Long-Term Survival of Patients With Non-Small Cell Lung Cancer Treated With Immune Checkpoint Inhibitor Monotherapy in Real-World Settings.

BACKGROUND: Immune checkpoint inhibitor (ICI) monotherapy is more effective than cytotoxic chemotherapy in improving overall survival (OS) among patients with advanced-stage non-small cell lung cancer (NSCLC). Recently, chemotherapy combined with ICI has been found to yield good outcomes. However, ICI monotherapy is still considered an important treatment option. Data on long-term progression-free survival (PFS) and OS in real-world settings are limited. PATIENTS AND METHODS: This was a multicenter retrospective observational study. A total of 435 consecutive patients histologically diagnosed with advanced, metastatic, or recurrent NSCLC treated with ICI monotherapy were enrolled in this study from December 2015 to December 2018. Clinical data were collected from electronic medical records and pharmacy databases. RESULTS: The PFS and OS of the patients were 3.4 and 13.0 months, respectively. The objective response and disease control rates were 22.8% and 54.9%, respectively, and the 4-year survival rate was 17.9%. Multivariate analyses revealed that elder patients (>70 years), good Eastern Cooperative Oncology Group Performance Status (ECOG PS) score, programmed death-ligand 1 tumor proportion score (PD-L1 TPS) of ≥ 50%, absence of bone metastasis, and presence of immune-related skin toxicity, which is an immune-related adverse event, were correlated with good PFS. Moreover, good ECOG PS score, PD-L1 TPS of ≥ 50%, absence of bone metastasis, and presence of skin toxicity were correlated with good OS. CONCLUSIONS: The 4-year survival rate was 17.9%. Good ECOG PS score, PD-L1 TPS of ≥ 50%, absence of bone metastasis, and presence of skin toxicity were correlated with good PFS and OS.

Two cases of chronic obstructive pulmonary disease evaluated by dynamic-ventilatory digital radiography for pulmonary function and assessment of treatment efficacy.

Spirometry is a crucial test used in the diagnosis and monitoring of patients with chronic obstructive pulmonary disease (COPD). Severe acute respiratory syndrome coronavirus 2 pandemic has posed numerous challenges in performing spirometry. Dynamic-ventilatory digital radiography (DR) provides sequential chest radiography images during respiration with lower doses of radiation than conventional X-ray fluoroscopy and computed tomography. Recent studies revealed that parameters obtained from dynamic DR are promising for evaluating pulmonary function of COPD patients. We report two cases of COPD evaluated by dynamic-ventilatory DR for pulmonary function and treatment efficacy and discuss the potential of dynamic DR for evaluating COPD therapy.

Suitability of Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration versus Paired Transbronchial Biopsy Specimens for Evaluating Programmed Death Ligand-1 Expression in Stage III and IV Lung Cancer: A Comparative Retrospective Study.

Objectives: Cancer cells usually escape tumor-reactive T-cell responses using immune checkpoint proteins, such as programmed death protein-1 (PD-1) and its ligand, programmed death ligand-1 (PD-L1). These proteins can be blocked by immune checkpoint inhibitors (ICIs); the decision on ICI-based first-line treatment for advanced lung cancers depends on the PD-L1 levels in tumor specimens. Determining the PD-L1 expression conventionally requires histological specimens from resected tumors and core biopsy specimens. Non-small cell lung cancer (NSCLC) is usually diagnosed at stage III or IV; therefore, only small biopsy specimens, such as those obtained via endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) are available. However, the suitability of EBUS-TBNA specimens determining the PD-L1 expression levels in advanced lung cancers remains unclear. Materials and Methods: Here, we investigated the concordance rate of PD-L1 expression between EBUS-TBNA and matched transbronchial biopsy (TBB) specimens. Using the 22C3 anti-PD-L1 antibody (immunohistochemistry), we determined the PD-L1 expression levels in paired specimens obtained from 69 patients (50 with advanced NSCLC and 19 with small cell lung cancer [SCLC]), as well as the efficacy of ICIs in these patients. Results: The concordance rate of PD-L1 expression between the EBUS-TBNA and TBB specimens was 78.3%. The κ values referent to the PD-L1-positive expression rate between EBUS-TBNA and TBB specimens were 0.707 and 0.676 at cutoff limits of ≥1% and ≥50%, respectively. Among the 19 SCLC patients, 16 (84.2%) exhibited no PD-L1 expression in both EBUS-TBNA and TBB specimens. Notably, the progression-free survival of patients with ≥50% PD-L1 expression in the paired specimens who received ICI treatment was 8.3 months. Conclusion: Collectively, our results validate the use of EBUS-TBNA specimens for the determination of the PD-L1 expression levels in the context of NSCLC and SCLC.

