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Purpose: Advanced non–small-cell lung cancer (NSCLC) patients harboring epidermal growth factor receptor (EGFR) mutations (deletion in exon 19 or L858R) show an impressive progression-free survival of 14 months when treated with erlotinib. However, the presence of EGFR mutations can only imperfectly predict outcome. We hypothesized that progression-free survival could be influenced both by the pretreatment EGFR T790M mutation and by components of DNA repair pathways.Experimental Design: We assessed the T790M mutation in pretreatment diagnostic specimens from 129 erlotinib-treated advanced NSCLC patients with EGFR mutations. The expression of eight genes and two proteins involved in DNA repair and four receptor tyrosine kinases was also examined.Results: The EGFR T790M mutation was observed in 45 of 129 patients (35%). Progression-free survival was 12 months in patients with and 18 months in patients without the T790M mutation (P = 0.05). Progression-free survival was 27 months in patients with low BRCA1 mRNA levels, 18 months in those with intermediate levels, and 10 months in those with high levels (P = 0.02). In the multivariate analysis, the presence of the T790M mutation (HR, 4.35; P = 0.001), intermediate BRCA1 levels (HR, 8.19; P < 0.0001), and high BRCA1 levels (HR, 8.46; P < 0.0001) emerged as markers of shorter progression-free survival.Conclusions: Low BRCA1 levels neutralized the negative effect of the T790M mutation and were associated with longer progression-free survival to erlotinib. We advocate baseline assessment of the T790M mutation and BRCA1 expression to predict outcome and provide alternative individualized treatment to patients based on T790M mutations and BRCA1 expression. Clin Cancer Res; 17(5); 1–9. ©2011 AACR.

Supplementary Figures S1-S3; Supplementary Tables S1-S14.

Management of low-grade gliomas (LGG) is based on clinical and radiologic features, including the Pignatti prognostic scoring system, which classifies patients as low- or high-risk. To determine whether molecular data can offer advantages over these features, we have examined the prognostic impact of several molecular alterations in LGG. In a cohort of 58 patients with LGG, we have retrospectively analyzed clinical and molecular characteristics, including the Pignatti criteria, IDH mutations, TP53 mutations, the 1p/19q deletion, and MGMT methylation, and correlated our findings with progression-free survival (PFS) and overall survival (OS). Mean age of patients was 45 years; 71% were classified as low-risk by the Pignatti system. IDH mutations were detected in 62%, p53 mutations in 17%, the 1p/19q codeletion in 46%, and MGMT methylation in 40% of patients. Survival analyses were performed in the 49 patients without contrast enhancement. In the univariate analysis, IDH mutations, the 1p/19q codeletion, and the combination of IDH mutations with the 1p/19q codeletion were associated with both longer PFS (P = 0.006, P = 0.037, and P = 0.003, respectively) and longer OS (P < 0.001, P = 0.02, and P < 0.001, respectively). The multivariate analysis identified absence of IDH mutations as a factor for greater risk of progression [hazard ratio (HR) = 3.1; P = 0.007]and death (HR = 6.4; P < 0.001). We suggest that IDH mutations may be more effective than the Pignatti score in discriminating low- and high-risk patients with LGG.

