Endocrine Abstracts

Introduction: Adrenocortical carcinoma (ACC) is a rare malignant tumor with heterogeneous prognosis. The median overall survival of all ACC patients is about 3-4 years. Complete surgical resection provides the only cure [Fassnacht M, et al., 2018]. In cases of advanced ACC, therapeutic options are limited. No effective second-line therapies are recommended for patients with disease progression to EDP chemotherapy scheme and Mitotane. It is essential to study alternative drugs, their combinations and tumor biological targets.

Objectives: The aim of the study is to evaluate somatostatin receptor (SSTR) types 2A and 5 expression in ACC.

Materials and methods: Formalin-fixed paraffin-embedded tissues from 69 patients were investigated. All the cases were reviewed according to the Weiss criteria to confirm the presence of ACC. Immunohistochemistry (IHC) staining was performed on 3 µm sections using the Leica Bond Max stainer. The primary antibodies anti-somatostatin receptor types 2A (UMB-1, Epitomics) and 5 (UMB-4, Epitomics) were incubated at the concentration 1:100. Only membranous staining was considered. The IHC results were evaluated through a semiquantitative approach as negative (0), weak (1+), moderate (2+) or strong (3+) in accordance with intensity of staining. The staining intensity was analysed using the following system: 1+ = faint staining at 100× magnification; 2+ = strong staining at 100× magnification, not entire circumference of tumor cell membranes stained at 400× magnification; 3+ = strong staining at 100× magnification, entire circumference of tumor cell membranes stained at 400× magnification [].

Results and Discussion: We identify moderate or strong staining intensity of SSTR types 2A and/or 5 expression in 49% of ACC spices. The detection of SSTR 2A and/or SSTR 5 expression in tumor tissue may be a promising marker of prolonged somatostatin analogs in the complex therapy of patients with advanced ACC, however, further research is required. There is no ability to evaluate effectiveness of their monotherapy, as well.