КОЛОРЕКТАЛЬНЫЙ РАК С МУТАЦИЕЙ В ГЕНЕ BRAF В РОССИЙСКОЙ ФЕДЕРАЦИИ: ЭПИДЕМИОЛОГИЯ И КЛИНИЧЕСКИЕ ОСОБЕННОСТИ. РЕЗУЛЬТАТЫ МНОГОЦЕНТРОВОГО ИССЛЕДОВАНИЯ

Introduction. mBRAF mCRC has the aggressive phenotype. The incidence of such mutation in Europe and the USA is around 8–14%, in Asian countries – 4–8%. The purpose of this population-based study was to determine the incidence and identifying prognostic factors in pts with mBRAF mCRC in Russia.  Materials and methods. A multicenter retrospective analysis of clinical data and treatment results of pts with mBRAF mCRC was  performed. The main method for determining mutations was a PCR. The main efficacy endpoint was progression free survival (PFS) at the 1 st line. Multivariate analysis was performed using Cox regression model.  Results and discussion. 437 out of 8648 pts (5.17%) with a known mutational status had mBRAF (V600). Clinical data were collected from 131/437 (30%): the right-sided primary tumor – in 58,6%, left-sided – in 19%, rectum – in 21,4%. ORR in pts with mBRAF was 31%, median PFS was 6 months. We didn’t revealed any differences between FOLFOXIRI and doublets (XELOX/ FOLFOX or XELIRI/FOLFIRI) in terms of PFS (HR 0.9, 95% CI 0.49–1.52, р = 0.6) and OS (HR 1.5, 95% CI 0.61–4.1, р = 0.35) in pts with mBRAF.  Conclusions . The incidence of mBRAF gene in the population of pts with mCRC in the Russia is low and we found a high incidence of localization of the primary tumor in the rectum. We didn’t reveal any differences between the usual duplets and standard regimen for such mutation - FOLFOXIRI in term of 1 st line PFS.