Increased chromosomal instability characterizes metastatic renal cell carcinoma

Area of Science:

• Oncology
• Genomics
• Cancer Evolution

Background:

• The evolutionary paths of untreated metastatic cancers, particularly clear cell renal cell carcinoma (ccRCC), remain largely uncharacterized.
• Understanding these trajectories is vital for developing effective cancer prevention and therapeutic strategies.

Purpose of the Study:

• To investigate the clonal origin and evolutionary patterns of treatment-naïve metastatic ccRCC.
• To identify key genomic alterations driving metastatic progression in ccRCC.

Main Methods:

• Whole genome or exome sequencing of 19 ccRCC tumor specimens and 8 matched normal kidney tissues.
• Analysis of clonal origin, parallel evolution, somatic copy number alterations (SCNA), and loss of heterozygosity (LOH).
• Functional validation of genes within selected SCNA regions.

Main Results:

• Identified clonal origin and parallel evolution between primary and metastatic ccRCC lesions in all patients.
• Demonstrated early divergence of evolutionary branches between primary and metastatic clones.
• Highlighted specific genomic aberrations, including LOH at 14q, loss of 14q32.31, and gain of 6p22.2, as highly selected events in metastatic ccRCC.
• Revealed that these selected genomic events interact to drive metastatic risk.

Conclusions:

• Metastatic ccRCC exhibits increased genome instability compared to primary tumors.
• Specific genomic alterations and their interactions play a crucial role in ccRCC metastatic evolution.
• These findings provide insights into ccRCC progression patterns with potential therapeutic implications.