ABSTRACT Purpose Pemetrexed, a standard antifolate chemotherapy for non‐squamous non‐small cell lung cancer (NSCLC), is often limited by acquired resistance. We investigated whether SRC kinase mediates pemetrexed resistance and whether SRC inhibition can suppress survival signaling in pemetrexed‐resistant NSCLC cells. Methods Pemetrexed‐resistant cell lines (PC9 R, NCI‐H460 R, and NCI‐H3122 R) were generated through chronic pemetrexed exposure. Protein phosphorylation profiling and Western blotting identified key signaling alterations. SRC was abrogated using transient and doxycycline‐inducible CRISPR/Cas9 systems, and reciprocal siRNA knockdown of SRC and thymidylate synthase (TS) was performed. Three SRC inhibitors—dasatinib, bosutinib, and saracatinib—were assessed using cell viability, colony formation, apoptosis, and cell cycle assays. Results All pemetrexed‐resistant cell lines demonstrated elevated phosphorylated SRC (p‐SRC Y416) and enhanced downstream signaling. SRC knockout reduced p‐SRC Y416, p‐STAT3, and p‐FAK, while increasing markers of DNA damage (γ‐H2AX) and apoptosis (cleaved caspase‐3), impairing cell viability and clonogenicity. SRC knockdown reduced TS expression in two resistant models, whereas TS knockdown did not suppress p‐SRC Y416. Among SRC inhibitors, dasatinib showed the most potent, dose‐dependent suppression of SRC signaling. Dasatinib also induced G0/G1 arrest, DNA damage, and apoptosis, thereby reducing colony formation. Conclusion SRC activation is a critical mechanism of acquired pemetrexed resistance in NSCLC and may contribute to resistance through TS‐associated survival signaling. SRC inhibition, particularly with dasatinib, disrupts pro‐survival pathways and promotes DNA damage‐mediated cell death in pemetrexed‐resistant cells. These findings support further investigation of SRC inhibitors, alone or with pemetrexed, as a biomarker‐guided therapeutic strategy for SRC‐activated pemetrexed‐resistant NSCLC.
ABSTRACT Lung cancer remains the leading cause of cancer‐related mortality globally. Although low‐dose computed tomography (LDCT) is the current standard for early screening, its high false‐positive rates and cumulative radiation exposure create a pressing clinical need for complementary, non‐invasive diagnostic tools. Exhaled breath analysis represents an accessible strategy for early detection and risk stratification. Early breathomics primarily focused on gas‐phase volatile organic compounds (VOCs). However, as volatile metabolites, VOCs are chemically unstable and highly susceptible to background ambient air and physiological confounders. Distinct from gas‐phase analysis, exhaled breath condensate (EBC) offers enhanced biomarker stability and functions as a lung‐proximal liquid biopsy. By capturing non‐volatile, high‐molecular‐weight analytes, including tumor‐derived nucleic acids and proteins, EBC more closely reflects the underlying molecular mechanisms of the respiratory microenvironment. Nevertheless, the clinical translation of EBC remains constrained by severe sample dilution, unstandardized collection device architectures, and pre‐analytical inconsistencies. This review summarizes the progression from VOCs profiling to EBC‐based platforms, detailing recent advances in sample harvesting, ultrasensitive detection technologies, and multi‐omics integration. Advancing EBC toward routine clinical use requires consensus‐driven standard operating procedures and the application of machine learning algorithms to high‐dimensional datasets. Future efforts should prioritize large‐scale, multicenter prospective trials to validate specific EBC signatures, thereby establishing this technology as a reliable liquid biopsy for precision pulmonary oncology.
ABSTRACT A false‐positive KRAS G12C on a multi‐PCR assay using the amplification refractory mutation system can potentially occur in cases harboring certain multi‐nucleotide variants other than KRAS G12C. A 62‐year‐old man with a large left upper lobe tumor was diagnosed with lung adenocarcinoma. A multi‐PCR assay by the AmoyDx Pan Lung Cancer PCR panel showed positivity for KRAS G12C and KRAS G12A/G12V/G12R/G13C. However, next‐generation sequencing revealed a KRAS variant of c.34_35delinsTC (p.G12S). KRAS G12S multi‐nucleotide variants may lead to false‐positive KRAS G12C results on the multi‐PCR assay.
