Efficacy of epidermal growth factor receptor inhibitors versus chemotherapy as second-line treatment in advanced non-small-cell lung cancer with wild-type EGFR: A meta-analysis of randomized controlled clinical trials

Background

EGFR mutation status is closely related to the efficacy of EGFR-TKIs in advanced non-small cell lung cancer (NSCLC). EGFR-TKIs have become the standard first-line treatment for advanced EGFR-mutation NSCLC, while for EGFR wild-type tumors, the preferred first-line treatment is chemotherapy. However, the efficacy of EGFR-TKIs as second-line treatment in EGFR wild-type NSCLC remains controversial. We sought to evaluate the effectiveness of EGFR-TKI as second-line treatment in EGFR wild-type NSCLC.

Methods

Randomized controlled trials that compared EGFR-TKIs with chemotherapy in previously treated advanced NSCLC with wild-type EGFR were included. We performed a meta-analysis to evaluate the effectiveness of EGFR-TKIs compared with standard chemotherapy. The endpoints were progression-free survival (PFS), overall survival (OS), and objective response rate (ORR).

Results

Six randomized controlled trials with a total of 990 patients with wild-type EGFR were included: 499 in the EGFR-TKIs group and 491 in the chemotherapy group. The results indicated that in the second-line treatment of EGFR wild-type advanced NSCLC, PFS was significantly inferior in the EGFR-TKIs group versus the chemotherapy group (HR = 1.37, 95% CI = 1.20–1.56, P < 0.00001). However, this significant difference did not translate into OS (HR = 1.02, 95% CI = 0.87–1.20, P = 0.81). ORR tended to favor chemotherapy but there was no significant difference compared with EGFR-TKI (RR = 1.77, 95% CI = 0.90–3.50, P = 0.10).

Conclusions

Chemotherapy improves PFS significantly but not OS, compared with EGFR-TKIs as a second-line treatment in advanced NSCLC with wild-type EGFR. Whether EGFR-TKIs should be used in EGFR wild-type patients should be considered carefully.     

Does KRAS mutational status predict chemoresistance in advanced non-small cell lung cancer (NSCLC)?

Background

Clinical implications of KRAS mutational status in advanced non-small cell lung cancer (NSCLC) remain unclear. To clarify this point, we retrospectively explored whether KRAS mutations could impact tumor response, and disease control rate (DCR) to first-line platinum-based chemotherapy (CT) as well as progression-free survival (PFS) or overall survival (OS).

Methods

Between June 2009 and June 2012, 340 patients with advanced (stage IIIB/IV) NSCLC were reviewed in a single institution (Institut Gustave Roussy). Two hundred and one patients had a biomolecular profile and received a platinum-based first-line CT. Patients with an unknown mutational status or with actionable alterations were excluded. We retained two groups: patients with KRAS mutated tumor (MUT) and patients with wild-type KRAS/EGFR (WT). Multivariate analyses with Cox model were used. Survival curves were calculated with Kaplan–Meier method.

Results

One hundred and eight patients were included in the analysis: 39 in the MUT group and 69 in the WT group. Baseline radiological assessment demonstrated more brain (P = 0.01) and liver (P = 0.04) metastases in MUT patients. DCR was 76% for MUT vs. 91% for WT group (P = 0.03), regardless of the type of platinum-based CT (use of pemetrexed or not). Although no statistically significant differences were found, shorter PFS (4.9 vs. 6.0 months; P = 0.79) and OS (10.3 vs. 13.2 months; P = 0.40) were observed for patients with KRAS mutated tumors in univariate analysis.

Conclusions

KRAS mutant tumors had a lower DCR after the first-line platinum-based CT, but this difference did not translate in PFS or OS. The presence of KRAS mutations may confer a more aggressive disease, with greater baseline incidence of hepatic and cerebral metastases.     

Impact of epidermal growth factor receptor mutations on intracranial treatment response and survival after brain metastases in lung adenocarcinoma patients

Introduction

Brain metastases (BM) commonly occur in patients with lung adenocarcinoma and usually lead to a poor prognosis and quality of life despite of radiotherapy. Epidermal growth factor receptor (EGFR) mutations have been widely demonstrated to be a predictive and prognostic factor for lung adenocarcinoma, however, its impact on BM from lung adenocarcinoma remains inconclusive. The present study aimed to elucidate the predictive role of EGFR mutations in BM treatment response and survival after BM in patients with lung adenocarcinoma.

