Nationwide data from comprehensive genomic profiling assays for detecting driver oncogenes in non-small cell lung cancer.

Driver oncogenes are investigated upfront at diagnosis using multi-CDx systems with next-generation sequencing techniques or multiplex reverse-transcriptase polymerase chain reaction assays. Additionally, from 2019, comprehensive genomic profiling (CGP) assays have been available in Japan for patients with advanced solid tumors who had completed or were expected to complete standard chemotherapy. These assays are expected to comprehensively detect the driver oncogenes, especially for patients with non-small cell lung cancer (NSCLC). However, there are no reports of nationwide research on the detection of driver oncogenes in patients with advanced NSCLC who undergo CGP assays, especially in those with undetected driver oncogenes at diagnosis. In this study, we investigated the proportion of driver oncogenes detected in patients with advanced NSCLC with undetectable driver oncogenes at initial diagnosis and in all patients with advanced NSCLC who underwent CGP assays. We retrospectively analyzed data from 986 patients with advanced NSCLC who underwent CGP assays between August 2019 and March 2022, using the Center for Cancer Genomics and Advanced Therapeutics database. The proportion of driver oncogenes newly detected in patients with NSCLC who tested negative for driver oncogenes at diagnosis and in all patients with NSCLC were investigated. Driver oncogenes were detected in 451 patients (45.7%). EGFR was the most common (16.5%), followed by KRAS (14.5%). Among the 330 patients with undetected EGFR, ALK, ROS1, and BRAF V600E mutations at diagnosis, 81 patients (24.5%) had newly identified driver oncogenes. CGP assays could be useful to identify driver oncogenes in patients with advanced NSCLC, including those initially undetected, facilitating personalized treatment.

AXL signal mediates adaptive resistance to KRAS G12C inhibitors in KRAS G12C-mutant tumor cells.

Recently, novel Kirsten rat sarcoma viral oncogene homolog (KRAS) inhibitors have been clinically developed to treat KRAS G12C-mutated non-small cell lung cancer (NSCLC) patients. However, achieving complete tumor remission is challenging. Therefore, the optimal combined therapeutic intervention with KRAS G12C inhibitors has a potentially crucial role in the clinical outcomes of patients. We investigated the underlying molecular mechanisms of adaptive resistance to KRAS G12C inhibitors in KRAS G12C-mutated NSCLC cells to devise a strategy preventing drug-tolerant cell emergence. We demonstrate that AXL signaling led to the adaptive resistance to KRAS G12C inhibitors in KRAS G12C-mutated NSCLC, activation of which is induced by GAS6 production via YAP. AXL inhibition reduced the viability of AXL-overexpressing KRAS G12C-mutated lung cancer cells by enhancing KRAS G12C inhibition-induced apoptosis. In xenograft models of AXL-overexpressing KRAS G12C-mutated lung cancer treated with KRAS G12C inhibitors, initial combination therapy with AXL inhibitor markedly delayed tumor regrowth compared with KRAS G12C inhibitor alone or with the combination after acquired resistance to KRAS G12C inhibitor. These results indicated pivotal roles for the YAP-GAS6-AXL axis and its inhibition in the intrinsic resistance to KRAS G12C inhibitor.

Visceral Adipose Tissue Percentage Compared to Body Mass Index as Better Indicator of Surgical Outcomes in Women with Obesity and Endometrial Cancer.

STUDY OBJECTIVE: To assess the impact visceral adipose tissue percentage (VAT%) on surgical outcomes during minimally invasive surgery in obese women with endometrial cancer. DESIGN: Retrospective observational cohort study. SETTING: Mie University Hospital, Japan. PATIENTS: Of the 73 women (body mass index [BMI] >30 kg/m2) with obesity and primary endometrial cancer, 52 underwent robotic surgery, while 21 underwent laparoscopic surgery between April 2014 and December 2022. INTERVENTIONS: We investigated the correlation between surgical outcomes (operative time and blood loss) and obesity (BMI and visceral adipose tissue percentage [VAT%]). MEASUREMENTS AND MAIN RESULTS: Abdominal fat-related parameters were measured at the level of the umbilicus using preoperative computed tomography. A weak negative correlation was found between BMI and VAT% (CC = -0.313, p = .001). Multivariate analysis showed that VAT% had a stronger correlation to total and practical operative time than BMI (ß = 0.338 vs 0.267, ß = 0.311 vs 0.209, respectively) and was an independent predictor of blood loss. VAT% was an independent predictive marker prolonged for operative time and increased blood loss during lymphadenectomy. CONCLUSION: VAT% could be an indicator of surgical outcomes for patients with obesity and endometrial cancer.

