A study led by investigators at Weill Cornell Medicine and NewYork-Presbyterian reports on Mar. 11 that a rare type of circulating tumor cell, known as a dual-positive (DP) cell, is associated with shorter survival times in patients with advanced breast cancer. The research highlights the potential significance of these under-studied cells in the progression of breast cancer.
Circulating tumor cells are breakaway cells from tumors that can lead to secondary tumors, or metastases, and are often found in the blood of cancer patients. DP cells are unique because they display both tumor-cell and immune-cell markers, suggesting they may be hybrid cells formed from fusions between tumor and immune cells. Previous studies have linked the presence of DP cells to worse outcomes in melanoma and pancreatic cancer.
The new study, published in Science Translational Medicine, found that DP cells were connected to shorter survival times for patients with advanced breast cancer, particularly those with triple-negative breast cancer—a more aggressive subtype lacking common tumor markers. Animal models used by the researchers also showed that DP cells could seed breast cancer metastases.
The research team initially analyzed blood samples from 340 women with advanced breast cancer who participated when the study began at Northwestern University. They found at least one DP cell in nearly 45 percent of participants. Patients with three or more detected DP cells had median survival times of just 23.5 months compared to 33.6 months for those with fewer than three detected DP cells. This association was confirmed in an additional group of 51 patients at NewYork-Presbyterian/Weill Cornell Medical Center.
Further analysis indicated that the risk linked to higher numbers of DP cells was mainly seen among patients with triple-negative breast cancer. The researchers also discovered that most analyzed DP cells bore a standard macrophage marker and were only detectable in mouse models when the animals had intact immune systems.
Dr. Massimo Cristofanilli, professor of medicine at Weill Cornell Medicine and senior author of the study, said: "Our current therapies target ordinary cancer cells, but DP cells have a different biology. We need to understand that better if we're going to target them effectively."
