Ke Fei

MiR-21 overexpression is associated with acquired resistance of EGFR-TKI in non-small cell lung cancer

BACKGROUND AND PURPOSE With the increasing use of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) in patients with advanced non-small cell lung cancer (NSCLC), its acquired resistance has become a major clinical problem. Recent studies revealed that miR-21 was involved into the resistance of cytotoxic agents. The aim of this study was to investigate its role in the acquired resistance of NSCLC to EGFR-TKI. METHODS EGFR-TKI-sensitive human lung adenocarcinoma cell line PC9 and the acquired resistant cell line, PC9R, were used. Lentiviral vectors were used to infect PC9 or PC9R to regulate the miR-21 expression. The expression of targeted proteins PTEN and PDCD4 was controlled by RNA interference. MicroRNA array, RT-PCR and TaqMan MicroRNA Assays were used to detect miR-21 expression. The MTT and Annexin V assays were used to determine proliferation and apoptosis. Western Blot and immunohistochemistry were used to analyze target protein expression (PTEN, PDCD4, Akt, p-Akt). We also constructed PC9R xenograft tumor model to observe the relationship between miR-21 and EGFR-TKI resistance in vivo and validated it in the clinical serum specimens of NSCLC patients treated with EGFR-TKI. RESULT MiR-21 was overexpressed in the EGFR-TKI resistant cell line PC9R relative to PC9. The level of miR-21 was reversely correlated with the expression of PTEN and PDCD4 and positive correlated with PI3K/Akt pathway. Inhibiting miR-21 with lentivirus vector induces apoptosis in PC9R cell line and inhibiting miR-21with ASO suppressed tumor growth in nude mice treated with EGFR-TKI. Furthermore, serum miR-21 expression in NSCLC patients treated with EGFR-TKI was significantly higher at the time of acquiring resistance than at baseline (p<0.01). CONCLUSION miR-21 is involved in acquired resistance of EGFR-TKI in NSCLC, which is mediated by down-regulating PTEN and PDCD4 and activating PI3K/Akt pathway.

Intratumoral Heterogeneity of ALK-Rearranged and ALK/EGFR Coaltered Lung Adenocarcinoma

PURPOSE Genetic intratumoral heterogeneity has a profound influence on the selection of clinical treatment strategies and on addressing resistance to targeted therapy. The purpose of this study was to explore the potential effect of intratumoral heterogeneity on both genetic and pathologic characteristics of ALK-rearranged lung adenocarcinoma (LADC). METHODS We tested ALK fusions and EGFR mutations in 629 patients with LADC by using laser-capture microdissection to capture spatially separated tumor cell subpopulations in various adenocarcinoma subtypes and to test for ALK fusions and EGFR mutations in ALK-rearranged, EGFR-mutated, and ALK/EGFR coaltered LADCs to compare the oncogenic driver status between different tumor cell subpopulations in the same primary tumor. RESULTS Among the 629 patients, 30 (4.8%) had ALK fusions, 364 (57.9%) had EGFR mutations, and two had ALK fusions that coexisted with EGFR mutations. Intratumoral heterogeneity of ALK fusions were identified in nine patients by reverse-transcriptase polymerase chain reaction. In the two patients with an ALK/EGFR coaltered status, genetic intratumoral heterogeneity was observed both between different growth patterns and within the same growth pattern. The relative abundance of ALK and EGFR alterations was different in the same captured area. ALK fusions were positively associated with a micropapillary pattern (P = .002) and were negatively associated with a lepidic pattern (P = .008) in an expanded statistical analysis of 900 individual adenocarcinoma components, although they appeared to be more common in acinar-predominant LADCs in the analysis of 629 patients. CONCLUSION Intratumoral genetic heterogeneity was demonstrated to coexist with histologic heterogeneity in both single-driver and ALK/EGFR coaltered LADCs. Altered oncogenic drivers in spatially separated subclones of the same tumor may be different.

