High-density sampling reveals volume growth in human tumours.

Area of Science:

• Oncology
• Evolutionary Biology
• Genomics

Background:

• Mutations in growing cell populations, like tumors, can track past evolution.
• Genomic analyses of tumors have illuminated evolutionary forces but lack empirical data on spatio-temporal dynamics.

Purpose of the Study:

• To investigate the spatio-temporal dynamics of tumor evolution using high-resolution spatial data.
• To determine how mutations and cells disperse within a tumor and the role of cell death.

Main Methods:

• Leveraged published 2D and 3D spatial genomic data from resected hepatocellular carcinomas.
• Applied spatial metrics to analyze mutation and cell dispersion patterns.
• Quantified the contribution of cell death to overall tumor growth.

Main Results:

• Tumor cells exhibit predominantly uniform growth within the tumor volume, rather than exclusively at the surface.
• Characterized the dispersal patterns of mutations and cells throughout the tumor.
• Assessed the impact of cell death on tumor growth dynamics.

Conclusions:

• The study provides empirical insights into the in vivo spatio-temporal evolution of tumors.
• Developed methods applicable to high-resolution spatial biology data for understanding early tumor evolution.
• Highlights uniform volumetric growth as a key characteristic of hepatocellular carcinoma evolution.