Edge effects in game-theoretic dynamics of spatially structured tumours

Area of Science:

• Mathematical Oncology
• Evolutionary Game Theory
• Cancer Biology

Background:

• Cancer dynamics are modeled as evolutionary games between cell phenotypes.
• Current models often ignore local neighborhood structure, assuming interactions depend solely on strategy abundance.

Purpose of the Study:

• To introduce spatial structure into the "go versus grow" game using the Ohtsuki-Nowak transform.
• To investigate how spatial structure influences the promotion of invasive cell strategies.

Main Methods:

• Application of the Ohtsuki-Nowak transform to model spatial structure in evolutionary games.
• Analysis of "go versus grow" dynamics within defined neighborhood structures.
• Examination of edge effects at static boundaries.

Main Results:

• Spatial structure can significantly promote the "go" (invasive) strategy.
• Tumors can exhibit a polyclonal boundary of invasive cells even without invasive cells in the bulk.
• An edge effect at static boundaries (e.g., blood vessels) can foster invasion.

Conclusions:

• Pathologic analyses must distinguish between bulk and edge tumor cells to accurately assess invasion.
• Spatial modeling is crucial for understanding cancer evolution and invasion dynamics.
• The approach is applicable to other evolutionary game models with changing interaction neighborhoods at system boundaries.