Genome-Wide MicroRNA Expression Analysis of Clear Cell Renal Cell Carcinoma by Next Generation Deep Sequencing

428 Background: About one-third of patients with clear cell renal cell carcinoma (ccRCC) exhibit metastasis at the time of diagnosis and show poor prognosis. The genetic and epigenetic alterations associated with metastasis in ccRCC have variably been studied, and their role in the metastatic process is unclear. The goals of the current study were to identify genomic copy number alterations (CNAs) associated with ccRCC metastasis and examine their clinical utility. Methods: In this IRB-approved study, genome-wide copy number profiling was performed on DNA from 144 ccRCC (81 primary and 63 metastatic lesions). Differential CNAs between primary and metastatic lesions and between different metastatic sites were identified using Fisher’s exact test. Associations between CNAs and overall survival (OS) were tested using the log rank statistic and Kaplan-Meier method. Genomic profiling data of 437 and 240 primary ccRCC (TCGA and PMID: 23797736, respecitively) were used for verification. Results: Between primary and metastatic lesions, 25 CNAs were significantly different (p<0.05). Of the 11 more frequent in metastatic lesions, nine retained significance when comparing stage IV and stage I TCGA ccRCC. For 368 TCGA locally-invasive tumors (stages I, II, and III), three CNAs (loss of 9p24.3-p13.3, 9p12-q11, and 9q21.12-q21.33) were associated with inferior survival (p=0.002). In the second dataset of 214 locally-invasive lesions, loss of 18q11.2-q23 correlated with shorter OS (p=0.025). Across metastatic lesions, nine CNAs were found to be significantly enriched in lung lesions and three in bone. In a subset of 127 ccRCC with known metastatic status at 5 years after diagnosis, two of these CNAs (gain of 7q36.1-36.3 in lung and loss of 22q13.2 in bone) were significantly enriched in the corresponding primary specimens. Conclusions: This study identified CNAs associated with ccRCC metastasis and common sites of metastasis that have the potential to serve as biomarkers to assist in better risk stratification of patients with this disease. Integrated analyses of genes mapping to the loci of genomic imbalance would further our understanding of the biology of metastasis in renal cancer.

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Prognostic and predictive biomarkers for clear cell renal cell carcinoma utilizing next generation sequencing.

Journal of Clinical Oncology ◽

10.1200/jco.2019.37.15_suppl.e16070 ◽

2019 ◽

Vol 37 (15_suppl) ◽

pp. e16070-e16070

Author(s):

Jamal Zekri ◽

Abdelrazak Meliti ◽

Mohammed Abhas Baghdadi ◽

Turki Sobahy ◽

Saba Imtiaz

Keyword(s):

Renal Cell Carcinoma ◽

Next Generation Sequencing ◽

Cell Carcinoma ◽

Renal Cell ◽

Clear Cell ◽

Predictive Biomarkers ◽

High Potential ◽

Next Generation ◽

Cell Renal Cell Carcinoma ◽

Generation Sequencing

e16070 Background: The management of the clear cell renal cell carcinoma (cc-RCC) has evolved over the past decade. Clinical patients’ and tumor characteristics have a limited role in predicting the outcome of these patients. The search for reliable prognostic and predictive biomarkers should be pursued in particular during the current era of next generation sequencing (NGS) technology. Methods: Formalin-Fixed Paraffin-Embedded (FFPE) tissue specimens of cc-RCC were sequenced using NGS and a customized gene panel testing for 72 tumor-related genes. High potential variants were defined by mutation effect (stop-loss, stop-gain, frame-shift substitutions or non-synonymous SNV) and class (pathogenic or likely pathogenic). Cases with identical variants were identified. Results: In total, all 47 cases had 69,052 variants, of which 20,453 were classified as high potential variants. Identical alterations in 15 genes were present in all samples. These genes are: MUC3A, MUC12, MUC7, SRRT, MUC2, MUC5AC, MUC5B, MUC22, MUC6, CR1, MUC4, MUC16, MUC19, MUC17 and MERTK. The numbers of identical and non-identical variants in these 15 genes were counted for each sample. Median number of variants was 377 and was selected as a cut off to define cases with high ( > 377) and low (≤377) variants number (HVN and LVN respectively). For the whole cohort, HVN was associated with shorter overall survival compared to LVN (Median 50 months vs. not reached; Log Rank P = 0.041). In the 11 patients who received anti-angiogenic tyrosine kinase inhibitors (TKIs), HVN was associated with a trend of shorter progression free survival (Median 5 vs. 10 months; Log Rank P = not significant). Conclusions: Alterations in SRRT, CR1, MERTK and MUCIN family genes are very common in RCC. HVN ( > 377) is associated with worse prognosis and may predict decreased benefit from anti-angiogenic TKIs.

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