Weight calibration in the joint modelling of medical cost and mortality.

Joint modelling of longitudinal and time-to-event data is a method that recognizes the dependency between the two data types, and combines the two outcomes into a single model, which leads to more precise estimates. These models are applicable when individuals are followed over a period of time, generally to monitor the progression of a disease or a medical condition, and also when longitudinal covariates are available. Medical cost datasets are often also available in longitudinal scenarios, but these datasets usually arise from a complex sampling design rather than simple random sampling and such complex sampling design needs to be accounted for in the statistical analysis. Ignoring the sampling mechanism can lead to misleading conclusions. This article proposes a novel approach to the joint modelling of complex data by combining survey calibration with standard joint modelling. This is achieved by incorporating a new set of equations to calibrate the sampling weights for the survival model in a joint model setting. The proposed method is applied to data on anti-dementia medication costs and mortality in people with diagnosed dementia in New Zealand.

Real-World Outcomes of Crizotinib in ROS1-Rearranged Advanced Non-Small-Cell Lung Cancer.

Real-world data on the use and outcomes of crizotinib in ROS1-rearranged non-small-cell lung cancer (NSCLC) are limited. This study aims to analyze the real-world efficacy of crizotinib in South Korea and explore the utilization of liquid biopsies that implement next-generation sequencing (NGS) using cell-free total nucleic acids. In this prospective multicenter cohort study, 40 patients with ROS1-rearranged NSCLC, either starting or already on crizotinib, were enrolled. Patients had a median age of 61 years, with 32.5% presenting brain/central nervous system (CNS) metastases at treatment initiation. At the data cutoff, 48.0% were still in treatment; four continued with it even after disease progression due to the clinical benefits. The objective response rate was 70.0%, with a median duration of response of 27.8 months. The median progression-free survival was 24.1 months, while the median overall survival was not reached. Adverse events occurred in 90.0% of patients, primarily with elevated transaminases, yet these were mostly manageable. The NGS assay detected a CD74-ROS1 fusion in 2 of the 14 patients at treatment initiation and identified emerging mutations, such as ROS1 G2032R, ROS1 D2033N, and KRAS G12D, during disease progression. These findings confirm crizotinib's sustained clinical efficacy and safety in a real-world context, which was characterized by a higher elderly population and higher rates of brain/CNS metastases. The study highlights the clinical relevance of liquid biopsy for detecting resistance mechanisms, suggesting its value in personalized treatment strategies.

Real-world outcome of crizotinib for anaplastic lymphoma kinase-positive lung cancer: Multicenter retrospective analysis in South Korea.

BACKGROUND: About 3%-5% of non-small cell lung cancer (NSCLC) presents positive anaplastic lymphoma kinase (ALK). Recently, several target agents have been approved as a treatment for ALK-positive NSCLC. This study aimed to analyze the real-world efficacy and outcome when administered crizotinib, the first approved target agent for ALK-positive NSCLC, according to first- or late-line treatment. METHODS: A total of 290 patients with ALK-positive advanced NSCLC who were treated with crizotinib in 15 institutions in South Korea from January 2009 to December 2018 were enrolled. RESULTS: The median age of patients was 57.0 years, and 50.3% were male. The median follow-up duration was 29.3 months. Among them, 113 patients received crizotinib as first-line therapy. The objective response rate (ORR) was 60.1% (57.0% for first-line recipients, 61.8% for second-/later-line). Median (95% CI) progression-free survival (PFS) was 13.7 (11.6-17.0) months. For first-line recipients, overall survival (OS) was 26.3 (17.6-35.0) months. No significant difference in ORR, PFS and OS, according to the setting of crizotinib initiation, was observed. In a multivariate Cox regression analysis, old age, male gender, initially metastatic, and number of metastatic organs were associated with poor PFS and OS. The most common adverse events were nausea and vomiting, and severe adverse event leading to dose adjustment was hepatotoxicity. CONCLUSIONS: ORR, PFS, OS, and adverse event profiles were comparable to previous clinical trials. Our findings could aid in the efficient management of ALK-positive lung cancer patients.

