Tumors across diverse organs harbor microbial communities that can shape cancer biology and therapeutic responses, yet the field remains polarized by technical and interpretive challenges. In this commentary, we synthesize functional and mechanistic evidence linking intratumoral microbes to cancer hallmarks; critically evaluate current detection approaches; and propose minimal technical and reporting standards to establish microbial presence, viability, and causality. We highlight common pitfalls and outline priorities to move the tumor microbiota field toward robust, clinically actionable insights.