PIK3CA somatic mutations in primary male breast cancer

Aims: Patients with breast cancer harboring PIK3CA somatic mutations have shown improved responses to PI3K inhibitors, yet the prevalence and distribution of PIK3CA mutations in male breast cancer (MBC) remain understudied. This study aims to evaluate the frequency and mutation spectrum of PIK3CA mutations in primary MBC, potentially guiding novel treatment options for this patient subgroup.

Methods: Tumor samples from 131 male patients diagnosed with primary invasive breast cancer between 1995 and 2022 in Bergisch Gladbach, Chemnitz, and Zwickau, Germany, were analyzed. PIK3CA mutations were assessed using next-generation sequencing (NGS) with the QIAseq Human Actionable Solid Tumor Panel, covering exons 2-21. Results were correlated with patient characteristics and follow-up data.

Results: Of the 131 cases, 103 were successfully analyzed. PIK3CA mutations were found in 27 tumors (26.3%). Mutations included H1047R (13 patients), E656K (5 patients), and single cases of H1057L, E103_P104del, C420R, E453K, E542K, and H855Y. There was no significant correlation between mutation frequency, tumor characteristics, or overall survival.

Discussion: This is the first study to comprehensively evaluate PIK3CA mutations in primary MBC using NGS. The findings suggest that over 25% of MBC patients may benefit from PIK3CA-targeted therapies. Further studies with larger cohorts are needed to assess the prognostic value of PIK3CA mutations in MBC.

Conclusion: A significant proportion of primary MBC tumors harbor PIK3CA mutations, indicating their potential eligibility for targeted PIK3CA therapy.

Publikationsverlauf

Artikel online veröffentlicht:
04. Juni 2025