The Real-World Outcome of First Line Atezolizumab in Extensive-Stage Small Cell Lung Cancer: A Multicenter Prospective Cohort Study.

PURPOSE: The addition of immune checkpoint inhibitors to chemotherapy has improved survival outcomes in patients with extensive-stage small cell lung cancer (ES-SCLC). However, their real-world effectiveness remains unknown. Therefore, we investigated the effectiveness of atezolizumab plus chemotherapy in ES-SCLC in actual clinical settings. MATERIALS AND METHODS: In this multicenter prospective cohort study, patients with ES-SCLC receiving or scheduled to receive atezolizumab in combination with etoposide and carboplatin were enrolled between June 2021 and August 2022. The primary outcomes were progression-free survival (PFS) and the 1-year overall survival (OS) rate. RESULTS: A total of 100 patients with ES-SCLC were enrolled from seven centers. Median age was 69 years, and 6% had an Eastern Cooperative Oncology Group performance status (ECOG PS) ≥ 2. The median PFS was 6.0 months, the 1-year OS rate was 62.2%, and the median OS was 13.5 months. An ECOG PS of 2-3 and progressive disease as the best response were poor prognostic factors for PFS, while an ECOG PS of 2-3 and brain metastasis were associated with poor prognosis for OS. In addition, consolidative thoracic radiotherapy was found to be an independent favorable prognostic factor for OS (hazard ratio, 0.336; p=0.021). Grade ≥ 3 treatment-related adverse events were observed in 7% of patients, with treatment-related deaths occurring in 2% of patients. CONCLUSION: We provided evidence of the favorable real-world effectiveness and safety of atezolizumab plus chemotherapy in ES-SCLC patients, including in the elderly and those with poor ECOG PS. Additional consolidative thoracic radiotherapy may also benefit ES-SCLC patients.

Real-world first-line afatinib for advanced EGFR mutation-positive non-small cell lung cancer in Korea: updated survival data.

Background: Data from clinical trials and real-world studies show that afatinib is effective in treating non-small cell lung cancer (NSCLC) harboring activating mutations in the epidermal growth factor receptor (EGFR) gene. A previous analysis of patients enrolled in the Korean Academy of Tuberculosis and Respiratory Disease (KATRD) EGFR cohort showed that first-line afatinib was well tolerated and effectiveness results were encouraging. At the time of the previous analysis, survival data were not mature. Here we briefly present updated survival data from the cohort. Methods: The study was a retrospective, multicenter (15 sites) review of electronic records of Korean adult patients (aged >20 years) with advanced EGFR mutation-positive NSCLC who initiated first-line afatinib (N=421). Progression-free survival (PFS) and overall survival (OS) were evaluated using Kaplan-Meier survival curves. Results: Overall, median PFS was 20.2 months and median OS was 48.6 months. OS rates at 36 and 60 months were 60.1% and 42.3%, respectively. Presence vs. absence of baseline brain metastases was associated with significantly reduced median PFS (14.9 vs. 28.0 months; P<0.001) and median OS (32.2 vs. 65.6 months; P<0.001). The presence of common baseline EGFR mutations (Del19, L858R) was associated with significantly prolonged median OS (49.6 vs. 30.1 months; P=0.017). In patients stratified by the presence/absence of T790M EGFR mutation, the T790M mutation was associated with significantly reduced median PFS (P=0.0005) but there was no significant difference between groups in survival (P=0.263). There were no significant differences in PFS or OS for patients stratified by afatinib dose reduction or by age group (<70 vs. ≥70 years). Conclusions: Afatinib was effective in Korean patients with EGFR mutation-positive NSCLC with median OS over 4 years. The presence of baseline brain metastases and/or uncommon EGFR mutations were associated with reduced survival. In the absence of baseline brain metastases, median OS was more than 5 years.

Erratum: Correction of Affiliations in the Article "Validity of Outcome Prediction Scoring Systems in Korean Patients with Severe Adult Respiratory Distress Syndrome Receiving Extracorporeal Membrane Oxygenation Therapy".