Material and methods

From January 2006 through February 2012, 180 of 505 lung adenocarcinoma patients developed BM during their disease course were reviewed for eligibility, and 139 patients, including 89 EGFR-mutant and 50 EGFR wild-type patients, were identified for analysis.

Results

Of the patients eligible for evaluation of treatment response, up to 85% received radiotherapy and the remaining took EGFR tyrosine kinase inhibitors (TKIs) as the front modality for BM. EGFR-mutant patients, compared with EGFR wild-type patients, had significantly greater intracranial treatment response of BM (84% vs. 48%, P = 0.002), experienced higher therapeutic efficacy to radiotherapy (86% vs. 52%, P = 0.005), and had longer median survival after BM diagnosis (13.2 vs. 6.8 months, P < 0.001). Furthermore, EGFR mutation (P = 0.002) and performance status (P = 0.009) were independently associated with BM treatment response. Additionally, EGFR mutation (P = 0.005), good performance status (P < 0.001) and absence of extracranial metastases (P = 0.033) correlated with better survival.

Conclusion

EGFR mutation is an independent predictive factor for both BM treatment response and survival after BM in patients with lung adenocarcinoma. Further prospective studies on incorporation of EGFR mutation status into therapeutic strategy and survival prediction system for lung adenocarcinoma with BM are warranted.     

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

Background and purpose

Continuous EGFR-TKI treatment beyond progression has shown promising benefit for some patients with acquired resistance to EGFR-TKIs. The aim of this study was to investigate the association of secondary T790M mutation at the time of progression with the efficacy of EGFR-TKI treatment beyond progression.

Methods

From March 2011 to March 2013, patients with advanced NSCLC who developed acquired resistance to EGFR-TKI and where a re-biopsy was performed at Tongji University Cancer Institute were included into this study. Scorpion ARMS was used to detect EGFR mutation status.

Results

A total of 54 patients were enrolled in this study with a median progression-free survival time (PFS1) of 10.9 months according to RECIST criteria. In all, 53.7% (29/54) had T790M mutation after the failure of EGFR-TKIs; PFS1 was not statistically significantly different between patients with T790M mutation and without (13.0 vs. 10.5 months, p = 0.894). In all, 41 patients received TKI treatment beyond progression, including 22 with local progression to receive additional local therapy and 19 with gradual progression to receive additional chemotherapy. The median progression-free survival time (PFS2) of patients who received EGFR-TKI beyond progression treatment was 3.5 months (95% CI, 2.689–4.311). Patients with T790M mutation had significantly longer PFS2 (6.3 vs. 2.6 months, p = 0.002) and overall survival (39.8 vs. 23.2 months, p = 0.044) than those without.

Conclusion

Patients with secondary T790M mutation at the time of progression having gradual or local progression after acquired resistance to EGFR-TKI benefit more from EGFR-TKI treatment beyond progression compared to those without T790M mutation.     

A prospective,phase II,open-label study (JO22903) of first-line erlotinib in Japanese patients with epidermal growth factor receptor (EGFR) mutation-positive advanced non-small-cell lung cancer (NSCLC)

Introduction

The epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitor erlotinib is associated with survival benefits in patients with EGFR mutation-positive non-small-cell lung cancer (NSCLC). This phase II, single-arm study examined the efficacy and safety of first-line erlotinib in Japanese patients with EGFR mutation-positive NSCLC.

Methods

Eligible patients received erlotinib 150 mg/day until disease progression or unacceptable toxicity. The primary endpoints were progression-free survival (PFS) and safety.

