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C. Dazzi
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P1.02 - Poster Session with Presenters Present (ID 454)
- Event: WCLC 2016
- Type: Poster Presenters Present
- Track: Biology/Pathology
- Presentations: 1
- Moderators:
- Coordinates: 12/05/2016, 14:30 - 15:45, Hall B (Poster Area)
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P1.02-005 - Frequency of Actionable Alterations in EGFR wt NSCLC: Experience of the Wide Catchment Area of Romagna (AVR) (ID 3934)
14:30 - 14:30 | Author(s): C. Dazzi
- Abstract
Background:
Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors have improved the outcome of patients with EGFR-mutated lung adenocarcinoma (ADC). However, EGFR mutation occurred in about only 10-15% of ADC, but other alterations are emerging as potential target of drugs. We analyzed the frequency of potentially targetable driver alterations in a series of advanced EGFR-wild type (wt) NSCLC patients.
Methods:
724 advanced EGFR-wt NSCLC patients enrolled from the Wide Catchment Area of Romagna (AVR) between January 2013 to December 2014 were included in the study. KRAS, BRAF, ERBB2, PIK3CA, NRAS, ALK, MAP2K1, RET and DDR2 mutations were analyzed by Myriapod[®]Lung Status kit (Diatech Pharmacogenetics) on MassARRAY[®] (SEQUENOM[®] Inc, California). ERBB4 was evaluated by direct sequencing and EML4-ALK and ROS1 rearrangements were assessed by immunohistochemistry or fluorescence in situ hybridization.
Results:
331 (45.7%) patients showed at least one alteration. Of these, 72.2%, 6.3%, 3.6%, 1.8%, 2.1% and 1.2% patients had mutations in KRAS, BRAF, PIK3CA, NRAS, ERBB2 and MAP2K1 genes, respectively. Only one patient showed a mutation in ERBB4 gene. EML4-ALK and ROS1 rearrangements were observed in 4.3% and 1.4% of all patients, respectively. The distribution of mutations in relation to gender and smoking habits is reported in the Table. Overlapping mutations were observed in 7 KRAS-mutated patients: 2 (28.6%) patients were also mutated in PIK3CA, 4 (57.1%) showed also an EML4- ALK translocation and one (14.3%) had a ROS1 rearrangement. One (0.3%) patient showed both BRAF and PIK3CA alterations. Correlation analyses between the different mutations and patient outcome are ongoing.
*: some data are missingGENE Mutated Patients N (%) Gender Smoking Habits* Female (%) Male (%) Smoker (%) Never Smoker (%) KRAS 239 (33) 93 (39) 146 (61) 115 (48.1) 9 (3.8) BRAF 21 (3) 11 (52.4) 10 (47.6) 11 (52.4) 1 (4.8) NRAS 6 (0.8) 4 (66.7) 2 (33.3) 4 (66.7) - PIK3CA 12 (1.6) 4 (33.3) 8 (66.7) 5 (41.7) - MAP2K1 4 (0.5) - 4 (100) 1 (25) - ERBB2 7 (0.9) 5 (71.4) 2 (28.6) - 1 (14.3) EML4-ALK 31 (4.3) 20 (64.5) 11 (35.5) 12 (38.7) 8 (25.8) ROS1 10 (1.4) 7 (70) 3 (30) 3 (30) 5 (50)
Conclusion:
Driver mutations were detected in about 50% of EGFR wt lung ADC patients. Such alterations could represent potential targets for therapy and could be evaluated in routine multiplexed testing to obtain a wider tumor molecular characterization.
