Smoking history as a predictive factor of treatment response in advanced non-small-cell lung cancer: a systematic review

Development of Clinical Prediction Score for Chemotherapy Response in Advanced Non-Small Cell Lung Cancer Patients

The outcomes of advanced non-small cell lung cancer (NSCLC) patients have been significantly improved with novel therapies, such as tyrosine kinase inhibitors and immune checkpoint inhibitors. However, in resource-limited countries, platinum-doublet chemotherapy is mainly used as a first-line treatment. We investigate clinical parameters to predict the response after chemotherapy, which may be useful for patient selection. A clinical prediction score (CPS) was developed, based on data from a retrospective cohort study of unresectable stage IIIB or IV NSCLC patients who were treated with platinum-doublet chemotherapy in the first-line setting with at least two cycles and an evaluated response by RECIST 1.1 at Surin Hospital Cancer Center, Thailand, between July 2014 and December 2018. The clinical parameters in the prediction model were derived by risk regression analysis. There were 117 responders (CR or PR) and 90 non-responders (SD or PD). The clinical prediction score was developed by six clinical parameters including gender, age, smoking status, ECOG, pre-treatment albumin, and histologic subtype. The AuROC of the model was 0.71 (95% CI 0.63-0.78). The internal validation was performed using a bootstrap technique and showed a consistent AuROC of 0.66 (95% CI 0.59-0.72). The prediction score ranged from 0-13, with a score of 0-8 meaning a low probability (PPV = 50%) and a score of 8.5-13 meaning a high probability (PPV = 83.7%) for chemotherapy response. Advanced NSCLC patients who cannot access novel therapies and have a CPS of 8.5-13 have a high probability for chemotherapy response in the first-line setting. This CPS could be used for risk communication and making decisions with patients, especially in regard to chemotherapy.

Do antiangiogenics promote clot instability? Data from the TESEO prospective registry and Caravaggio clinical trial

Background  Venous thromboembolism (VTE) is a common complication in cancer patients. Much of its morbidity stems from the development of fatal pulmonary embolisms (PE). Little is known about the factors involved in clot stability, with angiogenesis possibly being implicated.

Methods  The database is from the TESEO prospective registry that recruits cancer patients with VTE from 41 Spanish hospitals. Independent validation was conducted in a cohort from the Caravaggio trial. The objective is to evaluate the association between exposure to antiangiogenic therapies and the PE/VTE proportion in oncological patients.

Results  In total, 1,536 subjects were evaluated; 58.4% ( n  = 894) had a PE and 7% ( n  = 108) received antiangiogenic therapy (bevacizumab in 75%). The PE/VTE proportion among antiangiogenic-treated individuals was 77/108 (71.3%) versus 817/1,428 (57.2%) among those receiving other alternative therapies ( p  = 0.004). The effect of the antiangiogenics on the PE/VTE proportion held up across all subgroups except for active smokers or those with chronic obstructive pulmonary disease. Exposure to antiangiogenics was associated with increased PEs, odds ratio (OR) 2.27 (95% CI, 1.42–3.63). In the Caravaggio trial, PE was present in 67% of the individuals treated with antiangiogenics, 50% of those who received chemotherapy without antiangiogenic treatment, and 60% without active therapy ( p  = 0.0016).

Conclusion  Antiangiogenics are associated with increased proportion of PE in oncological patients with VTE. If an effect on clot stability is confirmed, the concept of thrombotic risk in cancer patients should be reconsidered in qualitative terms.

First- or second-generation epidermal growth factor receptor tyrosine kinase inhibitors in a large, real-world cohort of patients with non-small cell lung cancer

Background

There are limited comparisons of first- and second-generation EGFR tyrosine kinase inhibitors (TKIs) in large, real-world cohorts of non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations.

Methods

Patients with advanced NSCLC (N = 612) with common EGFR mutations receiving first-line gefitinib/erlotinib and afatinib were grouped and propensity-score matched. Progression-free survival (PFS), overall survival (OS) and secondary T790M mutations were analyzed.