Effects of Combined Therapeutic Targeting of AXL and ATR on Pleural Mesothelioma Cells.

Few treatment options exist for pleural mesothelioma (PM), which is a progressive malignant tumor. However, the efficacy of molecular-targeted monotherapy is limited, and further therapeutic strategies are warranted to treat PM. Recently, the cancer cell-cycle checkpoint inhibitors have attracted attention because they disrupt cell-cycle regulation. Here, we aimed to establish a novel combinational therapeutic strategy to inhibit the cell-cycle checkpoint kinase, ATR in PM cells. The siRNA screening assay showed that anexelekto (AXL) knockdown enhanced cell growth inhibition when exposed to ATR inhibitors, demonstrating the synergistic effects of the ATR and AXL combination in some PM cells. The AXL and ATR inhibitor combination increased cell apoptosis via the Bim protein and suppressed cell migration when compared with each monotherapy. The combined therapeutic targeting of AXL and ATR significantly delayed regrowth compared with monotherapy. Thus, optimal AXL and ATR inhibition may potentially improve the PM outcome.

Two-dimensional phase-contrast MRI reveals changes in uterine arterial blood flow in pregnant women administered tadalafil for fetal growth restriction.

INTRODUCTION: We aimed to examine the effect of uterine arterial (UtA) blood flow changes after tadalafil treatment for fetal growth restriction (FGR) using two-dimensional (2D) phase-contrast magnetic resonance imaging (PC-MRI). METHODS: We recruited 14 pregnant women with FGR aged 20-44 years, at ≥20 weeks' gestation, between May 2019 and July 2020. They underwent 2D PC-MRI for UtA blood flow measurement 3 days (interquartile range: 2-4) after diagnosis. This group (FGR group) was compared with 14 gestational age (GA)-matched healthy pregnant women (control group). Six patients in the FGR group received treatment with tadalafil administered at 20 mg twice daily after the first MRI until delivery. They underwent a second MRI a week later. RESULTS: The median total UtA blood/body surface area was 420 mL/min/m2 (290-494) in the FGR group and 547 mL/min/m2 (433-681) in the control group (p = 0.01). Percent increase in blood flow were significantly different between the FGR cases treated with tadalafil and control at 15.8 % (14.3-21.3) and 4.2 % (3.6-8.7), respectively (p = 0.03). DISCUSSION: UtA blood flow in pregnant women with FGR was significantly lower than that in healthy pregnant women. Tadalafil is expected to improve UtA blood flow, thereby improving placental function in pregnant patients with FGR.

RNA interference reveals the escape response mechanism of Paramecium to mechanical stimulation.

In Paramecium, a mechanical stimulus applied to the posterior portion of the cell causes a transient increase in membrane permeability to potassium ions, transiently rendering the membrane in a hyperpolarized state. Hyperpolarization causes a transient increase in Cyclic adenosine monophosphate (cAMP) concentration in the cilia, resulting in a transient fast-forward swimming of the cell. Schultz and coworkers (1992) reported that a unique adenylate cyclase (AC)-coupled potassium channel is involved in the reaction underlying this response, which is known as the "escape response." However, the AC responsible for this reaction remains to be identified. Moreover, the molecular linkage between mechanoreception and AC activation has not been elucidated adequately. Currently, we can perform an efficient and simple gene-knockdown technique in Paramecium using RNA interference (RNAi). Paramecium is one of the several model organisms for which whole-genome sequences have been elucidated. The RNAi technique can be applied to whole genome sequences derived from the Paramecium database (ParameciumDB) to investigate the types of proteins that elicit specific biological responses and compare them with those of other model organisms. In this review, we describe the applications of the RNAi technique in elucidating the molecular mechanism underlying the escape response and identifying the AC involved in this reaction. The findings of this study highlight the advantages of the RNAi technique and ParameciumDB.

COVID-19 during pregnancy could potentially affect placental function.

