Ovarian cancer is hard to detect

Ovarian cancer cannot be detected(external link) via cervical cancer screening (which used to be called a pap smear) and pelvic exams aren’t useful(external link) as a screening test.

Current Australian guidelines(external link) recommend women get tested for ovarian cancer if they have symptoms for more than a month(external link). But many of the symptoms(external link) – such as tiredness, constipation and changes in menstruation – are vague and overlap with other common illnesses.

This makes early detection a challenge. But it is crucial – a woman’s chances of surviving ovarian cancer(external link) are associated with how advanced the cancer is when she is diagnosed.

If the cancer is still confined to the original site with no spread, the five-year survival rate is 92%. But over half of women diagnosed with ovarian cancer first present when the cancer has already metastatised(external link), meaning it has spread to other parts of the body.

If the cancer has spread to nearby lymph nodes, the survival rate is reduced to 72%. If the cancer has already metastasised and spread to distant sites at the time of diagnosis, the rate is only 31%.

There are mixed findings on whether detecting ovarian cancer earlier leads to better survival rates. For example, a trial in the UK that screened more than 200,000 women failed to reduce deaths(external link).

That study screened the general public, rather than relying on self-reported symptoms. The new study suggests asking women to look for specific symptoms can lead to earlier diagnosis, meaning treatment can start more quickly.

Between June 2015 and July 2022, the researchers recruited 2,596 women aged between 16 and 90 from 24 hospitals across the UK.

They were asked to monitor for these 4 symptoms:

• persistent abdominal distension (women often refer to this as bloating)
• feeling full shortly after starting to eat and/or loss of appetite
• pelvic or abdominal pain (which can feel like indigestion)
• needing to urinate (pee) urgently or more often.

Women who reported at least 1 of 4 symptoms persistently or frequently were put on a fast-track pathway(external link). That means they were sent to see a gynaecologist within 2 weeks. The fast track pathway has been used in the UK since 2011, but is not specifically part of Australia’s guidelines.

Some 1,741 participants were put on this fast track. First, they did a blood test that measured the cancer antigen 125 (CA125). If a woman’s CA125 level was abnormal, she was sent to do a internal vaginal ultrasound.

The study indicates this process is better at detecting ovarian cancer than general screening of people who don’t have symptoms. Some 12% of women on the fast-track pathway were diagnosed with some kind of ovarian cancer.

A total of 6.8% of fast-tracked patients were diagnosed with high-grade serous ovarian cancer. It is the most aggressive form of cancer and responsible for 90% of ovarian cancer deaths.

Out of those women with the most aggressive form, 1 in 4 were diagnosed when the cancer was still in its early stages. That is important because it allowed treatment of the most lethal cancer before it had spread significantly through the body.

Image credit: Canva

There were some promising signs in treating those with this aggressive form. The majority (95%) had surgery and three quarters (77%) had chemotherapy. Complete cytoreduction – meaning all of the cancer appears to have been removed – was achieved in six women out of ten (61%).

It’s a promising sign that there may be ways to “catch” and target ovarian cancer before it is well-established in the body.

The study’s findings suggest this method of early testing and referral for the symptoms leads to earlier detection of ovarian cancer. This may also improve outcomes, although the study did not track survival rates.

It also points to the importance of public awareness about symptoms.

Clinicians should be able to recognise all of the ways ovarian cancer can present, including vague symptoms like general fatigue.

But empowering members of the general public to recognise a narrower set of 4 symptoms can help trigger testing, detection and treatment of ovarian cancer earlier than we thought.

This could also save GPs advising every woman who has general tiredness or constipation to undergo an ovarian cancer test, making testing and treatment more targeted and efficient.

Many women remain unaware of the symptoms(external link) of ovarian cancer. This study shows recognising them may help early detection and treatment.