Background: Recurrent and metastatic head and neck squamous cell carcinoma (HNSCC) has a dismal prognosis with limited progressionfree survival and overall survival, even when treated with different combinations of chemotherapy, targeted therapies and immunotherapy. We explored in vitro and in vivo the effect of the epidermal growth factor (EGFR) inhibitor, osimertinib, alone and in combination with dihydroartemisinin (DHA) in HNSCC. Methods: The combination of osimertinib with DHA was tested in the FaDu and CAL27 HNSCC cell lines. Tumor cell proliferation assays were conducted in cultured cells and mouse xenografts. Western blotting analysis of related signal pathways was performed to investigate the molecular mechanisms of the inhibitory effect of DHA and the combination. Other compounds, which inhibit signal transducer and activator of transcription 3 (STAT3), Src-family kinases (SFKs), sphingosine kinase 1 (SPHK1), or the receptor tyrosine kinase (RTK) AXL were also combined with osimertinib in vitro. Results: Osimertinib exerted synergistic cytotoxicity toward FaDu and CAL27 HNSCC cells when combined with DHA. DHA reversed the osimertinibinduced STAT3 and Src phosphorylation. The double combination inhibited AXL expression. The anticancer potential of osimertinib plus DHA combination was validated in vivo on FaDu and CAL27 xenografts in mice with significant tumor regression. Interpretation: The results illustrate that the combinatory therapy of osimertinib and DHA, as a repurposing anticancer drug, could be a novel therapeutic strategy for recurrent and/or metastatic HNSCC patients. The findings strongly indicate that a clinical trial is warranted to confirm the benefit of the combination. Funding Statement: Work in Dr. Rosell's laboratory is partially supported by a grant from La Caixa Foundation, an Instituto de Salud Carlos III grant (RESPONSE, PIE16/00011), an Instituto de Salud Carlos III grant (PI14/01678), a Marie Sklodowska-Curie Innovative Training Networks European Grant (ELBA No 765492) and a Spanish Association Against Cancer (AECC) grant (PROYE18012ROSE). Work in Dr. Cao's laboratory is partially supported by the Major National Science and Technology Program of China for Innovative Drug (2017ZX09101002-002-006), the Priority Academic Program Development of Jiangsu Higher Education Institutions (Integration of Chinese and Western Medicine) grant and Key R&D Program of Jiangsu Province (BE2018755). Declaration of Interests: The authors declare no potential conflicts of interest. Ethics Approval Statement: All procedures were based on Guide for Care and Use of Laboratory Animals of National Institutes of Health and approved by Institutional Animal Care and Use Committee of Jiangsu Province Academy of Traditional Chinese Medicine (SYXK 2016-0018).

Osimertinib is efficacious in lung cancer patients with epidermal growth factor receptor (Serum/plasma fromThirteen patients were included. Median time on osimertinib treatment was 10.6 months with a median progression-free survival of 13.6 months. Best response to osimertinib was partial response (PR), stable disease (SD) or progression (PD) in 46.1%, 30.8% and 23.1% of patients, respectively.Most of the patients were paucisymptomatic at baseline. Symptom improvement was reported in 66.6% of responder patients; while symptoms remained stable in 75% of patients with SD, and 66% of patients with PD had clinical deterioration.Three patterns of T790M changes during osimertinib treatment were identified. T790 remained detectable with PD or a short-lasting SD in 15.4% of the patients. T790M disappeared in 69.2% of patients with PR or SD. T790M disappeared, despite clinical and/or radiographic progression in 15.4% of the patients.Changes of T790M in serum/plasma in

Objective Homologous recombination (HR) is frequently impaired in sporadic high-grade serous ovarian carcinoma (sHGSOC) due to deficiencies in BRCA1/2 genes, a situation associated with hypersensitivity to platinum compounds. Alterations in other genes can also cause HR deficiency. Preclinical data show that RAP80 is an HR–pathway-related gene that influences BRCA1 activity. RAP80 has been reported to affect outcome in some solid neoplasms. This study investigates the role of RAP80 in sHGSOC survival. Methods mRNA expression of RAP80 was analyzed in tumor samples from 35 patients who postoperatively received standard platinum-based chemotherapy. The effects of RAP80 expression on progression-free survival (PFS) and overall survival (OS) were examined by means of Cox regressions. The clinical variables known to have prognostic value (FIGO stage, residual disease at surgery, and debulking surgery) were included as covariates in the analysis. BRCA1 was analyzed given the moderate correlations with RAP80. Results Median follow-up, PFS and OS were 61.3, 20.2 and 62.8 months, respectively. Low RAP80 expression levels were associated with shorter PFS ( HR = 1.449, p = 0.007) and OS ( HR = 1.331, p = 0.047). Conclusions This is the first study to show a potential prognostic role of RAP80 expression in patients with HGSOC. The results suggest that HR deficiency due to low RAP80 expression is not associated with hypersensitivity to platinum compounds in sHGSOC.