OBJECTIVE: COVID-19 is an ongoing pandemic and has been extensively studied. However, the effects of COVID-19 during pregnancy, particularly on placental function, have not been verified. In this study, we used blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) to evaluate whether COVID-19 incidence during pregnancy has any lasting effects with respect to placental oxygenation. METHODS: This is a case-control study, in which eight cases of singleton pregnancies before 30 weeks gestation with COVID-19 mothers were included. Placental oxygenation was evaluated using BOLD-MRI after 32 weeks of gestation. BOLD-MRI was consecutively performed under normoxia (21% O2), hyperoxia (100% O2), and normoxia for 4 min each. Individual placental time-activity curves were evaluated to calculate the peak score (peakΔR2*) and the time from the start of maternal oxygen administration to the time of peakΔR2* (time to peakΔR2*). Eighteen COVID-19-free normal pregnancies from a previous study were used as the control group. RESULTS: No significant differences were found between the two groups regarding maternal background, number of days of delivery, birth weight, and placental weight. The parameter peakΔR2* was significantly decreased in the COVID-19 group (8 ± 3 vs. 5 ± 1, p < .001); however, there was no significant difference in time to peakΔR2* (458 ± 74 s vs. 471 ± 33 s, p = .644). CONCLUSIONS: In this study, BOLD-MRI was used to evaluate placental oxygenation during pregnancy in COVID-19-affected patients. COVID-19 during pregnancy decreased placental oxygenation even post-illness, but had no effect on fetal growth; further investigation of the possible effects of COVID-19 on the fetus and mother is warranted.

Microvascular Dysfunction in Patients with Idiopathic Dilated Cardiomyopathy: Quantitative Assessment with Phase Contrast Cine MR Imaging of the Coronary Sinus.

PURPOSE: The purposes of this study were to compare global coronary flow reserve (CFR) between patients with idiopathic dilated cardiomyopathy (DCM) and risk-matched controls using cardiac MRI (CMR), and to evaluate the relationship between global CFR and CMR left ventricular (LV) parameters. METHODS: Twenty-six patients with DCM and 26 risk-matched controls who underwent comprehensive CMR examination, including stress-rest coronary sinus flow measurement by phase contrast (PC) cine CMR were retrospectively studied. LV peak global longitudinal, radial, and circumferential strains (GLS, GRS, and GCS) were determined by feature tracking. RESULTS: Patients with DCM had significantly lower global CFR compared with the risk-matched controls (2.87 ± 0.86 vs. 4.03 ± 1.47, P = 0.001). Among the parameters, univariate linear regression analyses revealed significant correlation of global CFR with LV end-diastolic volume index (r = -0.396, P = 0.045), LV mass index (r = -0.461, P = 0.018), GLS (r = -0.558, P = 0.003), and GRS (r = 0.392, P = 0.047). Multiple linear regression analysis revealed GLS as the only independent predictor of global CFR (standardized ß = -0.558, P = 0.003). CONCLUSION: Global CFR was significantly impaired in patients with idiopathic DCM and independently associated with LV GLS, suggesting that microvascular dysfunction may contribute to deterioration of LV function in patients with idiopathic DCM.

Mixed epithelial and stromal tumor of the kidney with long-term imaging follow-up.

Mixed epithelial and stromal tumor (MEST) of the kidney is a rare benign tumor with malignant potential, and is characterized by epithelial and stromal proliferation with a variety of cellularity and growth pattern. MEST of the kidney is often depicted as a well-defined, solid mass with a cystic component. However, due to the rarity of the disease, there are no reports of its progression in serial imaging examinations. This report presents the case of a 68-year-old woman with MEST who was followed for 13 years by computed tomography (CT). To the best of our knowledge, this is the first report of image findings of MEST of the kidney over a follow-up period longer than 10 years.

Concomitant Proton Pump Inhibitor Use With Pembrolizumab Monotherapy vs Immune Checkpoint Inhibitor Plus Chemotherapy in Patients With Non-Small Cell Lung Cancer.

