Blood RNA Test May Detect Precursors to Ovarian Cancer

High-grade serous ovarian cancer is often diagnosed at an advanced stage, limiting opportunities for early intervention. The disease frequently originates in the fallopian tube as serous tubal intraepithelial carcinoma, a microscopic, noninvasive precursor that cannot be detected through imaging or conventional blood-based cancer tests. This diagnostic gap highlights the need for earlier detection methods. New findings suggest that a blood-based RNA signature may help identify these precancerous changes before invasive cancer develops.

Researchers at Hoag Family Cancer Institute (Newport Beach, CA, USA) identified elevated blood levels of Tu-Stroma in women with serous tubal intraepithelial carcinoma and early-stage high-grade serous ovarian cancer. Tu-Stroma is an RNA molecule associated with weakening neighboring healthy cells to create space for cancer growth. By investigating this early interaction between cancerous and healthy tissue, the researchers identified a potential molecular warning signal that could reveal precancerous changes before tumors become detectable through conventional methods.

The eight-year, international, multi-institutional study, led by Hoag Family Cancer Institute, analyzed previously collected blood samples from women with confirmed diagnoses. In a separate validation group, the test detected serous tubal intraepithelial carcinoma in 92.3% of affected women and correctly identified 98.2% of healthy women. Modeling in a high-risk population suggested that approximately 72% of positive results would be accurate, while negative results would be correct nearly 100% of the time. The findings were published in Nature Medicine on November 10, 2026.

Building on these findings, Hoag researchers are planning prospective clinical studies involving women with and without elevated genetic risk of ovarian cancer. The studies will collect blood samples and monitor participants over time to assess how early Tu-Stroma can be detected, its reliability in identifying precursor disease, and its potential to guide clinical decisions. If validated, the blood test could support earlier intervention and risk-reduction strategies, particularly for women carrying BRCA1 or BRCA2 mutations.

“For women at high risk, this could transform how we approach prevention. Today, decisions about preventive surgery are largely guided by inherited risk, without knowing whether precancerous lesions are actually present. Our discovery could eventually provide that missing biological information. But our vision extends beyond early detection,” said Dr. Esha Madan, principal investigator and group leader of the Cell Competition in Tumor Microenvironment Laboratory at Hoag.

“We are already working on innovative approaches aimed at stopping these microscopic lesions from progressing, potentially eliminating the need for preventive surgery altogether. Our ultimate goal is not simply to detect ovarian cancer earlier, but to prevent invasive cancer from ever developing,” added Dr. Madan.

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Hoag Family Cancer Institute