Phase II study of the combination of S-1 with bevacizumab for patients with previously treated advanced non-squamous non-small-cell lung cancer.

BACKGROUND: We assessed the efficacy and safety of bevacizumab and S-1 chemotherapy for patients with previously treated advanced non-squamous non-small-cell lung cancer (NSCLC). METHODS: This was a prospective single-arm study, including patients with non-squamous NSCLC who had received at least one chemotherapy regimen along with a platinum-based regimen. Bevacizumab 15 mg/kg was intravenously administered every 3 weeks, and S-1 40 mg/m2 was orally administered twice daily from day 1 (evening) through day 15 (morning). The treatment continued for 3 weeks/cycle until disease progression or until unacceptable toxicities occurred. During the lead-in part, six patients were evaluated for dose-limiting toxicity (DLT) rate. In phase II, the primary endpoint was objective response rate (ORR). Secondary endpoints were progression-free survival (PFS), overall survival (OS), and safety. RESULTS: In the lead-in part, we evaluated the safety in the first six patients and observed no DLT. In phase II, a total of 46 patients were enrolled from September 2012 to December 2018. The median follow-up duration was 13.7 months [95% confidence interval (CI) 1.4-72.0]. The ORR was 28.3%. The median PFS and OS were 4.3 (95% CI 2.9-5.9) and 15.0 months (95% CI 9.8-30.3), respectively. The most common adverse events were hypertension (65.2%), diarrhea (47.8%), mucositis oral (45.7%), and proteinuria (43.5%), and the most common grade 3 adverse events were hypertension (23.9%) and proteinuria (6.5%). Grade 4/5 adverse events were not observed. CONCLUSION: Bevacizumab and S-1 combination chemotherapy showed high activity and were well tolerated in patients with previously treated advanced non-squamous NSCLC.

A Novel System to Detect Circulating Tumor Cells Using Two Different Size-selective Microfilters.

BACKGROUND/AIM: Clusters of circulating tumor cells (CTCs) increase metastatic potential compared to single CTC. However, conventional technologies have been unable to generate an accurate analysis of single and cluster CTCs in the peripheral blood. We propose an effective strategy to detect and isolate both single and cluster CTCs using two size-selective microfilters. MATERIALS AND METHODS: Five ml of whole blood were collected from 10 patients with epidermal growth factor receptor mutation-positive non-small cell lung cancer. Single and cluster CTCs were identified using precision microfiltration membranes with two distinct pore sizes together with anti-EpCAM antibody labeling. RESULTS: Single and cluster CTCs were detected by simultaneously using two size-selective microfilters. The EGFR-L858R mutation was detected in the DNA from cells captured using both microfilters. CONCLUSION: Our method can be used to detect and isolate single and cluster CTCs in the whole blood and may facilitate the development of a liquid biopsy strategy.

Real-World Efficacy of First-Line Pembrolizumab in Patients With Advanced or Recurrent Non-Small-Cell Lung Cancer and High PD-L1 Tumor Expression.

