Prevalencia y análisis clinicopatológico de pacientes con mutación en el gen PIK3CA con cáncer de mama avanzado Rh+/Her2- en el Instituto Oncológico Nacional De Panamá.

Background: The phosphoisitol 3-kinase (PI3K) signaling pathway, which promotes cancer cell growth and metabolism, is the most frequently mutated pathway in breast cancer and is associated with chemoresistance and poor prognosis. In this study we present the first analysis in Panamanian and regional population, with precise antations of the PIK3CA mutation, clinicopathological characteristics and prognosis. Methods: Exploratory study, where tumors were prospectively collected from 74 patients with RH+/Her2- metastatic breast cancer from the Instituto Oncológico Nacional between 2022 and 2023. A real-time PCR assay for mutation analysis was performed on DNA extracted from formalin-fixed, paraffin-embedded tumor material to detect mutations in exons 1, 4, 7, 9 and 20 of the PIK3CA gene. Results: The median age of the patients studied was 59 years. The mutation in PIK3CA was found in 33.8% (25/74) of patients with breast cancer, among them 44% were mutations in exon 20, 38% in exon 9, 13% in exon 4 and 5% in exon 1. A significant correlation was observed between the mutation and having history of cancer in the family (P = 0.005), and in postmepausal patients (P = 0.045). We did not found association between the mutation and histologic type, grade, tumor size or axillary status at diagnosis. Median progression-free survival was t reached in both groups and did not show a significant difference. Conclusion: The prevalence of the mutation is relatively high compared to international settings, it may offer an advantage in choosing the best treatment options and should be routinely evaluated during clinical interventions. [ABSTRACT FROM AUTHOR]