NCT06449989

Comparison of Molecular-Genetic Concordance of the Primary Tumor and Brain Metastases of Colorectal Cancer

• Status: Recruiting
• Phase: —
• Study type: Observational
• Enrollment: 30 (estimated)
• Sponsor: Blokhin's Russian Cancer Research Center · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

GENCONCOR-1 study is translational research aimed to investigate the concordance of the molecular genetic profile of the primary tumor and brain metastases (BM) of colorectal cancer (CRC). The study was conducted by post hoc analysis of pairs of samples of histological material with determination of the mutational status of genes KRAS, NRAS, BRAF, HER2 and MSI.

Detailed description

Brain metastases (BM) from colorectal cancer (CRC) are a rare event reported in less than 3% of patients with CRC (the reported incidence ranges from 0.27 to 3%). This course is associated with a poor prognosis. Treatment of these patients remains challenging. Nevertheless, given the rarity of the event, at this time not enough is known about molecular biology of BM from colorectal cancer and its concordance with matched primary tumors. In N.N. Blokhin National Medical Research Center of Oncology over 26 years (1998-2024) identified 108 patients with BM from CRC. Of this number, 72 patients had a history of neurosurgical resection of BM. In turn, for 32 patients access to a pair of tumor samples: from the primary tumor and from intracranial metastases. Tumor samples will be tested for mutation status of genes KRAS, NRAS, BRAF, HER2 and MSI. Analysis was limited to this pool of genes because of their clinical relevance and potential prognostic information. The molecular profile of the BM will be compared with the corresponding primary tumor with calculation of concordance rate (%).

Conditions

• Colorectal Cancer Metastatic
• Brain Metastases, Adult
• Ras (KRAS or NRAS) Gene Mutation
• BRAF Gene Mutation
• HER2 Gene Mutation
• MSI

Interventions

Type	Name	Description
DIAGNOSTIC_TEST	Tumor samples will be tested for mutation status of KRAS, NRAS, BRAF, HER2 and MSI	For molecular genetic research, archival formalin-fixed and paraffin-embedded tumor blocks will be used. Research method - HRM-PCR sequencing to determine mutation status of KRAS, NRAS and BRAF (RotorGene 6000, ABI Prism 3500) and fragmentation analysis to determine MSI (ABI Prism 3500) Subject to study: mutations in the KRAS, NRAS, BRAF genes, as well as MSI status and HER2neu expression (± amplification) Somatic mutations in the RAS family genes are planned to be studied in exons 2 (codons 12 and 13), exon 3 (codon 61) and exon 4 (codon 146). In the case of the BRAF gene - exon 15 (codons 597-601). Determination of microsatellite instability is planned using five markers: BAT25, BAT26, NR21, NR24, NR27, associated with structural and functional disorders of the DNA unpaired base repair system. Assessment of HER2 gene status is planned by immunohistochemical (IHC) screening of HER2neu expression. IHC-screening of HER2-status will be performed using an antibody clone 4B5 (Ventana).

Timeline

• Start date: 2024-04-01
• Primary completion: 2027-09-01
• Completion: 2027-09-01
• First posted: 2024-06-10
• Last updated: 2025-08-12

Locations

1 site across 1 country: Russia