Author contributions: Kolesnikov EN — data collection, analysis and interpretation; manuscript editing; Trifanov VS — study design; data collection, manuscript editing; Timoshkina NN — data analysis and interpretation; manuscript preparation; Snezhko AV — data acquisition; Gvaldin DYu — data analysis and interpretation; Meshcheryakova MYu — literature analysis; manuscript preparation.

Compliance with ethical standards: the study was approved by the Ethics Committee of the National Medical Research Centre for Oncology (Protocol № 3 dated February 9, 2021); informed consent was obtained from all study participants.