Ovarian Cancer: NICE Guidelines and Key Symptoms

As a gynaecologist, ovarian cancer is something I never want to miss. It is often called a “silent killer” — but that reputation is not entirely accurate. The symptoms are there; the problem is that they are vague, common, and too easily attributed to other causes. With important updates to the NICE referral guidelines, including new age-adjusted CA125 thresholds, now is the time for every woman to understand what to look for and when to seek help.

Why is ovarian cancer so difficult to catch early?

Ovarian cancer is the fifth most common cancer affecting women in the United Kingdom, with around 7,500 new cases diagnosed each year. Unlike cervical and breast cancer, there is no reliable national screening programme. The symptoms overlap with everyday complaints — bloating, feeling full, needing the toilet more often — which means they are frequently dismissed as irritable bowel syndrome, stress, or simply getting older.

The result is that the majority of ovarian cancers are diagnosed at an advanced stage, when treatment is more complex and outcomes are less favourable. Yet when caught early, the picture is dramatically different: survival rates at the earliest stage exceed ninety per cent.

This is precisely why I take persistent, vague abdominal symptoms seriously in my clinic. When a patient comes to me with persistent bloating, I do not dismiss it. I ask detailed questions about the timeline, the severity, and whether other symptoms have appeared alongside it. That careful history is often the first step towards the right diagnosis.

The symptoms every woman should know

The key word is persistent. Occasional bloating after a large meal is normal. Symptoms that occur on most days for three weeks or more are not. Watch for:

• Persistent bloating — not the kind that comes and goes, but a constant feeling of abdominal distension
• Feeling full quickly or a noticeable loss of appetite
• Pelvic or abdominal pain that is new, unexplained, and does not settle
• Urinary urgency or frequency — needing to go more often or more suddenly than usual
• Changes in bowel habit that cannot be explained by diet or other factors
• Unexplained weight loss or fatigue

Any one of these symptoms in isolation is unlikely to indicate ovarian cancer. But a combination of persistent changes, especially in a woman over 50, should always be investigated. I encourage my patients to trust their instincts — if something feels different and has not resolved after three weeks, it is worth discussing with your doctor.

Understanding CA-125: when it helps and when it misleads

CA-125 is a protein found on the surface of ovarian cancer cells, and a blood test measuring its level has long been used as part of the diagnostic pathway. However, CA-125 is far from a perfect test, and understanding its limitations is essential to avoiding both false reassurance and unnecessary alarm.

In my clinical experience, CA-125 is most reliable in postmenopausal women, where an elevated level in combination with concerning ultrasound findings is a strong indicator that further investigation is needed. In premenopausal women, the picture is far more nuanced. CA-125 can be raised by a number of entirely benign conditions, including endometriosis, ovarian cysts, fibroids, pelvic inflammatory disease, and even menstruation itself. I have seen patients referred in a state of considerable distress because their CA-125 was mildly elevated, when the cause was endometriosis rather than anything sinister.

Equally, a normal CA-125 does not entirely exclude ovarian cancer. Some early-stage cancers, particularly mucinous and clear cell subtypes, do not produce significant amounts of CA-125. This is why the test must always be interpreted alongside the clinical picture and ultrasound findings, never in isolation.

What are the new NICE guidelines changing?

Historically, the CA-125 blood test has used a single cut-off of 35 U/mL for all women. The problem, as I have described above, is that this threshold generates a high rate of false positives in younger women and may miss early disease in older women whose CA-125 rises above their own baseline but remains below 35.

The updated NICE guidance proposes age-adjusted CA-125 thresholds, which aim to reduce both false positives in younger women and missed diagnoses in older women. This is a significant step forward in making the referral pathway more accurate and more equitable. In practice, this means that the threshold for concern will be lower in postmenopausal women, allowing earlier detection, while being appropriately higher in premenopausal women, reducing unnecessary referrals for benign conditions.

The two-week wait pathway remains the gold standard for urgent assessment: if your GP suspects ovarian cancer based on symptoms, examination, and blood tests, you should be referred to a specialist within two weeks.

