Driver Mutations In Lung Cancer Research Articles

EP.02A.01 Gender-Specific Onset Age Distribution Among Different Driver Mutations in Lung Cancer

EP.02A.01 Gender-Specific Onset Age Distribution Among Different Driver Mutations in Lung Cancer

Potential role and prognostic value of Globo-H in lung cancer.

e20037 Background: Globo-H (GH), a globo-series carbohydrate antigen highly expressed on multiple epithelial cancers, is a promising target for cancer immunotherapy. Clinical trials have been conducted to evaluate the efficacy of anti-GH vaccine Adagloxad Simolenin/OBI-821 (in Ph 3) and OBI-833/OBI-821 (in Ph 2) in cancer patients. Epidermal growth factor receptor (EGFR) mutations are well known as a frequent class of driver mutations in lung cancer (LC), which are responsible for tyrosine kinase inhibitors. Besides high expression in cancer cells, GH has been implicated in regulation of EGFR signaling pathway. Knockdown of key enzyme involved in GH biosynthesis β1,3-galactosyltransferase V (β3GalT5) induces apoptosis through disruption of EGFR-related signaling protein complex. In addition, GH is reported to associate the EGFR mutant in LC patients. This study aims to further investigate the potential role of GH in LC. Methods: Clinical study: The level of GH expression was evaluated by immunohistochemistry (IHC) using H-score in clinical samples from 141 patients with lung adenocarcinoma. In vitro study: FACS and Western blotting methods were used to measure the levels of total EGFR, phospho-EGFRs or GH in LC cell lines. Microwestern protein array (MWA) analysis was performed in LC NCI-H1975 cells. Results: Clinical study: Positive GH expression (H score≥1; 18.4%) was significantly associated with poor differentiation grade (p = 0.044) in all samples and disease specific survival in patients with metastasis and stage 4 LC (p = 0.033). In vitro study: Inhibition of EGFR by an EGFR-specific shRNA resulted in a decrease of GH expression in LC cells while overexpression of EGFR resulted in an increase of GH levels. β3GalT5 knockout cells and anti-GH-antibody-treated cells showed a reduction of cell proliferation as well as the total level of EGFR and phosphor-EGFRs expression, which is consistent with the results from previous studies. MWA analysis on LC cells with β3GalT5 knockout, GH ceramide-treated β3GalT5 knockout cells and anti-GH Ab-treated LC cells indicated a positive correlation between the level of GH and EGFR-related signaling proteins including phosphor-JNK, phosphor-c-Jun, phosphor-PP2A, phosphor-PP2A, phosphor-AKT, and Cyclin D1 proteins. In addition, JNK signaling inhibitor partially reduced GH expression in NCI-H1975 cells. These results revealed the mechanistic link between GH regulation and tumor promoting signals in LC. Conclusions: GH expression was associated with the worse survival of LC patients in clinical setting. In addition, the level of GH is positively correlated with levels of EGFR and EGFR-related signaling proteins in vitro. Expression of GH can induce the expression of EGFR and vice versa in LC cells. Furthermore, EGFR downstream JNK signaling pathway might involve in GH regulation by EGFR. Taken together, GH-targeting therapy has a potential application for the treatment of LC patients.

Significance of programmed death-ligand 1 expression in resected lung cancer and its relationship with EGFR mutation.

Several studies have reported that the high expression of programmed death-ligand 1 (PD-L1) within tumor cells predicts a poor prognosis. However, the relationship between the PD-L1 expression and lymph node metastasis or driver mutations in lung cancer remains poorly understood. A total of 356 consecutive patients who underwent surgical resection for primary lung cancer were included in the study. There were 268 adenocarcinomas including 100 EGFR mutations, 67 squamous cell carcinomas (Sq), and 21 other histologies. The high expression of PD-L1 was defined as a tumor proportion score (TPS) of ≥50. The relationship between the PD-L1 expression and clinicopathological factors and recurrence-free survival (RFS) was analyzed. The PD-L1 expression was high in 75 patients. It was significantly related to smoking history, Sq histology, driver mutation negative, elevated serum carcinoembryonic antigen levels, and lymph node metastasis. Among patients with driver mutations, a high PD-L1 TPS was found in patients with EGFR G719X mutation. A significant difference in RFS was observed in adenocarcinoma patients. A multivariate analysis of adenocarcinoma cases revealed that tumor size and lymph node metastasis were independent prognostic factors for poor RFS, while the PD-L1 expression was not. A logistic regression analysis revealed that the absence of driver mutations, lymph node metastasis, and a history of smoking were significantly associated with the high expression of PD-L1. Lymph node metastasis was positively related with the high expression of PD-L1, resulting in poor RFS. A high PD-L1 TPS was observed in patients with the EGFR G719X mutation.

