During October Rose, the Curie Institute in France announced a groundbreaking project involving miniature models that can recreate the characteristics of tumors in a laboratory setting. This research is part of a global effort to develop "tumor-on-a-chip" technology, which aims to personalize breast cancer treatments. These models are smaller than a USB key and are designed to test various treatments to determine the most effective option for patients with complex forms of breast cancer. After a biopsy, researcher Stéphanie Descroix extracts a small piece of tumor, roughly the size of a strand of vermicelli, containing both cancerous and immune cells. These cells are combined with collagen to form a 3D structure that mimics real-life conditions, then injected into a small transparent compartment. The device has four small holes on its sides, which act as reservoirs for the nutrient medium needed to sustain the cells and for the drugs being tested. After four days in an incubator at human body temperature, the survival and death of the cells are measured using a special dye that makes them visible. This process helps evaluate how sensitive each patient’s tumor is to different treatments, particularly in complex cases like metastatic breast cancer. Triple-negative breast cancer, which accounts for 15% of all breast cancer cases and is more aggressive, benefits greatly from this approach. The microfluidic chip model allows testing of anticancer drugs outside the human body, and it is possible to create 10 to 30 chips simultaneously from a single biopsy, enabling the testing of multiple treatments. At this stage of research, initial studies have shown that in 80% of cases, these microtumors respond to treatments in the same way as tumors in animals. To confirm the accuracy of these models, a clinical trial will be launched next year. In addition to tumor-on-a-chip technology, researchers at the Curie Institute are also developing organoids—3D structures made from cancer cells taken from patients and placed in small hydrogel tubes where they self-organize like real tumors. These organoids are exposed to various chemotherapy treatments, and the responses are visualized in tumorograms to help identify the best treatment options. "Organoids are powerful because you can grow many from a small sample," explains Dr. Descroix. "But the disadvantage is that it takes time." In France, more than 61,000 breast cancer cases are diagnosed each year, with over 3,000 (or 5%) occurring in women under 40. The incidence of breast cancer has increased by over 12% in women under 35 in the past decade, according to Professor Anne Vincent-Salomon, director of the Institute of Women's Cancers. Triple-negative breast cancer, which disproportionately affects younger patients, is a major focus of research at the Curie Institute. Two clinical trials are currently underway: one (Skyline) aims to predict resistance to immunotherapy and understand its causes, while the other (Cupcake) seeks to detect cancer recurrence earlier by identifying metastases before symptoms appear. Dr. Florence Coussy, a gynecologist and oncologist at the Curie Institute, noted during a press conference that the proportion of this type of cancer with a worse short-term prognosis is twice as high in young women as in the general population (20% versus 10%). Breast cancer is the leading cause of cancer-related mortality among women, according to a dispatch published by AFP on September 16, 2026.