BACKGROUND: In clinical trials, first-line treatment with pembrolizumab improved overall survival (OS) in patients with advanced non-small-cell lung cancer (NSCLC) with a programmed death ligand 1 (PD-L1) tumor proportion score of ≥ 50%. However, data on the efficacy of this treatment between clinical trials and actual clinical practice are inconsistent. PATIENTS AND METHODS: Ninety-five patients with histologically diagnosed advanced or recurrent NSCLC and a PD-L1 tumor proportion score of ≥ 50% who received pembrolizumab as first-line treatment were consecutively enrolled onto this multicenter retrospective study from February 2017 to December 2018. Clinical data were collected from electronic medical records. We assessed the objective response rate, progression-free survival (PFS), OS, and immune-related adverse events (irAE), and determined their associations with clinical characteristics. RESULTS: The objective response rate was 40.0%. The median PFS was 6.1 months, and OS did not reach the median. Multivariate analyses revealed that nonadenocarcinoma histology (hazard ratio, 1.78; 95% confidence interval, 1.05-3.03; P = .015) and ≥ 3 metastatic sites (hazard ratio, 3.97; 95% confidence interval, 1.97-8.01; P < .001) were independently correlated with poor PFS. Patients with irAE and patients without interstitial lung disease had significantly longer PFS (14.0 and 4.9 months, respectively; P = .011) than patients without irAE or patients with interstitial lung disease. CONCLUSION: The outcome of patients receiving first-line pembrolizumab treatment was worse in those with nonadenocarcinoma and with a large number of metastatic sites. Patients with irAE and without interstitial lung disease had a more favorable outcome.

Drug resistance mechanisms in Japanese anaplastic lymphoma kinase-positive non-small cell lung cancer and the clinical responses based on the resistant mechanisms.

The treatment for anaplastic lymphoma kinase (ALK)-positive lung cancer has been rapidly evolving since the introduction of several ALK tyrosine kinase inhibitors (ALK-TKI) in clinical practice. However, the acquired resistance to these drugs has become an important issue. In this study, we collected a total of 112 serial biopsy samples from 32 patients with ALK-positive lung cancer during multiple ALK-TKI treatments to reveal the resistance mechanisms to ALK-TKI. Among 32 patients, 24 patients received more than two ALK-TKI. Secondary mutations were observed in 8 of 12 specimens after crizotinib failure (G1202R, G1269A, I1171T, L1196M, C1156Y and F1245V). After alectinib failure, G1202R and I1171N mutations were detected in 7 of 15 specimens. G1202R, F1174V and G1202R, and P-gp overexpression were observed in 3 of 7 samples after ceritinib treatment. L1196M + G1202R, a compound mutation, was detected in 1 specimen after lorlatinib treatment. ALK-TKI treatment duration was longer in the on-target treatment group than that in the off-target group (13.0 vs 1.2 months). In conclusion, resistance to ALK-TKI based on secondary mutation in this study was similar to that in previous reports, except for crizotinib resistance. Understanding the appropriate treatment matching resistance mechanisms contributes to the efficacy of multiple ALK-TKI treatment strategies.

Barcode sequencing identifies resistant mechanisms to epidermal growth factor receptor inhibitors in circulating tumor DNA of lung cancer patients.

Most patients with epidermal growth factor receptor (EGFR) mutation-positive non-small cell lung cancer (NSCLC) will inevitably develop acquired resistance induced by treatment with EGFR tyrosine kinase inhibitors (EGFR-TKI). The mechanisms of resistance to EGFR-TKI are multifactorial, and the detection of these mechanisms is critical for treatment choices in patients who have progressed after EGFR-TKI therapy. We evaluated the feasibility of a molecular barcode method using next-generation sequencing to detect multifactorial resistance mechanisms in circulating tumor DNA and compared the results with those obtained using other technologies. Plasma samples were collected from 25 EGFR mutation-positive NSCLC patients after the development of EGFR-TKI resistance. Somatic mutation profiles of these samples were assessed using two methods of next-generation sequencing and droplet digital PCR (ddPCR). The positive rate for EGFR-sensitizing mutations was 18/25 (72.0%) using ddPCR, 17/25 (68.0%) using amplicon sequencing, and 19/25 (76.0%) using molecular barcode sequencing. Rate of the EGFR T790M resistance mutation among patients with EGFR-sensitizing mutations was shown to be 7/18 (38.9%) using ddPCR, 6/17 (35.3%) using amplicon sequencing, and 8/19 (42.1%) using molecular barcode sequencing. Copy number gain in the MET gene was detected in three cases using ddPCR. PIK3CA, KRAS and TP53 mutations were detected using amplicon sequencing. Molecular barcode sequencing detected PIK3CA, TP53, KRAS, and MAP2K1 mutations. Results of the three assays were comparable; however, in cell-free DNA, molecular barcode sequencing detected mutations causing multifactorial resistance more sensitively than did the other assays.

