Distinct genomic features between osteosarcomas firstly metastasing to bone and to lung

Area of Science:

• Genomics
• Oncology
• Cancer Biology

Background:

• Osteosarcoma metastasis patterns (bone vs. lung) suggest different underlying genomic mechanisms.
• Distinct biological features are observed in osteosarcoma with initial bone-only metastasis versus initial lung metastasis.

Purpose of the Study:

• To analyze whole-exome sequencing (WES) data from osteosarcoma patients with varying relapse patterns.
• To redefine osteosarcoma subclassifications based on genetic alterations.
• To correlate genetic profiles with clinical courses and understand evolving cladograms.

Main Methods:

• Whole-exome sequencing (WES) analysis of 38 osteosarcoma cases, including paired primary and metastatic samples.
• Categorization of patients into initial bone metastasis (Group A) and initial pulmonary metastasis (Group B).
• Comparison of genomic profiles, including single-nucleotide variations and structural variants, between groups.

Main Results:

• Osteosarcoma with initial bone metastasis (Group A) predominantly features single-nucleotide variations, higher tumor mutation burden, neoantigen load, and tertiary lymphoid structures.
• Osteosarcoma with initial pulmonary metastasis (Group B) primarily exhibits structural variants.
• Genetic sequencing showed high conservation over time in evolving cladograms.

Conclusions:

• Osteosarcoma with single-nucleotide variations may predispose to bone metastasis and enhanced immunogenicity.
• Genetic profiles, specifically the type of variations, are linked to distinct metastatic patterns and potential immunogenic responses in osteosarcoma.