Enigmatic "Dual-Positive" Hybrid Cells Identified as High-Risk Indicator for Metastasis and Shorter Survival in Triple-Negative Breast Cancer

Weill Cornell Medicine researchers find that "dual-positive" hybrid cells in the blood predict shorter survival and increased metastasis in breast cancer patients.

By: AXL Media

Published: Mar 13, 2026, 6:01 AM EDT

Source: Information for this report was sourced from Weill Cornell Medicine

The Discovery of Biological Hybrids in the Bloodstream

Circulating tumor cells have long been recognized as the primary vehicles for cancer metastasis, but new research has identified a more complex player in the progression of advanced breast cancer. Investigators at Weill Cornell Medicine and NewYork-Presbyterian have focused their efforts on "dual-positive" (DP) cells, an enigmatic type of cell that carries markers for both tumors and immune cells. These hybrids are believed to result from rare fusions between cancer cells and macrophages, the body's immune "scouts." While previously linked to poor outcomes in melanoma and pancreatic cancer, this new study provides the first comprehensive evidence of their role in accelerating the spread of breast cancer.

Quantifying the Survival Risk for Advanced Patients

The research team analyzed blood samples from 340 women with advanced breast cancer, identifying at least one DP cell in nearly 45 percent of the participants. While DP cells are generally less numerous than ordinary circulating tumor cells, their presence is a potent indicator of reduced longevity. Patients with three or more detected DP cells had a median survival time of 23.5 months, compared to 33.6 months for those with fewer detected hybrids. This ten-month disparity in survival was validated through an additional cohort at NewYork-Presbyterian/Weill Cornell Medical Center, confirming that these unusual cells are a significant, overlooked factor in clinical outcomes.

Concentrated Danger in Triple-Negative Subtypes

The study found that the risk associated with DP cells is particularly concentrated among patients with triple-negative breast cancer (TNBC). This subtype is notoriously aggressive because it lacks the three most common receptors—estrogen, progesterone, and HER2—making it resistant to many standard hormonal and targeted therapies. Because DP cells are prevalent in these "cold" tumor environments, they may represent a critical mechanism that the cancer uses to navigate the body undetected. Dr. Carolina Reduzzi, assistant professor of cancer biology research, noted that understanding these cells is vital for developing better methods to monitor and predict treatment responses in the most difficult-to-treat cases.