The Risk of Malignancy Index: how I assess risk

When I evaluate a patient with a suspicious ovarian mass, I use a structured scoring system called the Risk of Malignancy Index (RMI). The RMI combines three factors: the CA-125 level, the ultrasound appearance of the mass, and the patient’s menopausal status. Each factor is scored and multiplied together to produce an overall risk score.

An RMI score below 25 suggests a low risk of malignancy, and in these cases conservative management with follow-up imaging is often appropriate. A score between 25 and 250 indicates a moderate risk, and I would typically discuss the findings with a gynaecological oncology multidisciplinary team. A score above 250 is considered high risk, and I would refer the patient urgently to a specialist cancer centre for further assessment and likely surgery.

The RMI is not infallible — no single tool is — but it provides a structured, evidence-based framework that helps me decide how urgently to act and where the patient should be managed. It is one of the reasons I believe that a thorough gynaecological ultrasound is so important: the ultrasound features are a critical component of this scoring system.

BRCA1, BRCA2, and family history: when genetics matter

A small but significant proportion of ovarian cancers — approximately fifteen to twenty per cent — are linked to inherited genetic mutations, most notably in the BRCA1 and BRCA2 genes. Women who carry a BRCA1 mutation have a lifetime ovarian cancer risk of approximately forty to sixty per cent, while those with BRCA2 mutations face a risk of around fifteen to thirty per cent. These are substantial figures, and identifying women at increased genetic risk is an important part of my clinical practice.

When I take a family history, I pay particular attention to patterns that suggest a hereditary component: ovarian cancer or breast cancer in first-degree relatives, cancers diagnosed at a young age, multiple family members affected, or a known BRCA mutation in the family. If the family history raises concern, I refer my patient to a clinical genetics service for formal risk assessment and, if appropriate, genetic testing.

For women who are found to carry a BRCA mutation, the discussion about risk reduction is deeply personal. Options include enhanced surveillance with regular ultrasound and CA-125 monitoring, or risk-reducing surgery — removal of the fallopian tubes and ovaries — which significantly reduces the risk of ovarian cancer. The timing of this surgery depends on the specific mutation, the woman’s age, and whether she has completed her family. It is never a decision I rush, and I always ensure my patients have time to consider all their options, often with the support of a specialist genetic counsellor.

My approach when I suspect ovarian cancer

If, after taking a history, performing an examination, reviewing blood tests, and carrying out an ultrasound, I have a genuine concern that an ovarian mass may be cancerous, I act swiftly. The referral pathway is clear and well established in the NHS and in private practice.

First, I arrange urgent blood tests if not already done, including CA-125 and often other tumour markers. I ensure that the ultrasound has been thorough and that I have all the information needed to calculate an RMI score. If the RMI is elevated or the ultrasound features are concerning, I refer the patient on the two-week wait (urgent cancer) pathway, which guarantees that she will be seen by a specialist — typically a gynaecological oncologist — within fourteen days.

In my experience, the speed of this pathway matters enormously. Ovarian cancer can progress quickly, and the difference between a two-week referral and a routine six-week appointment can be clinically significant. This is one of the reasons I believe strongly in not dismissing persistent symptoms, even when initial investigations seem reassuring. If something does not feel right, I would rather investigate one step further and find nothing than miss an early, treatable cancer.

The specialist cancer centre will typically arrange further imaging — often a CT scan of the chest, abdomen, and pelvis — and discuss the case at a multidisciplinary team meeting before recommending a management plan, which may include surgery, chemotherapy, or both.

When to push for investigation

If you are experiencing persistent symptoms, do not wait for them to resolve on their own. Here is what you can do:

1. Track your symptoms — note the duration, frequency, and severity of any changes. A symptom diary can be a powerful tool when speaking to your doctor
2. Be specific with your GP — describe your symptoms clearly and explain how long they have been present. Avoid minimising what you are experiencing
3. Ask for a CA-125 blood test and pelvic ultrasound if symptoms persist for three weeks or more
4. Mention any family history of ovarian or breast cancer — this may change how your GP approaches the investigation
5. Request a referral to a gynaecologist if initial results are inconclusive but your symptoms continue
6. Seek a second opinion if you feel your concerns are not being taken seriously