Cancer Advisor

Updated: September 2026  |  Focus: Cancer Resistance, Precision Oncology, Biomarkers, Tumor Evolution and Treatment Sequencing Why do cancer treatments stop working? Sometimes a cancer is resistant before treatment begins. In other cases, treatment initially works but the disease later progresses. This treatment resistance can arise through genetic evolution, tumor heterogeneity, pathway rewiring, changes in cell state, altered drug transport, DNA-repair mechanisms, immune escape and interactions within the tumor microenvironment. The Cancer Treatment Resistance Atlas organizes these complex relationships into a practical framework: Cancer Type → Biomarker → Treatment → Response → Resistance → Mechanism → Resistance Biomarker → Testing → Next-Treatment Strategy Modern cancer research increasingly recognizes resistance as a dynamic, evolutionary process rather than a single defect. A 2025 Nature Reviews Cancer roadmap from the National C...

Cancer Advisor  |  Updated September 19, 2026 The tumor microenvironment (TME) is the biological ecosystem surrounding a tumor. It includes immune cells, cancer-associated fibroblasts (CAFs), blood and lymphatic vessels, extracellular matrix, signaling molecules, nutrients, metabolites, oxygen gradients and physical conditions such as tissue stiffness, acidity and abnormal interstitial pressure. Modern oncology increasingly recognizes that cancer is not simply a collection of malignant cells. Tumor cells continuously interact with their surrounding tissue, while the surrounding tissue can influence tumor growth, invasion, metastasis, immune surveillance, drug delivery and treatment response. The National Cancer Institute defines the TME broadly as the normal cells, molecules and blood vessels surrounding and feeding a tumor, and notes that tumors can change their microenvironment while the microenvironment can influ...