Presence of PIK3CA mutation in patients with stage IV luminal breast cancer and its relationship with rapid progression

Background: Breast cancer is a disease of the mammary gland in which its cells grow and multiply abnormally. In Argentina, there were around 131,000 new cases of cancer, of which approximately 22,000 cases were of breast origin (2020). Although survival is increasing and its mortality rate is constantly decreasing due to great advances, in this work we will mention certain aspects related to rapid progression, increased mortality and lack of response to treatments that are associated with specific genetic mutations. We will address the PIK3CA pathway; one of the most active pathways in breast cancer, its relationship with the prognosis of the disease, resistance mechanisms and response to current treatments. Materials and methods: We will rely on academic literature, publications and our own experiences regarding this pathology, taking 23 patients with stage IV luminal breast cancer from the Lucen Clinic and the Marie Curie Hospital between 1998 and 2001. Results: 10 of them had the mutation in the PIK3CA pathway (43%) and 13 did not (57%). In addition to this, we will evaluate the survival time of the patients by comparing both groups; obtaining results that those who had this mutation had a lower average survival time, around 5-6 months, details that will be analyzed later. Conclusion: Therefore, we will conclude that metastatic breast cancer in stages IV that have the mutation of this gene will have a worse prognosis in terms of their quality of life, due to the chemoresistance generated by having the mutated PIK3CA pathway.