Results

The gefitinib/erlotinib and afatinib groups each contained 206 patients after matching. Compared with gefitinib/erlotinib, patients receiving afatinib achieved longer median PFS (16.3 versus 14.2 months; log-rank test p = 0.020) and had a lower risk of progression [hazard ratio (HR) 0.73 (95% confidence interval (CI), 0.57-0.94); p = 0.017]. Median OS (37.3 versus 34.2 months; log-rank test p = 0.500) and reduction in risk of death [HR 0.89 (95% CI, 0.65-1.23); p = 0.476] did not differ significantly between groups. T790M positivity was significantly higher in the gefitinib/erlotinib than afatinib group (70.9% versus 44.6%, p < 0.001). Multivariate analysis demonstrated that afatinib was independently associated with lower T790M positivity [odds ratio (OR) 0.27 (95% CI, 0.14-0.53); p < 0.001], whereas ⩾12 months PFS after EGFR-TKI treatment [OR 3.00 (95% CI, 1.56-5.98); p = 0.001] and brain metastasis [OR 2.12 (95% CI, 1.08-4.26); p = 0.030] were associated with higher T790M positivity. Sequential third-generation EGFR-TKI treatment was administered to 63 patients, in whom median OS after the second-third-generation and first-third-generation EGFR-TKI sequences were 38.8 and 29.1 months, respectively.

Conclusion

Compared with gefitinib/erlotinib, afatinib had a higher treatment efficacy and a lower secondary T790M positivity in a large, real-world cohort of Asian patients with EGFR-mutated NSCLC.

Genetic Variation and Recurrent Haplotypes on Chromosome 6q23-25 Risk Locus in Familial Lung Cancer

Although lung cancer is known to be caused by environmental factors, it has also been shown to have genetic components, and the genetic etiology of lung cancer remains understudied. We previously identified a lung cancer risk locus on 6q23-25 using microsatellite data in families with a history of lung cancer. To further elucidate that signal, we performed targeted sequencing on nine of our most strongly linked families. Two-point linkage analysis of the sequencing data revealed that the signal was heterogeneous and that different families likely had different risk variants. Three specific haplotypes were shared by some of the families: 6q25.3-26 in families 42 and 44, 6q25.2-25.3 in families 47 and 59, and 6q24.2-25.1 in families 30, 33, and 35. Region-based logarithm of the odds scores and expression data identified the likely candidate genes for each haplotype overlap: ARID1B at 6q25.3, MAP3K4 at 6q26, and UTRN (6q24.1) and PHACTR2 (6q24.2). Further annotation was used to zero in on potential risk variants in those genes. All four genes are good candidate genes for lung cancer risk, having been linked to either lung cancer specifically or other cancers. However, this is the first time any of these genes has been implicated in germline risk. Functional analysis of these four genes is planned for future work. SIGNIFICANCE: This study identifies four genes associated with lung cancer risk, which could help guide future lung cancer prevention and treatment approaches.

PD-L1 Expression and Outcome in Patients with Metastatic Non-Small Cell Lung Cancer and EGFR Mutations Receiving EGFR-TKI as Frontline Treatment

Background

Epidermal growth factor receptor (EGFR) mutations are most common in Eastern Asia, and frequencies of 30–50% have been reported. EGFR-tyrosine kinase inhibitors (TKIs) are recommended as first-line therapeutic options for non-small cell lung cancer (NSCLC) with sensitizing EGFR mutations. Several immune checkpoint inhibitors have been successful in improving the outcomes of advanced lung cancer. The expression of programmed cell death-ligand 1 (PD-L1) on tumor cells plays an important role in predicting the efficacy of programmed cell death protein 1/PD-L1 inhibitors. The role of PD-L1 expression in tumors with EGFR mutation and its influence on clinical outcomes remain controversial.

Methods

Patients with newly diagnosed metastatic NSCLC with sensitizing EGFR mutations who received the standard treatment, ie, EGFR-TKIs for mutant adenocarcinoma as the first-line treatment, were enrolled in this retrospective study. EGFR mutations and PD-L1 expression levels were detected by Cobas RT-PCR and Dako 22C3 immunohistochemistry staining, respectively.

Results

From January 2011 to February 2019, 114 patients were enrolled. The average age was 62 years (range 34–92), and 45 (39.5%) patients were male. Among these patients, EGFR mutation analysis revealed exon 19 in-frame deletion in 55 (48.2%) patients, exon 21 L858R in 53 (46.5%) patients, and uncommon mutations in 6 (5.3%) patients. Among these patients with EGFR mutations, PD-L1 expression levels by tumor proportion score (TPS) were <1% in 54 (46.9%) patients, 1–49% in 50 (44.2%) patients, and ≥50% in 10 (8.8%) patients. All patients received EGFR-TKIs as first-line treatment, and in the Kaplan-Meier analysis, progression-free survival was not significantly different among groups with different PD-L1 expression status.

