ESMO Congress-Madrid Spain October 20-24, 2023
Testing HR+ / HER2- patients with advanced or metastatic breast cancer for identification of tissue mutations in the PIK3CA gene. Results of a national program by the Hellenic Society of Medical Oncology (HeSMO)
Αυτή η διεύθυνση ηλεκτρονικού ταχυδρομείου προστατεύεται από τους αυτοματισμούς αποστολέων ανεπιθύμητων μηνυμάτων. Χρειάζεται να ενεργοποιήσετε τη JavaScript για να μπορέσετε να τη δείτε., Michail Nikolaou, Alexandros Ardavanis, Christos Tolis, Konstantia Loga, Ippokratis Korantzis, Anna Koumarianou, Athina Christopoulou, Georgios Papatsimpas, Alexandros Bokas, Kyriaki Pliarchopoulou, Eleftherios Kabletsas, Georgios Kesisis, Eirini Biziota, Konstantia Psianou, Sofia Karageorgopoulou, Eleni Sogka, Nikolaos Tsoukalas, Natalia Chatzifoti, Zenia Saridaki
On behalf of the Hellenic Society of Medical Oncology (HeSMO), Athens, Greece
View abstract in Annals of Oncology
Background: PIK3CA mutations have been identified in approximately up to 40% of breast cancer cases and PIK3CA targeting has already been incorporated in treatment algorithms, especially in the second line of ER+/HER2- patients. HeSMO launched a national program to provide PIK3CA mutation testing, which is officially not reimbursed, with the aim to identify mutations in the PIK3CA gene, and, therefore, lead to more therapeutic options.
Methods: All HR+/HER2- patients with a diagnosis of metastatic breast cancer were eligible to participate in this program. The result of the test was obtained using the COBAS® PIK3CA method, a diagnostic test specifically designed to detect mutations in the PIK3CA gene in tumor tissue samples (FFPE) attained by biopsy or surgically, which detects 17 different mutations in the PIK3CA gene, including the most commonly occurring in Exons 9 and 20.
Results: From June 2022 to March 2023, 149 patients from across the country were tested within this program. Sixty one (61) patients (40.94%) were detected with mutation in PIK3CA gene and 88 (59.06%) without mutation (Table 1). 23 patients had Exon 9 mutations (37.70%), 33 in Exon 20 (54.10%), and 8 had mutations in the remaining Exons 1, 4 and 7 (13.11%). In 1 sample 4 mutations were detected: (Exon 7/9/20), and 2 mutations in another 2 samples (Exon 9: E545X, Q546X and Exons 1/20), while in all other samples just 1 mutation was detected in each.
Conclusions: In our series, 40.94% of the patients tested, were detected with mutations in PIK3CA gene, in accordance with published data. Apart from the significant implications for treatment possibilities in a substantial patients’ population, these results provide valuable epidemiological data and strengthen our efforts for reimbursement of PIK3CA mutation testing in Greece.
Table 1. PIK3CA Mutation results of HeSMO’s program