Prediction for response duration to epidermal growth factor receptor-tyrosine kinase inhibitors in EGFR mutated never smoker lung adenocarcinoma

Objectives

Among non-small cell lung cancer (NSCLC) patients harboring activating epidermal growth factor receptor (EGFR) mutations, ∼20–30% exhibit de novo resistance to EGFR-tyrosine kinase inhibitor (TKI). The aim of this study was to examine whether mutations in the EGFR-downstream genes may be associated with de novo resistance to EGFR-TKIs in EGFR mutation-positive patients.

Materials and methods

Sixty-eight never-smoker adenocarcinoma patients with an activating EGFR mutation were included in the mutational analysis and 55 patients treated with EGFR-TKIs were analyzed for the treatment outcomes to EGFR-TKIs. We concurrently analyzed mutations in PIK3CA, PTEN, AKT and STK11, which are all EGFR-downstream genes. Mutations in PIK3CA, PTEN, AKT, and STK11 were analyzed by polymerase chain reaction-based sequencing.

Results

PIK3CA mutations were detected in 4.4% (3/68) of patients, PTEN mutations in 16.1% (11/68), AKT mutations in 5.9% (4/68), and STK11 mutations in 13.2% (9/68). One patient with an activating exon 21 L858R mutation concomitantly had an exon 20 T790M mutation in EGFR. The proportion of patients who had mutations in EGFR-downstream genes was 32.4% (22/68). When we analyzed the treatment outcome of 55 patients treated with EGFR-TKI, the presence of mutations in EGFR-downstream genes correlated with a poor overall response rate to EGFR-TKIs (63.6 vs.14.5% in patients with mutation in EGFR-downstream gene, P < 0.0001), shorter median progression-free survival (12.0 vs. 3.0 months, P = 0.060), and shorter median overall survival (18.9 vs. 25.0 months, P = 0.048).

Conclusion

Mutations in the EGFR-downstream genes may confer resistance to EGFR-TKIs and result in poor treatment outcomes in never-smoker adenocarcinoma patients with activating EGFR mutations.     

EGFR Mutation Subtypes Influence Survival Outcomes following First-Line Gefitinib Therapy in Advanced Asian NSCLC Patients

IntroductionActivating mutations in the EGFR gene have been shown to confer sensitivity to EGFR tyrosine kinase inhibitors in patients with advanced NSCLC. However, wide interpatient variability in treatment outcomes in response to EGFR tyrosine kinase inhibitors in these patients remains unaccounted for. This study aimed to evaluate the influence of EGFR mutation types and subtypes on survival outcomes in advanced Asian patients with NSCLC receiving first-line gefitinib therapy.MethodsPatients with stage IIIB or IV NSCLC who were harboring EGFR mutations, receiving first-line gefitinib treatment, and of Asian descent (N = 383) were evaluated. Overall survival (OS) and progression-free survival (PFS) were estimated by Kaplan-Meier analysis. Log-rank tests and Cox proportional hazards models were implemented to evaluate the differences in PFS and OS.ResultsSignificant differences in PFS were observed between patients carrying EGFR mutations in exons 18, 19, 20, and 21, with patients carrying EGFR exon 19 mutations having the longest median PFS (overall p = 8.88 × 10^-15). Comparison of PFS among the five different exon 19 mutation subtypes and among the two exon 19 deletion start codons did not reveal any significant differences. No significant difference was observed in OS among patients carrying EGFR mutations on different exons (overall p = 0.054); however, OS was found to be significantly different among the various subtypes of exon 19 mutations, with the 15–nucleotide deletion “non-ELREA” group having the shortest OS of 11.3 months (overall p = 0.025).ConclusionsEGFR mutation types and subtypes significantly influence survival outcomes in patients with advanced NSCLC who are receiving first-line gefitinib treatment.     