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P3.01 - Poster Session with Presenters Present (ID 469)
- Event: WCLC 2016
- Type: Poster Presenters Present
- Track: Biology/Pathology
- Presentations: 1
- Moderators:
- Coordinates: 12/07/2016, 14:30 - 15:45, Hall B (Poster Area)
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P3.01-038 - STAT3 and Src-YAP1 Inhibition Results in Greater Necitumumab Sensitivity in Lung Squamous Cell Carcinoma (ID 4242)
14:30 - 14:30 | Author(s): C. Dazzi
- Abstract
Background:
The anti-EGFR monoclonal antibody (mAb), necitumumab, has been recently approved in combination with chemotherapy, as 1st-line treatment for advanced lung squamous cell carcinoma (LSCC) patients, but with minimal survival benefit. Evidence continues to accumulate that signal transducer and activator of transcription 3 (STAT3) is a promising molecular target for cancer therapies. STAT3 is activated by tyrosine phosphorylation in response to EGF and interleukin-6 (IL-6). In addition to STAT3, IL-6 activates the Src family kinases, and subsequently YES-associated protein 1 (YAP1). STAT3 and Src-YAP1 activation contributes to EGFR inhibitor resistance and concomitant targeting of EGFR and STAT3-Src may represent an effective treatment strategy for LSCC.
Methods:
RNA was isolated from six LSCC cell lines and the mRNA expression analysis of EGFR, STAT3, Src and YAP1 was performed by TaqMan based qRT-PCR. Cell viability was assessed by MTT (thiazolyl blue) assay after treatment with necitumumab and evodiamine, an alkaloid isolated from the dried, unripe Evodia rutaecarpa (Juss.) Benth fruit that exerts an anticancer effect by inhibiting STAT3 and Src. Western blotting was performed to assess the effect of necitumumab on EGFR downstream signaling pathways.
Results:
We first evaluated the expression of EGFR in our panel of LSCC cell lines. We found that almost all of them homogeneously express high levels of EGFR. We then assessed the effect of necitumumab on EGFR downstream signaling in the SK-MES1 cell line. Treatment of SK-MES1 cells with 25ug/ml of necitumumab for seven days was unable to ablate STAT3, Src or YAP1 mRNA expression. Consistent with this, we found that necitumumab suppressed EGFR, ERK1/2 and AKT phosphorylation but increased STAT3 phosphorylation on the critical tyrosine residue 705 in a time and dose-dependent manner. We examined the growth inhibitory effect of the necitumumab and evodiamine combination. We performed an MTT cell proliferation assay on SK-MES1 cells and we used a constant ratio drug combination method to determine synergy, additivity, or antagonism. The combination of necitumumab and evodiamine resulted in a clear synergism in SK-MES1 cells as measured by the combination index (CI) analysis, with a CI of 0.74. Experiments in the rest of our LSCC cell lines are ongoing.
Conclusion:
Herein we have examined the role of STAT3 and Src-YAP1 in the context of treatment with the FDA-approved EGFR mAb, necitumumab. Our data provide initial evidence that co-activation of STAT3 and Src-YAP1 may limit the cellular response to EGFR inhibition in LSCC.
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P3.02b - Poster Session with Presenters Present (ID 494)
- Event: WCLC 2016
- Type: Poster Presenters Present
- Track: Advanced NSCLC
- Presentations: 2
- Moderators:
- Coordinates: 12/07/2016, 14:30 - 15:45, Hall B (Poster Area)
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P3.02b-006 - Role of TP53 Mutations in Determining Primary Resistance to First-Line Tyrosine Kinase Inhibitors in EGFR-Mutated NSCLC Patients (ID 3861)
14:30 - 14:30 | Author(s): C. Dazzi
- Abstract
Background:
Patients with non-small-cell lung cancer (NSCLC) carrying specific mutations at epidermal growth factor receptor (EGFR) gene are usually sensitive to treatments with tyrosine kinase inhibitors (TKIs). However, not all EGFR-mutated patients respond equally to TKI treatments, and approximately 20-30% show primary resistance. Although the mechanisms responsible for acquired resistance are known, those responsible for primary resistance are not completely understood. In this study we aimed to assess the role of TP53 mutations in a cohort of advanced EGFR-mutated NSCLC patients receiving first-line TKIs. We analyzed TP53 gene status in relation to outcome in terms of overall response rate, disease control rate (DCR), response duration, progression free survival (PFS) and overall survival (OS).
Methods:
We retrospectively analyzed 136 patients with advanced EGFR-mutated NSCLC treated with first-line TKIs from January 2012 to April 2015. Exons 5-8 of TP53 gene were amplified by PCR and sequenced by direct sequencing on 123 patients. DCR was defined as the sum of complete response, partial response and stable disease. The survival endpoints examined were PFS and OS. PFS was defined as the time from start of first-line treatment to disease progression or death, whichever occurred first. OS was defined as the time from start of first-line treatment to death.