Results

A high degree of concordance was observed between different mutation testing methodologies, suggesting feasibility of early, rapid detection of EGFR mutations. Median PFS was 11.8 months (95% confidence interval [CI]: 9.7–15.3) at data cut-off (1 June 2012) (n = 102). Exon 19 deletions seemed to be associated with longer PFS compared with L858R mutations; T790M mutations were tentatively linked with shorter PFS. The safety profile was as expected: rash (any grade; 83%) and diarrhea (any grade; 81%) were most common. Six interstitial lung disease (ILD)-like cases were reported, and 5 were confirmed as ILD-like events by the extramural committee. Two patients died of treatment-related pneumonitis (JAPIC Clinical Trials Information number: Japic CTI-101085).

Conclusion

Erlotinib should be considered for first-line treatment in this subset of Japanese patients, with close monitoring for ILD-like events.     

Bevacizumab plus chemotherapy for patients with advanced pulmonary adenocarcinoma harboring <Emphasis Type="Italic">EGFR</Emphasis> mutations

Purpose

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) and bevacizumab plus chemotherapy were effective for EGFR-mutant patients. However, the appropriated treatment orders remained controvertible. We investigated the efficacy of treatment orders between bevacizumab plus chemotherapy and EGFR-TKIs for EGFR-mutant patients with advanced pulmonary adenocarcinoma.

Patients and methods

This study involved 40 EGFR-mutant patients with advanced pulmonary adenocarcinoma who were treated with bevacizumab plus carboplatin and paclitaxel (Bev + CP) and EGFR-TKIs in different treatment orders or gemcitabine plus cisplatin (GP) in first-line setting. Seventeen patients were treated with Bev + CP and 10 cases with GP in first-line treatment. Thirteen patients received EGFR-TKIs after first-line Bev + CP regimen, while 13 patients were treated with first-line EGFR-TKIs. Progression-free survival (PFS), the response rate (ORR) and overall survival (OS) were evaluated.

Results

Median PFS of Bev + CP treatment was significantly longer in first-line than non-first-line settings (11.7 vs. 5.6 months, P = 0.003). Median OS was 37.8 months for EGFR-mutant patients with first-line Bev + CP followed by second-line EGFR-TKIs and 31.0 months for those with first-line EGFR-TKIs and non-first-line Bev + CP, respectively (P = 0.509). Median PFS was 11.7 (95% CI 10.6–12.8) months for Bev + CP group and 4.7 (95% CI 4.4–5.0) months for GP group with the hazard ratio of 0.17 (P = 0.001). ORR was 70.6 and 50.0% in the two groups, respectively (P = 0.415). However, there was no significant difference in median OS (33.7 vs 27.8 months, P = 0.293).

Conclusions

First-line Bev + CP followed by EGFR-TKIs might possibly provide favorable prognosis for EGFR-mutant patients. Bev + CP regimen significantly prolonged PFS in first-line than non-first-line settings. These findings warrant further investigations.

     

Impact of cigarette smoking on response to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors in lung adenocarcinoma with activating EGFR mutations

Objectives

The aim of this study is to evaluate the predictive impact of cigarette smoking on treatment outcomes of EGFR-tyrosine kinase inhibitors (TKIs) in lung adenocarcinoma patients with activating EGFR mutations.

Methods

We retrospectively analyzed 222 consecutive recurrent or unresectable lung adenocarcinoma patients who harbored activating EGFR mutations (exon 19 deletion or exon 21 L858R) and had received gefitinib or erlotinib. Detailed smoking histories were obtained from all patients according to a standard protocol.

Results

Of 222 EGFR-mutated patients, 65.3% were never-smokers, 19.8% were smokers with <30 pack-years, and 14.9% were smokers with ≥30 pack-years smoking dosage. The disease control rate (DCR) and objective response rate (ORR) of smokers with ≥30 pack-years were significantly lower than never-smokers and smokers with <30 pack-years (DCR, 78.8% vs. 93.1%, p = 0.016; ORR, 45.5% vs. 62.4%, p = 0.020). Smokers with ≥30 pack-years showed significantly shorter PFS than never-smokers (6.4 vs. 11.8 months, p = 0.001) and smokers with <30 pack-years (6.4 vs. 11.4 months, p = 0.033), as well as shorter overall survival from the time of metastatic diagnosis than never-smokers (33.6 vs. 46.2 months, p = 0.003). There was no survival difference between smokers with <30 pack-year and never smokers. In the multivariate analysis adjusted for age, sex, performance status, initial stage, and line of EGFR-TKI, the presence of smoking dosage ≥30 pack-years was an independent predictive factor for the disease progression to EGFR-TKIs (hazard ratio, 1.87; 95% confidence interval, 1.15–3.05; p = 0.012).