Importance: Immune checkpoint inhibitor (ICI) monotherapy with pembrolizumab and ICI plus chemotherapy have been approved as first-line treatments for non-small cell lung cancer (NSCLC) for patients with a programmed cell death ligand-1 (PD-L1) tumor proportion score (TPS) of 50% or more, but the choice between these 2 therapeutic options is unclear. Objective: To clarify the association of a history of concurrent medication use with treatment outcomes for ICIs with or without chemotherapy in patients with NSCLC with a high PD-L1 TPS and to determine whether these clinical histories are biomarkers for appropriate treatment selection. Design, Setting, and Participants: This retrospective, multicenter cohort study at 13 hospitals in Japan included patients with advanced NSCLC with a PD-L1 TPS of 50% or more who had received pembrolizumab ICI monotherapy or ICI plus chemotherapy as the initial treatment between March 2017 and December 2020. The median (IQR) follow-up duration was 18.5 (9.2-31.2) months. Data were analyzed from April 2022 through May 2023. Exposure: ICI monotherapy with pembrolizumab or ICI plus chemotherapy as first-line treatment. Main Outcomes and Measures: The primary analysis was the association of treatment outcomes with baseline patient characteristics, including concomitant drug history, after propensity score matching. Cox proportional hazard models were used to determine the associations of patient characteristics with survival outcomes. Logistic regression analysis was used to determine the association of concomitant medication history with treatment outcomes and other patient characteristics. Results: A total of 425 patients with NSCLC were enrolled in the study including 271 patients (median [range] age, 72 [43-90] years; 215 [79%] men) who were treated with pembrolizumab monotherapy as the first-line treatment and 154 patients (median [range] age, 69 [36-86] years; 121 [79%] men) who were treated with ICI plus chemotherapy as the first-line treatment. In multivariable analysis, a history of proton pump inhibitor (PPI) use was independently associated with shorter progression-free survival (PFS) in the pembrolizumab monotherapy group (hazard ratio [HR], 1.38; 95% CI, 1.00-1.91; P = .048), but not in the ICI plus chemotherapy group. In patients with a PPI history, both the median (IQR) PFS (19.3 [9.0 to not reached] months vs 5.7 [2.4 to 15.2] months; HR, 0.38; 95% CI, 0.20-0.72; P = .002) and the median (IQR) overall survival (not reached [9.0 months to not reached) vs 18.4 [10.5 to 50.0] months; HR, 0.43; 95% CI, 0.20-0.92; P = .03) were significantly longer in the ICI plus chemotherapy group than in the pembrolizumab monotherapy group. In patients without a history of PPI use, both the median (IQR) PFS (18.8 months [6.6 months to not reached] vs 10.6 months [2.7 months to not reached]; HR, 0.81; 95% CI, 0.56-1.17; P = .26) and the median (IQR) overall survival (not reached [12.6 months to not reached] vs 29.9 [13.3 to 54.3] months, HR, 0.75; 95% CI, 0.48-1.18; P = .21) did not differ between groups. Conclusions and Relevance: This cohort study found that a history of PPI use could be an important clinical factor in treatment decision-making for patients with NSCLC with a PD-L1 TPS of 50% or more.

Prospective Observational Study Evaluating the Prognostic Value of the G8 Screening Tool for Extensive-Stage Small Cell Lung Cancer Patients Who Received Programmed Death-Ligand 1 Inhibitor plus Platinum-Etoposide Chemotherapy.

BACKGROUND: Programmed death-ligand 1 (PD-L1) inhibitor plus platinum-etoposide chemotherapy is used as a first-line treatment for extensive-stage small cell lung cancer (ES-SCLC), regardless of age. OBJECTIVE: We examined the role of the Geriatric 8 (G8) screening tool for evaluating treatment outcomes in patients with ES-SCLC treated with PD-L1 inhibitor plus platinum-etoposide chemotherapy as first-line therapy. PATIENTS AND METHODS: Between September 2019 and October 2021, we prospectively evaluated patients with ES-SCLC treated with immunochemotherapy at ten institutions in Japan. The G8 score was assessed before treatment initiation. RESULTS: We evaluated 44 patients with ES-SCLC. Patients with G8 score > 11 had longer overall survival (OS) than those with G8 score ≤ 11 (not reached versus 8.3 months; log-rank test, p = 0.005). In univariate and multivariate analyses, G8 score > 11 [hazard ratio (HR) 0.34; 95% confidence interval (CI) 0.15-0.75; p = 0.008 and HR 0.34; 95% CI 0.14-0.82; p = 0.02, respectively) and performance status (PS) of 2 (HR 5.42; 95% CI 2.08-14.2; p < 0.001 and HR 6.94; 95% CI 2.25-21.4; p < 0.001, respectively) were independent prognostic factors for OS. Among patients with good PS (0 or 1), the OS in patients with G8 score > 11 was significantly longer than that in patients with G8 score ≤ 11 (not reached versus 12.3 months; log-rank test, p = 0.02). CONCLUSIONS: G8 score evaluation before treatment initiation was useful as a prognostic factor for ES-SCLC patients who received PD-L1 inhibitors and platinum-etoposide chemotherapy, even with good PS.

Early Tumor Shrinkage as a Predictor of Favorable Treatment Outcomes in Patients With Extensive-Stage SCLC Who Received Programmed Cell Death-Ligand 1 Inhibitor Plus Platinum-Etoposide Chemotherapy: A Prospective Observational Study.