Results:
TP53 mutations were observed in 37 (30.1%) patients:10 (27.0%), 6 (16.2%), 9 (24.3%) and 12 (32.4%) in exons 5, 6, 7 and 8, respectively. DCR was 70% in TP53-mutated patients compared to 88% in TP53-wt patients (relative risk, RR: 3.17 [95% CI 1.21-8.48], p=0.019). In particular, a 42% DCR was observed in patients with TP53 exon 8 mutation compared to 87% in exon 8 wt patients (RR 9.6 [2.71-36.63], p<0.001). Shorter median PFS and OS were observed in patients with TP53 exon 8 mutations compared to other patients (4.2 months vs 12.5 months [p=0.058] and 16.2 months vs 32.3 months [p=0.114], respectively); these differences became significant in the subgroup of patients with EGFR exon 19 deletion (4.2 months vs 16.8 months [p<0.001] and 7.6 months vs not reached [p=0.006], respectively), hazard ratio (HR) 6.99 (95% CI 2.34-20.87, p<0.001) and HR 4.75 (95% CI 1.38-16.29, p=0.013), respectively.
Conclusion:
TP53 mutations, in particular exon 8 mutations and those defined as nondisruptive, reduce responsiveness to TKI treatment and induce a worse prognosis in EGFR-mutated NSCLC patients, especially in those carrying exon 19 deletions.
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P3.02b-035 - Cell Free Tumor DNA to Monitor Response to Tyrosine Kinase Inhibitors in Patients with EGFR-Mutant Non-Small Cell Lung Cancer (ID 4038)
14:30 - 14:30 | Author(s): C. Dazzi
- Abstract
Background:
Treatment with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) has improved outcome of EGFR mutant non-small-cell lung cancer (mEGFR-NSCLC) patients. Monitoring the presence of EGFR sensitizing and resistance (such as T790M) mutations in response to treatment may have a clinical impact on the therapeutic strategy. Detecting these alterations in circulating free tumor DNA (cftDNA) can be an easier and more safe way to obtain information about the EGFR mutational status.
Methods:
Analyses have been conducted in NSCLC patients with a tissue-confirmed EGFR mutation, treated in first-line setting with TKIs. EGFR-sensitive and EGFR exon 20 mutations were analyzed in cftDNA extracted from plasma collected at baseline, after 8 and 20 days’ treatment, and every 4 months of therapy until progression. EGFR analyses were performed using PANAmutyper kit (PANAGENE).
Results:
Of the 16 mEGFR-NSCLC patients treated with first-line TKIs to date (4 with gefitinib, 2 with erlotinib and 10 with afatinib), 9 (56%) showed EGFR-sensitivity mutation at baseline in cftDNA: 6 had an exon 19 deletion, 1 an exon 21 L861Q mutation and 2 an exon 21 L858R mutation synchronous to exon 20 mutations (one insertion and one T790M point mutation). In these 2 last patients, exon 20 mutations were not identified in tumor tissue. The baseline mutation became undetectable in cftDNA in all the 6 patients with EGFR exon 19 deletion at different time point from the beginning of TKIs: in 5 patients after 21 days and in 1 after 8 days. All these patients had partial response at the first radiological evaluation. The subject harboring EGFR L858R mutation synchronous to exon 20 insertion was responsive to TKI and showed the disappearance of exon 20 insertion in cftDNA a the first clinical evaluation, whereas EGFR L858R disappeared after 4 cycles of treatment. Patient with EGFR L858R and T790M didn’t respond to TKI and progressed after 2 months of treatment. At present 3 out of 9 patients progressed but only one showed appearance of T790M in cftDNA during TKI. In the 7 mEGFR-NSCLC with undetectable cftDNA mutation at baseline no changes were seen during treatment.
Conclusion:
EGFR mutation analysis in cftDNA could give important information concerning the activity of TKIs. In particular the disappearance of mutation in cftDNA may be an early parameter of response that has to be validated in prospective trials. Moreover, cftDNA may give integrative information with respect to that obtained from tissue analysis, bypassing the problem of tumor heterogeneity.