Conclusions

Cigarette smoking dosage of ≥30 pack-years is an independent negative predictive factor of EGFR-TKI treatment outcome in lung adenocarcinoma patients with activating EGFR mutations.     

Evaluation of EGFR protein expression by immunohistochemistry using H-score and the magnification rule: Re-analysis of the SATURN study

Introduction

The phase III SATURN study demonstrated that first-line maintenance erlotinib extended progression-free survival (PFS) and overall survival (OS) versus placebo in patients with advanced non-small cell lung cancer (NSCLC). Analysis of epidermal growth factor receptor (EGFR) expression by immunohistochemistry (IHC) found no significant interaction between EGFR IHC status and PFS (p = 0.63) or OS (p = 0.52). The FLEX study of first-line cetuximab plus chemotherapy demonstrated that EGFR IHC expression was predictive of improved OS with cetuximab when assessed by H-score with a magnification rule. This novel method was used to reassess samples from SATURN.

Methods

The H-score method assigned a score of 0–300 to each patient, based on the percentage of cells stained at different intensities viewed at various magnifications. The discriminatory threshold was set at 200, per the FLEX study, and existing samples were re-read and classed as low (H-score < 200) or high (≥200) EGFR expression. PFS and OS were re-analyzed based on these new classifications.

Results

In the overall and EGFR wild-type populations, erlotinib provided a consistent survival benefit versus placebo. Hazard ratios (HRs) in the overall population were similar between EGFR IHC-positive and -negative patients for median PFS (HR 0.68 [95% confidence interval (CI) 0.53–0.86] and 0.76 [95% CI 0.62–0.93], respectively) and OS (HR 0.80 [95% CI 0.62–1.05] and 0.80 [95% CI 0.64–1.01] for IHC-positive and IHC-negative, respectively). In the EGFR wild-type population, HRs were again similar between EGFR IHC-positive and -negative subpopulations for PFS (HR 0.69 [95% CI 0.51–0.95] and 0.84 [95% CI 0.63–1.12], respectively) and OS (HR 0.78 [95% CI 0.55–1.10] and 0.76 [95% CI 0.55–1.05], respectively).

Conclusions

These data suggest that EGFR IHC does not have value as a marker to predict erlotinib benefit in the first-line maintenance setting for advanced NSCLC.     

Epidermal Growth Factor Receptor (EGFR)‐Tyrosine Kinase Inhibitor Treatment and Salvage Chemotherapy in EGFR‐Mutated Elderly Pulmonary Adenocarcinoma Patients

Background.

Lung cancer is frequently a disease of elderly patients. However, these patients are often treated less actively owing to a higher comorbidity rate and poor performance status. The efficacy of different treatments in elderly patients with epidermal growth factor receptor (EGFR)-mutated lung cancer is still unknown.

Materials and Methods.

We retrospectively reviewed the records of our pulmonary adenocarcinoma patients treated between 2010 and 2013. Data on patient age, type of tumor EGFR mutation, response to first-line EGFR-tyrosine kinase inhibitor (TKI) treatment, type of salvage chemotherapy, and efficacy of EGFR-TKI and salvage chemotherapy were collected.

Results.

In all, 473 of 1,230 stage IV adenocarcinoma patients had an EGFR mutation, and 330 of them received first-line TKI treatment. Of the 330 patients, 160 were ≥70 years old (elderly group) and 170 were <70 years old (younger group). The response rate and progression-free survival (PFS) with first-line TKI treatment were not significantly different. The elderly group had shorter median survival. A total of 107 patients received salvage chemotherapy after first-line EGFR-TKI treatment: 45 in the elderly group and 62 in the younger group. Their response rate and PFS were not significantly different; however, the younger group had longer median survival. Additional subgroup analysis showed that younger patients who received platinum-based chemotherapy or combination chemotherapy had better median survival than did the elderly patients. The PFS was longer among younger patients receiving a platinum-based regimen than that among the elderly patients.