Correlation between thyroid transcription factor-1 expression, immune-related thyroid dysfunction, and efficacy of anti-programmed cell death protein-1 treatment in non-small cell lung cancer.

BACKGROUND: Recent studies have suggested a correlation between immune-related thyroid dysfunction (irTD) and the superior efficacy of anti-programmed cell death protein-1 (anti-PD-1) treatment in non-small cell lung cancer (NSCLC). Embryologically, the lung and thyroid are similar in origin, and thyroid transcription factor-1 (TTF-1) expresses in both organs, including NSCLC. We explored our hypothesis that TTF-1 expression in NSCLC might correlate with irTD incidence and anti-PD-1 treatment efficacy. METHODS: We identified 132 patients with NSCLC treated with anti-PD-1 antibody at our hospital between December 2015 and June 2017. We evaluated TTF-1 expression in tumor by immunohistochemistry using a mouse monoclonal antibody (clone 8G7G3/1, 1:100, Dako). IrTD was defined as two or more successive abnormal levels of thyroid-stimulating hormone (TSH) during anti-PD-1 treatment. We retrospectively assessed correlations between TTF-1 expression in tumor, irTD incidence, and anti-PD-1 treatment efficacy. RESULTS: Of 132 patients, 67 (51%) and 65 (49%) were positive and negative for TTF-1, respectively. We observed irTD in 19 patients (6 positives and 13 negatives for TTF-1). The incidence of irTD was 9% and 20% in TTF-1-positive and TTF-1-negative NSCLCs, respectively (P=0.086). Particularly, in non-squamous (NSQ) cell carcinomas, the irTD incidence was significantly higher in patients negative for TTF-1 (30%) than in those positive for TTF-1 (9%; P=0.010), and TTF-1 expression was identified as a significant risk factor for irTD on multivariate logistic regression analysis [odds ratio (OR), 0.18; 95% confidence interval (CI), 0.05-0.59; P=0.005]. Furthermore, longer median progression-free survival (10.3 months) was observed in patients with TTF-1-negative NSCLC with irTD compared to those with TTF-1-positive NSCLC with irTD, TTF-1-positive NSCLC without irTD, and TTF-1-negative NSCLC without irTD (4.2, 1.4, and 2.4 months, respectively). CONCLUSIONS: TTF-1 expression in NSCLC might correlate with irTD and anti-PD-1 treatment efficacy.

Correlation between serum adenosine deaminase activity and efficacy of anti-programmed cell death-1 antibody.

OBJECTIVE: Serum adenosine deaminase (ADA) activity is a marker of immune reaction to several diseases. We evaluated changes in serum ADA in patients with lung cancer undergoing chemotherapy or anti-programmed cell death-1 (PD-1) therapy to examine the correlation between serum ADA and the therapy efficacy. MATERIALS AND METHODS: We assessed 50 patients with advanced lung cancer receiving chemotherapy or anti-PD-1 therapy. Serum ADA was measured before and on day 7 of the first treatment cycle and day 0 of subsequent cycles. Correlations between ADA change and efficacy of treatment were evaluated. RESULTS: Of the 50 patients, 20 were treated with chemotherapy and 30 were treated with anti-PD-1 therapy. Serum ADA decreased significantly between baseline and day 7 of the first cycle in patients undergoing chemotherapy, regardless of response (partial response [PR] or stable disease [SD]: -23% [-38 to +32; p = 0.002]; progressive disease [PD]: -12% [-42 to +6; p = 0.500]). Conversely, in patients undergoing anti-PD-1 therapy, serum ADA increased significantly between baseline and 7 days after the first dose and before subsequent doses in patients who had PR or SD. (day 7 of first cycle: +6% [-10 to +34; p = 0.034], day 0 of second cycle: 8% [-5 to +37; p = 0.002], day 0 of third cycle: 9% [-3 to +55; p = 0.002]). However, serum ADA did not significant change in PD patients undergoing anti-PD-1 therapy. Furthermore, early increases in serum ADA were associated with longer progression-free survival in patients receiving anti-PD-1 therapy (p = 0.006). CONCLUSION: Changes in serum ADA could be used to predict clinical benefit from anti-PD-1 therapy in patients with lung cancer. The association between changes in serum ADA and the efficacy of ant-PD-1 therapy thus remains inconclusive and requires further study.