This corrects the article on p. 932 in vol. 31, PMID: 27247503.

Healthcare utilization of lung cancer patients associated with exposure to fine particulate matter: A Korean cohort study.

BACKGROUND: Higher concentrations of particulate matter (PM) have been shown to cause deterioration of the symptoms of respiratory and cardiovascular disease in several regional studies. Here, we aimed to investigate the healthcare utilization of lung cancer patients associated with short-term exposure to PM at the national level in Korea. METHODS: We extracted the data of 210 558 subjects over a period of 3 years (2015-2017), who were diagnosed with lung cancer before 2015 and benefited from the National Health Insurance Sharing Service. We performed the interpolation method using the geographic information system to calculate the estimated mean PM2.5 and PM10 concentrations by regions and classified three groups as high (upper 10%), intermediate (10%-90%), and low (bottom 10%) based on the mean PM mass concentrations of the month. RESULTS: The monthly average number of outpatient visits was significantly increased in high PM2.5 urban areas (46.296 vs. 50.646, p = 0.015). In high PM2.5 nationwide regions, the monthly average number of emergency admission was significantly increased (0.528 vs. 0.785, p = 0.001). The outpatient visits tended to change with PM2.5 concentration and correlated with PM10 /PM2.5 concentrations in urban and nationwide areas. In high PM2.5 urban regions, there was a significant increase in bronchodilator prescriptions (3.102 vs. 3.758, p = 0.008). Concerning high PM2.5 nationwide regions, there were significantly increased prescriptions of antibiotics, steroids, bronchodilators, antihistamines, and mucolytics. CONCLUSIONS: This study suggests that exposure to PM2.5 is significantly associated with hospital utilization and drug prescription in lung cancer patients.

Real-world analysis of first-line afatinib in patients with EGFR-mutant non-small cell lung cancer and brain metastasis: survival and prognostic factors.

Background: Overall survival (OS) in patients with non-small cell lung cancer (NSCLC) and brain metastases (BMs) is poor. We aimed to identify prognostic factors and ascertain treatment outcomes of first-line afatinib for patients with epidermal growth factor receptor (EGFR)-mutant NSCLC with BM in a real-world setting. Methods: This retrospective observational study reviewed electronic records of patients with EGFR-mutant NSCLC who received first-line afatinib treatment between October 2014 and October 2019 in 16 hospitals across South Korea. The Kaplan-Meier method estimated time on treatment (TOT) and OS; multivariate analyses were performed using Cox proportional hazards (PH) models. Results: Among 703 patients who received first-line afatinib, 262 (37.3%) had baseline BM. Of 441 patients without baseline BM, 92 (20.9%) developed central nervous system (CNS) failure. Compared with patients without CNS failure, those with CNS failure during afatinib treatment were younger (P=0.012), had a higher Eastern Cooperative Oncology Group (ECOG) performance status (PS) (P<0.001), increased metastatic site involvement (P<0.001), advanced stage disease (P<0.001), with liver metastasis (P=0.008) and/or bone metastasis (P<0.001) at baseline. Cumulative incidence of CNS failure in years 1, 2 and 3 was 10.1%, 21.5% and 30.0%, respectively. In multivariate analysis, cumulative incidence was significantly higher in patients with ECOG PS ≥2 (P<0.001), uncommon EGFR mutations (P=0.001), and no baseline pleural metastasis (P=0.017). Median TOT was 16.0 months (95% CI: 14.8-17.2) and, in patients with CNS failure, without CNS failure, and with baseline BM was 12.2, 18.9, and 14.1 months, respectively (P<0.001). Median OS was 52.9 months (95% CI: 45.4-60.3) and, in patients with CNS failure, without CNS failure, and with baseline BM was 29.1, 67.3 and 48.5 months, respectively (P<0.001). Conclusions: First-line afatinib in the real-world setting showed clinically meaningful effectiveness in patients with EGFR-mutant NSCLC and BM. CNS failure was a poor prognostic factor for TOT and OS correlating with younger age, poor ECOG PS, higher metastatic number, advanced disease stage, uncommon EGFR mutations, and baseline liver and/or bone metastases.

