Limitations of screening
It is important to note that there is currently no national screening programme for ovarian cancer, because the consensus in the scientific community is that it does not provide accurate enough data to make a diagnosis.
Screening specifically for ovarian cancer has been found to have a high “false positive” rate, which can lead to harmless cysts being identified as potentially cancerous. In some cases this could lead to unnecessary surgery, which has many associated risks. In other cases, screening may fail to detect cancer.
Despite this, screening is available in some specific NHS units and may be conducted in cases where doctors decide it could offer some valuable information. Typically, this will only be considered for high risk patients (see the criteria below) and following in-depth consultation.
While further research into screening and the viable alternatives is conducted, women who are considered to be at risk from ovarian cancer (see below) are advised to consult their doctor first about any concerns.
What is the screening process?
Any screening process for ovarian cancer will begin with an initial consultation in the case of a person who has never been screened before. Using the criteria further down this page, a woman’s individual risk factor can be established, which helps inform the decision about whether or not screening is appropriate. The possible disadvantages of screening, including those outlined above, would be discussed.
If the screening is to proceed, the patient will undergo a blood test designed to measure the levels of a protein known as CA125 in their blood. Raised levels of CA125 in the bloodstream could indicate the presence of a cancerous tumour, but not always. The blood test alone is not sufficient to make a judgement, which is why it is only part of the process.
A transvaginal ultrasound scan is the second element of the screening process. A probe is inserted into the vagina to provide a somewhat more accurate view than an external ultrasound (i.e. the type that would commonly be used to monitor pregnancy). However, the reliability of the test is not high enough to draw definite conclusions because tumours (and even the ovaries themselves) may not always be visible.
Depending on your individual risk level and other factors, you may only require an initial visit. Alternatively, you may be recommended for an annual screen or a more frequent interval screen. Your doctor will discuss this with you when your results are delivered, usually either in person or by phone.
Risk groups for ovarian cancer
There are four different categories on the scale for a patient’s risk of developing ovarian cancer. The different categories are presented here with the approximate percentage of people in the group who are later diagnosed, and typical characteristics of those people.
Very High Risk (>30%)
- Carriers of the BRCA1 and BRCA2 genes
High Risk (>15%)
1st degree relatives
- Two or more with ovarian cancer at any age
- One with ovarian cancer and one with breast cancer under the age of 50
- One with ovarian cancer and two with breast cancer under the age of 60
- One with ovarian cancer, plus you have had breast cancer under the age of 50
- One with ovarian cancer, plus you and another relative have both had breast cancer under the age of 60
- One with ovarian cancer and three with colo-rectal cancer under the age of 50
- One with a confirmed genetic predisposition to either breast cancer or ovarian cancer
Increased Risk (1-5%)
- One 1st degree relative with ovarian cancer at any age
- One 1st degree relative with breast cancer under the age of 50
- You have been diagnosed with breast cancer under the age of 50
Population Risk (0.8%)
- No close relatives with ovarian cancer
Prevention methods for ovarian cancer
In order to significantly reduce the risk of ever developing cancer of the ovaries, there are some options available to patients. Removal of the ovaries via laparoscopic surgery almost entirely eliminates the risk of developing ovarian cancer. Cancerous cells can still form in the peritoneum which surrounds the ovaries, but the overall risk is 98% lower as a result of the operation.
A common, non-surgical solution for patients who want to lower their risk level without an operation is taking the pill, which has been shown to lead to a 60% lower chance of developing cancer in the ovaries when taken over at least five years.