Detection of epidermal growth factor receptor mutations in plasma by mutant‐enriched PCR assay for prediction of the response to gefitinib in patients with non‐small‐cell lung cancer

The high frequency of epidermal growth factor receptor (EGFR) mutations in tyrosine kinase inhibitor‐responsive non‐small‐cell lung cancer (NSCLC) cases is now well established, highlighting the predictive value of activating EGFR mutations in guiding the clinical use of EGFR‐targeted therapies. However, specimen source and methods for EGFR mutation analysis are limited by tissue availability and technical feasibility in clinical application. Therefore, the current study is designed to establish a blood‐based approach for the assessment of EGFR mutations in NSCLC patients, in particular the advanced stage, and to test its clinical application. Plasma samples were obtained from the enrolled 134 NSCLC patients. The detection rate of the EGFR exon19 deletions and exon21 L858R was 49.3% (66/134) by the blood‐based, mutant‐enriched polymerase chain reaction. In the paired tumor and plasma samples, the detected mutant types of each pair respectively by direct sequencing and mutant‐enriched polymerase chain reaction were concordant in 17 of 18 (94.4%). In the patients treated with gefitinib as a second‐line therapy, those with plasma EGFR mutation have a prolonged median progression‐free survival compared with those with EGFR wild type (7.609 vs. 2.877 months, p = 0.002). On comparing the efficacy of gefitinib with that of docetaxel, it was found that the median progression‐free survival was significantly longer for patients treated with gefitinib than those with docetaxel in those harboring plasma EGFR mutation (7.609 vs. 3.192 months, p = 0.006). These results suggest that the blood‐based EGFR mutations test has the ability to provide a reliable guidance for clinical decision making for the treatment of the advanced NSCLC patients. © 2009 UICC     

Epithelial phenotype as a predictive marker for response to EGFR‐TKIs in non‐small cell lung cancer patients with wild‐type EGFR

Epithelial‐to‐mesenchymal transition (EMT) has profound impacts on cancer progression and also on drug resistance, including epidermal growth factor receptor tyrosine kinase inhibitors (EGFR‐TKIs). Nowadays, there is still no predictive biomarker identified for the use of EGFR‐TKIs in non‐small cell lung cancer (NSCLC) patients with wild‐type EGFR. To clarify the role of EMT phenotype as a predictive marker for EGFR‐TKI, we performed a retrospective study in 202 stage IV or recurrent NSCLC patients receiving gefitinib or erlotinib therapy from June 2008 to September 2012 in our institute. Clinical data and EGFR mutational status were collected, while epithelial, epithelial to mesenchymal, not specified or mesenchymal phenotype were classified according to EMT markers such as E‐cadherin, fibronectin, N‐cadherin and vimentin by immunohistochemistry. Epithelial phenotype was more frequently found in patients with EGFR mutation (p = 0.044). Epithelial phenotype was associated with a significantly higher objective response rate (23.5 vs. 11.1 vs. 0.0 vs. 2.4%, p = 0.011), longer progression‐free survival (4.4 vs. 1.9 vs. 1.7 vs. 1.0 months, p < 0.001) and longer overall survival (11.5 vs. 8.9 vs. 4.5 vs. 4.9 months, p < 0.001) compared to epithelial to mesenchymal, not specified and mesenchymal phenotype in the wild‐type EGFR subgroup. In the subgroup with EGFR mutation, the trend remained but without a statistically significant difference. In conclusion, epithelial phenotype was more likely expressed in patients with EGFR mutation and was associated with a better outcome in advanced NSCLC patients with wild‐type EGFR, which indicates that the EMT phenotype might be a potential marker to guide EGFR‐TKI therapy in this population.     

Clinicopathologic and Genomic Factors Impacting Efficacy of First-Line Chemoimmunotherapy in Advanced NSCLC

IntroductionAlthough programmed cell death protein 1 and programmed death-ligand 1 (PD-L1) blockade in combination with platinum-doublet chemotherapy has become a mainstay of first-line treatment for advanced NSCLC, factors associated with efficacy of chemoimmunotherapy (CIT) are not well characterized.MethodsIn this multicenter retrospective analysis, clinicopathologic and genomic data were collected from patients with advanced NSCLC (lacking sensitizing genomic alterations in EGFR and ALK) and evaluated with clinical outcomes to first-line CIT.ResultsAmong 1285 patients treated with CIT, a worsening performance status and increasing derived neutrophil-to-lymphocyte ratio in the blood were associated with a significantly reduced objective response rate (ORR), median progression-free survival (mPFS), and median overall survival (mOS). With increasing PD-L1 tumor proportion scores of less than 1%, 1% to 49%, 50% to 89%, and greater than or equal to 90%, there was a progressive improvement in ORR (32.7% versus 37.5% versus 51.6% versus 61.7%, p < 0.001), mPFS (5.0 versus 6.1 versus 6.8 versus 13.0 mo, p < 0.001), and generally mOS (12.9 versus 14.6 versus 34.7 versus 23.1 mo, p = 0.009), respectively. Of 789 NSCLCs with comprehensive genomic data, NSCLCs with a tumor mutational burden (TMB) greater than or equal to the 90th percentile had an improved ORR (53.5% versus 36.4%, p = 0.004), mPFS (10.8 versus 5.5 mo, p < 0.001), and mOS (29.2 versus 13.1 mo, p < 0.001), compared with those with a TMB less than the 90th percentile. In all-comers with nonsquamous NSCLC, the presence of an STK11, KEAP1, or SMARCA4 mutation was associated with significantly worse ORR, mPFS, and mOS to CIT (all p < 0.05); this was also observed in the KRAS-mutant subgroup of NSCLCs with co-occurring mutations in STK11, KEAP1, or SMARCA4 (all p < 0.05). In KRAS wild-type NSCLC, KEAP1 and SMARCA4 mutations were associated with a significantly shorter mPFS and mOS to CIT (all p < 0.05), but STK11 mutation status had no significant impact on mPFS (p = 0.16) or mOS (p = 0.38).ConclusionsIn advanced NSCLC, better patient performance status, low derived neutrophil-to-lymphocyte ratio, increasing PD-L1 expression, a very high TMB, and STK11/KEAP1/SMARCA4 wild-type status are associated with improved clinical outcomes to first-line CIT.     

