Two Worlds, One Battle: How Bacteria and Malignancies Converge on Drug Resistance.

Drug resistance represents one of the most critical challenges in modern medicine, undermining the efficacy of therapies across both bacterial infections and cancer. Although these conditions arise in fundamentally distinct biological systems, they are governed by shared evolutionary pressures that drive the emergence and selection of resistant populations. This narrative review provides an integrative, cross-disciplinary perspective on drug resistance, focusing on bacteria and cancer and emphasizing the shared evolutionary and molecular mechanisms underlying treatment failure in both domains. Key resistance strategies include efflux-mediated drug export, target modification, enzymatic drug inactivation, metabolic reprogramming, epigenetic and transcriptional plasticity, and protection conferred by specialized microenvironments. These processes are further reinforced by phenotypic heterogeneity, including bacterial persister cells and cancer stem-like cells, which contribute to recurrence and multidrug resistance. Collectively, these parallels define drug resistance as a convergent evolutionary phenomenon driven by adaptability under selective pressure. Recognizing these shared mechanisms reveals important translational opportunities for therapeutic intervention. Strategies such as combination therapy, drug repurposing, nanotechnology-enabled delivery systems, and host-directed approaches offer promising avenues to prevent, delay, or overcome resistance. By integrating insights from microbiology and oncology, this review proposes a unified framework for resistance biology and highlights the potential of cross-disciplinary strategies to improve treatment durability and clinical outcomes.