ESR1 and breast carcinoma: Overall, the results obtained in the U-PIK study validate the PIK3CA mutational status testing performed through cobas® and PCR/Sanger sequencing (and NGS) at the eight Portuguese centers participating in this study and show the feasibility of adopting these methodologies as part of the clinical routine practice of patients with advanced ER+/HER2-breast carcinoma, decentralizing the analysis from reference laboratories.