Study Finds Blood Signal That May Flag Ovarian Cancer at Its Earliest Stage

Ovarian cancer has long been feared because it so rarely announces itself before it spreads. A study published this week offers measured hope: researchers say a molecular signal in the blood appears to mark the disease at its earliest, precancerous stage.

The work, from the Hoag Family Cancer Institute at Hoag Memorial Hospital Presbyterian in Newport Beach, California, appeared Nov. 10 in Nature Medicine. Dr. Rajan Gogna, Hoag's director of translational research, and Dr. Esha Madan, who leads one of the institute's laboratories, headed the eight-year international effort.

The signal is Tu-Stroma, an RNA molecule the researchers tie to the way cancer weakens neighboring healthy cells to make room for growth. Newsweek reported that tumor cells package it into tiny extracellular vesicles and ship it to nearby tissue.

The target was serous tubal intraepithelial carcinoma, or STIC, a microscopic, non-invasive lesion that usually forms in the fallopian tube and can give rise to high-grade serous ovarian cancer, which Medical Daily called the most common and deadly type. STIC does not show up on imaging or standard cancer blood tests and is usually found only by chance during surgery to remove the tubes or ovaries.

Medical Daily reported that the team measured Tu-Stroma in blood from 506 people: 43 with isolated STIC, 232 with high-grade serous cancer, 143 controls with normal tissue and 88 with benign growths. Levels were elevated in women with STIC and with early-stage disease. In a separate validation group, the test caught 92.3 percent of women with STIC and correctly cleared 98.2 percent of healthy women. At separating STIC from healthy controls, it outperformed the older CA125 blood marker on a standard accuracy score, 0.99 to 0.59.

Newsweek reported that Tu-Stroma levels did not rise significantly as the cancer advanced, suggesting the molecule reflects an early biological process rather than tumor size, and Madan said it also performed well in premenopausal women. "Ovarian cancer does not begin the day we discover a tumor," Gogna said in Hoag's announcement.

The American Cancer Society estimates that about 21,010 American women will be diagnosed with ovarian cancer in 2026 and about 12,450 will die of it; a woman's lifetime risk is about 1 in 91, though the death rate has fallen 45 percent since 1976. Newsweek, citing the society, reported that only around 20 percent of cases are caught early.

Part of the problem is screening itself. The National Cancer Institute says neither pelvic exams nor transvaginal ultrasound, even combined with the CA-125 blood test, has been shown to reduce deaths, and false alarms can lead to unneeded removal of the ovaries. The U.S. Preventive Services Task Force recommends against screening women who have no symptoms and no known hereditary high-risk syndrome, Medical Daily noted.

The researchers say the test could eventually help women at high inherited risk, such as BRCA1 or BRCA2 carriers, make decisions about preventive surgery. Madan told Newsweek that removing the tubes and ovaries can save a life but, for a younger woman, can also mean losing natural fertility and entering immediate surgical menopause. For couples still hoping to welcome children, a signal that could one day help time that decision would be a real blessing.

Dr. Ronny Drapkin of the University of Pennsylvania's Penn Ovarian Cancer Research Center, who was not involved, called the findings "very exciting and potentially transformative" but said the test is not yet ready for clinical use. Medical Daily noted the study used stored blood from women with known diagnoses, a design that can overstate real-world accuracy, and that only 43 had isolated STIC. Modeling suggests about 72 percent of positive results in high-risk women would be accurate, meaning roughly one in four could be false alarms. Gogna cautioned that "a negative result cannot currently exclude STIC or justify delaying recommended preventive surgery".

Until a validated test arrives, knowing the warning signs remains a woman's best defense. The American Cancer Society lists bloating, pelvic or belly pain, trouble eating or feeling full quickly, and urinary urgency or frequency as the most common symptoms. These usually have harmless causes, but the society advises seeing a doctor when they persist, mark a change from normal and occur more than 12 times a month. Women with a strong family history, Lynch syndrome or a BRCA mutation can ask about genetic counseling and prevention options.

Hoag plans prospective studies that will enroll women with and without elevated genetic risk and follow them over time to learn how early the signal appears, how reliably it flags precursor disease and whether it can guide care. The team is also exploring ways to stop STIC lesions from progressing. No product, price or regulatory timeline has been announced.

This is patient science worth cheering, aimed at protecting women, and the families who love them, before harm takes root. It is an early chapter, not the final word. For now, the wise course is the old one: know the signs, know your family history and keep talking with a trusted doctor.