ABSTRACT Background Precise localization is critical for sublobar resection of small pulmonary nodules. We evaluated the safety, technical efficiency, and clinical outcomes of preoperative percutaneous dye‐localization using a cone‐beam computed tomography (CBCT)‐enabled flat‐panel detector interventional fluoroscopy system in a hybrid operating room (HOR). Methods We retrospectively reviewed 74 consecutive patients (137 lesions) who underwent image‐guided localization followed by video‐assisted thoracoscopic surgery (VATS) sublobar resection (wedge resection or segmentectomy) between 2022 and 2023 at Chia‐Yi Christian Hospital. Procedural workflow, localization success, surgical margins, and perioperative outcomes were systematically analyzed. Results Technical localization success was achieved in 100% of lesions (mean nodule diameter: 8.59 ± 4.85 mm). The procedure required a mean of 1.31 ± 0.67 puncture attempts per lesion at a mean depth of 5.22 ± 1.86 cm. Procedure‐related pneumothorax occurred in 29.7% (22/74) of patients, with 14.9% (11/74) requiring pigtail catheter drainage; pneumothorax occurrence was significantly associated with multiple puncture attempts ( p < 0.001) and lower‐lobe lesions ( p = 0.001). Lower‐lobe location was significantly associated with requiring more puncture attempts ( p = 0.028). For malignant lesions, the mean pathological resection margin was 17.16 ± 8.73 mm, with 92.31% achieving a margin‐to‐tumor ratio (MTR) ≥ 1. The mean postoperative hospital stay was 3.04 ± 1.16 days. Conclusions Single‐stage image‐guided dye‐localization and VATS sublobar lung resection in an HOR using a biplane CBCT‐enabled platform is safe, feasible, and effective. This streamlined workflow ensures high technical success and adequate surgical margins with manageable complications. Further studies are warranted to evaluate long‐term oncological outcomes.
ABSTRACT Background Large cell neuroendocrine carcinoma (LCNEC) is a rare and aggressive lung neuroendocrine neoplasm with poor prognosis. Recently, DLL3‐targeted bispecific T‐cell engagers (BiTEs) have shown promising efficacy in small cell lung cancer, and clinical trials are ongoing in LCNEC. This study evaluated DLL3 expression and CD8+ tumor‐infiltrating lymphocytes (TILs) infiltration in LCNEC and investigated their clinical significance and association with tarlatamab efficacy. Methods We retrospectively reviewed consecutive patients who were diagnosed with LCNEC. Immunohistochemical analyses for DLL3 and CD8 were performed. DLL3 positivity was defined as staining in ≥ 1% of tumor cells. CD8+ TIL infiltration was graded as low, moderate, or high. Results Among 77 screened LCNEC cases, 44 were eligible for analysis. The median age was 75 years. DLL3 expression was observed in 70.5% of cases and was associated with worse survival. Low CD8+ TIL infiltration was observed in 59.1% of cases. Patients with high CD8+ TIL infiltration demonstrated significantly longer survival than those with low infiltration ( p = 0.03). Among representative clinical cases, a patient with DLL3 (+)/CD8 TILs (−) LCNEC achieved marked tumor shrinkage, whereas a patient with DLL3 (−)/CD8 TILs (−) LCNEC showed no response. Conclusions DLL3 is frequently expressed in LCNEC and correlates with a poorer prognosis. A majority of LCNEC cases are immunologically characterized as cold tumors lacking CD8+ TILs, which contributes to unfavorable clinical outcomes. Tarlatamab induced a robust antitumor response even in a DLL3 (+) cold tumor. DLL3‐BiTE represents a promising therapeutic strategy for DLL3 (+) LCNEC.