Frequency and clinical significance of NF1 mutation in lung adenocarcinomas from East Asian patients

NF1 is a tumor suppressor gene that negatively regulates Ras signaling. NF1 deficiency plays an important role in carcinogenesis. To investigate the frequency and clinical significance of NF1 mutation, we examined mutation status of NF1, TP53, LKB1 and RB1 in 704 surgically resected lung adenocarcinomas from East Asian patients using semiconductor-based Ion Torrent sequencing platform. Common driver events, including mutations in EGFR, KRAS, HER2, BRAF, MET, and fusions affecting ALK, RET and ROS1, were also concurrently detected. The correlation between NF1 mutations and clinicomolecular features of patients was further evaluated. Among 704 patients, 42 NF1 mutations were found in 33 patients (33/704, 4.7%), including 14 patients harboring EGFR/NF1 comutations (14/33, 42.4%). Comparing with EGFR-mutant patients, patients harboring NF1 mutations were closely associated with solid component subtype (p = 0.028). Comparing with KRAS mutations, NF1 mutations were found more common in female and never smokers (p = 0.003 and p = 0.004, respectively). Kaplan–Meier survival analysis revealed that patients harboring NF1 mutation had similar disease-free survival (DFS) and overall survival (OS) with patients with KRAS mutation. Although frequently overlapped with EGFR mutation, patients harboring NF1 mutation had significantly shorter DFS (p = 0.019) and OS (p = 0.004) than patients with EGFR mutation. During follow-up, one female patient with EGFR exon 19 deletion and NF1 Q1815X comutation showed poor response to EGFR TKIs (Gefitinib and Osimertinib) after disease relapse. In conclusion, NF1 mutations define a unique molecular and clinicopathologic subtype of lung adenocarcinoma. Examination of NF1 mutation may contribute to molecular subtyping and therapeutic intervention of lung adenocarcinoma.     

Additional prognostic role of EGFR activating mutations in lung adenocarcinoma patients with brain metastasis: Integrating with lung specific GPA score

ObjectiveWhile several prognostic models have been presented in NSCLC patients with brain metastasis, none of these models have included molecular markers as an index. The aim of our study was to evaluate the prognostic value of EGFR mutations and to integrate these EGFR mutations into the prognostic index in NSCLC patients with brain metastasis.Materials and methodsWe analyzed retrospectively 292 lung adenocarcinoma patients with brain metastasis. Clinico-pathological features and overall survival (OS) were compared between patients with EGFR mutations and patients with EGFR wild type. EGFR mutation status was integrated with lung specific graded prognostic assessment (GPA) score.ResultsAmong 292 patients, EGFR mutation status was tested in 183 patients. One hundred and five patients (57.4%) had EGFR activating mutations, 14 (7.7%) had EGFR non-activating mutations and 64 (35.0%) had EGFR wild type. OS was significantly longer in patients with EGFR activating mutations than in those with EGFR wild type patients (20.4 vs. 10.1 months, p = 0.002). However, patients with EGFR non-activating mutations did not show superior OS compared with EGFR wild type patients (14.6 vs. 10.1 months, p = 0.83). Multivariate analysis revealed that the presence of EGFR activating mutation is an independent positive prognostic factor for OS (adjusted hazard ratio 0.56, p = 0.002).ConclusionsEGFR activating mutations have a prognostic role in lung adenocarcinoma patients with brain metastasis that is independent of other known prognostic factors. The frequency of EGFR mutation was higher than expected. The presence of EGFR activating mutations should be included as an index in the prognostic models for lung adenocarcinoma patients with brain metastasis.     