Initial Tumor Necrosis Factor-Alpha and Endothelial Activation Are Associated with Hemorrhagic Complications during Extracorporeal Membrane Oxygenation.

Studies on inflammatory markers, endothelial activation, and bleeding during extracorporeal membrane oxygenation (ECMO) are lacking. Blood samples were prospectively collected after ECMO initiation from 150 adult patients who underwent ECMO for respiratory failure between 2018 and 2021. After excluding patients who died early (within 48 h), 132 patients were finally included. Their tumor necrosis factor-alpha (TNF-α), tissue factor (TF), soluble thrombomodulin (sTM), and E-selectin levels were measured. A Cox proportional hazards regression model was used to estimate the hazard ratio for hemorrhagic complications during ECMO. The 132 patients were divided into hemorrhagic (n = 23, H group) and non-complication (n = 109, N group) groups. The sequential organ failure assessment score, hemoglobin level, and ECMO type were included as covariates in all Cox models to exclude the effects of clinical factors. After adjusting for these factors, initial TNF-α, TF, sTM, E-selectin, and activated protein C levels were significantly associated with hemorrhagic complications (all p < 0.001). TNF-α, TF, and E-selectin better predicted hemorrhagic complications than the model that included only the aforementioned clinical factors (clinical factors only (area under the curve [AUC]: 0.804), reference; TNF-α (AUC: 0.914); TF (AUC: 0.915); E-selectin (AUC: 0.869)). Conclusions: TNF-α levels were significantly predictive of hemorrhagic complications during ECMO.

Evaluation of Blood Tumor Mutation Burden for the Efficacy of Second-Line Atezolizumab Treatment in Non-Small Cell Lung Cancer: BUDDY Trial.

This study aimed to investigate the feasibility of blood-based biomarkers, including blood tumor mutation burden (bTMB), to predict atezolizumab efficacy in relapsed and advanced non-small cell lung cancer (NSCLC). Stage IV NSCLC patients who had previously received platinum-doublet chemotherapy were recruited and received 1200 mg of atezolizumab every three weeks. Blood was collected to obtain plasma cell-free DNA (cfDNA) before the first cycle (C0) and at the fourth cycle (C4). bTMB was measured by CT-ULTRA in patients with cfDNA over 10 ng. The objective response rate (ORR) of the enrolled 100 patients was 10%, and there was no difference in ORR according to bTMB (cutoff: 11.5 muts/Mb) at C0 (high bTMB: 8.1% vs. low bTMB: 11.1%). However, the C4/C0 bTMB ratio was significantly lower in the durable clinical benefit (DCB) patients. The cfDNA concentration at C0, the C4/C0 ratio of the cfDNA concentration, the highest variant allele frequency (hVAF), and the VAF standard deviation (VAFSD) were significantly lower in the DCB patients. In the multivariate analysis, a high cfDNA concentration at C0 (cutoff: 8.6 ng/mL) and a C4/C0 bTMB ratio greater than 1 were significantly associated with progression-free survival. These results suggest that baseline levels and dynamic changes of blood-based biomarkers (bTMB, cfDNA concentration, and VAFSD) could predict atezolizumab efficacy in previously treated NSCLC patients.

Final Report on Real-World Effectiveness of Sequential Afatinib and Osimertinib in EGFR-Positive Advanced Non-Small Cell Lung Cancer: Updated Analysis of the RESET Study.

