Funding: the study was carried out within the framework of the Government Assignment № FZEG-2020-0060 of the Ministry of Science and Higher Education of the Russian Federation in the field of scientific research “Algorithms for molecular genetic diagnosis of malignant neoplasms and approaches to their targeted therapy using cellular and genetic technologies”.

Author contribution: Golubinskaya EP — clinical data analysis, immunohistochemistry, manuscript editing; Sataieva TP, Fomochkina II — systematic analysis, manuscript writing; Kubyshkin AV — statistical analysis, manuscript editing; Makalish TP — sample preparation for morphological assessment, immunohistochemistry; Shkolyar NA — biopsy sample collection and preparation; Galyshevskaya AA, Varghese DV — morphometric data processing.

Compliance with ethical standards: the study was approved by the Ethics Committee of the Medical Academy named after S. I. Georgievsky (protocol № 15 dated December 5, 2020); the study was conducted in accordance with the Declaration of Helsinki 1964 (revised in 1975 and 1983), Good Clinical Practice (GCP) standards and the Federal Law № 323-FZ “On the Basics of Protecting the Health of Citizens in the Russian Federation” dated November 21, 2011. The informed consent was submitted by all patients.