Molecular profile of early-stage and advanced-stage of renal cell cancer in China.

Abstract

e16071 Background: The mutation spectrum has been extensively studied in Renal Cell Cancer (RCC), a heterogeneous disease. While major investigations have focused on metastatic RCC (mRCC). This study intended to explore the molecular characteristics between early-stage (stage I/Ⅱ) and advanced-stage (Ⅲ/Ⅳ) of RCC patients (pts). Methods: 36 tumor specimens were obtained from individual pts diagnosed RCC, including 22 tissues paired with blood samples. Somatic mutations were identified via targeted next generation sequencing with Acornmed panel including 808 genes associated with tumor development. Sequencing data were analyzed to call tumor specific single nucleotide variants (SNV), small insertions and deletions (InDels), copy number alterations (CNA) and chromosomal rearrangements. Clinical data of a cohort from TCGA who had RCC was collected and analyzed. Results: Among the 36 pts enrolled, 61% were early-stage group and 39% were advanced-stage group. The most frequently mutated genes in RCC were VHL (50%), PBRM1 (14%), BAP1 (11%), TP53 (11%) and PIK3CA (6%). Truncating mutations were the most frequent alterations accounting for 66% (33/50) of genetic alterations. Mutations in VHL, BAP1, PBRM1 and TP53 were shared by both early and advanced RCC. While mutations in PIK3CA, CDKN2C, EGFR, FAMCA, GRIN2A, KDM6A, SOX17, TSC1 and APC were only detected in early stage group. KNSTRN, KRAS, MYD88, NF2, ATM, PTEN and STAT5B mutations were only detected in advanced group. Among 22 plasma samples, genomic alterations were detected in 40.9% (9/22) of pts postoperatively, such as TP53, PIK3CA, PTEN, and APC. Functional annotation clustering revealed that 4/9 in these genes were tumor suppressors, which negatively regulated apoptosis. Pts with genomic alterations in TP53 (p = 0.0034), PIK3CA (p = 0.0015) or PTEN (p = 0.00017) had worse OS significantly (TCGA). Conclusions: VHL, PBRM1, BAP1 were the most important driver genes mainly detected in all stages of RCC. The heterogeneity between early and advanced-stage may be related with clinical status. Gene alterations in plasma ctDNA postoperatively should have the potential to stratify patients with different prognostic outcome.