PURPOSE: This study aimed to report the final analysis of time-on-treatment (TOT) and overall survival (OS) in patients with advanced-stage epidermal growth factor receptor (EGFR)+ non-small cell lung cancer (NSCLC) who received sequential afatinib and osimertinib and to compare the outcomes with other second-line regimens (comparator group). MATERIALS AND METHODS: In this updated report, the existing medical records were reviewed and rechecked. TOT and OS were updated and analyzed according to clinical features using the Kaplan-Meier method and log-rank test. TOT and OS were compared with those of the comparator group, in which most patients received pemetrexed-based treatments. A multivariable Cox proportional hazard model was used to evaluate features that could affect survival outcomes. RESULTS: The median observation time was 31.0 months. The follow-up period was extended to 20 months. A total of 401 patients who received first-line afatinib were analyzed (166 with T790M+ and second-line osimertinib, and 235 with unproven T790M and other second-line agents). Median TOTs on afatinib and osimertinib were 15.0 months (95% confidence interval [CI], 14.0 to 16.1) and 11.9 months (95% CI, 8.9 to 14.6), respectively. The median OS in the osimertinib group was 54.3 months (95% CI, 46.7 to 61.9), much longer than that in the comparator group. In patients who received osimertinib, the OS was longest with Del19+ (median, 59.1; 95% CI, 48.7 to 69.5). CONCLUSION: This is one of the largest real-world studies reporting the encouraging activity of sequential afatinib and osimertinib in Asian patients with EGFR+ NSCLC who acquired the T790M mutation, particularly Del19+.

Korean Real-World Data on Patients With Unresectable Stage III NSCLC Treated With Durvalumab After Chemoradiotherapy: PACIFIC-KR.

INTRODUCTION: This study aimed to investigate real-world evidence for efficacy and safety of durvalumab consolidation (DC) after chemoradiotherapy (CRT) in patients with unresectable stage III NSCLC. METHODS: Patients with stage III NSCLC who started DC after CRT between September 2018 and December 2020 and were treated at five tertiary hospitals in the Republic of Korea were included. The primary end point was real-world progression-free survival (rwPFS). Secondary end points were overall survival, objective response rate, and adverse events including radiation pneumonitis (RP) and immune-related adverse events (irAEs). RESULTS: A total of 157 patients were enrolled. At the median follow-up of 19.1 months, median rwPFS of DC was 25.9 months (95% confidence interval: 16.5-35.4) and the 1-, 2-, and 3-year rwPFS rates were 59.4%, 51.8%, and 43.5%, respectively. The median overall survival was not mature, and objective response rate of DC was 51.0%. High programmed death-ligand 1 expression (≥50%) and development of RP requiring steroid treatment were significantly associated with longer (p = 0.043) and shorter rwPFS (p = 0.036), respectively. RP, RP requiring steroid treatment, and irAEs developed in 57 (36.3%), 42 (26.8%), and 53 (33.8%) patients, respectively. Among peripheral blood cell counts at the initiation of DC, a high derived monocyte-to-lymphocyte ratio was the most significant risk factor for the development of RP requiring steroid treatment (OR 44.76, 95% CI: 8.89-225.43, p < 0.001) and irAEs (OR 2.85, 95% CI: 1.27-6.41, p = 0.011). CONCLUSIONS: Compared with the outcome of the PACIFIC trial, these real-world data revealed favorable survival benefits of DC after CRT in patients with unresectable stage III NSCLC. Blood-based biomarkers could predict higher-grade RP and irAEs before the initiation of DC.

Real-World Study of Osimertinib in Korean Patients with Epidermal Growth Factor Receptor T790M Mutation-Positive Non-Small Cell Lung Cancer.