Background: The efficacy of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in EGFR-mutant non-small cell lung cancer (NSCLC) is limited by adaptive activation of cell survival signals. We hypothesized that both signal transducer and activator of transcription 3 (STAT3) and Src-YES-associated protein 1 (YAP1) signaling are dually activated during EGFR TKI treatment to limit therapeutic response.Methods: We used MTT and clonogenic assays, immunoblotting, and quantitative polymerase chain reaction to evaluate the efficacy of EGFR TKI alone and in combination with STAT3 and Src inhibition in three EGFR-mutant NSCLC cell lines. The Chou-Talalay method was used for the quantitative determination of drug interaction. We examined tumor growth inhibition in one EGFR-mutant NSCLC xenograft model (n = 4 mice per group). STAT3 and YAP1 expression was evaluated in tumors from 119 EGFR-mutant NSCLC patients (64 in an initial cohort and 55 in a validation cohort) by quantitative polymerase chain reaction. Kaplan-Meier and Cox regression analyses were used to assess the correlation between survival and gene expression. All statistical tests were two-sided.Results: We discovered that lung cancer cells survive initial EGFR inhibitor treatment through activation of not only STAT3 but also Src-YAP1 signaling. Cotargeting EGFR, STAT3, and Src was synergistic in two EGFR-mutant NSCLC cell lines with a combination index of 0.59 (95% confidence interval [CI] = 0.54 to 0.63) for the PC-9 and 0.59 (95% CI = 0.54 to 0.63) for the H1975 cell line. High expression of STAT3 or YAP1 predicted worse progression-free survival (hazard ratio [HR] = 3.02, 95% CI = 1.54 to 5.93, P = .001, and HR = 2.57, 95% CI = 1.30 to 5.09, P = .007, respectively) in an initial cohort of 64 EGFR-mutant NSCLC patients treated with firstline EGFR TKIs. Similar results were observed in a validation cohort.Conclusions: Our study uncovers a coordinated signaling network centered on both STAT3 and Src-YAP signaling that limits targeted therapy response in lung cancer and identifies an unforeseen rational upfront polytherapy strategy to minimize residual disease and enhance clinical outcomes.

Purpose: Advanced non–small-cell lung cancer (NSCLC) patients harboring epidermal growth factor receptor (EGFR) mutations (deletion in exon 19 or L858R) show an impressive progression-free survival of 14 months when treated with erlotinib. However, the presence of EGFR mutations can only imperfectly predict outcome. We hypothesized that progression-free survival could be influenced both by the pretreatment EGFR T790M mutation and by components of DNA repair pathways. Experimental Design: We assessed the T790M mutation in pretreatment diagnostic specimens from 129 erlotinib-treated advanced NSCLC patients with EGFR mutations. The expression of eight genes and two proteins involved in DNA repair and four receptor tyrosine kinases was also examined. Results: The EGFR T790M mutation was observed in 45 of 129 patients (35%). Progression-free survival was 12 months in patients with and 18 months in patients without the T790M mutation (P = 0.05). Progression-free survival was 27 months in patients with low BRCA1 mRNA levels, 18 months in those with intermediate levels, and 10 months in those with high levels (P = 0.02). In the multivariate analysis, the presence of the T790M mutation (HR, 4.35; P = 0.001), intermediate BRCA1 levels (HR, 8.19; P < 0.0001), and high BRCA1 levels (HR, 8.46; P < 0.0001) emerged as markers of shorter progression-free survival. Conclusions: Low BRCA1 levels neutralized the negative effect of the T790M mutation and were associated with longer progression-free survival to erlotinib. We advocate baseline assessment of the T790M mutation and BRCA1 expression to predict outcome and provide alternative individualized treatment to patients based on T790M mutations and BRCA1 expression. Clin Cancer Res; 17(5); 1–9. ©2011 AACR.