Features of anaplastic lymphoma kinase rearrangement in early-stage lung cancer: Analysis of a nationwide Japanese database.

Anaplastic lymphoma kinase (ALK) rearrangement is a representative driver mutation in lung cancer. However, the biology of early-stage ALK-rearranged lung cancer remains unclear. We aimed to assess the clinicopathological features, prognostic implications, and influence of ALK rearrangement on the postoperative course in surgically resected lung cancer. We retrospectively analyzed data from the Japanese Joint Committee of Lung Cancer Registry database. Of the 12 730 patients with lung adenocarcinoma, 794 (6.2%) were tested for ALK rearrangement and were included. ALK rearrangements were detected in 76 patients (10%). The 5-year overall survival (OS) rate was significantly higher in the ALK rearrangement-positive group than in the ALK rearrangement-negative group (p = 0.030). Multivariable analysis revealed that ALK rearrangement was an independent prognostic factor for improved OS (hazard ratio, 0.521; 95% confidence interval, 0.298-0.911; p = 0.022). Regarding the postrecurrence state, there was no difference in the initial recurrence sites between both groups. Administration of ALK-tyrosine kinase inhibitors (TKIs) improved postrecurrence survival in any treatment lines. In one of the largest national surveys, ALK rearrangement was associated with improved long-term outcomes in surgically resected patients. ALK-TKIs may be an important treatment strategy for ALK rearrangement-positive lung adenocarcinoma in the postrecurrence state.

Novel LTK fusions based on NGS sequencing data in Chinese patients with solid tumors.

3144 Background: Leukocyte receptor tyrosine kinase ( LTK) gene has the same kinase domain (PTKc_ALK_LTK) as ALK, and could functionally response to ALK inhibitors such as lorlatinib. Previous study reported that CLIP1-LTK fusion was a novel oncogenic driver mutation in lung cancer (occur in 0.4% of non-small cell lung cancer), which was sensitive to the ALK tyrosine kinase inhibitor lorlatinib. So far, LTK fusion has been rarely reported. Methods: A total of 11 Chinese solid tumor patients were reviewed, including 6 cases of LTK positive rearrangements in DNA and 5 cases of LTK positive fusion in RNA. FFPE samples were collected for NGS-based 450 cancer gene panel detection in both DNA and RNA level, and matched blood samples were used as normal control to filter out germline mutations. LTK fusions were analyzed by OrigiFus algorithm. Results: We found 6 patients with LTK rearrangements by DNA-based NGS detection, including lung adenocarcinoma, colorectal cancer, stomach cancer, spindle cell sarcoma of small intestine, adenocarcinoma of the pancreas, and cancer of unknown primary, and 5 soft tissue sarcoma patients with RPAP1 E25- LTK E2 fusions by RNA-based NGS detection. We analyzed the patterns of partner genes and breakpoints of the 6 LTK rearrangements. The partner genes included NUSAP1 (n=2), NDUFAF1 (n=1), LOC105370802 (n=1), EHD4 (n=1), and AGBL1 (n=1). All these partner genes were located on the same chromosome as LTK, rather than CLIP1, which was identified as a translocation. The breakpoints on LTK included exon20 (n=2), intron1 (n=2), exon6 (n=1), and exon10 (n=1). Five of the 6 fusions consisted of a complete PTKc_ALK_LTK domain. Among the 6 LTK rearrangements, LTK E20- NUSAP1 E2 was predicted as a fusion. Interestingly, this clinical real-world sample also harbored a classic NTRK1 fusion, LMNA E2- NTRK1 E11. The other NUSAP1- LTK was predicted to have a transcript of 3’-3’, but one of the breakpoints was observed at LTK exon6, which could be located at the kinase domain, so the possibility of eventual fusion cannot be excluded. The two NUSAP1-LTK fusions were found in a stomach tumor and a soft tissue sarcoma, respectively. One non-small-cell lung cancer (NSCLC) patient had a breakpoint detected on LTK exon10, which is the same as the exon of CLIP1- LTK reported. Conclusions: This study revealed novel LTK fusions/rearrangements and their cancer distribution in Chinese patients with solid tumors. We gave the details of these fusions/rearrangements which enrich our understanding of the LTK fusion. Although the small number of cases, our analysis promoted the attention on LTK and its potential value of drug research and clinical treatment in pan-cancer.