Intertumor heterogeneity of non‐small‐cell lung carcinomas revealed by multiplexed mutation profiling and integrative genomics

Non‐small‐cell lung cancer (NSCLC) is a heterogeneous disease, with a burden of genomic alterations exceeding most other tumors. The goal of our study was to evaluate the frequencies of co‐occurring mutations and copy‐number aberrations (CNAs) within the same tumor and to evaluate their potential clinical impact. Mass‐spectrometry based mutation profiling using a customized lung cancer panel evaluating 214 mutations across 26 key NSCLC genes was performed on 230 nonsquamous NSCLC and integrated with genome‐wide CNAs and clinical variables. Among the 138 cases having at least one mutation, one‐third (41, 29.7%) showed two or more mutations, either in the same gene (double mutation) or in different genes (co‐mutations). In epidermal growth factor receptor (EGFR) mutant cancers, there was a double mutation in 18% and co‐mutations in the following genes: TP53 (10%), PIK3CA (8%), STK11 (6%) and MET (4%). Significant relationships were detected between EGFR mutation and 1p, 7p copy gains (harboring the EGFR gene) as well as 13q copy loss. KRAS mutation was significantly related with 1q gain and 3q loss. For Stage I, tumors harboring at least one mutation or PIK3CA mutation were significantly correlated with poor prognosis (p‐value = 0.02). When combining CNAs and mutational status, patients having both KRAS mutation and the highest related CNA (3q22.3 copy loss) showed a significant poorer prognosis (p‐value = 0.03). Our study highlights the clinical relevance of studying tumor complexity by integrative genomic analysis and the need for developing assays that broadly screen for both “actionable” mutations and copy‐number alterations to improve precision of stratified treatment approaches.     

TP53 mutation and survival in aggressive B cell lymphoma

TP53 is mutated in 20–25% of aggressive B‐cell lymphoma (B‐NHL). To date, no studies have addressed the impact of TP53 mutations in prospective clinical trial cohorts. To evaluate the impact of TP53 mutation to current risk models in aggressive B‐NHL, we investigated TP53 gene mutations within the RICOVER‐60 trial. Of 1,222 elderly patients (aged 61–80 years) enrolled in the study and randomized to six or eight cycles of CHOP‐14 with or without Rituximab (NCT00052936), 265 patients were analyzed for TP53 mutations. TP53 mutations were demonstrated in 63 of 265 patients (23.8%). TP53 mutation was associated with higher LDH (65% vs. 37%; p < 0.001), higher international prognostic index‐Scores (IPI 4/5 27% vs. 12%; p = 0.025) and B‐symptoms (41% vs. 24%; p = 0.011). Patients with TP53 mutation were less likely to obtain a complete remission CR/CRu (CR unconfirmed) 61.9% (mut) vs. 79.7% (wt) (p = 0.007). TP53 mutations were associated with decreased event‐free (EFS), progression‐free (PFS) and overall survival (OS) (median observation time of 40.2 months): the 3 year EFS, PFS and OS were 42% (vs. 60%; p = 0.012), 42% (vs. 67.5%; p < 0.001) and 50% (vs. 76%; p < 0.001) for the TP53 mutation group. In a Cox proportional hazard analysis adjusting for IPI‐factors and treatment arms, TP53 mutation was shown to be an independent predictor of EFS (HR 1.5), PFS (HR 2.0) and OS (HR 2.3; p < 0.001). TP53 mutations are independent predictors of survival in untreated patients with aggressive CD20+ lymphoma. TP53 mutations should be considered for risk models in DLBCL and strategies to improve outcome for patients with mutant TP53 must be developed.     