Importance The EURTAC trial demonstrated the greater efficacy of erlotinib compared with chemotherapy for the first-line treatment of European patients with advanced non–small-cell lung cancer (NSCLC) harboring oncogenic epidermal growth factor receptor ( EGFR ) mutations (exon 19 deletion or L858R mutation in exon 21) in tumor tissue. Objective To assess the feasibility of using circulating free DNA (cfDNA) from blood samples as a surrogate for tumor biopsy for determining EGFR mutation status and to correlate EGFR mutations in cfDNA with outcome. Design, Setting, and Participants This prespecified analysis was a secondary objective of the EURTAC trial using patients included in the EURTAC trial from 2007 to 2011 with available baseline serum or plasma samples. Patients had advanced NSCLC, oncogenic EGFR mutations in the tumor, and no prior chemotherapy for metastatic disease and were treated with erlotinib or chemotherapy. EGFR mutations were examined in cfDNA isolated from 97 baseline blood samples by our novel peptide nucleic acid–mediated 5´ nuclease real-time polymerase chain reaction (TaqMan) assay. Main Outcomes and Measures Overall survival (OS), progression-free survival (PFS), and response to therapy were correlated with type of EGFR mutations in cfDNA. Results In samples from 76 of 97 (78%) patients with usable blood samples, EGFR mutations in cfDNA were detected. Median OS was shorter in patients with the L858R mutation in cfDNA than in those with the exon 19 deletion (13.7 [95% CI, 7.1-17.7] vs 30.0 [95% CI, 19.3-37.7] months; P EGFR mutations in cfDNA identified the L858R mutation in tumor tissue or in cfDNA as a marker of shorter OS (hazard ratio [HR], 2.70 [95% CI, 1.60-4.56]; P P = .008). For patients with the L858R mutation in tissue, median OS was 13.7 (95% CI, 7.1-17.7) months for patients with the L858R mutation in cfDNA and 27.7 (95% CI, 16.1-46.2) months for those in whom the mutation was not detected in cfDNA (HR, 2.22 [95% CI, 1.09-4.52]; P = .03). In the multivariate analysis of the 76 patients with EGFR mutations in cfDNA, only erlotinib treatment remained an independent predictor of longer PFS (HR, 0.41 [95% CI, 0.23-0.74]; P = .003). Conclusions and Relevance The peptide nucleic acid–mediated 5´ nuclease real-time polymerase chain reaction (TaqMan) assay used in this study can be used to efficiently assess EGFR mutations in cfDNA. The L858R mutation in cfDNA may be a novel surrogate prognostic marker. Trial Registration clinicaltrials.gov Identifier:NCT00446225

The presence of single nucleotide polymorphisms (SNPs) in DNA repair genes, such as xeroderma pigmentosum group D (XPD), can impair DNA repair capacity, thereby affecting chemotherapy efficacy and clinical outcome of patients. Assessment of XPD polymorphisms can permit better stratification of patients into more refined risk categories and optimize decision-making for multidisciplinary treatment in locally advanced nonsmall cell lung cancer (NSCLC). Objective: The aim of this study was to evaluate whether xeroderma pigmentosum group D (XPD) and ribonucleotide reductase subunit M1 (RRM1) polymorphisms influenced clinical outcome in patients with stage IIIA-B nonesmall-cell lung cancer (NSCLC) treated with neoadjuvant gemcitabine/cisplatin/docetaxel followed by surgery. Materials and Methods: A total of 109 patients with stage IIIA and IIIB NSCLC were prospectively genotyped to examine a potential association between XPD 312 (aspartic acid [Asp]/asparagine [Asn]), XPD 751 (lysine [Lys]/glutamine [Gln]), and RRM1 (-37 C/A) polymorphisms with response and survival. Results: The median survival was 32.14 months for carriers of XPD 312 Asp/Asp and 12.04 months for those with the variant Asn allele (P = .05). In addition, event-free survival was longer for patients with the XPD 312 Asp/Asp genotype compared with patients with Asp/Asn or Asn/Asn (P = .03). A similar but nonsignificant trend was observed for the XPD 751 genotype. In a multivariate analysis, complete resection and age emerged as prognostic factors for overall survival; in patients with incomplete resection or exploratory thoracotomy, XPD 312 was the most significant prognostic factor (P = .03). Conclusion: The XPD 312 single nucleotide polymorphism is a prognostic factor for survival in patients with locally advanced NSCLC receiving induction.

The EURTAC trial demonstrated that the tyrosine kinase inhibitor (TKI) erlotinib was superior to chemotherapy as first-line therapy for advanced non-small cell lung cancers (NSCLC) that harbor EGFR activating mutations in a predominantly Caucasian population. Based on EURTAC and several Asian trials, anti- EGFR TKIs are standard of care for EGFR mutation-positive NSCLC. We sought to validate a rapid multiplex EGFR mutation assay as a companion diagnostic assay to select patients for this therapy. Samples from the EURTAC trial were prospectively screened for EGFR mutations using a combination of laboratory-developed tests (LDTs), and tested retrospectively with the cobas EGFR mutation test (EGFR PCR test). The EGFR PCR test results were compared to the original LDT results and to Sanger sequencing, using a subset of specimens from patients screened for the trial. Residual tissue was available from 487 (47%) of the 1044 patients screened for the trial. The EGFR PCR test showed high concordance with LDT results with a 96.3% overall agreement. The clinical outcome of patients who were EGFR -mutation detected by the EGFR PCR test was very similar to the entire EURTAC cohort. The concordance between the EGFR PCR test and Sanger sequencing was 90.6%. In 78.9% of the discordant samples, the EGFR PCR test result was confirmed by a sensitive deep sequencing assay. This retrospective study demonstrates the clinical utility of the EGFR PCR test in the accurate selection of patients for anti- EGFR TKI therapy. The EGFR PCR test demonstrated improved performance relative to Sanger sequencing.