Lung Adenocarcinoma with Lynch Syndrome and the Response to Nivolumab.

Lynch syndrome is caused by mutations in mismatch repair genes that lead to microsatellite instability (MSI). An increased number of mutation-associated neoantigens have been observed in patients with high-frequency MSI (MSI-H) cancer; in addition, membranous programmed death ligand-1 (PD-L1) tends to be expressed at higher levels in MSI-H cancers than in microsatellite-stable cancers. MSI-H cancer patients are therefore considered to be susceptible to immune checkpoint blockade. We herein report for the first time a case of lung adenocarcinoma with Lynch syndrome and the response to nivolumab.

The prevalence and clinical features of asthma-COPD overlap (ACO) definitively diagnosed according to the Japanese Respiratory Society Guidelines for the Management of ACO 2018.

Background Asthma-COPD overlap (ACO) is a disease that shares clinical features of both asthma and COPD. The purpose of this study is to investigate the prevalence and clinical features of ACO. Methods We retrospectively reviewed data for 170 patients with persistent airflow limitation and diagnosed them according to "The Japanese Respiratory Society Guidelines for the Management of ACO 2018". Results Of the 170 patients, 111 were diagnosed as follows : COPD (74 patients, 66.6%), ACO (34 patients, 30.6%), and asthma (3 patients, 2.8%). There was no significant difference in clinical features between ACO and COPD patients. The following pulmonary function tests were significantly lower in ACO than in COPD patients : forced expiratory volume in 1 second/forced vital capacity, peak expiratory flow, maximal mid-expiratory flow, and the maximum expiratory flow at 50%and75%. The following respiratory impedance parameters were significantly higher in ACO than in COPD patients : respiratory resistance (Rrs) at 5 Hz (R5), Rrsat 20 Hz (R20), R5-R20, and low-frequency reactance area. Conclusions About 30% of patients with persistent airflow limitation were diagnosed with ACO. ACO patients had lower lung function and higher respiratory impedance compared with COPD patients. J. Med. Invest. 66 : 157-164, February, 2019.

Improvement in the survival of patients with stage IV non-small-cell lung cancer: Experience in a single institutional 1995-2017.

OBJECTIVES: In the past two decades several antineoplastic agents have been approved for the treatment of advanced non-small-cell lung cancer (NSCLC), and the management of these patients has drastically changed. However, there is limited information regarding the impact of these advances on patient survival in clinical practice. MATERIALS AND METHODS: We analyzed the survival of patients with stage IV NSCLC who received any treatment in the Cancer Institute Hospital of the Japanese Foundation for Cancer Research (JFCR) between January 1, 1995 and March 1, 2017. A total of 1,547 consecutive patients were included in this case series. In this analysis, five diagnostic periods were evaluated: 1995-1999 (period A), 2000-2004 (period B), 2005-2009 (period C), 2010-2014 (period D), and 2015-2017 (period E). We compared overall survival (OS) between the periods before and after propensity score matching (PSM) and in patients with EGFR mutation, with ALK fusion gene, or without driver mutation. RESULTS: In the past two decades the OS of patients with stage IV NSCLC improved. The median OSs for periods A, B, C, D, and E were 9.0, 11.0, 13.7, 17.9 months, and not reached, respectively. After PSM with known baseline characteristics, the trend of improvement in OS was similar. However, the OS of patients with EGFR mutation or ALK fusion gene did not improve between periods, despite the availability of several tyrosine kinase inhibitors in Japan. The OS of patients without a driver mutation was slightly longer in the period E. CONCLUSION: The introduction of new classes of drugs has significantly improved the survival of patients with stage IV NSCLC. However, the approval of similar types of drugs may not be associated with further improvement in survival.

