Researchers in California have found a molecular warning signal in the blood that can identify ovarian cancer at its earliest precancerous stage, long before a tumour forms or symptoms appear, according to Hoag and Medical Xpress. The study, led by researchers at the Hoag Family Cancer Institute and published on Tuesday 10 November in Nature Medicine, found raised blood levels of an RNA molecule called Tu-Stroma in women with the precancerous condition and early-stage high-grade serous ovarian cancer.
The precancerous stage, serous tubal intraepithelial carcinoma (STIC), is a group of microscopic abnormal cells in the fallopian tubes, invisible to imaging scans and conventional cancer blood tests — one reason high-grade serous ovarian cancer, the most common and most lethal form, is usually diagnosed only after it has spread, according to Hoag as reported by Medical Xpress. The researchers focused on how cancer weakens neighbouring healthy cells to create space for tumour growth, and found that Tu-Stroma, an RNA molecule linked to that process, rises in the blood at this earliest stage.
The study ran for eight years and brought together scientists and clinical samples from multiple countries to develop and validate the blood test, according to Hoag. In a separate group of women used to validate the findings, the test detected STIC in 92.3 percent of the women who had it and correctly identified 98.2 percent of healthy women, according to Medical Xpress and CLP Magazine. The team also modelled a high-risk population, finding that about 72 percent of positive results would be accurate — roughly three in ten positives would be false alarms needing follow-up — while a negative result would be correct nearly 100 percent of the time.
Readers should note the limits of the work. The study analysed blood samples collected previously from women with confirmed diagnoses, so it does not yet prove the test can predict cancer in real time, according to Medical Xpress. The idea that the signal could reveal cancer years before conventional tests can detect a tumour is the researchers' suggestion, not a proven outcome. Tu-Stroma is a research discovery, not a clinical test: no patient can ask a doctor for it today, and no timeline for one has been announced.
Led by Dr Rajan Gogna and Dr Esha Madan, the researchers now plan prospective clinical studies involving women with and without an elevated genetic risk of ovarian cancer, according to Hoag. The long-term goal is a clinically validated blood test that could transform how the disease is watched for and prevented. For now, the finding offers the first realistic prospect of a blood-based early warning system for a cancer that has long resisted early detection.