Background: c-Met mutations play a critical role in the development and progression of primary tumors and metastases. Activation of the HGF/SF-c-Met pathway determines a poor prognosis in non-small-cell and small-cell lung cancer (SCLC) patients. Missense mutations of c-Met have been identified in SCLC patients located in the juxtamembrane (JM) and in the Sema domain. To determine the role of the c-Met pathway in SCLC, we have investigated the presence of c-Met mutations in SCLC patients. Patients and methods: Forty-four tumor tissue samples from SCLC patients were obtained with bronchoscopy before beginning treatment. Analysis of c-Met mutations was performed in exon 2 and exon 14. Results: Of the 44 patients included in this study, 23 were classified as limited disease and were treated with sequential or concurrent chemotherapy and thoracic radiotherapy. Twenty-one patients with extensive disease received chemotherapy alone, the majority with cisplatin or carboplatin plus etoposide. The median survival was 14 months (95% CI: 9.4 to 18.5 months) and the 2- and 5-year survival rates were 24% and 15%, respectively. Previously identified missense mutations E168D, R988C and T1010I in c-Met were not found in our study. However, novel mutations were identified, including T995I in the juxtamembrane domain (T995I) and a mutation which does not change amino acid in codon 178 in the Sema domain. Conclusion: In SCLC patients, the presence of mutations in c-Met gene is a rare event. Other genetic alterations involved in the HGF/SF-c-Met pathway should be assessed to define the role of this signaling pathway in SCLC.

Background Immunohistochemistry (IHC) with mutation-specific antibodies may be an ancillary method of detecting EGFR mutations in lung cancer patients. Methods EGFR mutation status was analyzed by DNA assays, and compared with IHC results in five non-small-cell lung cancer (NSCLC) cell lines and tumor samples from 78 stage IV NSCLC patients. Results IHC correctly identified del 19 in the H1650 and PC9 cell lines, L858R in H1975, and wild-type EGFR in H460 and A549, as well as wild-type EGFR in tumor samples from 22 patients. IHC with the mAb against EGFR with del 19 was highly positive for the protein in all 17 patients with a 15-bp (ELREA) deletion in exon 19, whereas in patients with other deletions, IHC was weakly positive in 3 cases and negative in 9 cases. IHC with the mAb against the L858R mutation showed high positivity for the protein in 25/27 (93%) patients with exon 21 EGFR mutations (all with L858R) but did not identify the L861Q mutation in the remaining two patients. Conclusions IHC with mutation-specific mAbs against EGFR is a promising method for detecting EGFR mutations in NSCLC patients. However these mAbs should be validated with additional studies to clarify their possible role in routine clinical practice for screening EGFR mutations in NSCLC patients.

Nicotine acetylcholine receptors (nAChRs) are associated with resistance to gemcitabine, cisplatin and paclitaxel in non-small-cell lung cancer (NSCLC) cell lines. Three single nucleotide polymorphisms (SNPs) of CHRNA3, CHRNA5 and LOC123688 increase lung cancer risk. These SNPs may have influenced outcome in patients treated in our phase III trial. Stage IV NSCLC patients were treated with customized chemotherapy based on ERCC1 (excision repair cross-complementing 1) mRNA expression. Patients in the control arm received docetaxel/cisplatin; patients in the genotypic arm with low levels of ERCC1 received docetaxel/cisplatin; patients in the genotypic arm with high levels of ERCC1 received docetaxel/gemcitabine. DNA was extracted from lymphocytes, and CHRNA3 (rs1051730), CHRNA5 (rs16969968) and LOC123688 (rs8034191) SNPs were genotyped with the Taqman allele discrimination assay. A significant interaction was found for CHRNA3 and PS (P = 0.02). In patients with PS 0, CT patients had a better response than both CC (P = 0.01) and TT (P = 0.02) patients, and patients in the low genotypic group also had a better response (P = 0.01). When the CHRNA3 genotype was added in the multivariate analysis for progression-free survival, an improvement was observed in the low genotypic group in PS 0 patients (P = 0.02). PS 0 patients in the low genotypic group with the CT genotype attained an 84% response rate, 12.1-month progression-free survival, and 19-month median survival. CHRNA3 (rs1051730) genotyping can improve customized chemotherapy based on tumor assessment of ERCC1 mRNA in stage IV NSCLC with PS 0.

