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NCT Number: NCT06449989

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

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.

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Key information

Conditions

Colorectal Cancer Metastatic BRAF Gene Mutation Brain Diseases Brain Metastases, Adult Brain Neoplasms Central Nervous System Diseases Central Nervous System Neoplasms HER2 Gene Mutation MSI Neoplasms Neoplasms by Site Nervous System Diseases Nervous System Neoplasms Ras (KRAS or NRAS) Gene Mutation

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Blokhin's Russian Cancer Research Center

Moscow, 115478, Russia

Location status: Recruiting

Location contact

David Halafyan, MD

CONTACT

[email protected]

+7(930)928-00-72

About this study

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 (%).

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Men and women over 18 years of age.
  • Histologically confirmed cancer of the colon or rectum.
  • Histologically confirmed metastatic lesion of the brain.
  • Neurosurgical resection for brain metastases of colorectal cancer.
  • Presence of paired tumor samples (both primary tumor and intracranial material).

Exclusion criteria

  • Missing one sample from a pair of tumor samples.
  • Low quality or lack of tumor material for molecular genetic research.

Treatment and study plan

Tumor samples will be tested for mutation status of KRAS, NRAS, BRAF, HER2 and MSI

Diagnostic Test

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).

Primary outcomes

  1. Concordance rate (%)

    Time frame: 1 month

    Concordance rate (%) between mutational status of the brain lesions and their corresponding primary tumor. Calculated as the ratio of concordant cases to total cases.

Secondary outcomes

  1. Intracranial progression-free survival (CNS-PFS1)

    Time frame: 3 months

    Time from the date of cancer diagnosis to the date of detection of brain metastases.

  2. Overall survival (OS)

    Time frame: 6 months

    Time from the date of detection of brain metastases to the date of death.

  3. Intracranial progression-free survival (CNS-PFS2)

    Time frame: 3 months

    Time from the date of neurosurgical resection to the date of intracranial progression (continued growth or distant brain metastases) or death.

Study contacts

Contact information is provided by the study sponsor or research team.

David Halafyan, MD

CONTACT

[email protected]

+7(930)928-00-72

Sponsors and collaborators

Lead sponsor

Blokhin's Russian Cancer Research Center

Other

Registry information

Acronym: GENCONCOR-1

Important dates

Study start
2024
Primary completion
2027
Study completion
2027
First posted
Jun 10, 2024
Registry last updated
Aug 12, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

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This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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