Breast cancer survivors have a significantly elevated risk of developing other cancers later in life, and a new modeling study suggests that annual blood-based multicancer screening tests could catch these cancers much earlier than current methods. Researchers at Fred Hutch Cancer Center found that survivors, particularly those with hormone receptor-negative breast cancers, could benefit substantially from yearly blood tests that screen for multiple cancer types at once.

Why Are Breast Cancer Survivors at Higher Risk?

Surviving breast cancer is a major victory, but it doesn't eliminate future cancer risk. In fact, breast cancer survivors face roughly a 17% higher chance of developing another type of cancer compared to women of the same age with no cancer history. This elevated risk stems from several factors, including shared genetic risk factors, side effects from cancer treatment, and natural hormonal changes. The risk is even higher for survivors of hormone receptor-negative breast cancers, which don't depend on estrogen or progesterone for growth.

Beyond the risk of cancer recurrence, survivors can develop entirely new primary cancers years or even decades after their original diagnosis. Current survivorship guidelines focus almost exclusively on monitoring for breast cancer recurrence through mammograms, leaving a significant gap in screening for other malignancies.

What Did the Research Show About Multicancer Blood Tests?

Researchers led by Dr. Kemal Gogebakan at Fred Hutch used mathematical modeling to simulate what would happen if breast cancer survivors received annual multicancer early detection (MCED) blood tests. These tests work by analyzing blood for cancer-associated proteins and patterns in circulating cell-free DNA, allowing doctors to detect multiple cancer types from a single sample.

The study simulated hundreds of thousands of virtual women between ages 50 and 74, comparing outcomes for breast cancer survivors versus average-risk women. The researchers tracked 16 different cancer types and tested various scenarios based on how sensitive the blood tests might be at catching early-stage tumors.

The results were striking. Across every scenario tested, multicancer screening reduced late-stage cancer diagnoses more effectively in breast cancer survivors than in average-risk women. In the most optimistic scenario, hormone receptor-negative survivors saw up to 111 late-stage diagnoses prevented per 100,000 person-years, representing a 26% relative reduction. By comparison, average-risk women saw 84 late-stage diagnoses prevented per 100,000 person-years, a 20% reduction.

Which Cancers Would Benefit Most From This Screening?

The study identified specific cancers that would drive the most benefit from multicancer blood testing in breast cancer survivors:

• Lung Cancer: Accounted for 34-38% of all late-stage diagnoses prevented across all groups, making it the single largest contributor to screening benefit
• Colorectal Cancer: Contributed 14-16% of the late-stage cancer reduction, representing the second most impactful cancer type
• Ovarian Cancer: Contributed about 10-11% of the benefit in hormone receptor-negative survivors, nearly double its contribution in hormone receptor-positive survivors and average-risk women, since hormone receptor-negative breast cancer carries specifically elevated ovarian cancer risk

"The ovarian cancer finding in hormone receptor-negative survivors was particularly striking; this elevation in hormone receptor-negative survivors is a genuinely new finding that underscores the importance of thinking about survivor subgroups separately," explained Dr. Kemal Gogebakan.

Dr. Kemal Gogebakan, Researcher at Fred Hutch Cancer Center

How Could This Change Survivorship Care?

Currently, breast cancer survivorship guidelines focus almost entirely on watching for recurrence or new breast tumors. The Fred Hutch study argues that blood-based multicancer tests could fill a critical gap by screening for the many other cancers survivors face elevated risk of developing. The researchers also noted that a targeted approach focusing specifically on lung, colorectal, and ovarian screening might capture most of this benefit with even higher sensitivity for each individual cancer.

"This is one of the first studies to quantify the potential benefit of multicancer screening in a high-risk population. Breast cancer survivors represent an important high-risk group in which multicancer screening may have distinct clinical value," stated Dr. Kemal Gogebakan.

Dr. Kemal Gogebakan, Researcher at Fred Hutch Cancer Center

The research was published in JCO Precision Oncology and was funded by the Rosalie and Harold Rea Brown Endowed Chair and the National Cancer Institute. The authors plan to extend their modeling framework to other high-risk survivor populations, including childhood cancer and colorectal cancer survivors.

What Should Breast Cancer Survivors Know Right Now?

While these findings are promising, multicancer blood tests are not yet standard in survivorship care guidelines. However, some survivors are already accessing these tests on their own initiative. Dr. Gogebakan emphasized the importance of informed decision-making: "It is important for survivors to be aware of their excess cancer risk even many years after their initial diagnosis, and equally important to be able to offer them interventions to mitigate that risk".

Dr. Gogebakan

Survivors should discuss their individual cancer risk profile with their oncology team, particularly if they had hormone receptor-negative breast cancer. The conversation should include whether multicancer screening might be appropriate for their specific situation, as the potential benefits appear to be greatest for those at highest risk of developing subsequent malignancies.