Conclusion.

Elderly patients with disease progression after first-line EGFR-TKI treatment can receive chemotherapy and have a response rate similar to that of younger patients.

Implications for Practice:

The aim of the present study was to investigate the efficacy of first-line epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) treatment in elderly patients and the outcomes of subsequent salvage chemotherapy after disease progression. The most important finding was that elderly patients with disease progression after first-line EGFR-TKI treatment can receive salvage chemotherapy and have a response rate similar to that of younger patients who received salvage chemotherapy.     

EGFR mutations and clinical outcomes of chemotherapy for advanced non-small cell lung cancer: A meta-analysis

Background

This meta-analysis was performed to assess whether epidermal growth factor receptor (EGFR) mutation status was associated with objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) in patients with advanced non-small cell lung cancer (NSCLC) treated with chemotherapy.

Method

We systematically identified eligible articles investigating the effects of chemotherapy in patients with NSCLC stratified by EGFR mutation status. The summary risk ratio (RR) for ORR and hazard ratios (HRs) for both PFS and OS were calculated using the inverse variance formula of meta-analysis.

Results

Identification for the current meta-analysis: 5 prospective studies (n = 875) and 18 retrospective studies (n = 1934) for ORR; 2 prospective studies (n = 434) and 10 retrospective studies (n = 947) for PFS; 2 prospective studies (n = 438) and 7 retrospective studies (n = 711) for OS. The ORR was significantly higher in patients with EGFR mutations in prospective studies (RR = 1.42; 95% confidence interval [CI], 1.16–1.74; P = 0.001), but not in retrospective studies (RR = 1.12; 95% CI, 0.96–1.32; P = 0.146). There was no obvious association between EGFR mutations and PFS both in prospective (HR = 0.84; 95% CI: 0.65–1.09; P = 0.197) and retrospective (HR = 1.02; 95% CI: 0.87–1.18; P = 0.838) studies. Association between EGFR mutations and OS was also not seen in prospective studies (HR = 0.74; 95% CI: 0.27–2.05; P = 0.566), but was seen in retrospective studies (HR = 0.48; 95% CI: 0.33–0.72; P < 0.001; I² = 75.9%; P < 0.001) with significant heterogeneity.

Conclusion

EGFR mutations in advanced NSCLC may be associated with higher ORRs to chemotherapy, but may have nothing to do with PFS and OS. Further prospective studies are required to identify the influence of EGFR mutations on chemotherapy effects in advanced NSCLC.     

Incidence of T790M mutation in (sequential) rebiopsies in EGFR-mutated NSCLC-patients

Aim

Non-small cell lung cancer (NSCLC)-patients with an epidermal growth factor receptor (EGFR)-mutation have median progression-free survival (PFS) of 12 months on tyrosine kinase inhibitors (TKIs). Resistance is mediated by the EGFR T790M-mutation in the majority of patients. Longitudinal follow-up data are lacking. We retrospectively evaluated EGFR-mutated NSCLC-patients who were rebiopsied after TKI-treatment. A subgroup was sequentially rebiopsied along the course of the disease.

Patients and methods

Advanced EGFR-mutated NSCLC-patients who had both a pre-TKI biopsy and post-TKI biopsy available were included. Information on treatments and (re)biopsies was collected chronologically. Primary endpoint was the incidence of the T790M-mutation.

Results

Sixty-six patients fulfilled the inclusion criteria. In first post-TKI biopsies, T790M-mutation was detected in 34 patients (52%) of patients. Twenty-seven patients had subsequent post-TKI rebiopsies with mutation analysis available; in 10 patients (37%) the T790M-status in subsequent post-TKI rebiopsies was not consistent with the T790M-status of the first post-TKI biopsy. Progression free survival (PFS) on TKI-treatment was 12.0 months. Objective response rate on TKI-treatment was 81%. Patients developing T790M-mutation at post-TKI biopsy had longer median PFS compared to T790M-negative patients (14.2 versus 11.1 months respectively (P = 0.034)) and longer overall survival (45.9 months versus 29.8 months respectively (P = 0.213)). Transformation to SCLC was detected in 1 patient (2%).