Introduction: In recent years, programmed cell death-ligand 1 (PD-L1) inhibitor plus platinum-etoposide chemotherapy was found to have favorable clinical outcomes in patients with extensive-stage SCLC (ES-SCLC). The usefulness of early tumor shrinkage (ETS) has been reported in various types of cancers. Nevertheless, there have been few reports evaluating ETS in ES-SCLC. Therefore, this study aimed to evaluate the role of ETS in the clinical outcomes of patients with ES-SCLC receiving chemoimmunotherapy. Methods: We prospectively identified 46 patients with ES-SCLC who received PD-L1 inhibitor plus platinum-etoposide chemotherapy at 10 institutions in Japan between September 2019 and October 2021. Of them, 35 patients were selected for analyses. Results: The responders (progression-free survival [PFS] ≥ 6.0 mo) had significantly greater tumor shrinkage at the first evaluation than the nonresponders (PFS < 6.0 mo) (65.0% versus 53.7%, p = 0.03). We defined the cutoff value for ETS as a 57% change from the baseline on the basis of the receiver operating characteristic results to determine the optimal tumor shrinkage rate at the first evaluation for identifying responders. The patients with ES-SCLC who achieved ETS had longer PFS and overall survival than those who did not achieve ETS (5.6 versus 4.0 mo, log-rank test p = 0.001 and 15.0 versus 8.3 mo, log-rank test p = 0.02). In the multivariate analyses, ETS was significantly associated with PFS and overall survival (hazard ratio = 0.27, 95% confidence interval: 0.12-0.63, p = 0.002 and hazard ratio = 0.34, 95% confidence interval: 0.13-0.85, p = 0.02). Conclusions: Our prospective observational study indicated that ETS was related to favorable clinical outcomes for patients with ES-SCLC receiving PD-L1 inhibitor plus platinum-etoposide chemotherapy.

Application of Deep Learning-Based Denoising Technique for Radiation Dose Reduction in Dynamic Abdominal CT: Comparison with Standard-Dose CT Using Hybrid Iterative Reconstruction Method.

The purpose is to evaluate whether deep learning-based denoising (DLD) algorithm provides sufficient image quality for abdominal computed tomography (CT) with a 30% reduction in radiation dose, compared to standard-dose CT reconstructed with conventional hybrid iterative reconstruction (IR). The subjects consisted of 50 patients who underwent abdominal CT with standard dose and reconstructed with hybrid IR (ASiR-V50%) and another 50 patients who underwent abdominal CT with approximately 30% less dose and reconstructed with ASiR-V50% and DLD at low-, medium- and high-strength (DLD-L, DLD-M and DLD-H, respectively). The standard deviation of attenuation in liver parenchyma was measured as image noise. Contrast-to-noise ratio (CNR) for portal vein on portal venous phase was calculated. Lesion conspicuity in 23 abdominal solid mass on the reduced-dose CT was rated on a 5-point scale: 0 (best) to -4 (markedly inferior). Compared with hybrid IR of standard-dose CT, DLD-H of reduced-dose CT provided significantly lower image noise (portal phase: 9.0 (interquartile range, 8.7-9.4) HU vs 12.0 (11.4-12.7) HU, P < 0.0001) and significantly higher CNR (median, 5.8 (4.4-7.4) vs 4.3 (3.3-5.3), P = 0.0019). As for DLD-M of reduced-dose CT, no significant difference was found in image noise and CNR compared to hybrid IR of standard-dose CT (P > 0.99). Lesion conspicuity scores for DLD-H and DLD-M were significantly better than hybrid IR (P < 0.05). Dynamic contrast-enhanced abdominal CT acquired with approximately 30% lower radiation dose and generated with the DLD algorithm exhibit lower image noise and higher CNR compared to standard-dose CT with hybrid IR.

Complementary prognostic value of stress perfusion imaging and global coronary flow reserve derived from cardiovascular magnetic resonance: a long-term cohort study.