Comparative genomics between matched solid and lepidic portions of semi-solid lung adenocarcinomas

BackgroundGenetic changes that drive the transition from lepidic to invasive cancer development within a radiographic ground glass or semi-solid lung lesion (SSL) are not well understood. Biomarkers to predict the transition to solid, invasive cancer within SSL are needed. MethodsPatients with surgically resected SSL were identified retrospectively from a surgical database. Clinical characteristics and survival were compared between stage I SSL (n = 65) and solid adenocarcinomas (n = 120) resected during the same time period. Areas of normal lung, in situ lepidic, and invasive solid tumor were microdissected from within the same SSL specimens and next generation sequencing (NGS) and Affymetrix microarray of gene expression were performed. ResultsThere were more never smokers, Asian patients, and sub-lobar resections among SSL but no difference in 5-year survival between SSL and solid adenocarcinoma. Driver mutations found in both lepidic and solid invasive portion were EGFR (43%), KRAS (21%), and DNMT3A (5%). CEACAM5 was the most upregulated gene found in solid, invasive portions of SSL. Lepidic and invasive solid areas had many similarities in gene expression, however there were some significant differences with the gene SPP1 being a unique biomarker for the invasive component of a SSL. ConclusionsCommon lung cancer driver mutations are present in in situ lepidic as well as invasive solid portions of a SSL, suggesting early development of driver mutations. CEACAM5 and SPP1 emerged as promising biomarkers of invasive potential in semi-solid lesions. Other studies have shown both genes to correlate with poor prognosis in lung cancer and their role in evolution of semi-solid lung lesions warrants further study.

Clinicopathological characteristics and molecular analysis of lung cancer associated with ciliated muconodular papillary tumor/bronchiolar adenoma

Ciliated muconodular papillary tumor/bronchiolar adenoma (CMPT/BA) is a recently introduced benign lung tumor. It remains unclear whether CMPT/BA is associated with a specific type of lung cancer (LC). We studied the clinicopathological characteristics and genetic profiles of the coexisting primary LC and CMPT/BA (LCCM) cases. We identified eight LCCM (0.4%) from the resected Stage 0-III primary LC (n = 1945). The LCCM cohort was male-dominant (n = 8), elderly (median 72 years old), and most were smokers (n = 6). In addition to the adenocarcinoma (n = 8), we detected two squamous cell carcinomas and one small cell carcinoma-in some cases, multiple cancer. The target sequence/whole exome sequence (WES) revealed no shared mutations between CMPT/BA and LC. One exceptional case was invasive mucinous adenocarcinoma harboring an HRAS mutation (I46N, c.137T>A), but it was likely to be a single nucleotide polymorphism based on variant allele frequency (VAF). Other driver mutations in LC included EGFR (InDel, n = 2), BRAF(V600E) (n = 1), KRAS (n = 2), GNAS (n = 1), and TP53 (n = 2). BRAF(V600E) was the most frequent mutation in CMPT/BA (60%). In contrast, LC showed no specific trend in driver gene mutations. In conclusion, our study revealed differences in the gene mutation profiles of CMPT/BA and LC in coexisting cases, suggesting mostly independent clonal tumorigenesis of CMPT/BA from LC.

Advances in the Treatment of EGFR Exon 20ins Mutant NSCLC

Lung cancer has become one of the most dangerous cancers to human health and the mortality rate is the highest among all the causes of cancer death. Non-small cell lung cancer (NSCLC) accounts for about 80%-85% of lung cancer. Chemotherapy is the main treatment for advanced NSCLC, but the 5-year survival rate is low. Epidermal growth factor receptor (EGFR) mutations are the most common driver mutations in lung cancer, but EGFR exon 20 insertions (EGFR ex20ins) mutation belongs to one of the rare mutations, accounting for about 4%-10% of overall EGFR mutations, thus around 1.8% of advanced NSCLC patients. In recent years, targeted therapies represented by EGFR tyrosine kinase inhibitors (TKIs) have become an important treatment option for patients with advanced NSCLC, however, NSCLC patients with EGFR ex20ins mutation are not sensitive to most of EGFR-TKIs treatments. Currently, some of the targeted drugs for EGFR ex20ins mutation have achieved significant efficacy, while some of them are still under clinical investigation. In this article, we will describe various treatment methods for EGFR ex20ins mutation and their efficacy. .

