a different risk profile.

This page explains these types, what symptoms to look out for, and what to do if you’re concerned. Early detection is key, so we’ll also cover how to advocate for yourself during the diagnosis process and what treatment options are available.

What are ovaries?

The ovaries are two small glands that sit close to the fallopian tubes and uterus. The ovaries produce eggs inside follicles which are like little sacs. Each month a few follicles will develop and one or two will be ‘chosen’ to fully develop and release an egg during ovulation. During ovulation the follicle will become fluid filled and release an egg which is picked up by one of the fallopian tubes through which it passes it to the uterus.

What is an ovarian cyst?

Usually after ovulation the follicle dissolves, but sometimes they remain and develop into a cyst. Most of the time cysts will go unnoticed causing no symptoms, and occasionally you might experience mild symptoms. Symptoms can include:

• A dull and heavy feeling, or sudden severe and sharp pain in your pelvic area
• Pain during sex
• Difficulty emptying your bowels
• Needing to wee more frequently
• Heavy, irregular or lighter periods than normal
• Bloating
• Feeling full after a little food.

How common are ovarian cysts?

With 2 in 10 women developing at least one ovarian cyst in their lifetime, they are fairly common.

How common is it for an ovarian cyst to be cancerous?

Most ovarian cysts are non-cancerous. In women under 50, malignant (cancerous) cysts are rare. However, the risk increases after menopause.

Causes and risk factors for cancerous ovarian cysts

Several factors can increase the likelihood of developing a cancerous ovarian cyst.

Age

The risk of ovarian cysts being cancerous increases with age, particularly after menopause.

Genetics

Genetic factors, including BRCA1 and BRCA2 gene mutations, can increase the risk of ovarian cancer. Women with these gene mutations may want to discuss regular monitoring with their doctor.

Polycystic Ovary Syndrome (PCOS)

PCOS itself isn’t directly linked to cancer, but some studies suggest women with PCOS may have a slightly higher risk of developing ovarian cancer.

Different types of cysts

There are several different types of ovarian cyst. Most of these are non-cancerous (benign) but occasionally they can be cancerous (malignant). Less than 1% of ovarian cysts before the menopause will be cancerous.

Benign ovarian cysts

Most ovarian cysts are benign, meaning they’re not cancerous. Here are some common types:

• Corpus luteum cyst - these cysts develop when the follicle closes after the egg has been released, allowing fluid to build up inside the follicle. These cysts usually disappear within 1 month. They occur every month to produce hormones that would support a growing pregnancy, and disappear if pregnancy doesn’t occur.
• Endometriomas - you may get this type of cyst if you have endometriosis. This type of cyst occurs when cells similar to the endometrial tissue, attach to an ovary and cause a build up of blood which forms a cyst.
• Follicle cyst - these cysts develop when the egg fails to be released from the follicle. These cysts usually disappear within 3 months.
• Polycystic ovary syndrome (PCOS) - is a condition where the multiple eggs begin the process of maturation in the follicle but they are not released. This means the ovary gives the appearance of being filled with lots of small cysts.

Potentially cancerous cysts

Some cysts carry a higher risk of being cancerous, particularly in postmenopausal women or those with a family history of ovarian cancer. These include:

• Cystadenomas: – these cysts develop from cells on the surface of the ovary. These tumours are usually non-cancerous (benign) but occasionally they can be cancerous (malignant).
• Dermoid cyst: – these cysts are sometimes called teratomas, and develop when cells become trapped inside ovarian tissue. They are most often seen in women between the ages of 20 and 40. These tumours are usually non-cancerous (benign) but occasionally they can be cancerous (malignant).

What are the symptoms of a cancerous ovarian cyst?

Symptoms of ovarian cysts and ovarian cancer are very similar. Ovarian cancer symptoms include:

• Persistent stomach pain
• Persistent bloating
• Difficulty eating or feeling full more quickly
• Needing to wee more frequently

If you are experiencing these symptoms, it is important to speak to your GP as soon as possible. Your GP should refer you for an ultrasound scan and if a cyst is found you may have a follow up ultrasound scan a few weeks later. If there is any concern that your cyst is cancerous, your GP should arrange CA125 blood test and refer you to a gynaecologist for further investigation.

What should I do if I don’t feel I’m being listened to?

Monitor your symptoms on a daily basis and keep a record to take to your GP. You may want to take a friend or family member for support. If you don’t feel you are being listened to by your GP, you can ask to see another GP at your surgery or consider changing your surgery. 

Dr Booke Vandermolen is an NHS doctor training as a Registrar in Obstetrics and Gynaecology in London. She has experience clinically dealing with all aspects of women’s health and pregnancy, including assessing patients with a range of gynaecological concerns, and performing surgical procedures.

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