A tri-component organoid model reveals field-cancerized fibroblasts as key drivers of LUAD recurrence and drug resistance.

Lung adenocarcinoma (LUAD) is a leading cause of cancer-related mortality, driven by extensive tumor heterogeneity and therapy resistance. Conventional models fail to capture the dynamic interactions between cancer cells and the tumor microenvironment (TME), limiting therapeutic advancements. Here, we present a tricomponent organoid platform integrating patient-derived lung cancer tumoroids (LCTs), normal lung organoids (LOs), and field-cancerized fibroblasts to dissect LUAD heterogeneity and treatment resistance mechanisms. This platform uniquely enables the simultaneous investigation of tumor-specific vulnerabilities, stromal contributions to drug resistance, and normal tissue toxicity. Spatial and bulk transcriptomic analyses reveal LUAD-specific gene signatures and highlight cancer-associated fibroblasts (CAFs) as key drivers of a pro-tumorigenic TME, reinforcing tumor survival and recurrence. Functional drug screening demonstrates that LCTs exhibit selective sensitivity to pemetrexed while fibroblasts remain universally resistant, underscoring stromal barriers to therapy. The inclusion of LOs allows direct assessment of drug toxicity on healthy lung tissue, bridging a critical gap in preclinical modeling. By capturing the tumor-stroma interplay with patient specificity, this organoid platform advances precision oncology, paving the way for more effective therapeutic strategies targeting both LUAD cells and the supportive microenvironment.