RESUMO
PURPOSE: Brain metastasis (BM) in colorectal cancer (CRC) is a rare event with poor prognosis. Apart from (K)RAS status and lung and bone metastasis no biomarkers exist to identify patients at risk. This study aimed to identify a gene expression signature associated with colorectal BM. METHODS: Three patient groups were formed: 1. CRC with brain metastasis (BRA), 2. exclusive liver metastasis (HEP) and, 3. non-metastatic disease (M0). RNA was extracted from primary tumors and mRNA expression was measured using a NanoString Panel (770 genes). Expression was confirmed by qPCR in a validation cohort. Statistical analyses including multivariate logistic regression followed by receiver operating characteristic (ROC) analysis were performed. RESULTS: EMILIN3, MTA1, SV2B, TMPRSS6, ACVR1C, NFAT5 and SMC3 were differentially expressed in BRA and HEP/M0 groups. In the validation cohort, differential NFAT5, ACVR1C and SMC3 expressions were confirmed. BRA patients showed highest NFAT5 levels compared to HEP/M0 groups (global p = 0.02). High ACVR1C expression was observed more frequently in the BRA group (42.9%) than in HEP (0%) and M0 (7.1%) groups (global p = 0.01). High SMC3 expressions were only detectable in the BRA group (global p = 0.003). Only patients with BM showed a combined high expression of NFAT5, ACVR1C or SMC3 as well as of all three genes. ROC analysis revealed a good prediction of brain metastasis by the three genes (area under the curve (AUC) = 0.78). CONCLUSIONS: The NFAT5, ACVR1C and SMC3 gene expression signature is associated with colorectal BM. Future studies should further investigate the importance of this biomarker signature.
Assuntos
Biomarcadores Tumorais , Neoplasias Encefálicas , Neoplasias Colorretais , Humanos , Neoplasias Encefálicas/secundário , Neoplasias Encefálicas/genética , Neoplasias Colorretais/patologia , Neoplasias Colorretais/genética , Masculino , Feminino , Pessoa de Meia-Idade , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Idoso , Transcriptoma , Neoplasias Hepáticas/secundário , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Prognóstico , Perfilação da Expressão Gênica , Curva ROC , Adulto , Regulação Neoplásica da Expressão GênicaRESUMO
The aim of the study was to investigate the predictive impact of extracranial metastatic patterns on course of disease and survival in patients with colorectal cancer (CRC) and brain metastasis (BM). A total of 228 patients (134 male [59%], 94 female [41%]) with histologically proven CRC and BM were classified into different groups according to extracranial metastatic patterns. Time intervals to metastatic events and survival times from initial CRC diagnosis, extracranial and intracranial metastasis were analyzed. Extracranial organs mostly affected were liver (102 of 228 [44.7%]) and lung (96 of 228 [42.1%]). Liver and lung metastases were detected in 31 patients (13.6%). Calculated over the entire course of disease, patients with lung metastasis showed longer overall survival (OS) than patients with liver metastasis or patients without lung metastasis (43.9 vs 34.6 [P = .002] vs 35.0 months [P = .002]). From the date of initial CRC diagnosis, lung metastasis occurred later in CRC history than liver metastasis (24.3 vs 7.5 months). Once lung metastasis was diagnosed, BM occurred faster than in patients with liver metastasis (15.8 vs 26.0 months; Δ 10.2 months). Accordingly, OS from the diagnosis of liver metastasis was longer than from lung metastasis (27.1 vs 19.6 months [P = .08]). Once BM was present, patients with lung metastasis lived longer than patients with liver metastasis (3.8 vs 1.1 months [P = .028]). Shortest survival times in all survival categories analyzed revealed patients with concurrent liver and lung metastasis. Patients with CRC and BM form a heterogeneous cohort where extracranial metastasis to liver or lungs predicts survival.