In spite of the dismal outcome of glioblastoma multiforme (GBM), we are in a position to provide a ray of hope to patients and families. Methylation of MGMT in tumor occurs in approximately a third of patients and predicts meaningful response and survival to adjuvant radiotherapy plus temozolomide. Limited access to tumor tissue in some patients could be circumvented by examining MGMT methylation in circulating serum DNA, although this approach needs to be validated. Molecular signatures are also promising prognostic and predictive markers, and clinical trials should be carried out to validate their use in the selection of patients for specific targeted therapies. Gene expression by quantitative PCR of key components of these molecular signatures could pave the way for easy identification of different subgroups of patients. Translational clinical trials are warranted in order to detect the subgroups of patients resistant to radiotherapy who may derive benefit from novel therapies, including antiangiogenic drugs.

e16571 Background: Genome instability is a major feature of high-grade serous ovarian carcinomas (HGSOC), partially driven by defects in homologous recombination (HR). BRCA1 promoter hypermethylati...

2046 Background: Current therapy of LGG is based on clinical, radiologic and histologic ( Pignatti prognostic classification ) features .In the last years genomic profile of LGG has been investigat...

e19112 Background: EGFR-m in NSCLC and its responsiveness to TKI has proved beneficial in a subset of NSCLC patients (p) Breast cancer (BC) represents the most incident neoplasm among women. The co...

Germline inactivation of LKB1 is responsible for Peutz-Jeghers syndrome, an autosomal dominant disorder characterized by benign hamartomas of the GI tract and an increased predisposition to certain cancers, including lung. Acquired mutations in LKB1 are rarely observed in most sporadic tumor types except for adenocarcinomas of the lung where up to 50% harbor inactivating mutations. In this study, we focused on LKB1 mutations in lung cancer cell lines originating from large cell carcinomas. We identified a novel 1.5kb interstitial deletion within LKB1 gene in H157 cancer cells. Homozygosity mapping-of-deletion analysis (HOMOD) analysis showed that the deletion is accompanied by LOH of one parental allele, indicating biallelic inactivation of LKB1. This deletion results in an LKB1 transcript lacking exons 2 and 3 and a predicted in-frame deletion of 58 amino acids within the kinase domain of the LKB1 protein. The truncated transcript was expressed at relatively low levels, and the truncated LKB1 protein was virtually undetectable in this cell line. To determine the impact of LKB1 protein truncation on its function, we examined AMPK-alpha, a downstream target of LKB1 kinase activity triggered by low energy stress conditions. Phosphorylation of AMPK-alpha was attenuated in H157 cells treated with 2-deoxyglucose, and could be rescued by expression of an exogenous GFP-LKB1 fusion protein. Therefore, our data suggest that LKB1 function is compromised in H157. Of the four cell lines and six primary tumors of large cell lung carcinoma origin that have been evaluated in this and other studies, LKB1 mutations have been found in three cases. These results suggest that, in addition to adenocarcinomas, acquired loss of function mutations in LKB1 may also be frequently involved in the pathogenesis of large cell lung carcinomas.

Gene methylation and K-ras mutations were examined in tumor and paired serum DNA of 50 resected non-small-cell lung cancer patients. RASSF1A, death associated protein kinase and target of methylation-induced silencing were methylated in 17/50 (34%), 23/50 (45%) and 18/50 (35%) tumors, respectively, and in 17/50 (34%), 20/50 (40%) and 17/50 (34%) sera, respectively. Methylation in tumor and serum were closely correlated (P=0.001), but no correlation was found with survival. Twelve K-ras mutations (cysteine) were found in serum and nine mutations were found in tumor (five cysteine, one alanine, one aspartic, one arginine, and one valine). K-ras mutations in serum correlated significantly with survival (P=0.01).

e22110 Background: Identification of distinct oncogenic driver mutations is routinely used to guide clinical care in NSCLC patients (p). Tumor tissue availability is one of the major challenges for...