Conclusion

Incidence of T790M-mutation at first post-TKI biopsy in this cohort of EGFR-mutated NSCLC-patients was 52%. Detection of T790M-mutation was not consistent over time; some patients who were T790M-positive at first post-TKI biopsy became T790M-negative in later post-TKI rebiopsies and vice versa. T790M-positive patients showed longer PFS than T790M-negative patients. Whether the low incidence of transformation to SCLC is justifying post-TKI rebiopsy in EGFR-mutated NSCLC-patients with acquired TKI-resistance in regular clinical practice is debatable.     

AKT inhibition synergistically enhances growth-inhibitory effects of gefitinib and increases apoptosis in non-small cell lung cancer cell lines

Objectives

EGFR inhibitors are ineffective against most EGFR wild-type non-small cell lung cancer, for which novel treatment strategies are needed. AKT signalling is essential for mediating EGFR survival signals in NSCLC. We evaluated the combination of gefitinib and two different AKT inhibitors, the allosteric inhibitor AKTi-1/2 and the ATP-competitive pan-AKT inhibitor AZD5363, in EGFR-mutant (HCC-827 and PC-9) and -wild-type (NCI-H522, NCI-H1651), non-small cell lung cancer cell lines.

Materials and methods

Drug interaction was studied in two EGFR mutant and two EGFR wild-type non-small cell lung cancer cell lines by calculating combination index (CI) using median effect analysis. The effects on p-EGFR, p-ERK, p-AKT, p-S6 and apoptosis were studied by Western blot analysis.

Results

The combination of gefitinib and AKTi-1/2 or AZD5363 showed synergistic growth inhibition in all cell lines. CI values for the combination of gefitinib and AKTi-1/2 were 0.35 (p = 0.0048), 0.56 (p = 0.036), 0.75 (p = 0.13) and 0.64 (p = 0.0003) in NCI-H522, NCI-H1651, HCC-827 and PC-9 cell lines, respectively; CI values of 0.45 (p = 0.0087) and 0.22 (p < 0.0001) were observed in NCI-H522 and PC-9 cells, respectively, when gefitinib was combined with AZD5363. Additive inhibition of signalling output through AKT and key downstream proteins (S6) and increased apoptosis were demonstrated.

Conclusion

Dual inhibition of EGFR and AKT may be a useful up-front strategy for patients with EGFR-mutant and -wild-type non-small cell lung cancer.     

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.     

Possible differential EGFR-TKI efficacy among exon 19 deletional locations in EGFR-mutant non-small cell lung cancer

Background

Exon 19 deletion mutations (Del-19s) and the exon 21 L858R point mutation are the most common epidermal growth factor receptor (EGFR) mutations. In Del-19, several subtypes actually exist, consisting of the deletional location with or without amino acid insertion/substitution. Little evidence has been described whether the Del-19 subtype affects EGFR-tyrosine kinase inhibitor (TKI) efficacy.

Methods

Between December 2005 and July 2012, we investigated 105 patients harboring a Del-19 who had received EGFR-TKIs. Efficacies of EGFR-TKIs such as response rate (RR), progression-free survival (PFS), and overall survival (OS) were retrospectively evaluated among various patient characteristics.

Results

Among these 105 patients with Del-19s, 78 (74%) patients had a deletion from E746 (Del-E746), and 27 (26%) exhibited a deletion from L747 (Del-L747). Median PFS of Del-E746 (11.7 months, 95% confidence interval [CI]: 9.3–15.6) was significantly longer than Del-L747 (10.0 months, 95% CI: 6.4–12.7) (p = 0.022). Insertions/substitutions were found in 19 patients (18%), and 91 patients (82%) were without insertions/substitutions. Median PFS without insertions/substitutions (11.7 months, 95% CI 9.3–15.2) was significantly longer than with insertions/substitutions (10.0 months, 95% CI: 4.0–10.6) (p = 0.024). No relationships were found for RR among all patient characteristics. In multivariate analysis, performance status (PS) (0/1 vs 2/3) and initial deletion site (Del-E746 vs Del-L747) were significant factors for longer PFS, whereas PS, gender (male vs female) and histology (adeno vs squamous) for longer OS.

