A new Israeli study announced on Wednesday discovered that certain immune cells actually help breast cancer grow and spread in its later stages, according to the Press Service of Israel (TPS-IL). This surprising finding could lead to new ways to diagnose and treat advanced breast cancer.
The study was led by Tel Aviv University’s Dr. Sandra Camargo and PhD student Ori Moskowitz in the lab of Dr. Merav Cohen, with help from scientists from the Weizmann Institute and The Netherlands. The results, published in the peer-reviewed Nature Cancer journal, pinpointed the role of immune cells called neutrophils.
“In our lab, we study how cells talk to each other, especially in cancer,” said Cohen. “We found that neutrophils, which usually fight infections, are being used by cancer cells to help the tumor grow.”
The team used advanced tools to look closely at breast tissue in mice at different life stages, including mice with cancer. They used a special technique called single-cell RNA sequencing to study how different cells interact. In advanced cancer, they saw many neutrophils near cancer cells — more than in healthy tissue.
While neutrophils are part of the immune system and exist throughout the body, the study focused specifically on breast cancer because of the unique tumor microenvironment found in breast tissue and the way cancer develops there.
The scientists found that cancer cells used other immune cells — called macrophages — to bring neutrophils into the tumor. Once inside, the neutrophils physically interacted with the cancer cells and released substances helping the tumor grow, form new blood vessels, and spread to other parts of the body.
“To test this, we shut down neutrophils in mice with advanced breast cancer,” said Camargo and Moskowitz. “When we did that, tumor growth and blood vessel formation dropped significantly.”
The team also looked at data from women with Stage 3 and 4 breast cancer. They found that patients with more active neutrophil signals in their tumors had lower survival rates, showing that these immune cells are linked to worse outcomes.
“In light of our findings, we believe neutrophils could be used in two ways,” the researchers said. “As targets for new drugs, and as warning signs that a patient’s cancer is more advanced or aggressive.”
Dr. Cohen added: “This discovery changes how we think about the immune system and cancer. Neutrophils aren’t just bystanders—they’re helping the cancer. If we can block them or their signals, we might be able to slow the disease.”
The discovery that neutrophils actively support tumor progression — rather than merely being present — means scientists can now develop drugs aimed at blocking neutrophil recruitment, activation, or their interactions with cancer cells. By disrupting this newly identified communication pathway, treatments might also prevent the tumor from co-opting the immune system to its advantage.
Neutrophil-related molecular signatures can potentially serve as biomarkers to detect and monitor advanced breast cancer. Testing for these signatures in blood or tissue could help identify patients at higher risk of rapid progression or metastasis, allowing for more tailored treatment plans.
The use of single-cell RNA sequencing and cell-pair analysis in this study also introduces a new methodological approach for studying cancer–immune interactions in finer detail.