A Novel TP53 Gene Mutation Sustains Non-Small Cell Lung Cancer through Mitophagy.

Lung cancer is the leading cause of cancer death in the world. In particular, non-small-cell lung cancer (NSCLC) represents the majority of the lung cancer population. Advances in DNA sequencing technologies have significantly contributed to revealing the roles, functions and mechanisms of gene mutations. However, the driver mutations that cause cancers and their pathologies remain to be explored. Here, we performed next-generation sequencing (NGS) on tumor tissues isolated from 314 Chinese NSCLC patients and established the mutational landscape in NSCLC. Among 656 mutations, we identified TP53-p.Glu358Val as a driver mutation in lung cancer and found that it activates mitophagy to sustain cancer cell growth. In support of this finding, mice subcutaneously implanted with NSCLC cells expressing TP53-p.Glu358Val developed larger tumors compared to wild-type cells. The pharmaceutical inhibition of autophagy/mitophagy selectively suppresses the cell proliferation of TP53-null or TP53-p.Glu358Val-expressing lung cancer cells. Together, our study characterizes a new TP53 mutation identified from Chinese lung cancer patients and uncovers its roles in regulating mitophagy, providing a new insight into NSCLC treatment.

Abstract 5781: Molecular positive margin of surgical resections is a strong biomarker for tumor recurrence in pIIIA-N2 NSCLC patients

Abstract Background: The high recurrence rate of stage pIIIA-N2 NSCLC patients may reflect inadequate removal of all residual tumor cells despite conventional histologic negative surgery margin. The NGS-detected BRM status was possible to serve as a more accurate examination to identify those patients with a high-risk of postoperative recurrence. Methods: We retrospectively studied 119 stage IIIA-N2 NSCLC patients who received curative-intent surgery plus adjuvant chemotherapy/chemoradiotherapy, and all of the patients were classified with negative resection margin by the conventional histologic method. Each patient had paired tumor and bronchial resection margin (BRM) samples, which were analyzed using next-generation sequencing (NGS) of 474 cancer-related genes, and we explored the prognostic values of various clinical and molecular features. Results: Among the 119 stage IIIA-N2 NSCLC patients with histologic negative resection margins, the BRM samples from 56 patients (47.1%) were positive for tumor mutations, including multiple lung cancer driver mutations. The number and the variant allele frequency of genetic alterations in BRM samples were generally lower than that of the paired tumor samples. Notably, patients who were positive for NGS-detected BRM mutations had significantly shorter disease-free survival (DFS) than the negative patients (p=0.001, HR 2.18, 95%CI 1.37~3.47). Several other clinical/molecular features were also found to be significantly associated with DFS, including the metastatic lymph node ratio (MLNR), smoking history, and KRAS mutation status, and NGS-assessed BRM status remained to be statistically significant in multivariable analysis by including all of these prognostic factors (p =0.020, HR 1.82, 95%CI 1.10~3.02). Conclusions: We demonstrated that the molecular positive margin of surgical resections was a strong and independent biomarker for disease recurrence in pIIIA-N2 NSCLC patients. Our results emphasized the clinical utility of molecular diagnostic approaches to detect minimal residual disease after surgical resection, which could potentially facilitate the stratification of high-risk patients for personalized and appropriate treatments. Citation Format: Li Li, Kewen He, Jiaohui Pang, Yang Xu, Yang Shao, Shuanghu Yuan, Jinming Yu. Molecular positive margin of surgical resections is a strong biomarker for tumor recurrence in pIIIA-N2 NSCLC patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5781.

Intra-tumor and Inter-tumor Heterogeneity in MET Exon 14 Skipping Mutations and Co-mutations in Pulmonary Pleomorphic Carcinomas