Conclusion

For patients with metastatic NSCLC and EGFR mutations, PD-L1 expression is not uncommon, but no significant influence on clinical outcomes was observed in patients receiving standard initial treatment.

Responses of smoking and nonsmoking cancer patients to drug treatment: A protocol for systematic review and meta-analysis

INTRODUCTION

Smoking is well-known to increase cancer risk, particularly risk of lung cancer, and negatively affects efficacy of cancer treatment. However, recent evidence suggests that among cancer patients, paradoxically, smokers respond to treatment better than non-smokers. We propose to conduct a focused review and meta-analysis to compare response to drug treatment between smoking and non-smoking cancer patients.

METHODS AND DESIGN

We will collect data from large clinical trials of therapies for cancer patients which have included smokers and non-smokers. We will search PubMed, PMC/ MEDLINE, SCOPUS, Embase, and the registries for clinical trials and four major clinical journals up to June 30, 2019. Search terms will be "Drug name" phase-3" or "Drug name" phase-III." Data collection will be focused on randomized clinical trials of cancer drugs that enrolled at least 100 participants and reporting treatment results from smoking and nonsmoking patients. Initial selection criteria will be clinical trial studies of drug treatment of 100 or more cancer patients, and reporting hazard ratios (HR) for smokers and non-smokers. Two persons will be searching such publications independently, or data will be provided, double checked, or confirmed by authors. Multiple sub-group analyses will be conducted by at least two persons to avoid bias or experimental errors.

DISCUSSION

The results will clarify whether smoking and response to treatment of cancer are linked not. Our results may possibly identify drug/s that work better among cancer patients who are smokers.

TRIAL REGISTRATION

PROSPERO registration number: CRD42019146402.

Cumulative smoking dose affects the clinical outcomes of EGFR-mutated lung adenocarcinoma patients treated with EGFR-TKIs: a retrospective study

Background

Although lung adenocarcinoma with activating epidermal growth factor receptor (EGFR) mutations is common in never smokers, one-third of the patients are ever-smokers. We aimed to investigate the effect of cumulative smoking dose(CSD) on clinical outcomes, including progression-free survival (PFS) and overall survival (OS), in patients with EGFR-mutated lung adenocarcinoma receiving EGFR-tyrosine kinase inhibitors (TKIs).

Methods

We retrospectively analyzed 142 patients with EGFR-mutation positive advanced or recurrent lung adenocarcinoma who were administered gefitinib, erlotinib, afatinib, and osimertinib. These patients were classified based on their CSD as never smokers, light smokers (≤10 pack-years [PYs]), moderate smokers (11–30 PYs), and heavy smokers (> 30 PYs). PFS and OS were analyzed according to smoking subgroups via Kaplan-Meier curves.

Results

Among the 142 patients, 91 (64.1%), 12 (8.5%), 22 (15.5%), and 17 (12%) were never, light, moderate, and heavy smokers, respectively. CSD was inversely associated with median PFS in a statistically significant dose-dependent manner (11.8 months (mo), 11.0 mo, 7.4 mo, and 3.9 mo; p < 0.001). Statistically significant negative association was observed between CSD and median OS (33.6 mo, 26.3 mo, 20 mo, and 8.9 mo; p < 0.001). In the multivariate analysis adjusted for age, sex, performance status, stage, and timing of EGFR-TKIs, CSD was an independent predictive factor for disease progression (hazard ratio [HR], 4.00; 95% confidence interval [CI], 1.95–8.23; p = 0.012) and OS (HR, 3.9; 95% CI, 1.84–8.28; p < 0.001).

Conclusion

CSD is an important predictive and prognostic factor in patients with EGFR-mutated lung adenocarcinoma, and associated smoking-related gene signatures might affect the outcomes.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4691-0) contains supplementary material, which is available to authorized users.

Real-World Data on Prognostic Factors for Overall Survival in EGFR Mutation-Positive Advanced Non-Small Cell Lung Cancer Patients Treated with First-Line Gefitinib

BACKGROUND

This study aimed to identify independent prognostic factors for overall survival (OS) of patients with advanced non-small cell lung cancer (NSCLC) harboring an activating epidermal growth factor receptor (EGFR) mutation and receiving gefitinib as first-line treatment in real-world practice.

MATERIALS AND METHODS

We enrolled 226 patients from June 2011 to May 2013. During this period, gefitinib was the only EGFR-tyrosine kinase inhibitor reimbursed by the Bureau of National Health Insurance of Taiwan.