e19088 Background: Treatment of EGFR mutated NSCLC p with EGFR TKIs in phase III trials has shown improved efficacy to standard chemotherapy. However, it can be difficult to obtain sufficient tumor tissue for analysis of EGFR m status in a large proportion of p. Nevertheless, so far, no data exists for NSCLC p treated according to EGFR m status in serum alone. Methods: We reviewed our database to identify EGFR mutated p, excluding those for whom status was available in both serum and tissue. We analyzed p treated with an EGFR TKI for whom EGFR m status was known in serum only (status in tissue unknown due to insufficient material). At the same time, we reviewed p in whom EGFR m status in tissue was available over the same period in order to compare clinical characteristics and efficacy parameters: PFS, ORR and overall survival (OS). EGFR m analysis was performed in cell free circulating DNA (cfDNA)isolated from serum and plasma using the QIAmp DNA blood mini kit. Results: 9 p with EGFR m detected in serum and 33 p with EGFR m in tissue were included. In EGFR mutated p in serum, median age 63; male 55.6%; non-smokers 33.3%; former smokers 44.4%; ECOG PS 0-1 66.7%; adenocarcinoma 77.8%; deletion19 33.3%, L858R 66.7%; EGFR TKI treatment in 1st line 44.4%; 2nd or 3rd line 55.6%. ORR: complete response (CR) 22.2%; partial response (PR) 22.2%; stable disease (SD) 22.2%; progressive disease (PD) 11.1%. 2p had poor PS and died prior to evaluation. mPFS 4.7 months (mo). mOS 18 mo. In p with EGFR m in tissue, median age 61; male 36.4%; non-smokers 75.8%; former smokers 24.2%; adenocarcinoma 87.9%; deletion19 75.8%; L858R 24.2%; 1st line 54.5%; 2nd or 3rd line 45.5%. ORR: CR 15.2%; PR 57.6%; SD 12.1%; PD 15.2%. mPFS 8.9 mo. mOS 32.7 mo. The multivariate analysis for OS considering EGFR m in serum differed according to PS (PS 0-1 16.6 mo vs PS > 2 5.2 mo). Conclusions: Obtaining sufficient tissue from NSCLC p for analysis of EGFR m status and other molecular alterations can be difficult. Determination of EGFR m in serum alone is feasible, yields similar results to mutation status in tissue, and could permit us to take treatment decisions.

10596 Background: Anti-EGFR inhibitors are superior to chemotherapy in first-line therapy of advanced EGFR-mutant NSCLC. The EURTAC trial was a randomized Phase III trial of erlotinib vs. chemotherapy in patients with EGFR-mutant NSCLC. Interim results showed significant improvement in progression-free survival (R. Rosell, ASCO 2011). An accurate rapid in vitro diagnostic for EGFR mutations is needed to select patients for this therapy. Methods: Prospective EGFR mutation testing for the trial was performed on laser-capture microdissected tumor cells using a combination of 3 lab-developed tests (LDTs), including a Length Analysis of Fluorescently-labeled PCR (Genescan) method for exon 19 deletions, a Taqman-based PCR assay for exon 21 mutation with laser-capture macrodissected tumor cells, and secondary Sanger sequencing. A subset of samples from the trial was retrospectively tested with an AS-PCR assay (cobas EGFR mutation test) which detects L858R and > 29 exon 19 deletions. The test provides automated results within 8 h; the DNA required can be isolated from one 5-micron tissue section. Four methods were compared: AS-PCR assay, LDT, direct Sanger sequencing and massively parallel sequencing (MPS; 454, Branford, CT). Results: LDT results were obtained for 1044 screened patients. Residual tumor blocks were available for 487 patients (47%), including 303 wild-type, 172 mutant (135 enrolled on the trial) and 12 inconclusive cases by the LDT. Comparison of AS-PCR and LDT results showed a positive percent agreement (PPA) – 93.7% (CI 88.8%, 96.5%), and negative percent agreement (NPA) – 97.5% (94.9%, 98.8%). Comparison of AS-PCR and Sanger results showed a PPA of 96.6% (91.7%, 98.7%) but an NPA of 88.3% (84.1%, 91.5%). Among 34 AS-PCR+/Sanger- case, MPS confirmed the presence of exon 19 deletions in 25 cases and L858R mutations in 7. Direct comparison of AS-PCR and MPS results showed a PPA of 93.1% (88.1%, 96.1%) and NPA of 97.7% (95.0%, 98.9%). Clinical outcomes for cases with mutations detected by the AS-PCR test will be presented. Conclusions: The AS-PCR assay was highly concordant with the LDT and MPS, and more sensitive than Sanger sequencing.