BackgroundMET exon 14 skipping mutation is a driver mutation in lung cancer and is highly enriched in pulmonary pleomorphic carcinomas (PPCs). Whether there is intratumor or intertumor heterogeneity in MET exon 14 skipping status or in co-occurring genetic alterations in lung cancers driven by MET exon 14 skipping is unknown. MethodsWe analyzed tumor specimens obtained from 23 PPC patients (10 autopsied and 13 surgically resected). MET exon 14 skipping was detected by RT-PCR. For patients with MET exon 14 skipping mutation, further analyses were performed. Genomic DNA (gDNA) was extracted from various histological components for each patient who underwent surgical resection (to assess intratumor heterogeneity). In autopsied patients, gDNA and total RNA were extracted from all metastatic lesions (to assess intertumor heterogeneity). ResultsMET exon 14 skipping mutation was detected in 4 patients (4/23, 17.4%): two surgically resected and two autopsied patients. We found no intratumor or intertumor heterogeneity in MET exon 14 skipping mutation status in these patients. We observed intratumor and intertumor heterogeneity in the copy number variations and/or mutational status of cancer-related genes; some of these differences may have an impact on MET tyrosine kinase inhibitor (TKI) efficacy. ConclusionIn our exploratory analysis of four cases, we observed that MET exon 14 skipping mutations are distributed homogeneously throughout histological components and between metastatic lesions. Our results also suggest that there is marked intertumor and intratumor heterogeneity in co-occurring genetic alterations, and therapeutic implications of such heterogeneity should be evaluated in future studies.

Assessment of Clonal Expansion Using CarcSeq Measurement of Lung Cancer Driver Mutations and Correlation With Mouse Strain- and Sex-Related Incidence of Spontaneous Lung Neoplasia.

Quantification of variation in levels of spontaneously occurring cancer driver mutations (CDMs) was developed to assess clonal expansion and predict future risk of neoplasm development. Specifically, an error-corrected next-generation sequencing method, CarcSeq, and a mouse CarcSeq panel (analogous to human and rat panels) were developed and used to quantify low-frequency mutations in a panel of amplicons enriched in hotspot CDMs. Mutations in a subset of panel amplicons, Braf, Egfr, Kras, Stk11, and Tp53, were related to incidence of lung neoplasms at 2 years. This was achieved by correlating median absolute deviation (MAD) from the overall median mutant fraction (MF) measured in the lung DNA of 16-week-old male and female, B6C3F1 and CD-1 mice (10 mice/sex/strain) with percentages of spontaneous alveolar/bronchioloalveolar adenomas and carcinomas reported in bioassay control groups. A total of 1586 mouse lung mutants with MFs >1 × 10-4 were recovered. The ratio of nonsynonymous to synonymous mutations was used to assess the proportion of recovered mutations conferring a positive selective advantage. The greatest ratio was observed in what is considered the most lung tumor-sensitive model examined, male B6C3F1 mice. Of the recurrent, nonsynonymous mouse mutations recovered, 55.5% have been reported in human tumors, with many located in or around the mouse equivalent of human cancer hotspot codons. MAD for the same subset of amplicons measured in normal human lung DNA samples showed a correlation of moderate strength and borderline significance with age (a cancer risk factor), as well as age-related cumulative lung cancer risk, suggesting MAD may inform species extrapolation.

Real-world efficacy and safety of lorlatinib in treating advanced ALK-positive non-small cell lung cancer patients.

Anaplastic lymphoma kinase (ALK) translocation is a rare driver mutation in lung cancer. This study was aimed to report on the efficacy of lorlatinib in real-world practice and to evaluate the impact of prior ALK inhibitor treatments. We retrospectively evaluated patients with ALK-positive non-small cell lung cancer (NSCLC) treated with lorlatinib regarding its efficacy, the impact of prior ALK inhibitor treatments and the adverse events, in particular dyslipidemia. A total of 22 ALK-positive patients were analyzed. All patients had received at least one second-generation ALK inhibitor(s), while 12 patients had a history of crizotinib treatment. For lorlatinib, the objective response rate was 35.7%, and disease control rate was 64.3%. Their progression-free survival (PFS) was 6.2 months. With prior therapies, patients receiving only second-generation ALK inhibitor(s) treatment showed PFS longer than those with both crizotinib and second-generation ALK inhibitor(s) treatments (15.2 vs. 6.2 months). Moreover, patients who showed benefits from prior ALK inhibitor(s) also had a PFS longer than those who did not (6.5 vs. 3.5 months). Regarding adverse events, 94.7% of patients had dyslipidemia and 21.1% of them were in grade 3 or 4. None of these patients discontinued the treatment due to dyslipidemia. No acute complication occurred with dyslipidemia. The real-world efficacy of lorlatinib and adverse events were similar to those reported in clinical trials. Interestingly, the history and responses of prior ALK inhibitor treatments may influence the efficacy of subsequent lorlatinib treatment.