RESULTS

The median progression-free survival and median OS were 11.9 months (95% confidence interval [CI]: 9.7-14.2) and 26.9 months (21.2-32.5), respectively. The Cox proportional hazards regression model revealed that postoperative recurrence, performance status (Eastern Cooperative Oncology Grade [ECOG] ≥2), smoking index (≥20 pack-years), liver metastasis at initial diagnosis, and chronic hepatitis C virus (HCV) infection were independent prognostic factors for OS (hazard ratio [95% CI] 0.3 [0.11-0.83], p = .02; 2.69 [1.60-4.51], p < .001; 1.92 [1.24-2.97], p = .003; 2.26 [1.34-3.82], p = .002; 3.38 [1.85-7.78], p < .001, respectively). However, brain metastasis (BM) at initial diagnosis or intracranial progression during gefitinib treatment had no impact on OS (1.266 [0.83-1.93], p = .275 and 0.75 [0.48-1.19], p = .211, respectively).

CONCLUSION

HCV infection, performance status (ECOG ≥2), newly diagnosed advanced NSCLC without prior operation, and liver metastasis predicted poor OS in EGFR mutation-positive advanced NSCLC patients treated with first-line gefitinib; however, neither BM at initial diagnosis nor intracranial progression during gefitinib treatment had an impact on OS.

IMPLICATIONS FOR PRACTICE

The finding that chronic hepatitis C virus (HCV) infection might predict poor overall survival (OS) in epidermal growth factor receptor mutation-positive advanced non-small cell lung cancer (NSCLC) patients treated with first-line gefitinib may raise awareness of benefit from anti-HCV treatment in this patient population. Brain metastasis in the initial diagnosis or intracranial progression during gefitinib treatment is not a prognostic factor for OS. This study, which enrolled a real-world population of NSCLC patients, including sicker patients who were not eligible for a clinical trial, may have impact on guiding usual clinical practice.

Familial Lung Cancer: A Brief History from the Earliest Work to the Most Recent Studies

Lung cancer is the deadliest cancer in the United States, killing roughly one of four cancer patients in 2016. While it is well-established that lung cancer is caused primarily by environmental effects (particularly tobacco smoking), there is evidence for genetic susceptibility. Lung cancer has been shown to aggregate in families, and segregation analyses have hypothesized a major susceptibility locus for the disease. Genetic association studies have provided strong evidence for common risk variants of small-to-moderate effect. Rare and highly penetrant alleles have been identified by linkage studies, including on 6q23-25. Though not common, some germline mutations have also been identified via sequencing studies. Ongoing genomics studies aim to identify additional high penetrance germline susceptibility alleles for this deadly disease.

The impact of smoking status on radiologic tumor progression patterns and response to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors in lung adenocarcinoma with activating EGFR mutations

BACKGROUND

The aim of this study was to evaluate the impact of smoking on the treatment outcome of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) in patients with EGFR-mutant lung adenocarcinoma, with consideration of other factors including radiologic tumor progression pattern according to patient smoking status.

METHODS

A total of 224 patients with EGFR mutant lung adenocarcinomas that were treated with EGFR-TKIs were retrospectively reviewed. Radiologic tumor progression pattern and treatment outcomes were evaluated according to smoking history.

RESULTS

There were no significant differences in radiologic tumor progression pattern based on smoking status. There were no significant differences in survival between never-smokers and smokers or among never-, former-, and current-smokers, but there was a trend of shorter progression free survival (PFS) and poorer overall survival (OS) in smokers compared with never-smokers. In multivariate analysis, long-term smokers had shorter PFS and poorer OS than those who had never smoked.

CONCLUSIONS

A history of smoking had no significant effect on radiologic tumor progression pattern; however, smoking history is a negative predictive factor of survival in patients with EGFR-mutant lung adenocarcinoma undergoing EGFR-TKI therapy.

