Researchers in California say they have found a molecular warning signal in the blood that can identify the earliest precancerous stage of the most common and deadliest form of ovarian cancer — a discovery that could one day allow the disease to be caught years before a tumour can be seen.
The signal is an RNA molecule called Tu-Stroma, found at elevated levels in the blood of women with serous tubal intraepithelial carcinoma, known as STIC, and with early-stage high-grade serous ovarian cancer. The eight-year study, led by Dr Rajan Gogna and Dr Esha Madan at the Hoag Family Cancer Institute in Newport Beach, was published in Nature Medicine on 10 November.
High-grade serous ovarian cancer often begins not in the ovary but in the fallopian tube, as STIC — a cluster of abnormal cells that is microscopic, non-invasive and invisible to imaging and to conventional cancer blood tests. It is usually found only by chance, during surgery to remove the fallopian tubes or ovaries. Because ovarian cancer is so often diagnosed only after it has spread, a test that can spot its precursor could change the outlook for patients.
In a separate group of women used to validate the findings, the test detected STIC in 92.3% of women who had it and correctly identified 98.2% of healthy women. When the researchers modelled how it might perform in a high-risk population, about 72% of positive results would be accurate, while a negative result would be correct nearly 100% of the time.
The finding could matter most for women at elevated genetic risk, including those carrying BRCA1 or BRCA2 mutations, who today often face difficult decisions about preventive surgery to remove their fallopian tubes and ovaries, sometimes before completing their families and at the cost of early menopause. Dr Madan said the discovery could eventually provide the missing biological information — whether precancerous lesions are actually present — and the team is already working on approaches aimed at stopping those lesions from progressing, potentially removing the need for preventive surgery altogether.
The researchers stress that this is a discovery, not yet a clinical test. The published study analysed previously collected blood samples from women with confirmed diagnoses, and prospective clinical studies — following women over time, with and without elevated genetic risk — are now planned to establish how early the signal can be detected and whether it can guide clinical decisions. This account is based on the researchers’ own announcement of the peer-reviewed findings; the underlying Nature Medicine paper was not independently reviewed for this article.
Sources: Hoag, “Researchers Discover Blood-Based Warning Signal for Ovarian Cancer at Its Earliest Precancerous Stage”, GlobeNewswire, 10 November 2026 — https://www.globenewswire.com/news-release/2026/11/10/3399264/0/en/researchers-discover-blood-based-warning-signal-for-ovarian-cancer-at-its-earliest-precancerous-stage.html ; Nature Medicine, 10 November 2026.