Conclusions

Our data indicated better efficacy of EGFR-TKI in Del-E746 than Del-L747. Deletional locations may affect EGFR-TKI efficacy.     

A phase II study of erlotinib in combination with bevacizumab versus chemotherapy plus bevacizumab in the first-line treatment of advanced non-squamous non-small cell lung cancer

Background

Molecularly targeted agents for non-small cell lung cancer (NSCLC) can provide similar efficacy to chemotherapy without chemotherapy-associated toxicities. Combining two agents with different modes of action could further increase the efficacy of these therapies. The TASK study evaluated the efficacy and safety of the epidermal growth factor receptor tyrosine kinase inhibitor erlotinib in combination with the anti-angiogenic agent bevacizumab as first-line therapy in unselected, advanced non-squamous NSCLC patients.

Methods

Patients were recruited from December 2007 to September 2008. Planned sample size was 200 patients, a total of 124 patients were randomized. Patients were randomized using a minimization algorithm 1:1 to receive bevacizumab (iv 15 mg/kg day 1 of each 21-day cycle) plus chemotherapy (gemcitabine/cisplatin or carboplatin/paclitaxel standard doses, 4–6 cycles) (BC arm) or bevacizumab plus erlotinib (p.o. 150 mg/day; BE arm) until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS). If the hazard ratio (HR) of PFS for BE relative to BC was above 1.25 at the pre-planned interim analysis in favor of BC, the study would be re-evaluated. Secondary endpoints included overall survival, response rate and safety.

Results

All randomized patients (n = 63 BE; n = 61 BC) were evaluated for the efficacy analyses. At the updated interim analysis, median PFS was 18.4 weeks (95% confidence interval [CI] 17.0–25.1) versus 25.0 weeks (95% CI 20.6–[not reached]) for BE versus BC, respectively (HR for death or disease progression, BE relative to BC, 2.05, p = 0.0183). The incidence of death was 19% for BE treatment compared with 11.5% for BC treatment. The HR for PFS at the updated interim analysis was above 1.25, therefore patients on the BE arm were permitted to change arms or switch to another drug and the study was terminated. Adverse events reported were as expected.

Conclusions

The TASK study did not show a benefit in terms of PFS for the combination of erlotinib with bevacizumab in unselected first-line advanced non-squamous NSCLC compared with chemotherapy plus bevacizumab.     

Number of liver metastatic nodules affects treatment options for pulmonary adenocarcinoma patients with liver metastases

Background

In patients with non-small cell lung cancer (NSCLC), the development of liver metastasis (LM) is a poor prognostic factor. Whether systemic treatment combined with local treatment for LM has benefit for NSCLC patients with LM is unknown.

Methods

We retrospectively reviewed and analyzed the clinical data and tumor epidermal growth factor receptor (EGFR) mutation status of 673 pulmonary adenocarcinoma patients, including 85 patients who developed LM at any time point in the course of the disease. Radiofrequency ablation (RFA) with real-time ultrasonographic guidance was used for local treatment of LM in these patients, if appropriate.

Results

Patients with an EGFR mutation were more prone to having synchronous LM than patients with EGFR wild-type (50.0% vs. 23.5%, P = 0.019). Fifty-six patients (65.9%) had ≦5 LM nodules. The median overall survival (OS) of patients with ≦5 LM nodules was 7.6 months compared with 2.9 months for those with multiple nodules (P < 0.001). The independent prognostic factors after LM were performance status, EGFR mutation, synchronous LM and LM numbers. The independent prognostic factors for patients with ≦5 LM nodules were performance status, EGFR mutation, LM concomitant with adrenal metastasis and having received RFA. Patients who received RFA treatment (n = 6) had longer OS after LM than those without RFA treatment (n = 42) (23.1 vs. 7.9 months, P = 0.035).

Conclusions

We recommend that patients with a better performance status and ≦5 LM nodules be considered for systemic treatment combined with RFA when LM develops.     

Consolidative Local Ablative Therapy Improves the Survival of Patients With Synchronous Oligometastatic NSCLC Harboring EGFR Activating Mutation Treated With First-Line EGFR-TKIs

Introduction

The aim of the current study was to investigate whether consolidative local ablative therapy (LAT) can improve the survival of patients with stage IV EGFR-mutant NSCLC who have oligometastatic disease treated with first-line EGFR–tyrosine kinase inhibitor (TKI) therapy.