EGFR mutation status and its impact on survival of Chinese non-small cell lung cancer patients with brain metastases

Brain metastasis (BM) is a leading cause of death in patients with non-small cell lung cancer (NSCLC). EGFR mutations in primary NSCLC lesions have been associated with sensitivity to EGFR tyrosine kinase inhibitor (TKI). Therefore, it has become important to understand EGFR mutation status in BM lesions of NSCLC, and its clinical implications. BM samples of 136 NSCLC patients from South China, in which 15 had paired primary lung tumors, were retrospectively analyzed for EGFR mutation by amplification mutation refractory system (ARMS). Effect of BM EGFR mutations on progression-free survival (PFS) and overall survival (OS) was evaluated by Kaplan–Meier curves and log-rank test. EGFR mutations were detected in 52.9 % (72 of 136) of the BM lesions, with preference in female and never-smokers. A concordance rate of 93.3 % (14 of 15) was found between the primary NSCLC and corresponding BM. Positive prediction value of testing primary NSCLCs for BM EGFR mutation is 100.0 %, and negative prediction value is 87.5 %. Median PFS of BM surgery was 12 and 10 months (P?=?0.594) in the wild-type and mutant group, respectively. Median OS of BM surgery was 24.5 and 15 months (P?=?0.248) in the wild-type and mutant group, respectively. In conclusion, EGFR mutation status is highly concordant between the primary NSCLC and corresponding BM. The primary NSCLC could be used as surrogate samples to predict EGFR mutation status in BM lesions or vice versa. Moreover, EGFR mutations showed no significant effect on PFS or OS of NSCLCs with BM.     

Mutation incidence and coincidence in non small-cell lung cancer: meta-analyses by ethnicity and histology (mutMap)

BackgroundMeta-analyses were conducted to characterize patterns of mutation incidence in non small-cell lung cancer (NSCLC).DesignNine genes with the most complete published mutation coincidence data were evaluated. One meta-analysis generated a ‘mutMap’ to visually represent mutation coincidence by ethnicity (Western/Asian) and histology (adenocarcinoma [ADC] or squamous cell carcinoma). Another meta-analysis evaluated incidence of individual mutations. Extended analyses explored incidence of EGFR and KRAS mutations by ethnicity, histology, and smoking status.ResultsGenes evaluated were TP53, EGFR, KRAS, LKB1, EML4-ALK, PTEN, BRAF, PIK3CA, and ErbB2. The mutMap highlighted mutation coincidences occurring in ≥5% of patients, including TP53 with KRAS or EGFR mutations in patients with ADC, and TP53 with LKB1 mutation in Western patients. TP53 was the most frequently mutated gene overall. Frequencies of TP53, EGFR, KRAS, LKB1, PTEN, and BRAF mutations were influenced by histology and/or ethnicity. Although EGFR mutations were most frequent in patients with ADC and never/light smokers from Asia, and KRAS mutations were most frequent in patients with ADC and ever/heavy smokers from Western countries, both were detected outside these subgroups.ConclusionsPotential molecular pathology segments of NSCLC were identified. Further studies of mutations in NSCLC are warranted to facilitate more specific diagnoses and guide treatment.     

Outcomes after combined modality therapy for EGFR-mutant and wild-type locally advanced NSCLC

Background.

Epidermal growth factor receptor (EGFR) mutations identify a unique biological subtype of non-small cell lung cancer (NSCLC). Treatment outcomes for EGFR-mutant locally advanced NSCLC patients have not been well described.

Methods.

We retrospectively examined outcomes after combined modality therapy including thoracic radiation therapy (RT) in 123 patients with locally advanced NSCLC and known EGFR mutation status. Outcomes were compared using Kaplan–Meier analysis, the log-rank test, and multivariate Cox regression models.

Results.

All 123 patients underwent thoracic RT; 25% had tumors with EGFR mutations and 94% had stage III disease. Overall, 81% received chemotherapy concurrent with RT and 55% underwent surgical resection. With a median follow-up of 27.5 months, the overall survival (OS) rate was significantly higher in patients with EGFR-mutant tumors than in those with wild-type EGFR tumors (2-year estimate: 92.6% versus 69.0%; p = .04). The 2-year relapse-free survival and distant recurrence rates did not differ significantly by genotype. The 2-year locoregional recurrence rate (LRR) was significantly lower in EGFR-mutant than in wild-type EGFR patients (17.8% versus 41.7%; p = .005). EGFR-mutant genotype was associated with a lower risk for LRR on multivariate analysis, but not OS, after adjusting for surgery and other potential confounders.

Conclusion.

We observed that EGFR-mutant patients with locally advanced NSCLC treated with RT had lower rates of LRR than wild-type EGFR patients, raising the hypothesis that EGFR mutations may confer sensitivity to RT and/or chemotherapy. The association between mutation status and OS after combined modality therapy was less robust. Our data may serve as a useful baseline estimate of outcomes by EGFR genotype for future prospective studies.     

