Abstract P6-04-12: Immunoprofile of TIL, genetics of Fc receptor gama and apoptosis activation in patients with Her2-positive breast cancer – Pilot study
Authors: Stanek L , Tesarova P , Vocka M , Musil Z , Kasparova K , Petruzelka L 
Published: May 2016

Possible markers helping us to detect molecular-immunologically patients with Her2 positivity are Fc-gamma receptors (FcR). FcR binds to CH3 section of Fc trastuzumab fragment and is the key factor for activation of cell lysis via immune system cells (NK cells, macrophages). Tumors, where the H131R mutation decreased the effect of NK cells and macrophages, show a higher percentage of tumor cells entering apoptosis and activation of tumor infiltrating lymphocytes (TIL) (CD8+), which can result in tumor volume reduction and inhibition and thus extend overall survival.

In the pilot study included 50 patients with histologically verified breast cancer treated in the Department of Oncology (First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague) participated in our pilot study. 40 patients were with a median age of 49.4 years (14 postmenopausal [46.7%] and 16 premenopausal [53.3%]) with detected HER-2 FISH amplification (histologically 18 patients with HER-2 subtype which means without hormone receptor positivity and 12 patients with luminal B subtype and thus hormone receptor positive). All patients were without evidence of distal metastases (6 in stage I, 13 in stage II and 11 in stage III). A control group was formed of 10 patients with a median age of 49.2 years (4 postmenopausal [40.0%] and 6 premenopausal [60.0%]) and without HER-2 amplification (histologically 7 patients with luminal A subtype, 2 patients with luminal B subtype and 1 patient with basal-like subtype). All patients of the control group were without evidence of distal metastases (2 in stage I, 6 in stage II and 2 in stage III). All patients signed the written informed consent.

Our aim was to carry out the H131R mutation analysis using the StripAssay (ViennaLab, Austrian) method in correlation with clinical data, to quantify cells entering apoptosis using molecular method TUNEL (DeadEnd, Fluorometric TUNEL System, USA) and to immunohistochemically determine the expression and ratio of CD8 (Clone C8/144B) to CD4 (Clone 4B12) (Dako, Denmark) in a tumor.

Results showed that in Her2-positive patients responding badly to biological treatment according to the clinical data the H131R mutation in the FcR gene was detected in 34/40 (85%) cases (26 heterozygotes / 8 homozygotes). Kaplan-Meier analysis of patients with the H131R mutation (FcR mutation / activation of apoptosis / CD8 positivity) showed significant differences in patients' survival from the generalization of a tumor – 28 vs 83 months. In patients with longer survival molecular analysis TUNEL confirmed a large number of cells entering apoptosis (20-30% in the field of vision) and activated antitumor immunity (CD8+ positivity) in more than 60% of a tumor and concurrently no expression (CD4-).

Our study showed that in Her2-positive patients with detected H131R mutation in the FcR gene the function of NK cells and macrophages in tumor inhibition was decreased (blocked). However, in some patients the apoptotic pathway was activated and the process of programmed cell death was induced. Increased expression of CD8 was a positive prognostic factor, with a longer survival of these patients.

Dedication: PRVOUK-P-27/LF1/1., MZ 00064203.

Citation Format: Stanek L, Tesarova P, Vocka M, Musil Z, Kasparova K, Petruzelka L. Immunoprofile of TIL, genetics of Fc receptor gama and apoptosis activation in patients with Her2-positive breast cancer – Pilot study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-04-12.