PURPOSE: Although osimertinib is the standard-of-care treatment of epidermal growth factor receptor (EGFR) T790M mutation-positive non-small cell lung cancer, real-world evidence on the efficacy of osimertinib is not enough to reflect the complexity of the entire course of treatment. Herein, we report on the use of osimertinib in patients with EGFR T790M mutation-positive non-small cell lung cancer who had previously received EGFR tyrosine kinase inhibitor (TKI) treatment in Korea. MATERIALS AND METHODS: Patients with confirmed EGFR T790M after disease progression of prior EGFR-TKI were enrolled and administered osimertinib 80 mg daily. The primary effectiveness outcome was progression-free survival, with time-to-treatment discontinuation, treatment and adverse effects leading to treatment discontinuation, and overall survival being the secondary endpoints. RESULTS: A total of 558 individuals were enrolled, and 55.2% had investigator-assessed responses. The median progression-free survival was 14.2 months (95% confidence interval [CI], 13.0 to 16.4), and the median time-to-treatment discontinuation was 15.0 months (95% CI, 14.1 to 15.9). The median overall survival was 36.7 months (95% CI, 30.9 to not reached). The benefit with osimertinib was consistent regardless of the age, sex, smoking history, and primary EGFR mutation subtype. However, hepatic metastases at the time of diagnosis, the presence of plasma EGFR T790M, and the shorter duration of prior EGFR-TKI treatment were poor predictors of osimertinib treatment. Ten patients (1.8%), including three with pneumonitis, had to discontinue osimertinib due to severe adverse effects. CONCLUSION: Osimertinib demonstrated its clinical effectiveness and survival benefit for EGFR T790M mutation-positive in Korean patients with no new safety signals.

MHY4571, a novel diarylcyclohexanone derivative, exerts anti-cancer activity by regulating the PKA-cAMP-response element-binding protein pathway in squamous cell lung cancer.

BACKGROUND: The protein kinase A (PKA)/cAMP response element-binding protein (CREB) has been suggested to be related to the inhibition of the proliferation of non-small cell lung cancer (NSCLC) cells. This study aimed to investigate the efficacy of a novel diarylcyclohexanone derivative, MHY4571, in regulating the PKA-CREB pathway and to study its anti-tumor role in squamous NSCLC. METHODS: We designed MHY4571 as a novel PKA inhibitor with acceptable in silico ADME properties and tested it in vitro in lung cancer cell lines and in vivo in xenograft and orthotopic mouse models of squamous cell lung carcinoma. RESULTS: MHY4571 inhibited PKA activity (> 70% inhibition) and suppressed the expression of p-PKA and p-CREB dose-dependently. MHY4571 treatment reduced lung cancer cell viability and promoted caspase 3-dependent apoptotic cell death. Orally administered MHY4571 significantly suppressed lung tumor growth in xenograft and orthotopic mouse models. PKA catalytic subunit alpha-silencing by siRNA (siPKA) strongly attenuated CREB phosphorylation; siCREB did not alter PKA protein levels or its phosphorylation, suggesting that PKA is an upstream regulator of CREB activity. MHY4571 acted synergistically with cisplatin (on co-treatment) to induce apoptotic cell death in lung cancer cells. CONCLUSIONS: Our results imply that MHY4571 may be a potential drug candidate for squamous cell lung cancer treatment.

Clinical outcomes of hyperprogression based on volumetry in non-small cell lung cancer after immune checkpoint inhibitor treatment.

BACKGROUND: Hyperprogressive disease (HPD) is a novel pattern of the treatment course after immune checkpoint inhibitor (ICI) therapy in patients with non-small cell lung cancer (NSCLC). This study aimed to investigate the clinical characteristics, outcomes, and associated factors of HPD using a semiautomatic volume measurement. METHODS: This retrospective study enrolled patients with recurrent and/or metastatic NSCLC treated with ICIs between January 2015 and August 2019 at eight tertiary centers in Korea. HPD was defined according to the tumor growth kinetics and time to treatment failure. Tumor volume was measured using a semiautomatic software. RESULTS: A total of 219 NSCLC patients with 35 HPD by volumetric measurement (HPDv) (15.9%) were enrolled. The median duration of overall survival (OS) and OS after ICI treatment (ICI-OS) were 34.5 and 18.4 months, respectively. HPDv patients had significantly worse progression-free survival (PFS) than progressive disease patients without HPDv (1.16 vs. 1.82 months, p-value <0.001). ICI-OS did not significantly differ between patients with HPDv and those without HPDv (2.66 vs. 5.4 months, p = 0.105). PD-L1 expression lower than 50%, more than three metastatic sites, neutrophil-to-lymphocyte ratio equal to or higher than 3.3, and hemoglobin level lower than 10 were found to be associated with HPDv. CONCLUSIONS: There is no standardized definition of HPD. However, defining HPD in NSCLC patients treated with ICI using a semiautomatic volume measurement software is feasible.