ROS1 fusions in Chinese patients with non-small-cell lung cancer

BACKGROUND To determine the prevalence and clinicopathological features of ROS1 fusions in Chinese patients with non-small-cell lung cancer (NSCLC). METHODS Formalin-fixed and paraffin-embedded (FFPE) tissue sections from 392 patients with NSCLC were screened for ROS1 fusions by multiplex RT-PCR and all ROS1 fusions were validated by direct sequencing. The relationship between ROS1 fusions and clinicopathological features and the prognostic effect of the ROS1 fusion status on survival were analyzed. RESULTS In this study, 8 of 392 (2.0%) evaluable samples were found to harbor ROS1 fusions. Of the ROS1-positive patients, seven presented with adenocarcinoma, and one with adenosquamous carcinoma. The ratio of female to male and never smoker to smokers in a ROS1 fusion-positive group was 5:3. There was no statistically significant difference in age, sex, smoking history, histological type and pathological stage between ROS1 fusion-positive and ROS1 fusion-negative patients. ROS1 fusion-negative patients had a significantly longer survival when compared with ROS1 fusion-positive patients (P = 0.041). Lower pathological stage, younger age and ROS1 fusion-negative status were significantly associated with better prognosis on multivariate analysis. CONCLUSIONS ROS1 fusions occurred in ∼2.0% of Chinese patients with NSCLC and had no specific clinicopathological feature. ROS1 fusion-negative patients may have a better survival than ROS1 fusion-positive patients.BACKGROUND To determine the prevalence and clinicopathological features of ROS1 fusions in Chinese patients with non-small-cell lung cancer (NSCLC). METHODS Formalin-fixed and paraffin-embedded (FFPE) tissue sections from 392 patients with NSCLC were screened for ROS1 fusions by multiplex RT-PCR and all ROS1 fusions were validated by direct sequencing. The relationship between ROS1 fusions and clinicopathological features and the prognostic effect of the ROS1 fusion status on survival were analyzed. RESULTS In this study, 8 of 392 (2.0%) evaluable samples were found to harbor ROS1 fusions. Of the ROS1-positive patients, seven presented with adenocarcinoma, and one with adenosquamous carcinoma. The ratio of female to male and never smoker to smokers in a ROS1 fusion-positive group was 5:3. There was no statistically significant difference in age, sex, smoking history, histological type and pathological stage between ROS1 fusion-positive and ROS1 fusion-negative patients. ROS1 fusion-negative patients had a significantly longer survival when compared with ROS1 fusion-positive patients (P = 0.041). Lower pathological stage, younger age and ROS1 fusion-negative status were significantly associated with better prognosis on multivariate analysis. CONCLUSIONS ROS1 fusions occurred in ∼2.0% of Chinese patients with NSCLC and had no specific clinicopathological feature. ROS1 fusion-negative patients may have a better survival than ROS1 fusion-positive patients.

KIF5B‐RET fusions in Chinese patients with non–small cell lung cancer

It has been established that “ret proto‐oncogene” (RET) fusions are oncogenic drivers in non–small cell lung cancer (NSCLC). The prevalence and clinicopathologic characteristics of RET fusions in Chinese patients with NSCLC remain unclear. The objective of the current study was to determine the prevalence and clinicopathologic characteristics of KIF5B‐RET fusions (fusions of the RET and kinesin family member 5B [KIF5B] genes) in Chinese patients with NSCLC.

T790M mutation is associated with better efficacy of treatment beyond progression with EGFR-TKI in advanced NSCLC patients

BACKGROUND AND PURPOSE Continuous EGFR-TKI treatment beyond progression has shown promising benefit for some patients with acquired resistance to EGFR-TKIs. The aim of this study was to investigate the association of secondary T790M mutation at the time of progression with the efficacy of EGFR-TKI treatment beyond progression. METHODS From March 2011 to March 2013, patients with advanced NSCLC who developed acquired resistance to EGFR-TKI and where a re-biopsy was performed at Tongji University Cancer Institute were included into this study. Scorpion ARMS was used to detect EGFR mutation status. RESULTS A total of 54 patients were enrolled in this study with a median progression-free survival time (PFS1) of 10.9 months according to RECIST criteria. In all, 53.7% (29/54) had T790M mutation after the failure of EGFR-TKIs; PFS1 was not statistically significantly different between patients with T790M mutation and without (13.0 vs. 10.5 months, p = 0.894). In all, 41 patients received TKI treatment beyond progression, including 22 with local progression to receive additional local therapy and 19 with gradual progression to receive additional chemotherapy. The median progression-free survival time (PFS2) of patients who received EGFR-TKI beyond progression treatment was 3.5 months (95% CI, 2.689-4.311). Patients with T790M mutation had significantly longer PFS2 (6.3 vs. 2.6 months, p = 0.002) and overall survival (39.8 vs. 23.2 months, p = 0.044) than those without. CONCLUSION Patients with secondary T790M mutation at the time of progression having gradual or local progression after acquired resistance to EGFR-TKI benefit more from EGFR-TKI treatment beyond progression compared to those without T790M mutation.

