Professionals at the Virgen Macarena and Cabimer Hospital investigate the role of myeloid suppressor cells in metastatic breast cancer

This study opens the door to new, more efficient immunological therapeutic strategies that improve the prognosis and quality of life of patients 

Professionals from the Virgen Macarena University Hospital and the Andalusian Center for Molecular Biology and Regenerative Medicine of Seville (Cabimer) are developing a joint research project that aims to determine the role of myeloid suppressor cells in metastatic breast cancer and analyze their molecular mechanism with the aim of developing new immunological therapeutic strategies that improve the prognosis and quality of life of patients. 

Breast cancer is the leading cause of cancer death in women at worldwide. Thanks to advances in early detection and treatments, survival rates have improved significantly when diagnosis is made in early stages. However, the prognosis worsens drastically in advanced stages. When the cancer reaches a metastatic stage, the five-year survival rate drops to 32% and current treatments only achieve temporarily control the disease, without offering a definitive cure. 

At this critical stage of the disease, the tumor has acquired the ability to evade the immune system, allowing it to survive, spread, and resist conventional treatments. One of the key pieces in this process is a population of immune cells called myeloid suppressor cells (MDSCs) These cells, which under normal conditions can be protective by regulating inflammation, are used by the tumor to silence the immune response and promote its expansion. 

Previous research developed by medical oncology professionals in collaboration with the Clinical Biochemistry Service of the Virgen Macarena Hospital has shown that patients with advanced/ metastatic breast cancer have high levels in peripheral blood of suppressor cells of myeloid origin (MDSC) and regulatory T lymphocytes (Treg) compared to a population of healthy women, without oncological pathology. This finding has revealed the state of immunosuppression that characterizes these patients. 

The information obtained from the ‘Multiomic characterization of suppressor cells of myeloid origin in advanced breast cancer’ research will allow generating biomarkers that help stratify patients according to their levels and functional types of myeloid suppressor cells and predict their response to treatments. From this information, it will be possible to open the door to a more personalized approach, in the that patients can receive therapies tailored to their specific immune profile. 

This research project is built on a strategic collaboration between two leading research groups in their respective fields: the ‘Translational Research in Cancer Immunology and Immunotherapy’ group, led by the head of the Oncology Service at the Virgen Macarena Hospital, Luis de la Cruz, and the group ‘Metabolic Regulation and Signaling in Cancer’, led by Patricia Altea in Cabimer. 

Both teams are already working together on other cutting-edge initiatives, such as the development of patient-derived organoids for breast cancer, an innovative tool that allows therapies to be evaluated under conditions highly representative of the real tumor environment. collaboration has already demonstrated its scientific, technical and ethical viability. Since 2024, there has been an operational circuit for the collection of tumour samples supported by the corresponding approved clinical and biosafety protocols. In addition, Cabimer's group provides an advanced infrastructure to perform complex metabolomic studies using liquid/gas chromatography coupled to mass spectrometry, essential to characterize the metabolism of tumor and immunosuppressive cells. 

The project is also supported by a collaborative network of oncologists, clinical biochemists, pathologists and radiologists from the Virgen Macarena Hospital and the Biobank of the Public Health System of Andalusia. 

Charity Gala 

The research scientific has the support of the María Jesús Vera Foundation and the ABU Group that will organize, on October 24, a charity dinner at the Real Club Pineda in Seville with the aim of raising funds for the project. The reservation of a place for this charity dinner that contributes to the development of this research on metastatic breast cancer can be made on the Group's website ABU. 

Research activity 

The Medical Oncology Unit of the Virgen Macarena Hospital maintains more than 240 active clinical trials, including immunotherapy lines and targeted therapies in various types of cancer, including breast cancer. 

In recent years, the health center has promoted and coordinated academic projects such as the PANGEA clinical trial Breast that sought to identify predictive biomarkers of response in tissue and blood of patients with advanced breast cancer treated with combined systemic therapies, as well as the suppressor cell study (GEICAM, 2019) focused on the characterization of the immune system in patients with advanced breast cancer, comparing with healthy cohorts, and evaluating how these profiles affect prognosis and response to treatment. In the context of clinical trials, the HUVM was the main recruiter in Spain of the MONALEESA-3 study that studied the combination of a new drug with hormonal therapy, achieving a 28% increase in overall survival in postmenopausal women, and whose results were published in the New England Journal of Medicine setting a new standard of care in advanced breast cancer. 

In addition, the prestigious journal ‘Nature Cancer’ recently published an article about a study carried out with the participation of professionals from the Virgen Macarena University Hospital regarding how the immune system can collaborate with the tumor in certain cases and types of breast cancers (HR HER2−) to generate resistance to generally efficient treatments. The project explains why some cases of the most common type of breast cancer, known as luminal or hormone-sensitive, could fail to respond to one of the most frequent and successful therapies, and provides information about possible therapeutic ways to reverse this refractoriness .