Abstract 2525: Low frequency TP53 mutations in airway epithelial cells serve as lung cancer risk biomarker

Abstract Background: Lung cancer is the leading cause of cancer-related death in men and women in the United States. Based on evidence from controlled trials in the United States and Europe that low dose CT (LDCT) screening significantly reduces lung cancer mortality, the United States Preventative Services Tasks Force (USPSTF) recommends LDCT screening for individuals with high demographic risk based on age and smoking history. However, a large fraction of lung cancers occur in individuals who do not meet LDCT screening threshold criteria. Thus, there is a need for biomarkers that supplement demographic factors to more accurately detect those at highest lung cancer risk and include additional individuals who will benefit from LDCT screening. An initial study from this lab demonstrated that TP53 mutations with 0.05-1.0% variant allele fraction (VAF) were significantly more prevalent (p<0.005) in grossly normal airway epithelial cell (AEC) specimens from lung cancer cases compared to non-cancer controls matched for smoking and age. Here, we present an expanded follow-up study aimed at testing this biomarker according to PRospective-specimen-collection, retrospective-Blinded-Evaluation (PRoBE) design. Methods: AEC specimens were prospectively collected through the National Cancer Institute Early Detection Research Network (EDRN) program from 60 subjects at high demographic risk for lung cancer by bronchoscopic brush biopsy at Vanderbilt University Medical Center. Genomic (g)DNA was extracted from each AEC specimen and stored at -80 degrees Celsius. Subjects matched for age and smoking history who subsequently did or did not develop lung cancer were identified and gDNA specimens, blinded with respect to cancer status, were shipped to the University of Toledo. gDNA specimens were quantified and 50,000 gDNA copies were included in each NGS library preparation. Synthetic DNA internal standards (IS) were prepared for multiple lung cancer driver mutations within the TP53 gene and mixed with each AEC gDNA specimen prior to competitive multiplex PCR NGS library preparation. By controlling for technical error, this approach enables reliable detection of mutations with VAF as low as 5 x 10-4 (0.05%) (Craig et al, BMC Cancer, 2019). Results: Following library preparation and sequencing on Illumina Novaseq, there was sufficient library complexity to detect TP53 VAF <0.05% in >90% of AEC specimens. The data are currently in pipeline analysis. After analysis is complete, VCF files will be sent to Vanderbilt for unblinding and validation of the biomarker. Conclusions: Based on preliminary data, we expect that sufficient AEC gDNA is available from most subjects enrolled in the EDRN program for TP53 low VAF biomarker analysis, and the previously reported method (Craig et al, BMC Cancer, 2019) is reliable and feasible. The current study should provide additional information regarding validity of the biomarker. Citation Format: Daniel J. Craig, Erin L. Crawford, Pierre P. Massion, Thomas Morrison, James C. Willey. Low frequency TP53 mutations in airway epithelial cells serve as lung cancer risk biomarker [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2525.

Mutational analysis of rare insertions and deletions in exon 18 and 19 of HER2 in Chinese patients with different cancer types.

3069 Background: HER2 belongs to the same family with EGFR and is known as an important cancer driver gene. Kinase domain insertions and deletions (KD indels) are frequent driver mutations in both EGFR and HER2. The most common HER2 KD indels are the exon 20 insertions while others are rarely reported. Our study aimed to investigate the role of less common HER2 KD indels in solid tumors. Methods: This study was performed in 63,267 Chinese patients including 53,591 patients with lung cancer, 5,888 patients with colorectal cancer, 3,774 patients with breast cancer and 14 patients with renal pelvis cancer. Tissue or plasma samples from the patients were subjected to capture-based targeted sequencing covering HER2 and other cancer related genes. The sequencing data of each patient were retrospectively collected and analyzed. The HER2 exon 18/19 indels identified in our study were compared with data from COSMIC and MSKCC. In vitro analysis in Ba/F3 cell lines was performed to assess drug response of different HER2 exon 18/19 indels. Results: We identified recurrent HER2 KD indels in exon 18 and 19, with a frequency of 0.04% (25/63,267). The data from COSMIC and MSKCC reported the prevalence of HER2 exon 18/19 indels ranging from 0.04% to 0.23% among breast, cervical, and pancreatic cancers. In our study, HER2 exon 18/19 indels were identified in 20 patients with lung cancer (0.037%), two with colorectal cancer (0.034%), two with breast cancer (0.053%) and one with renal pelvis cancer (7.143%). Only two patients (8%) harbored concurrent actionable driver mutations including EGFR mutation and MET amplification. Meanwhile, high level of normalized allelic frequency of HER2 exon 18/19 indels was presented in most patients (22/25, 88%). In lung cancer, the presence of EGFR driver mutation was less common in patients with HER2 exon 18/19 indels than wild type HER2 (5% vs. 47.4%, p < 0.01). The rates of concurrent driver mutations in lung cancer were comparable between HER2 exon 18/19 indels and the two established HER2 drivers, exon 20 insertions and S310 mutations. The in vitro proliferation assay demonstrated that E698_P699insLL mutation in HER2 exon 18 and L755_E757delinsPQ mutation in HER2 exon 19 both conferred a survival advantage to Ba/F3 cells. Dose-response curves showed inhibitory effects on cell viability of several HER2 tyrosine kinase inhibitors including neratinib, lapatinib, poziotinib and afatinib. In particular, lapatinib, poziotinib and afatinib demonstrated comparable or stronger inhibitory ability toward the two HER2 mutants than wild type HER2 in terms of IC50. Conclusions: Our study revealed a novel class of HER2 KD indels in exon 18/19 that may act as driver mutations in several cancer types. The drug response observed in vitro indicated the potential to use anti- HER2 targeted therapies for HER2 exon 18/19 indels. Further studies on this rare type of HER2 mutation are warranted.

