The limited efficacy of currently approved immunotherapies in EGFR-driven lung adenocarcinoma (LUAD) underscores the need to better understand alternative mechanisms governing local immunosuppression to fuel novel therapies. Elevated surfactant and GM-CSF secretion from the transformed epithelium induces tumor-associated alveolar macrophage (TA-AM) proliferation, which supports tumor growth by rewiring inflammatory functions and lipid metabolism. TA-AM properties are driven by increased GM-CSF–PPARγ signaling and inhibition of airway GM-CSF or PPARγ in TA-AMs suppresses cholesterol efflux to tumor cells, which impairs EGFR phosphorylation and restrains LUAD progression. In the absence of TA-AM metabolic support, LUAD cells compensate by increasing cholesterol synthesis, and blocking PPARγ in TA-AMs simultaneous with statin therapy further suppresses tumor progression and increases proinflammatory immune responses. These results reveal new therapeutic combinations for immunotherapy-resistant EGFR-mutant LUADs and demonstrate how cancer cells can metabolically co-opt TA-AMs through GM-CSF–PPARγ signaling to provide nutrients that promote oncogenic signaling and growth. Significance: Alternate strategies harnessing anticancer innate immunity are required for lung cancers with poor response rates to T cell–based immunotherapies. This study identifies a targetable, mutually supportive, metabolic relationship between macrophages and transformed epithelium, which is exploited by tumors to obtain metabolic and immunologic support to sustain proliferation and oncogenic signaling. This article is featured in Selected Articles from This Issue, p. 384

Navigation bronchoscopy has reached a new horizon in its evolution. Combining with real-time imaging modalities, such as cone-beam computed tomography (CBCT) and augmented fluoroscopy (AF), navigation success can finally be confirmed with high degree of accuracy in real-time. With utilization of this modality, additional clinical observations are being made to help address the CT-body divergence problem and further improve navigation accuracy. This review focuses on description of CBCT navigation technique, provide tips on addressing CT-Body divergence, and review evidence for CBCT applications in navigation bronchoscopy.