EGFR L858R mutation is associated with lung adenocarcinoma patients with dominant ground-glass opacity

OBJECTIVES To retrospectively identify quantitative computed tomographic (CT) features that correlate with the three major driver gene mutations in surgically resected lung adenocarcinomas with dominant ground-glass opacity (GGO) stratified by the International Association for the Study of Lung Cancer (IASLC), American Thoracic Society (ATS), and European Respiratory Society (ERS) classification in a Chinese cohort of patients. MATERIALS AND METHODS Surgically resected lung adenocarcinomas from Shanghai Pulmonary Hospital were enrolled. EGFR, KRAS and EML4-ALK mutations were detected by qPCR. Clinical and pathological characteristics including gender, age, TNM stage, smoking status and CT pattern were analyzed. Histologic subtype was classified according to IASLC/ATS/ERS classification. At preoperative chest CT, the percentage of GGO volume, diameter, solid volume and total tumor volume of each tumor were measured by using a semiautomated algorithm. Distribution of driver gene mutations was evaluated by using the Fisher exact test, the Students t test, and Pearson correlation analysis. RESULTS AND CONCLUSION 788 in total and 158 GGO tumors were taken in this cohort. GGO pattern occurred at a significantly higher frequency in younger, female and non-smoking patients. EGFR/KRAS mutations and EML4-ALK fusions were similar between GGO and solid adenocarcinomas. GGO volume and diameter showed correlation with EGFR mutation. With regard to association between lung adenocarcinoma histological subtypes and GGO features, GGO proportion was significantly higher in lepidic predominant adenocarcinomas, including adenocarcinoma in situ, minimally invasive adenocarcinoma, and lepidic predominant invasive adenocarcinoma. No significant differences of driver gene mutations were found between subtypes of lung adenocarcinoma. It is important that we understand GGO lesions of lung adenocarcinoma to identify molecular biomarkers including EGFR, KRAS and EML4-ALK. These markers would offer useful information for determining the appropriate strategy to treat lung adenocarcinoma with GGO lesions detected by helical CT.

Risk factors for major adverse events of video-assisted thoracic surgery lobectomy for lung cancer.

Aims: The purpose of this study was to identify the risk factors for major adverse events of VATS (Video-Assisted Thoracic Surgery) lobectomy for primary lung cancer. Methods: 1806 Patients (1032 males, 57.1%) planned to undergo VATS lobectomy for stage IA-IIIA lung cancer from July 2007 to June 2012. The Thoracic Morbidity and Mortality Classification TM&M system was used to evaluate the presence and severity of complications. Postoperative complications were observed during a 30-day follow up. Univariate and multivariate analysis were used to analyze the independent risk factors for major adverse events. Results: Successful rate of VATS lobectomy was 97.6% (1763/1806). Major complications occurred in 129 patients (7.3%), with a mortality of 0.3% (5/1763). Pulmonary complications contribute up to 90.7% of the major complications and 80% of mortality. Logistic regression indicated that comorbidities, elder age ≥70y, operative time ≥240min and hybrid VATS were predictors for major adverse events (P<0.05). Hybrid and converted VATS lobectomy result in higher major adverse events compared with complete VATS, 15.1%, 20.9% and 7.4% respectively (P=0.013). Conclusions: The overall complication rate and mortality of VATS lobectomy are low, while major complications sometimes occur. Pulmonary complications are the most common major complications and cause of mortality. Age ≥70y, comorbidities, operative time ≥240min and Hybrid VATS are predictors of major adverse events.

Preoperative nomogram for identifying invasive pulmonary adenocarcinoma in patients with pure ground-glass nodule: A multi-institutional study.