Next-generation sequencing analysis identifies genomic alterations in pathological morphologies: A case of pulmonary carcinosarcoma harboring EGFR mutations.

OBJECTIVES: Pulmonary carcinosarcoma is a rare lung malignancy and little analysis has been performed to identify associated genomic alterations. We used next-generation sequencing (NGS) to analyze a pulmonary carcinosarcoma harboring an epidermal growth factor receptor (EGFR) mutation. MATERIALS AND METHODS: The lung carcinosarcoma used for this study contained components of adenocarcinoma and chondrosarcoma and originated from a 73-year-old female. Both components carried deletion mutations in exon 19 of EGFR and both had equally strong EGFR protein expression. This study analyzed the biological and genetic characteristics of both components, using NGS and immunohistochemical (IHC) staining. RESULTS AND CONCLUSION: IHC staining revealed that both total EGFR and deletion mutation specific EGFR proteins were equally expressed in both components. Intriguingly, identification of genomic alterations with NGS found five identical alterations in four genes (EGFR, CBLB, TP53, and MEN1) that were shared by the two components, and that each component had a large number of individual alterations. Additionally, we focused on an alpha-thalassemia/mental retardation syndrome X-linked (ATRX) mutation which was only present in the sarcoma component. ATRX protein expression was also only detected in the sarcoma component. This is the first report of the exhaustive genomic alterations in a pulmonary carcinosarcoma harboring an EGFR mutation. The results show that our case had the same EGFR status in both components. The EGFR mutation is the driver mutation in both components. In our case, we found that TP53 may be a common alteration and ATRX may be a specific alteration in the sarcoma component.

EGFR T790M mutation after chemotherapy for small cell lung cancer transformation of EGFR-positive non-small cell lung cancer.

In non-small cell lung cancer (NSCLC) with an epidermal growth factor receptor (EGFR) mutation, 50%-65% of cases acquire resistance after treatment with EGFR-tyrosine kinase inhibitors (EGFR-TKIs) because of an EGFR T790M point mutation and 3%-14% of these cases transformed to small cell lung cancer (SCLC). Generally, the EGFR T790M secondary mutation develops with ongoing ATP competitive inhibition. We present a case of a 76-year-old woman with lung adenocarcinoma harboring an EGFR-L858R mutation who received first-line gefitinib and developed SCLC transformation. She was administered several chemotherapy agents, including a platinum doublet. The primary lesion that showed SCLC transformation had reconverted to adenocarcinoma with EGFR L858R and T790M mutations at the time of a second re-biopsy. Therefore, she was administered osimertinib, which resulted in clinical remission. This case suggested that serial biopsies are necessary even after SCLC transformation.

Characterization of Computed Tomography Imaging of Rearranged During Transfection-rearranged Lung Cancer.

BACKGROUND: Rearranged during transfection (RET)-rearranged non-small-cell lung cancer (NSCLC) is relatively rare and the clinical and computed tomography (CT) image characteristics of patients with an advanced disease stage have not been well documented. PATIENTS AND METHODS: We identified patients with advanced-stage RET-rearranged NSCLC treated in the Cancer Institute Hospital, Japanese Foundation for Cancer Research, and analyzed the clinical and CT imaging characteristics. RESULTS: In 21 patients with advanced RET-rearranged NSCLC, RET rearrangements were identified using fluorescence in situ hybridization and/or reverse transcriptase-polymerase chain reaction. The fusion partner genes were identified as KIF5B (57%), CCDC6 (19%), and unknown (24%). CT imaging showed that 12 primary lesions (92%) were peripherally located and all were solid tumors without ground-glass, air bronchograms, or cavitation. The median size of the primary lesions was 30 mm (range, 12-63 mm). Of the 18 patients with CT images before initial chemotherapy, 12 (67%) showed an absence of lymphadenopathy. Distant metastasis included 13 with pleural dissemination (72%), 10 with lung metastasis (56%), 8 with bone metastasis (44%), and 2 with brain metastasis (11%). CONCLUSION: Advanced RET-rearranged NSCLC manifested as a relatively small and peripherally located solid primary lesion with or without small solitary lymphadenopathy. Pleural dissemination was frequently observed.

