The recent NHS-Galleri coverage in the UK renewed interest in blood-based detection, but ovarian cancer is unusual; more nuanced to the individual. The question remains as to whether any test can actually shift diagnosis earlier in a way that improves outcomes.

With the ovarian cancer drug market estimated at $3.8 billion in 2024 and projected to nearly double to $7.4 billion by 2034, according to Nova One Advisor market research, this article explores the substantial unmet need in ovarian cancer early detection today, why it is this disease has remained so difficult to catch early on, and the question of what, outside of diagnostics, could bring the hope that patients – women – with this disease are waiting for.

But to return to a very mortal question – why is it that so many women die from this disease? The WE Forum put it matter-of-factly: “it is a consequence of how women experience it within health systems that were not designed with it in mind.” Symptoms of the disease include bloating, persistent pelvic pain, and changes in appetite; they are non-specific and frequently overlooked or mistaken for less serious conditions.

According to Cancer Research UK, ovarian cancer can affect “anyone born with female reproductive organs, including the ovaries and fallopian tubes. This includes women, transgender men, and non-binary people.” There is also an inherited genetic risk, including faults in BRCA 1 or BRCA 2, RAD51C or RAD51D, BRIP1, or PALB2.

Importantly, there is no national screening programme for ovarian cancer in the UK. This is because there isn't a test that reliably picks up ovarian cancer at an early stage. Nonetheless, tests that are used to attempt to help diagnose ovarian cancer include the CA125 blood test and transvaginal ultrasound. CA125 is a protein that circulates in the blood. As Cancer Research UK notes, “most women have a low level of CA125 in their blood.” However, it might be raised in women with some types of ovarian cancer, with some doctors calling CA125 a type of “tumour marker”. But some non-cancerous conditions of the womb and ovaries can also raise the levels of CA125, including endometriosis, fibroids, pelvic inflammatory disease, and even pregnancy.

Indeed, the University of Northampton is leading a study looking at a possible link between endometriosis and the development of ovarian cancer, considering whether “the condition can affect the growth and spread of certain ovarian cancers.” The research suggests “people with endometriosis are between two and four times more likely to develop ovarian cancer,” with sub-type ovarian clear cell carcinoma particularly of concern.

The largest unmet diagnostic need is lack of a reliable means to detect earlier stage I–II cancers before they spread. It has been found that ultrasound tests can’t find ovarian cancers earlier either, nor save lives. Existing tools like pelvic examination, transvaginal ultrasound, and CA 125 either lack sensitivity for early disease detection and/or specificity in average risk women. Clinicians still depend on non-specific symptoms and imaging triggered by concern for a pelvic mass.

Rather, most cases of ovarian cancer are diagnosed at an advanced stage (III-IV). In consequence, most women present with bulky peritoneal or disseminated disease, where five year survival falls sharply. There is, therefore, intense interest in identifying a biomarker signature, including CA 125, other serum proteins, circulating tumour DNA, and imaging, but nothing has yet reached the level of a validated screening platform for average risk women.

Meanwhile, in a setting closer to home, it was thought that GRAIL’s Galleri test might bring hope. As The Independent wrote, the blood test is designed to detect multiple cancers before symptoms appear – otherwise known as a ‘multi-cancer early detection’ (MCED) test – working by identifying DNA shed by cancer cells in the bloodstream; a ‘fingerprint’ of cancer.

The Galleri website asserts that, “Around 1% of people ages 50-79 are expected to receive a Cancer Signal Detected test result. This result will include the predicted tissue type or organ associated with the signal, called a Cancer Signal Origin (CSO). After diagnostic evaluation, around 40% of these people are expected to have a confirmed cancer diagnosis.”

However, Ovarian Cancer Action – writing in October 2025 – noted that PATHFINDER-2 study of the Galleri multi-cancer early detection test and the results, presented at ESMO 2025, showed that, while the test certainly successfully identified some cancers early, none of the cancers it detected at an early stage were ovarian cancer.

Separately, there have even been studies into whether utilisation of one of the most common monthly sanitary products for women – the tampon – could help improve the early diagnosis of ovarian cancer. Launched by a team of researchers in Southampton, the clinical trial is funded by a grant from The Eve Appeal, the leading gynaecological cancer charity.