Plasmatic KRAS Kinetics for the Prediction of Treatment Response and Progression in Patients With KRAS-mutant Lung Adenocarcinoma

IntroductionKRAS is the most common driver mutation in lung cancer. ctDNA-based assessment offers advantages over tumor as a minimally invasive method able to capture tumor heterogeneity. Monitoring KRAS mutational load in ctDNA may be useful in the management of the patients. MethodsConsecutive patients diagnosed with KRAS mutant lung adenocarcinoma in the tumor biopsy were included in this study. Plasma samples were obtained at different time points during the course of the disease. KRAS mutations in plasma were quantified using digital PCR and correlated with mutations in tumor and with radiological response and progression. ResultsTwo hundred and forty-five plasma samples from 56 patients were analyzed. The rate of detection of KRAS mutations in plasma in our previously characterized KRAS-mutant cases was 82% overall, reaching 96% in cases with more than 1 metastatic location. The dynamics of KRAS mutational load predicted response in 93% and progression in 63% of cases, 33 and 50 days respectively in advance of radiological evaluation. Progression-free survival for patients in whom ctDNA was not detectable in plasma after treatment initiation was significantly longer than for those in whom ctDNA remained detectable (7.7 versus 3.2 months; HR: 0.44, p=0.004). ConclusionsThe detection of KRAS mutations in ctDNA showed a good correlation with that in tumor biopsy and, in most cases, predicted tumor response and progression to chemotherapy in advance of radiographic evaluation. The liquid biopsies for ctDNA-based molecular analyses are a reliable tool for KRAS testing in clinical practice.

The landscape of kinase domain duplication in Chinese lung cancer patients.

BackgroundKinase domain duplication (KDD) is a special type of large genomic rearrangement (LGR), occurring in the kinase domain of protein kinase genes. KDD of some lung cancer driver genes, such asEGFRKDD, has been identified and implicated to be oncogenic in non-small cell lung cancer (NSCLC). The present study aims to interrogate the spectrum of KDD occurring on classic driver genes in Chinese lung cancer patients without the presence of classic lung cancer driver mutations.MethodsWe retrospectively enrolled 10,525 Chinese lung cancer patients who met the following inclusion criteria; (I) do not carry classic lung cancer driver mutations in any of the 8 driver genes and (II) tyrosine kinase inhibitor (TKI)-naïve. Capture-based targeted sequencing was performed on tissue or plasma samples. LGR and KDD were identified by using in-house analysis scripts. The prevalence and distribution of LGR and KDD in our cohort were analyzed.ResultsThe median age of the cohort was 64 years with 68.7% being male. Among all patients, 23.2% and 51.8% were diagnosed with stage III and IV disease respectively. We identified 43 cases (0.41%) harboring LGR in one of the driver genes (EGFR/ERBB2/ALK/RET/ROS1/MET/BRAF), with 24 (0.23%) patients harboring KDD. Of the patients harboring KDD, a majority (n=19) harbored canonical EGFR-KDD involving exons 18–25, whilst one patient harbored duplications of EGFR exons 18–26. There were three MET-KDD patients; in two, the alteration occurred in exons 15–21 and in one, the alteration occurred in exons 3–21. One patient harbored RET-KDD involving exons 12–18. KDD showed a comparable prevalence in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) (0.33% vs. 0.11%, P=0.118). Nineteen non-KDD LGRs, spanning six genes including EGFR (n=6), MET (n=3), ALK (n=4), ROS1 (n=2), ERBB2 (n=2) and BRAF (n=2), were found, each occurring in one patient. The prevalence of LGR in LUADs and LUSCs was comparable (0.55% vs. 0.38%, P=0.452).ConclusionsWe observed a prevalence of 0.41% and 0.23% for LGR and KDD, respectively. Twenty-four different LGR alterations, including 5 KDDs and 19 non-KDD LGRs, were observed. KDDs mainly occurred in EGFR involving exons 18–25 and non-KDD LGRs were distributed more randomly. The prevalence of LGR/KDD in LUSCs and LUADs was comparable.