Purpose To construct a preoperative nomogram to differentiate invasive pulmonary adenocarcinomas (IPAs) from preinvasive lesions in patients with solitary pure ground-glass nodules (GGN). Methods A primary cohort of patients with pathologically confirmed pulmonary solitary pure GGN after surgery were retrospectively studied at five institutions from January 2009 to September 2015. Half of the patients were randomly selected and assigned to a model-development cohort, and the remaining patients were assigned to a validation cohort. A nomogram predicting the invasive extent of the solitary GGNs was constructed based on the independent risk factors. Predictive performance was evaluated by concordance index (C-index) and calibration curve. Results Out of 898 cases included in the study, 501 (55.8%) were preinvasive lesions and 397 (44.2%) were IPAs. In the univariate analysis, lesion size (p < 0.001), lesion margin (p = 0.041), lesion shape (p < 0.001), mean computed tomography (CT) value (p = 0.018), presence of pleural indentation (p = 0.017), and smoking status (p = 0.014) were significantly associated with invasive extent. In multivariate analysis, lesion size (p < 0.001), lesion margin (p = 0.042), lesion shape (p < 0.001), mean CT value (p = 0.014), presence of pleural indentation (p = 0.026), and smoking status (p = 0.004) remained the predictive factors of invasive extent. A nomogram was developed and validation results showed a C-index of 0.94, demonstrating excellent concordance between predicted and observed results. Conclusions We established and validated a novel nomogram that can identify IPAs from preinvasive lesions in patients with solitary pure GGN.

Single-port video-assisted thoracic surgery in 1063 cases: a single-institution experience

OBJECTIVES Single-port video-assisted thoracic surgery (VATS) technique has been used for thoracic diseases. There was no report about single-port VATS in large series. Outcomes following single-port VATS were analysed to determine its efficacy and safety. METHODS From June 2012 to June 2014, 1063 single-port VATSs were performed by four surgeons. Patient demographics, perioperative parameters, histopathology and outcomes were analysed. RESULTS There were 1063 patients (524 men and 539 women). The median age was 56.1 ± 8.7 years (range, 15-86 years). Lobectomy was performed in 569 patients, segmentectomy in 162, wedge resection in 264, pleural biopsy in 7, drainage of effusion in 20, pleural tumour resection in 5, mediastinal tumour resection in 54, mediastinal tumour biopsy in 2, bilobectomy in 7, sleeve lobectomy in 3 and pneumonectomy in 2. Synchronous bilateral single-port VATS was performed in 27 cases, whereas metachronous bilateral single-port VATS was performed in 5 cases. Pathological diagnoses included primary lung cancer in 635 cases, metastatic lung cancer in 19, mediastinal tumour in 56, pleural disease in 32 and benign pulmonary conditions in 353. Fifteen intraoperative vascular injuries were identified in 15 patients. The total conversion rate was 4.6%. The average operation time was 135 ± 31 min (range, 30-230 min), and the average blood loss was 117 ± 47 ml (range, 50-2000 ml). The median intensive care unit stay was 1 day (0-4 days). The postoperative hospital stay was 6.2 ± 2.6 days on average. There was no operative death, and operative complications occurred in 59 patients (5.6%). The 1-year overall survival and 1-year disease-free survival for the primary lung cancer group were 98 and 96%, respectively. CONCLUSIONS Our findings indicate that single-port VATS for thoracic diseases is safe and feasible.

Air bronchogram: A potential indicator of epidermal growth factor receptor mutation in pulmonary subsolid nodules

OBJECTIVES Evaluation of pulmonary subsolid nodule is a longstanding clinical problem. We aimed to validate the computed tomography (CT) features correlating with pathological invasiveness and to explore any imaging findings associated with epidermal growth factor receptor (EGFR) mutation in lung adenocarcinoma. METHODS A total of 204 patients with pathologically proven stage IA adenocarcinoma who had preoperative CT and data on EGFR status were enrolled in this retrospective study. Quantitative CT features including tumor size and solid volume proportion (SVP) were measured on multiplanar reconstructed images. Pathological analysis was stratified into adenocarcinoma in situ and minimally invasive adenocarcinoma (AIS/MIA), and invasive adenocarcinomas (IAs). RESULTS There were 93 AIS/MIA and 111 IAs. EGFR mutation was detected in 109 (53.4%) cases. In radiopathological analysis, IAs were significantly in larger tumor size (15.8mm vs. 10.9mm), higher SVP (18.3% vs. 1.1%) and more likely to present air bronchogram, vascular invasion, lobulated/irregular shape, non-smooth margin and pleural tag than AIS/MIA. The multivariate logistic regression indicated that tumor size (OR=1.337) and SVP (OR=1.198) were significant differentiating factors of IAs from AIS/MIA. In radiogenomic analysis, EGFR status differed in tumor size, air bronchogram and margin. The multivariate logistic regression disclosed that the presence of an air bronchogram (OR=3.451) was significantly associated with EGFR mutation after adjustment for age, gender and smoking status. CONCLUSIONS In subsolid nodules, tumor size and SVP were significant predictors of pathological invasiveness. In addition, the presence of air bronchogram was suggestive of activated EGFR mutation.