PIK3CA mutational status in tissue and plasma as a prognostic biomarker in HR+/HER2- breast cancer

Researchers analyzed tissue and plasma samples from patients with luminal breast cancer to analyze the prognostic impact of PIK3CA mutations in HR+/HER2- disease. They found that patients with mutations in PIK3CA, especially those with mutations in exon 9, showed worse outcomes in advanced luminal disease, and that prognosis was unclear in early-stage disease. They also noted that in this study, tissue samples were the most effective diagnostic method, and that further research is needed to improve the role of liquid biopsies in this setting.