Selective gene amplification to detect the T790M mutation in plasma from patients with advanced non-small cell lung cancer (NSCLC) who have developed epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) resistance.

BACKGROUND: The epidermal growth factor receptor (EGFR) T790M mutation is associated with resistance to EGFR tyrosine kinase inhibitors (EGFR-TKIs) in non-small cell lung cancer (NSCLC). However, tissues for the genotyping of the EGFR T790M mutation can be difficult to obtain in a clinical setting. The aims of this study were to evaluate a blood-based, non-invasive approach to detecting the EGFR T790M mutation in advanced NSCLC patients using the PointMan™ EGFR DNA enrichment kit, which is a novel method for the selective amplification of specific genotype sequences. METHODS: Blood samples were collected from NSCLC patients who had activating EGFR mutations and who were resistant to EGFR-TKI treatment. Using cell-free DNA (cfDNA) from plasma, EGFR T790M mutations were amplified using the PointMan™ enrichment kit, and all the reaction products were confirmed using direct sequencing. The concentrations of plasma DNA were then determined using quantitative real-time PCR. RESULTS: Nineteen patients were enrolled, and 12 patients (63.2%) were found to contain EGFR T790M mutations in their cfDNA, as detected by the kit. T790M mutations were detected in tumor tissues in 12 cases, and 11 of these cases (91.7%) also exhibited the T790M mutation in cfDNA samples. The concentrations of cfDNA were similar between patients with the T790M mutation and those without the mutation. CONCLUSIONS: The PointMan™ kit provides a useful method for determining the EGFR T790M mutation status in cfDNA.

High ratio of T790M to EGFR activating mutations correlate with the osimertinib response in non-small-cell lung cancer.

OBJECTIVES: Osimertinib is a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor that can overcome resistance due to the Thr790Met (T790M) mutation. However, osimertinib occasionally shows limited efficacy in a small population of patients. We investigated the correlation between the ratio of T790M to EGFR activating mutation and the response to osimertinib. MATERIALS AND METHODS: Between April 2016 and April 2017, 44 patients started osimertinib therapy at the Cancer Institute Hospital of the Japanese Foundation for Cancer Research. We performed EGFR mutation analysis of cytological samples from 33 patients using droplet digital PCR. We calculated the ratio of T790M to EGFR activating mutations and correlated it with the systemic response to osimertinib. RESULTS: In tumors from the 33 patients, the average ratio of T790M to EGFR activating mutations was 0.420. Twenty-one of the 33 patients had tumors with a T790M ratio of ≥0.4. The osimertinib response rate was significantly higher (92.3%) in patients with a T790M ratio of ≥0.4 than in those with a T790M ratio of <0.4 (52.6%; p = 0.0237). We examined the correlation between the T790M ratio and the tumor reduction rate and obtained a coefficient of r = 0.417 (p = 0.0175). In patients with a T790M ratio of ≥0.4, the median progression-free survival was 355 days, which was longer, but not significant, than that in patients with a T790M ratio of <0.4 (median: 264 days). In patients with a T790M ratio of ≥0.4, the median treatment duration from first-line therapy onward was 931 days, which was significantly longer than that in patients with a T790M ratio of <0.4 (median, 567.5 days) (p = 0.044). CONCLUSION: The T790M ratio to EGFR activating mutation in tumor may correlate with the response to osimertinib, and patients with a higher T790M ratio have a longer treatment history.

Dramatic response to alectinib in inflammatory myofibroblastic tumor with anaplastic lymphoma kinase fusion gene.

Inflammatory myofibroblastic tumor (IMT) is a neoplasm characterized by the proliferaton of myofibroblasts with the infiltration of inflammatory cells. There is no standard treatment for patients with recurrent or metastatic IMT. We describe here a patient with hyper-progressive IMT with an anaplastic lymphoma kinase (ALK) fusion gene that dramatically responded to alectinib without adverse events. His dramatic and enduring response supports the observation that alectinib may be considered a good treatment option for rare aggressive ALK-positive tumors.