Can Nutritional Supplementation Increase the Risk Of Crizotinib-Associated Hepatotoxicity: A Clinical Case Example

Non-small cell lung cancer (NSCLC) is the leading cause of cancer death. The identification of oncogenetic driver mutation in lung cancer led to a therapeutic revolution by the discovery of targetable genetic alterations including the anaplasic lymphoma kinase (ALK) fusion oncogene and ROS1 . The tyrosine kinase inhibitor “Crizotinib” improved clinical outcome and prolonged responses. Severe hepatotoxicity is a rare adverse event .We report a case of Crizotinib-induced acute hepatitis with a probable drug-bergamot interaction

Genome analysis of peeling archival cytology samples detects driver mutations in lung cancer.

IntroductionsWhen tumor tissue samples are unavailable to search for actionable driver mutations, archival cytology samples can be useful. We investigate whether archival cytology samples can yield reliable genomic information compared to corresponding formalin‐fixed paraffin‐embedded (FFPE) tumor samples.Patients and MethodsPretreatment class V archival cytology samples with adequate tumor cells were selected from 172 lung cancer patients. The genomic profiles of the primary lung tumors have been analyzed through whole‐exome regions of 53 genes. We compared the genomic profiles based on the oncogenicity and variant allele frequency (VAF) between the archival cytology and the corresponding primary tumors. We also analyzed the genomic profiles of serial cytological samples during the treatment of EGFR‐TKI.ResultsA total of 43 patients were analyzed with the paired samples for DNA mutations and other three patients were analyzed for their fusion genes. A total of 672 mutations were detected. Of those, 106 mutations (15.8%) were shared with both samples. Sixty of seventy‐seven (77.9%) shared mutations were oncogenic or likely oncogenic mutations with VAF ≧10%. As high as 90% (9/10) actionable driver mutations and ALK and ROS1 fusion genes were successfully detected from archival cytology samples. Sequential analysis revealed the dynamic changes in EGFR‐TKI‐resistant mutation (EGFR p.T790M) during the course of treatment.ConclusionArchival cytology sample with adequate tumor cells can yield genetic information compared to the primary tumors. If tumor tissue samples are unavailable, we can use archival cytology samples to search for actionable driver mutations.

Plasmatic KRAS Kinetics for the Prediction of Treatment Response and Progression in Patients With KRAS-mutant Lung Adenocarcinoma

IntroductionKRAS is the most common driver mutation in lung cancer. ctDNA-based assessment offers advantages over tumor as a minimally invasive method able to capture tumor heterogeneity. Monitoring KRAS mutational load in ctDNA may be useful in the management of the patients. MethodsConsecutive patients diagnosed with KRAS mutant lung adenocarcinoma in the tumor biopsy were included in this study. Plasma samples were obtained at different time points during the course of the disease. KRAS mutations in plasma were quantified using digital PCR and correlated with mutations in tumor and with radiological response and progression. ResultsTwo hundred and forty-five plasma samples from 56 patients were analyzed. The rate of detection of KRAS mutations in plasma in our previously characterized KRAS-mutant cases was 82% overall, reaching 96% in cases with more than 1 metastatic location. The dynamics of KRAS mutational load predicted response in 93% and progression in 63% of cases, 33 and 50 days respectively in advance of radiological evaluation. Progression-free survival for patients in whom ctDNA was not detectable in plasma after treatment initiation was significantly longer than for those in whom ctDNA remained detectable (7.7 versus 3.2 months; HR: 0.44, p=0.004). ConclusionsThe detection of KRAS mutations in ctDNA showed a good correlation with that in tumor biopsy and, in most cases, predicted tumor response and progression to chemotherapy in advance of radiographic evaluation. The liquid biopsies for ctDNA-based molecular analyses are a reliable tool for KRAS testing in clinical practice.