The PI3K/AKT/mTOR pathway is frequently activaed across many cancers. AKT1 is a subfamily of serine/threonine protein kinases, affecting cell survival, proliferation and invasion. The prior reports from Western country have shown AKT1 mutation in 3-6% of breast cancer and in 2-3% of endometrial cancer. However, the clinico-pathological features of AKT1 E17K mutation in Asian female cancers is unclear. In this study, we examined breast cancer samples and endometrial cancer samples for mutation in AKT1 hotspot at our institution.
For patients with breast cancer and endometrial cancer, we retrospectively analyzed tissue samples preserved between January 2008 and June 2015 in a biobank at national cancer center hospital. We extracted DNA and determined AKT1 mutation with PNA-LNA clamp methods. Kaplan-Meier analysis was performed to analyze relapse-free survival (RFS) after surgery and overall survival (OS) for breast cancer patient.
A total of 469 patients were analyzed. Three hundred and twenty-nine patients were breast and 140 were endometrial cancer. The median age was 52 (range 22-90). In breast cancer patients, 305 patients were initially stage I to III, and thirty-two patients were initially Stage IV. The number of tumor subtype was hormone receptor (HR) positive and HER2 negative tumor; 248 (74%), HR positive and HER2 positive tumor; 44 (13%), HR negative and HER2 positive tumor; 28 (8%), and Triple negative tumor; 17 (5%), respectively. We detected AKT1 mutation in 24 patients (7.3%) of breast-cancer patients and 7 patients (5.0%) of endometrial-carcinoma patients. In breast cancer patients, there were 176 relapses and 32 deaths. Median RFS was 79 months in patients with AKT1 wild type and 75 months in patients with AKT1 mutation (p-value:0.77).
We detected AKT1 mutation in 31 patients (6.6%) of 469 breast and endometrial cancer. RFS in breast cancer patients is not significantly different by AKT1 mutation status.
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Legal entity responsible for the study
National Cancer Center Hospital
All authors have declared no conflicts of interest.