BACKGROUND: Phase-contrast cine cardiovascular magnetic resonance (CMR) quantifies global coronary flow reserve (CFR) by measuring blood flow in the coronary sinus (CS), allowing assessment of the entire coronary circulation. However, the complementary prognostic value of stress perfusion CMR and global CFR in long-term follow-up has yet to be investigated. This study aimed to investigate the complementary prognostic value of stress myocardial perfusion imaging and global CFR derived from CMR in patients with suspected or known coronary artery disease (CAD) during long-term follow-up. METHODS: Participants comprised 933 patients with suspected or known CAD who underwent comprehensive CMR. Major adverse cardiac events (MACE) comprised cardiac death, non-fatal myocardial infarction, unstable angina, hospitalization for heart failure, stroke, ventricular arrhythmia, and late revascularization. RESULTS: During follow-up (median, 5.3 years), there were 223 MACE. Kaplan-Meier curve analysis revealed a significant difference in event-free survival among tertile groups for global CFR (log-rank, p < 0.001) and between patients with and without ischemia (p < 0.001). The combination of stress perfusion CMR and global CFR enhanced risk stratification (p < 0.001 for overall), and prognoses were comparable between the subgroup with ischemia and no impaired CFR and the subgroup with no ischemia and impaired CFR (p = 0.731). Multivariate Cox proportional hazard regression analysis showed that impaired CFR remained a significant predictor for MACE (hazard ratio, 1.6; p = 0.002) when adjusted for coronary risk factors and CMR predictors, including ischemia. The addition of impaired CFR to coronary risk factors and ischemia significantly increased the global chi-square value from 88 to 109 (p < 0.001). Continuous net reclassification improvement and integrated discrimination with the addition of global CFR to coronary risk factors plus ischemia improved to 0.352 (p < 0.001) and 0.017 (p < 0.001), respectively. CONCLUSIONS: During long-term follow-up, stress perfusion CMR and global CFR derived from CS flow measurement provided complementary prognostic value for prediction of cardiovascular events. Microvascular dysfunction or diffuse atherosclerosis as shown by impaired global CFR may play a role as important as that of ischemia due to epicardial coronary stenosis in the risk stratification of CAD patients.

Exploratory analysis of immunochemotherapy compared to chemotherapy after EGFR-TKI in non-small cell lung cancer patients with EGFR mutation: A multicenter retrospective study.

BACKGROUND: Patients with epidermal growth factor receptor (EGFR)-mutated, advanced non-small cell lung cancer have received immunochemotherapy as one of the treatment options after tyrosine kinase inhibitor (TKI) failure. METHODS: We retrospectively examined EGFR-mutant patients treated with atezolizumab-bevacizumab-carboplatin-paclitaxel (ABCP) therapy or platinum-based chemotherapy (Chemo) after EGFR-TKI therapy at five institutions in Japan. RESULTS: A total of 57 patients with EGFR mutation were analyzed. The median progression-free survival (PFS) and overall survival (OS) in the ABCP (n = 20) and Chemo (n = 37) were 5.6 and 20.9 months, 5.4 and 22.1 months, respectively (PFS, p = 0.39; OS, p = 0.61). In programmed death-ligand 1 (PD-L1)-positive patients, median PFS in the ABCP group was longer than in the Chemo group (6.9 vs. 4.7 months, p = 0.89). In PD-L1-negative patients, median PFS in the ABCP group was significantly shorter than in the Chemo group (4.6 vs. 8.7 months, p = 0.04). There was no difference in median PFS between the ABCP and Chemo groups in the subgroups of brain metastases, EGFR mutation status, or chemotherapy regimens, respectively. CONCLUSION: The effect of ABCP therapy and chemotherapy was comparable in EGFR-mutant patients in a real-world setting. The indication for immunochemotherapy should be carefully considered, especially in PD-L1-negative patients.

Adaptive resistance to lorlatinib via EGFR signaling in ALK-rearranged lung cancer.

Anaplastic lymphoma kinase (ALK)-tyrosine kinase inhibitors rarely elicit complete responses in patients with advanced ALK-rearranged non-small cell lung cancer (NSCLC), as a small population of tumor cells survives due to adaptive resistance. Therefore, we focused on the mechanisms underlying adaptive resistance to lorlatinib and therapeutic strategies required to overcome them. We found that epidermal growth factor receptor (EGFR) signaling was involved in the adaptive resistance to lorlatinib in ALK-rearranged NSCLC, activation of which was induced by heparin-binding EGF-like growth factor production via c-Jun activation. EGFR inhibition halted ALK-rearranged lung cancer cell proliferation by enhancing ALK inhibition-induced apoptosis via suppression of Bcl-xL. Xenograft models showed that the combination of EGFR inhibitor and lorlatinib considerably suppressed tumor regrowth following cessation of these treatments. This study provides new insights regarding tumor evolution due to EGFR signaling after lorlatinib treatment and the development of combined therapeutic strategies for ALK-rearranged lung cancer.