7540 Background: Different exon 19 deletion types have shown different in vitro sensitivity to erlotinib, with the lower IC50 for deletion E746_A750 (ELREA) (Yuza et al. Cancer Biol Ther 2007). This information prompted us to examine outcome according to type of exon 19 deletion in the EURTAC study. Methods: The EURTAC trial (clinicaltrials.gov NCT00446225) randomized 174 p with EGFR exon 19 deletions or L858R mutations to receive erlotinib or chemotherapy. Progression-free survival (PFS) was 9.7 months (m) vs 5.2 m, respectively (P

// Teresa Moran 1 , Eudald Felip 1 , Joaquim Bosch-Barrera 2 , Itziar de Aguirre 3 , Jose Luis Ramirez 3 , Carles Mesia 4 , Enric Carcereny 1 , Diana Roa 2 , Elia Sais 2 , Yolanda Garcia 5 , Remei Blanco 6 , Silvia Sanchez 7 , Claudia Rosa Villacorta 7 , Cristina Queralt 3 , Jose Maria Velarde 8 and Rafael Rosell 3 1 Medical Oncology Department, Catalan Institute of Oncology - Badalona, Hospital Universitari Germans Trias i Pujol, Badalona, Universitat Autonoma de Barcelona (UAB), Barcelona, Spain 2 Medical Oncology Department, Catalan Institute of Oncology-Girona, Hospital Universitari Doctor Trueta Girona, Girona, Spain 3 Molecular Biology Laboratory of Cancer Dr. Rosell, Can Ruti Campus: Institute Germans Trias i Pujol (IGTP), Catalan Institute of Oncology, Badalona, Spain 4 Medical Oncology Department, Catalan Institute of Oncology - Hospital Duran i Reynalds, l’Hospitalet de Llobregat, Barcelona, Spain 5 Medical Oncology Department, Hospital Parc Tauli, Sabadell, Barcelona, Spain 6 Medical Oncology Department, Consorci Sanitari de Terrassa, Terrassa, Barcelona, Spain 7 Research Nurse Team, Catalan Institute of Oncology - Badalona, Hospital Universitari Germans Trias i Pujol, Badalona, Spain 8 Statistics Department, Fundacio Germans Trias i Pujol, Badalona, Spain Correspondence to: Teresa Moran, email: mmoran@iconcologia.net Keywords: EGFR-T790M mutation; serum/plasma; osimertinib; acquired resistance; EGFR tyrosine kinase inhibitors Received: March 19, 2018 Accepted: May 02, 2018 Published: June 05, 2018 ABSTRACT Background: Osimertinib is efficacious in lung cancer patients with epidermal growth factor receptor ( EGFR ) mutations and acquired resistance (AR) to EGFR tyrosine kinase inhibitors due to EGFR -T790M mutation (T790M). We sought to describe T790M changes in serum/plasma during osimertinib therapy and correlate these changes with treatment outcomes. Material and methods: Serum/plasma from EGFR -mutant lung cancer patients with T790M-AR was collected before and during osimertinib treatment. Changes in T790M were evaluated using a peptide-nucleic acid-PCR assay, and correlated with clinical and radiographic response. Results: Thirteen patients were included. Median time on osimertinib treatment was 10.6 months with a median progression-free survival of 13.6 months. Best response to osimertinib was partial response (PR), stable disease (SD) or progression (PD) in 46.1%, 30.8% and 23.1% of patients, respectively. Most of the patients were paucisymptomatic at baseline. Symptom improvement was reported in 66.6% of responder patients; while symptoms remained stable in 75% of patients with SD, and 66% of patients with PD had clinical deterioration. Three patterns of T790M changes during osimertinib treatment were identified. T790 remained detectable with PD or a short-lasting SD in 15.4% of the patients. T790M disappeared in 69.2% of patients with PR or SD. T790M disappeared, despite clinical and/or radiographic progression in 15.4% of the patients. Conclusion: Changes of T790M in serum/plasma in EGFR -mutant lung cancer patients with T790M-AR might be a useful marker of symptomatic and radiographic outcome to osimertinib. Longer follow-up is needed to establish if subsequent emergence of T790M could be a marker of resistance.