Prevalence of Pik3ca-Mutations and Response to First-Line Endocrine Therapy in a Population of Bulgarian Patients with HR(+) HER2(–) Metastatic Breast Cancer // Честотата на PIK3CA-мутацията и отговорът към първа линия ендокринна терапия в популацията от български пациентки с HR(+)HER2(-) метастазирал карцином на гърдата

The study examined 250 patients with metastatic HR(+)/HER2(–) breast cancer, diagnosed and treated between January 2016 and November 2022 at three hospitals in Bulgaria (Nadezhda Hospital - Sofia, St. Marina University Hospital – Varna, Acibadem City Clinic Hospital Tokuda – Sofia). The prevalence of the PIK3CA mutation and its relationship to certain clinicopathological characteristics of the patients and their response to first-line therapy were investigated. The data analysis was retrospective. All patients provided histological samples for examination after signing informed consent. Some of the patients were diagnosed at the metastatic stage, while others were diagnosed at an early stage and later progressed. All patients received first-line therapy. The results showed that the PIK3CA mutation among Bulgarian patients was 29.2%, which is comparable to the frequency reported in several international studies. The study did not find a statistically significant difference in median progression-free survival and OS in first-line therapy with ET±CDK4/6 inhibitor in patients with confirmed PIK3CA mutation and those without mutation.

Grantor dc:publisher

Medical University of Varna

Year dc:date

2026

Authors dc:creator

• Gencheva, Radostina
• Генчева, Радостина

• breast cancer
• PIK3CA mutation
• metastatic stage
• Онкология / Oncology

Repository record dc:identifier

http://repository.mu-varna.bg/handle/nls/4430

OAI identifier oai:identifier

oai:repository.mu-varna.bg:nls/4430