Experimental blood test detects early signs of ovarian cancer in study

WASHINGTON — Researchers have unveiled a promising medical development that could help detect early signs of ovarian cancer before malignant tumours become detectable by conventional methods. The approach is an experimental blood test that measures a specific molecule in the blood.

The study, published in the journal Nature Medicine on Nov. 10, 2026, showed the test's ability to detect microscopic changes that precede one of the most aggressive types of ovarian cancer.

The test's sensitivity in the validation group was 92.3%, and it correctly identified women without the disease 98.2% of the time.

Scientists say the results could pave the way for a new method of early detection, though further studies are needed before the test is approved for routine medical use.

Detecting cancer before a malignant tumour forms

The study focuses on a type of ovarian cancer known as high-grade serous carcinoma, one of the types responsible for a large share of deaths linked to the disease.

This cancer often begins with abnormal changes inside the lining of the fallopian tubes, known scientifically as STIC.

These changes are microscopic and non-invasive, which makes them extremely difficult to detect with medical imaging or conventional blood tests.

In many cases, these lesions are found only when tissue is examined after surgery to remove the fallopian tubes or ovaries.

The new test could allow this early stage to be identified in the future without the need for surgery for diagnostic purposes.

How the new blood test works

The test measures an RNA molecule known as Tu-Stroma, which is found inside tiny vesicles that travel through the blood.

Researchers found elevated levels of this molecule in women with precancerous changes, as well as in some women with early-stage ovarian cancer.

The research team believes this marker is linked to interactions between abnormal cells and the healthy tissue around them.

Detecting it may make it possible to identify early biological changes before the disease progresses to a more dangerous stage.

Study involved more than 500 people

The study was carried out by an international team led by researchers from the Hoag Family Cancer Institute in California, and the related research lasted eight years.

The scientists analyzed blood samples previously collected from 506 people, including healthy cases, benign tumours, precancerous lesions, and ovarian cancer cases at various stages.

In a separate group used to validate the results, the test detected 92.3% of STIC cases.

Its specificity was 98.2%, meaning it gave a correct negative result for that share of the healthy women in the evaluation.

The results point to encouraging performance, but they do not mean the test can detect every case of ovarian cancer or definitively rule out the disease.

New hope for women at hereditary risk

The findings could be especially significant for women who carry genetic mutations that raise the likelihood of ovarian cancer, such as BRCA1 and BRCA2.

Some of these women face difficult decisions about preventive surgery to remove the fallopian tubes and ovaries in order to reduce their cancer risk.

The researchers' models showed that when the test is applied to a high-risk group, about 72% of positive results may be correct, while the accuracy of negative results approached 100% under the model's assumptions.

Scientists hope the test will eventually provide additional information that helps doctors and patients make more precise preventive decisions.

However, these estimates are based on statistical modelling and are not proof that the test is effective in broad clinical screening programs.

Is the test available to patients?

Despite the encouraging results, the test remains at the research stage and has not become an approved test for routine ovarian cancer screening.

The researchers plan future studies that follow women over time, to determine how well the marker can predict the disease and whether its accuracy holds across different population groups.

Scientists will also need to determine whether detecting these changes early actually helps reduce deaths and improve health outcomes.

For now, a medical assessment remains necessary when persistent symptoms appear, such as abdominal bloating, pelvic pain or feeling full quickly.

The finding underscores that the future of cancer diagnosis may increasingly depend on detecting early molecular changes rather than waiting for tumours to appear.