First-Line Nivolumab Plus Ipilimumab With Chemotherapy Versus Chemotherapy Alone for Metastatic NSCLC in CheckMate 9LA: 3-Year Clinical Update and Outcomes in Patients With Brain Metastases or Select Somatic Mutations

IntroductionIn the phase 3 CheckMate 9LA study, nivolumab plus ipilimumab with chemotherapy prolonged overall survival (OS) versus chemotherapy alone. We report updated efficacy and safety (≥3 y of follow-up), clinical outcomes in patients with baseline brain metastases, and exploratory somatic mutation analyses.MethodsAdults with stage IV or recurrent NSCLC, no known sensitizing EGFR or ALK alterations, and Eastern Cooperative Oncology Group performance status less than or equal to 1 were randomized 1:1 to nivolumab 360 mg every 3 weeks plus ipilimumab 1 mg/kg every 6 weeks with chemotherapy (two cycles) or chemotherapy alone (four cycles). Assessments included OS, progression-free survival (PFS), and objective response rate. Exploratory analyses included systemic and intracranial efficacy in patients with or without baseline brain metastases, in addition to OS and PFS by KRAS, TP53, STK11, and KEAP1 somatic mutation status in patients with nonsquamous NSCLC.ResultsWith a minimum follow-up of 36.1 months, nivolumab plus ipilimumab with chemotherapy continued to prolong OS versus chemotherapy alone in the intent-to-treat population (median [hazard ratio; 95% confidence interval] OS: 15.8 versus 11.0 mo [0.74; 0.62–0.87]; 3-y OS: 27% versus 19%). Efficacy outcomes were improved in patients with pretreated baseline brain metastases (median [hazard ratio; 95% confidence interval] OS: 19.3 versus 6.8 mo [0.45; 0.29–0.70]; systemic PFS: 9.7 versus 4.1 mo [0.44; 0.28–0.69]; intracranial PFS: 11.4 versus 4.6 mo [0.42; 0.26–0.68]). A trend of OS benefit was observed in patients treated with nivolumab plus ipilimumab with chemotherapy versus chemotherapy alone, despite KRAS, TP53, and STK11 tumor mutations. Extended follow-up revealed no new safety signals.ConclusionsWith a 3-year minimum follow-up, nivolumab plus ipilimumab with two cycles of chemotherapy continued to have long-term, durable efficacy versus chemotherapy alone; a manageable safety profile; and survival benefit in patients with or without baseline brain metastases or select somatic mutations, further supporting the regimen as first-line treatment for patients with metastatic NSCLC.     

EGFR-TKIs plus local therapy demonstrated survival benefit than EGFR-TKIs alone in EGFR-mutant NSCLC patients with oligometastatic or oligoprogressive liver metastases

To investigate whether addition of local therapy to EGFR-TKIs could provide survival benefit than EGFR-TKIs alone in EGFR-mutant NSCLC patients with oligometastatic or oligoprogressive liver metastases (LM). Patients with EGFR-mutant NSCLC and oligometastatic or oligoprogressive LM who met inclusion criteria were retrospectively identified. The primary endpoint was progression-free survival (PFS); secondary endpoints included overall survival (OS) and patterns of failure. Addition of local therapy was associated with a significantly longer PFS (13.8 vs. 8.6 m, p <0.001) and OS (31.2 vs. 18.5 m, p <0.001) in whole group. In oligometastatic cohort, 20 patients received EGFR-TKIs and 23 received EGFR-TKIs plus local therapy as first-line treatment. Addition of local therapy showed a significantly longer PFS (12.9 vs. 7.9 m, p = 0.041) and OS (36.8 vs. 21.3 m, p = 0.034) than EGFR-TKIs alone. In oligoprogressive cohort, 24 patients received continuation of EGFR-TKIs plus local therapy and 25 received switching chemotherapy. Median PFS2 (13.9 vs. 9.2 m, p = 0.007) and OS (28.3 vs. 17.1 m, p = 0.011) was significantly longer in combined group than in switching chemotherapy group. Distant metastatic sites progression was the major pattern of failure in combined group while locoregional recurrence was the major reason in monotherapy or switching chemotherapy group. Our study suggested that EGFR-TKIs plus local therapy showed prolonged survival benefit than EGFR-TKIs alone in EGFR-mutant NSCLC patients with oligometastatic or oligoprogressive LM, indicating addition of local therapy would be alternative choice in this clinical scenario.     