The feasibility of granzyme B levels using an amperometric immunosensor for lung cancer detection.

Background: Low-dose computed tomography (LDCT) has improved the early detection of lung cancer. However, LDCT scans present several disadvantages, including the abundance of false-positive results, which lead to a high socioeconomic cost, psychological burden, and repeated exposure to radiation. Therefore, the identification of complementary biomarkers is needed to select high-risk individuals for LDCT. Here, we showed that granzyme B testing with the novel immunosensor has diagnostic value for identifying patients with lung cancer. Methods: We enrolled 44 patients with lung cancer and 51 health controls at Pusan National University Yangsan Hospital in Korea between March 2018 and September 2019. The immunosensor analyzed serum granzyme B levels, and their association with lung cancer detection was evaluated with machine learning models. Results: Serum granzyme B levels were assessed in samples from patients with lung cancer and healthy individuals. Granzyme B testing showed 100% sensitivity, 80% specificity, and an area under the curve of 0.938 for lung cancer detection. After combining granzyme B testing with clinical predictors such as age, smoking status, or pack-years, results from the five-fold cross-validation with random forest model improved diagnostic accuracy of 92.1%, with a sensitivity, specificity, and area under the curve of 92.0%, 92.1%, and 0.977, respectively. Conclusions: This feasibility study suggested that granzyme B may be utilized to detect lung cancer.

Effects of Different Centrifugation Protocols on the Detection of EGFR Mutations in Plasma Cell-Free DNA.

OBJECTIVES: Various preanalytical factors, including the collection tube, storage conditions, and centrifugation, affect the detection results of plasma cell-free DNA (cfDNA). We compared the effect of different centrifugation protocols on the detection of EGFR mutations in cfDNA. METHODS: We analyzed 117 plasma specimens from 110 patients with non-small cell lung cancer using the cobas EGFR Mutation Test v2 (Roche Diagnostics). We compared the identified EGFR mutations and semiquantitative index values from the 1- and 2-step centrifugation groups and confirmed the clinical impact of differences in the results after further high-speed centrifugation. RESULTS: We detected EGFR mutations in 44 (37.6%) and 47 (40.2%) samples that were centrifuged once and twice, respectively; the 2 groups showed an 89.7% (105/117) concordance and a strong correlation in their semiquantitative index values (r = 0.929). Among the 12 inconsistent result pairs, 9 samples of 2-step centrifugation (75%) were consistent with the results of a recent tissue biopsy. CONCLUSIONS: Additional high-speed centrifugation has been shown to increase the sensitivity of EGFR mutation detection in a commercial in vitro diagnostic real-time polymerase chain reaction device and is an optimal preanalytical factor for detecting low-allele frequency gene mutations using low concentrations of cfDNA.

Granzyme B for predicting the durable clinical benefit of anti-PD-1/PD-L1 immunotherapy in patients with non-small cell lung cancer.

Background: To identify immunotherapy biomarkers, we examined granzyme B levels in peripheral blood PD-1+ CD8+ T cells and their relationship with treatment outcomes in patients with non-small cell lung cancer (NSCLC). Methods: To evaluate the association of granzyme B with response to immunotherapy, we tested blood samples obtained from 16 patients with stage IIIC to IV NSCLC receiving immune-checkpoint inhibitor treatment. We used flow cytometry to measure the change in the percentage of PD1+ CD8+ T cells expressing granzyme B before (t0) and after (t1) immunotherapy, and we evaluated for an association with tumor response to therapy, progression-free survival (PFS) and overall survival (OS). Additionally, we measured immune markers correlated with immunotherapy response by enzyme-linked immunosorbent assay. Results: We found that the sequential change of granzyme B+ T cells after immunotherapy (t1/t0) significantly predicted durable clinical benefit (DCB) compared to no clinical benefit (NCB) (P=0.048), and prolonged PFS (P=0.025). Patients who demonstrated a PD-L1 tumor proportion score (TPS) >50% showed NCB if patients had low granzyme B t1/t0 levels (<0.805). Additionally, all patients with 1% PD-L1 TPS (or higher) and high granzyme B t1/t0 (≥0.805) showed DCB. Therefore, granzyme B t1/t0 may be an adjunctive marker with available PD-L1 TPS. Conclusions: Our findings revealed that sequential change in granzyme B might be utilized as a predictive biomarker of immune checkpoint inhibitor monotherapy.