Epidermal growth factor receptor mutation analysis in previously unanalyzed histology samples and cytology samples from the phase III Iressa Pan-ASia Study (IPASS)

Objectives

Epidermal growth factor receptor (EGFR) mutation testing is standard practice after lung adenocarcinoma diagnosis, and provision of high-quality tumor tissue is ideal. However, there are knowledge gaps regarding the utility of cytology or low tumor content histology samples to establish EGFR mutation status, particularly with regard to the proportion of testing performed using these sample types, and the lack of an established link with efficacy of treatment.

Methods

The randomized phase III Iressa Pan-ASia Study (IPASS; ClinicalTrials.gov identifier NCT00322452) of first-line gefitinib versus chemotherapy analyzed samples meeting preplanned specifications (n = 437 evaluable for EGFR mutation; n = 261 mutation-positive). This supplementary analysis assessed tumor content and mutation status of histology (n = 99) and cytology samples (n = 116) which were previously unanalyzed due to sample quality, type, and tumor content (<100 cells). Objective response rate (ORR) and change in tumor size with gefitinib treatment were assessed.

Results

EGFR mutation testing was successful in 80% and 19% of previously unanalyzed histology and cytology samples, respectively. Mutations were detected in 54 tumors previously described as mutation-unknown (histology, n = 45; cytology, n = 9). ORRs in mutation-positive cytology (83%) and histology (74%) subgroups were consistent with previous analyses (71%). Tumor size decrease was consistent across previously analyzed and unanalyzed samples (all mutation subgroups), with less consistency across ORRs in mutation-negative cytology (16%) and histology (25%) subgroups versus the previous analysis (1%).

Conclusions

Histology samples with low tumor content and cytology samples can be used for EGFR mutation testing; patients whose mutation status was confirmed using these sample types achieved a response to treatment consistent with those confirmed using high-quality histology samples. Better sample quantity/quality can potentially reduce false-negative results.     

Clinical characteristics of non-small cell lung cancer patients who experienced acquired resistance during gefitinib treatment

Background

The NSCLC patients who experienced good clinical responses to an EGFR-TKI will inevitably develop acquired resistance. A great deal of research is being carried out to discover the molecular mechanisms underlying this resistance. In comparison, few studies have been conducted to find out about the clinical characteristics of acquired resistance in the patients who had responded to an EGFR-TKI. Herein we investigated clinical characteristics of NSCLC patients who experienced acquired resistance during gefitinib therapy.

Patients and methods

We reviewed NSCLC patients who showed a clinical benefit from initial gefitinib therapy. All clinical data were obtained from 11 centers of Korean Molecular Lung Cancer Group (KMLCG). The clinical manifestations of acquired resistance, time to progression (TTP), and post-progression survival (PPS) after gefitinib failure were analyzed retrospectively.

Results

A total of 417 patients were recruited. Median TTP was 10.2 months (95% CI, 9.5–10.9). TTP showed a significant longer duration in female, non-smoker, and patients with adenocarcinoma. At the time of acquired resistance, 63.3% of the patients showed symptomatic deterioration. Sites of disease progression were as follows: primary lung lesion in 58.4%, previous metastasis in 38.3%, and new metastasis in 54.2%. Patients with EGFR wild type showed a tendency of higher frequency in symptomatic deterioration and newly development of CNS metastasis compared with patients with EGFR mutation. There was a significant difference in newly development of lung metastasis between patients with exon 19 deletion and those with L858R mutation (41.4% vs. 6.3%, p = 0.02). PPS was 8.9 months (95% CI, 7.4–10.4). Smoking history, PS, new CNS lesion and subsequent chemotherapy were independent factors for PPS.

Conclusion

This study suggests that clinical manifestations of acquired resistance may be different according to EGFR mutation status and EGFR mutation genotype. In addition, subsequent chemotherapy confers clinical benefit in terms of PPS in NSCLC patients who experienced acquired resistance after gefitinib therapy.