Overall, the problem is that “ovarian cancer often starts deep in the pelvis, shedding very little tumour DNA until later stages, which means testing for DNA in the bloodstream isn’t a viable option,” Ovarian Cancer Action stated. Instead, they’re looking at OvarianVax, led by Professor Ahmed Ahmed at the University of Oxford and funded by Ovarian Cancer Action and Cancer Research UK – aiming to develop the world’s first preventive ovarian cancer vaccine.

“This approach could one day protect women who carry inherited gene faults, such as BRCA1/2, or who are otherwise at high risk, offering hope not just for earlier detection, but true prevention,” the organisation stated. “One day, we hope it could be used for all women.”

From an early diagnosis standpoint, the landscape is yet bleak. However, turning from the potential of blood tests to a vaccine, in May 2026, Rare Cancer News reported that experimental, immunotherapy cancer vaccine Tedopi, when given in combination with the approved injection therapy Keytruda (pembrolizumab), outperformed standard-of-care treatment in delaying disease progression in people with difficult-to-treat, chemotherapy-sensitive ovarian cancer. Developed by Ose Immunotherapeutics, the data from the Phase 2 TEDOVA trial showed that the two-treatment combination worked better than available options at slowing cancer progression among trial participants.

TEDOVA tested the experimental therapy in 185 people with platinum-sensitive ovarian cancer. The trial, sponsored by the non-profit clinical research group Arcagy-Gineco, enrolled participants at 40 study centres across Europe. Merck’s Keytruda is already approved to help treat certain individuals with ovarian cancer.

And in mid-June, CellxLife, Inc., a clinical-stage biotechnology company developing precision dendritic cell immunotherapies for cancer, announced that it had entered into an exclusive licensing agreement with the Mayo Clinic for a novel dendritic cell cancer vaccine in two Phase II clinical trials for ovarian cancer. Deep Dive spoke with Eric von Hofe, PhD, chief executive officer of CellxLife, to find out more.

Dendritic cells (DCs) are the cell type that decides what antigens the immune system should respond to and how they should respond. Because of this functionality, they are the key players in generating a new immune response.

“By taking control of DCs ex vivo,” explained von Hofe, “we can make precision immunotherapies that are tailored to the patient’s tumour antigens. For the ovarian cancer study, that antigen is folate receptor alpha (FRα), which is highly expressed on ovarian cancer cells, but very weakly on normal cells.”

Indeed, the DCs are also treated with a cytokine so that they can prevent the formation of immune-suppressive regulatory T-cells in the patient – abundant in ovarian cancer patients.

“The important point is that killing tumour cells is a natural function of immune cells, but sometimes immune cells need to be ‘taught’ what proteins identify the cancer cells,” said von Hofe. “DCs are the ideal cell type to do this ‘teaching’.”

And from the patient perspective, the DC cancer vaccine is a low toxicity, maintenance-like intervention.

“It has a very different mechanism of action compared to standard treatments and has shown good potential in generating a long-lived response, in terms of relapse free survival,” explained von Hofe. “This is what makes it stand out from conventional therapies. Platinum-based chemotherapy, bevacizumab, and PARP inhibitors work only when the agent is present in the patient. After repeat dosing, resistance ultimately arises and the agents become ineffective at producing long-term remissions.”

So, there is hope. Nonetheless, the question around the possibility for early detection remains unanswered.

“The biology of the disease and anatomy both hinder early detection,” said von Hofe. “Many high grade cancers arise in the fallopian tube and spread to the peritoneal cavity while the primary lesion is still microscopic, so there is often no discrete ovarian mass to visualise or palpate in the truly early window.”

There is, then, still a long road ahead. Furthermore, diagnostics in ovarian cancer will only be of use if they tangibly change the treatment pathway. That means any successful technology will need to not just prove it can identify the right patients earlier, but fit into clinical workflows, and withstand scrutiny from regulators, payers, and health systems. In that sense, ovarian cancer is less a “new test” story than a test of whether precision diagnostics can finally become precision care.