Clonal competition with alternating dominance in multiple myeloma

Area of Science:

• Oncology
• Genomics
• Cancer Evolution

Background:

• Tumor evolution is increasingly recognized as a complex process.
• Understanding the genomic changes in multiple myeloma over time is crucial for treatment strategies.

Purpose of the Study:

• To investigate the genomic evolutionary paths of multiple myeloma tumors.
• To identify different temporal tumor types based on genomic stability and evolution.
• To model clonal competition and dynamics in multiple myeloma.

Main Methods:

• Serial genomic analysis of 28 multiple myeloma patient samples across disease course.
• Classification of tumors into temporal types: genetically stable, linearly evolving, or heterogeneous clonal mixtures.
• Detailed longitudinal analysis of one high-risk patient with 7 time points.
• Utilized Vk*MYC genetically engineered mouse model for preclinical studies.

Main Results:

• Standard-risk multiple myeloma patients exhibited minimal genomic changes over time.
• Cytogenetically high-risk multiple myeloma patients displayed significantly more genomic alterations.
• Identified three distinct temporal tumor evolutionary patterns.
• Observed competing subclones with alternating dominance and eventual linear evolution in one high-risk case.

Conclusions:

• Multiple myeloma tumors exhibit diverse evolutionary trajectories influenced by patient risk stratification.
• Genomic instability is a hallmark of high-risk multiple myeloma, leading to complex clonal dynamics.
• Preclinical models can effectively recapitulate in vivo clonal competition and therapeutic selection processes.