Novel Population of Macrophages Associated with  Better Prognosis in Breast Cancer; Finding at Odds with Previous Thinking; FOLR2+ Macrophages Are Associated with T-Cell Immune Response to Breast Cancer

In contrast to the current consensus, the presence of macrophages around breast cancer is not necessarily a bad sign, according to the work conducted by Eliane Piaggio’s (PhD) Translational Immunotherapy team at Institut Curie. Biologists reveal a new population of macrophages that is associated with better prognosis in breast cancer patients. These results were published in Cell on March 23, 2022. The article is titled “Tissue-Resident FOLR2+ Macrophages Associate With CD8+ T Cell Infiltration in Human Breast Cancer.”It is now well established that the immune system plays crucial roles in breast cancer. When the immune system is inhibited by the tumor environment, tumors can grow freely. But when correctly activated, immune cells impede tumor development. The role of macrophages--immune cells subtype installed in tissues--in these processes has yet to be understood. Researcher in the field generally consider macrophage infiltration in tumors to be a bad sign. But the work of researchers from Institut Curie describe a more complex picture. They show that a macrophage sub-population associates with an active immune response directed against the tumor and with increase survival of patients.