Ovarian Cancer Warning Signs Could Be Detected Before Invasive Tumours Even Develop, Study Finds

A new blood test could help identify the earliest biological warning signs of ovarian cancer before invasive tumours develop, potentially giving women at increased risk more time to make crucial decisions about their health.

Ovarian cancer remains particularly challenging to diagnose because early symptoms can be difficult to recognise, and existing imaging techniques often miss very small abnormalities.

According to the American Cancer Society, only around 20% of ovarian cancers are diagnosed at an early stage, highlighting the need for better detection methods.

Researchers at the Hoag Family Cancer Institute in California discovered a molecular signal that can reveal microscopic changes associated with ovarian cancer, even when conventional imaging methods cannot detect a tumour.

The findings, published in Nature Medicine on 10 November, could offer a different approach to detecting a disease that is frequently diagnosed only after it has spread.

Blood Test Detects Hidden Precancerous Changes

Ovarian cancer can begin with microscopic abnormalities in the lining of the fallopian tubes, known as serous tubal intraepithelial carcinoma (STIC). These precancerous lesions can develop without noticeable symptoms or visible tumours, making them particularly difficult to identify through conventional screening methods.

However, the research team discovered that women with STIC have elevated blood levels of an RNA molecule called Tu-Stroma. The molecule acts as a biological messenger, allowing abnormal cells to influence the healthy tissue surrounding them and potentially making it easier for cancer to develop.

The study analysed previously collected blood samples from women whose diagnoses were already known. When researchers measured Tu-Stroma levels in blood samples, they detected STIC in 92.3% of affected women while correctly identifying 98.2% of healthy women.

In a modelled high-risk population, approximately 72% of positive results would be accurate, while negative results would be correct nearly 100% of the time.

Study leader Rajan Gogna said the research took a different approach to early detection by looking for molecular warning signs before invasive cancer develops.

Findings Could Change Preventive Surgery Decisions

The discovery could be particularly significant for women with inherited genetic risk factors, including BRCA1 and BRCA2 mutations, who face an increased likelihood of developing ovarian cancer.

Some women at high risk are advised to undergo preventive surgery to remove their fallopian tubes and ovaries, even when there is no confirmed cancer.

Although the procedure can substantially reduce cancer risk, it can also mean losing natural fertility and experiencing immediate surgical menopause, with potential long-term consequences for hormonal health.

Co-author Dr Esha Madan said preventive surgery decisions are largely guided by inherited risk rather than evidence of whether precancerous lesions are actually present. She suggested that Tu-Stroma could eventually provide clinicians with additional biological information when discussing prevention options with patients.

Dr Ronny Drapkin, director of the Penn Ovarian Cancer Research Center and a co-author of the study, described the findings as exciting and potentially transformative. However, he cautioned that the test is not yet ready for clinical use and requires confirmation through larger studies following women over time.

The research team is preparing for prospective clinical studies at Hoag Family Cancer Institute to investigate the marker further. If subsequent research confirms its effectiveness, the blood test could eventually help identify ovarian cancer's earliest warning signs before conventional methods reveal a tumour.