RAS mutation is a prognostic biomarker in colorectal cancer patients with metastasectomy

Studies have demonstrated a relationship between clinical outcomes after curative resection for colorectal cancer (CRC) and gene mutations of the EGFR pathway; however, no studies have examined metastatic CRC (mCRC) patients with metastasectomy. The aim of this study was to evaluate the relationship between gene mutations of EGFR pathway and clinical outcomes after metastasectomy in mCRC patients. A total of 1,053 patients histopathologically confirmed CRC received a genotyping test for the EGFR pathway from February 2012 to October 2013. Detailed information was obtained through review of medical records. Gene mutations of EGFR pathway were analyzed by Luminex assay. Overall survival (OS) and recurrence free survival were estimated by the Kaplan‐Meier method and the log‐rank test was used to compare the survival outcomes by gene mutation status. A total of 132 patients received metastasectomy. The frequencies of KRAS exon 2, KRAS exon 3.4, NRAS, BRAF, and PIK3CA mutations were 38.6% (51/132), 3.6% (5/132), 5.1% (7/132), 5.1% (7/132), and 8.7% (12/132), respectively. With a median follow‐up of 84.1 months (57.2—NA) for a survivor, the 4‐year OS rate was 65.6% for mCRC with RAS mutation, and 81.3% for mCRC with wild‐type RAS (p < 0.05). We observed a statistically significant correlation for only the RAS mutation and OS. In multivariate analysis, RAS mutation and liver metastasis were independent factors for shorter OS. There were no significant differences between gene mutations of EGFR pathway and recurrence free survival. RAS mutation in mCRC metastasectomy patients was associated with shorter overall survival.     

Optimization of patient selection for EGFR-TKIs in advanced non-small cell lung cancer by combined analysis of KRAS, PIK3CA, MET, and non-sensitizing EGFR mutations

Background

We present a comprehensive analysis of KRAS, PIK3CA, MET, and non-sensitizing EGFR mutations in advanced non-small cell lung cancer (NSCLC) patients treated with tyrosine kinase inhibitors (TKIs), with the aim of clarifying the relative contribution of these molecular alterations to resistance.

Patients and methods

One hundred and sixty-six patients with advanced NSCLC treated with EGFR-TKIs with available archival tissue specimens were included. EGFR (exons 18–21), KRAS (exons 2, 3), PIK3CA (exons 9, 20), and MET (exons 14, 15) mutations were analyzed using PCR-based sequencing. Among all the mutations evaluated, only KRAS, PIK3CA, MET, and non-sensitizing EGFR mutations, defined as “TKI non-sensitizing mutations” were used for response, time to progression (TTP), and overall survival (OS) analysis.

Results

TKI non-sensitizing mutations were associated with disease progression (p?=?0.001), shorter TTP (p?p?=?0.03). Cox’s multivariate analysis including histology and performance status showed that TKI non-sensitizing mutations were independent factors for shorter TTP (p?p?=?0.01).

Conclusions

When KRAS, PIK3CA, MET, and non-sensitizing EGFR mutations are concomitant, up to 96.0% of NSCLC patients unlikely to respond to TKIs can be identified, and they represented independent negative prognostic factors. Comprehensive molecular dissection of EGFR signaling pathways should be considered to select advanced NSCLC patients for TKIs therapies.     

ASP8273 tolerability and antitumor activity in tyrosine kinase inhibitor‐naïve Japanese patients with EGFR mutation‐positive non‐small‐cell lung cancer

Epidermal growth factor receptor (EGFR) activating mutations occur in approximately 50% of East Asian patients with non‐small‐cell lung cancer (NSCLC) and confer sensitivity to tyrosine kinase inhibitors (TKIs). ASP8273 is an irreversible EGFR‐TKI, given orally, that inhibits EGFR activating mutations and has shown clinical activity in patients with EGFR mutation‐positive NSCLC. Epidermal growth factor receptor‐TKI‐naïve Japanese adult patients (≥20 years) with NSCLC harboring EGFR mutations were enrolled in this open‐label, single‐arm, phase II study (ClinicalTrials.gov identifier NCT02500927). Patients received ASP8273 300 mg once daily until discontinuation criteria were met. The primary end‐point was to determine the safety of ASP8273 300 mg; the secondary end‐point was antitumor activity defined by RECIST version 1.1. Thirty‐one patients (12 men and 19 women; median age, 64 years [range, 31‐82 years]) with EGFR mutation‐positive NSCLC were enrolled; as of 23 February 2016, 25 patients (81%) were still on study. Of the 31 patients, 27 (87%) had an exon 19 deletion (n = 13, 42%) or an L858R (n = 14, 45%) EGFR activating mutation, and two (7%) had an L861Q mutation. Five patients (16%) had other EGFR activating mutations, two had an activating mutation and the T790M resistance mutation. The most commonly reported treatment‐emergent adverse event was diarrhea (n = 24, 77%). All patients had at least one post‐baseline scan; one patient (3%) achieved a confirmed complete response, 13 (42%) had a confirmed partial response, and 15 (48%) had confirmed stable disease (disease control rate, 94% [n = 29/31]) per investigator assessment. Once‐daily ASP8273 at 300 mg was generally well tolerated and showed antitumor activity in TKI‐naïve Japanese patients with EGFR mutation‐positive NSCLC.     