First-line Afatinib in Patients With Non-small-cell Lung Cancer With Uncommon EGFR Mutations in South Korea.

BACKGROUND/AIM: Non-small cell lung cancers (NSCLCs) harboring uncommon epidermal growth factor receptor (EGFR) mutations are heterogeneous and show variable prevalence and clinical responses to EGFR tyrosine kinase inhibitors. We investigated the characteristics of uncommon EGFR mutations and the clinical efficacy of afatinib in patients with NSCLC harboring uncommon EGFR mutations. PATIENTS AND METHODS: In this multicenter, retrospective study, we analyzed patients with NSCLC with uncommon EGFR mutations in 16 South Korean institutes. Mutations were categorized according to their incidence: 1) major uncommon mutations (G719X and L861Q), 2) compound mutations, and 3) minor uncommon mutations (exon 20 insertion, S768I, and de novo T790M). RESULTS: Of 703 patients with EGFR-mutant NSCLC, 64 (9.1%) had uncommon EGFR mutations. Afatinib demonstrated activity against tumors harboring major uncommon mutations [median time of treatment (TOT): 20.3 months, 95% confidence interval (CI)=15.1-25.5; overall survival (OS): 30.6 months, 95% CI=26.3-34.8] and compound mutations (median TOT: 12.3 months, 95% CI=7.7-17.0; OS: 29.1 months, 95% CI=20.4-37.7) but not against tumors harboring minor uncommon mutations (median TOT: 3.8 months, 95% CI=1.7-6.0; OS: 8.5 months, 95% CI=5.2-11.7). The S768I mutation was present in 14 patients (1.99%). The median TOT and OS were not significantly different between S768I mutations and resistant exon 20 mutations. CONCLUSION: Afatinib is effective in patients with NSCLC harboring major uncommon and compound EGFR mutations.

Head-to-Head Comparison between Xpert MTB/RIF Assay and Real-Time Polymerase Chain Reaction Assay Using Bronchial Washing Specimens for Tuberculosis Diagnosis.

BACKGROUND: With the introduction of Xpert MTB/RIF assay (Xpert), its incorporation into tuberculosis (TB) diagnostic algorithm has become an important issue. The aim of this study was to evaluate the performance of the Xpert assay in comparison with a commercial polymerase chain reaction (PCR) assay. METHODS: Medical records of patients having results of both Xpert and AdvanSure TB/NTM real-time PCR (AdvanSure) assays using the same bronchial washing specimens were retrospectively reviewed. RESULTS: Of the 1,297 patients included in this study, 205 (15.8%) were diagnosed with pulmonary TB. Using mycobacterial culture as the reference method, sensitivity of the Xpert assay using smear-positive specimens was 97.5%, which was comparable to that of the AdvanSure assay (96.3%, p=0.193). However, the sensitivity of the Xpert assay using smear-negative specimens was 70.6%, which was significantly higher than that of the AdvanSure assay (52.9%, p=0.018). Usng phenotypic drug susceptibility testing as the reference method, sensitivity and specificity for detecting rifampicin resistance were 100% and 99.1%, respectively. Moreover, a median turnaround time of the Xpert assay was 1 day, which was significantly shorter than 3 days of the AdvanSure assay (p<0.001). CONCLUSION: In comparison with the AdvanSure assay, the Xpert assay had a higher sensitivity using smear-negative specimens, a shorter turnaround time, and could reliably predict rifampin resistance. Therefore, the Xpert assay might be preferentially recommended over TB-PCR in Korean TB diagnostic algorithm.