The U.K. National Institute for Health and Care Excellence (NICE) is proposing a significant shift in how ovarian cancer risk is assessed in primary care, recommending age-based thresholds for the CA125 blood test in place of the current one-size-fits-all approach.
The draft guidance aims to help GPs identify ovarian cancer earlier, particularly in older women, while reducing unnecessary investigations in younger patients, where the test is less predictive. NICE has opened a public consultation on the proposed changes, which runs until 2 February 2026.
Ovarian cancer remains one of the hardest cancers to diagnose early. Around 1 in 50 women will develop the disease in their lifetime, with roughly 7,000 new cases diagnosed each year in the UK. Symptoms such as bloating, abdominal pain, and early satiety are often vague and overlap with benign conditions, meaning many cases are identified only once the disease has progressed.
At the center of the proposed update is the CA125 blood test, which measures a protein that can be elevated in ovarian cancer. Under current NICE guidance, all women with CA125 levels of 35 IU/ml or above are referred for further investigation, regardless of age. While simple, that fixed threshold has limitations.
NICE’s guideline committee found that a single cutoff can miss cancers in older women, whose baseline risk is higher even at lower CA125 levels, while at the same time triggering unnecessary ultrasounds and referrals in younger women, where elevated CA125 is more likely to be caused by non-cancerous conditions.
The draft recommendations propose age-adjusted CA125 thresholds that better reflect how ovarian cancer risk rises with age. By aligning referral decisions more closely with individual risk, NICE says GPs will be able to make more targeted and timely referrals, improving early detection while easing pressure on diagnostic services.
The guidance also draws a clear line for younger patients. For women under 40, NICE concludes that CA125 testing alone is not sufficiently accurate to guide clinical decisions. Instead, GPs are advised to consider directly arranging an ultrasound scan for women in this age group who present with persistent symptoms suggestive of ovarian cancer.
“This tailored approach will ensure that women at greatest risk are identified and referred sooner,” said Eric Power, deputy director at NICE’s Centre for Guidelines. “At the same time, it will reduce unnecessary investigations and help free up NHS resources.”
Beyond ovarian cancer, the draft update introduces other refinements to NICE’s suspected cancer pathway. One proposal recommends that people aged 60 and over with unexplained weight loss of more than 5% over six months should receive an urgent investigation or referral under the suspected cancer pathway, reflecting evidence that weight loss in older adults can be an early red flag for malignancy.
The guideline committee also flagged a growing evidence gap around unexpected bleeding in women taking hormone replacement therapy (HRT). With HRT use rising in England, NICE is calling for further research to clarify when such bleeding should prompt investigation for endometrial cancer, acknowledging uncertainty that currently complicates GP decision-making.
Taken together, the proposals reinforce NICE’s broader push toward risk-stratified cancer diagnosis, moving away from blunt thresholds and toward more personalized assessment tools in primary care. GPs rely heavily on NICE guidance when deciding which patients require urgent referral, and the suspected cancer guideline underpins the identification of around 143,000 new cancer cases in England each year.
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If adopted, the changes could have meaningful downstream effects not only on earlier ovarian cancer detection, but also on how diagnostic capacity is used across the NHS. Earlier diagnosis is consistently linked to better outcomes, while unnecessary imaging and referrals can delay care for higher-risk patients.
The draft guidance is now open for public and professional feedback, with NICE expected to review consultation responses before issuing final recommendations later in 2026. For primary care clinicians, the proposed update signals a shift toward more nuanced, evidence-driven triage, with the potential to improve cancer outcomes without increasing system strain.