Compound EGFR mutation is frequently detected with co-mutations of actionable genes and associated with poor clinical outcome in lung adenocarcinoma

Compound EGFR mutations, defined as double or multiple mutations in the EGFR tyrosine kinase domain, are frequently detected with advances in sequencing technology but its clinical significance is unclear. This study analyzed 61 cases of EGFR mutation positive lung adenocarcinoma using next-generation sequencing (NGS) based repeated deep sequencing panel of 16 genes that contain actionable mutations and investigated clinical implication of compound EGFR mutations. Compound EGFR mutation was detected in 15 (24.6%) of 61 cases of EGFR mutation-positive lung adenocarcinoma. The majority (12/15) of compound mutations are combination of the atypical mutation and typical mutations such as exon19 deletion, L858R or G719X substitutions, or exon 20 insertion whereas 3 were combinations of rare atypical mutations. The patients with compound mutation showed shorter overall survival than those with simple mutations (83.7 vs. 72.8 mo; P = 0.020, Breslow test). Among the 115 missense mutations discovered in the tested genes, a few number of actionable mutations were detected irrelevant to the subtype of EGFR mutations, including ALK rearrangement, BCL2L11 intron 2 deletion, KRAS c.35G>A, PIK3CA c.1633G>A which are possible target of crizotinib, BH3 mimetics, MEK inhibitors, and PI3K-tyrosine kinase inhibitors, respectively. 31 missense mutations were detected in the cases with simple mutations whereas 84 in those with compound mutation, showing that the cases with compound missense mutation have higher burden of missense mutations (P = 0.001, independent sample t-test). Compound EGFR mutations are detected at a high frequency using NGS-based repeated deep sequencing. Because patients with compound EGFR mutations showed poor clinical outcomes, they should be closely monitored during follow-up.     

Impact of Tumor Suppressor Gene Co-Mutations on Differential Response to EGFR TKI Therapy in EGFR L858R and Exon 19 Deletion Lung Cancer

BackgroundIn most studies, patients with EGFR L858R mutant non-small cell lung cancer (NSCLC) have a shorter duration of response to EGFR tyrosine kinase inhibitor (TKI) therapy than do patients with EGFR exon 19 deletion NSCLC. The role that co-mutations play in this observation is unknown.MethodsWe performed a single-institution retrospective analysis of patients with EGFR-mutant NSCLC (exon 19 deletion or L858R mutation) who received frontline EGFR TKI for metastatic disease between 2014 and 2019, and who had STAMP next-generation sequencing (NGS), a 130-gene platform. Time to treatment failure (TTF) and overall survival were calculated using Cox models adjusted for age, race, and brain metastases. Co-mutations in key tumor suppressor genes (TP53, RB1, KEAP1, CDKN2A, or CTNNB1) were identified and their effects on outcomes were evaluated. Analyses were stratified according to receipt of osimertinib versus nonosimertinib as frontline EGFR TKI.ResultsOf 137 patients, 72 (57%) had EGFR exon 19 deletions and 65 (43%) had EGFR L858R mutations. Median TTF and OS on frontline TKI was shorter for the L858R cohort versus the exon 19 deletion cohort in univariate analysis. In adjusted models, this difference persisted for TTF but was no longer significant for OS. The difference in TTF in L858R mutant tumors was driven by the presence of co-mutations in key tumor suppressor genes.ConclusionPatients with metastatic NSCLC with mutations in EGFR L858R had shorter TTF on frontline TKI compared to patients with EGFR exon 19 deletions. Co-mutations in tumor suppressor genes may play an important role in the differential response to TKI therapy.