Impact of active smoking on survival of patients with metastatic lung adenocarcinoma harboring an epidermal growth factor receptor (EGFR) mutation

Lung cancer in smokers and non-smokers demonstrates distinct genetic profiles, and cigarette smoking affects epidermal growth factor receptor (EGFR) function and causes secondary EGFR tyrosine kinase resistance. We evaluated the effect of active smoking in patients with metastatic lung adenocarcinoma. A total of 132 metastatic lung adenocarcinoma patients, diagnosed between 2008 and 2013, with known EGFR mutation status, were evaluated retrospectively. Among these patients, 40 had an activating EGFR mutation. Patients who continued smoking during the treatment were defined as active smokers. Former smokers and never smokers were together defined as non-smokers. The outcomes of the treatment in relation to the EGFR mutation and smoking status were evaluated. The median follow-up time was 10.5 months. The overall response rate for the first-line therapy was significantly higher among the EGFR-mutant patients (p = 0.01), however, smoking status had no impact on the response rate (p = 0.1). The EGFR-mutant active smokers progressed earlier than the non-smokers (p < 0.01). The overall survival (OS) of the non-smokers and patients treated with erlotinib was significantly longer (p = 0.02 and p = 0.01, respectively). Smoking status did not affect the OS in EGFR wild type tumors (p = 0.49) but EGFR-mutant non-smokers had a longer OS than the active smokers (p = 0.01).The active smokers treated with erlotinib had poorer survival than the non-smokers (p = 0.03). Multivariate analysis of EGFR-mutant patients showed that erlotinib treatment at any line and non-smoking were independent prognostic factors for the OS (p = 0.04 and p = 0.01, respectively). Smoking during treatment is a negative prognostic factor in metastatic lung adenocarcinoma with an EGFR mutation.

Tobacco and lung cancer: risks, trends, and outcomes in patients with cancer

Tobacco use, primarily associated with cigarette smoking, is the largest preventable cause of cancer mortality, responsible for approximately one-third of all cancer deaths. Approximately 85% of lung cancers result from smoking, with an additional fraction caused by secondhand smoke exposure in nonsmokers. The risk of lung cancer is dose dependent, but can be dramatically reduced with tobacco cessation, especially if the person discontinues smoking early in life. The increase in lung cancer incidence in different countries around in the world parallels changes in cigarette consumption. Lung cancer risks are not reduced by switching to filters or low-tar/low-nicotine cigarettes. In patients with cancer, continued tobacco use after diagnosis is associated with poor therapeutic outcomes including increased treatment-related toxicity, increased risk of second primary cancer, decreased quality of life, and decreased survival. Tobacco cessation in patients with cancer may improve cancer treatment outcomes, but cessation support is often not provided by oncologists. Reducing the health related effects of tobacco requires coordinated efforts to reduce exposure to tobacco, accurately assess tobacco use in clinical settings, and increase access to tobacco cessation support. Lung cancer screening and coordinated international tobacco control efforts offer the promise to dramatically reduce lung cancer mortality in the coming decades.

Impact of Smoking and Brain Metastasis on Outcomes of Advanced EGFR Mutation Lung Adenocarcinoma Patients Treated with First Line Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors

Objectives

This purpose of this study was to examine clinical-pathologic factors – particularly smoking and brain metastases – in EGFR mutation positive (M+) lung adenocarcinoma (ADC) to determine their impact on survival in patients treated with first line EGFR TKI.

Methods

A retrospective review of EGFR mutation reflex testing experience for all ADC diagnosed at a tertiary Asian cancer centre from January 2009 to April 2013. Amongst this cohort, patients with advanced EGFR M+ ADC treated with first line EGFR TKI were identified to determine factors that influence progression free and overall survival.

Results

444/742 (59.8%) ADC reflex tested for EGFR mutations were EGFR M+. Amongst never-smokers (n=468), EGFR M+ were found in 74.5% of females and 76.3% of males, and amongst ever smokers (n=283), in 53.3% of females and 35.6% of males. Exon 20 mutations were found more commonly amongst heavy smokers (> 50 pack years and > 20 pack years, Pearson’s chi square p=0.044, and p=0.038 respectively). 211 patients treated with palliative first line TKI had a median PFS and OS of 9.2 and 19.6 months respectively. 26% of patients had brain metastasis at diagnosis. This was significantly detrimental to overall survival (HR 1.85, CI 1.09-3.16, p=0.024) on multivariate analysis. There was no evidence that smoking status had a significant impact on survival.

Conclusions

The high prevalence of EGFR M+ in our patient population warrants reflex testing regardless of gender and smoking status. Smoking status and dosage did not impact progression free or overall survival in patients treated with first line EGFR TKI. The presence of brain metastasis at diagnosis negatively impacts overall survival.

Impact of smoking status on EGFR-TKI efficacy for advanced non-small-cell lung cancer in EGFR mutants: a meta-analysis

BACKGROUND

The strong association between smoking history and the presence of epidermal growth factor receptor (EGFR) mutations has been proven in non-small-cell lung cancer (NSCLC), which explains the favorable response to EGFR-tyrosine kinase inhibitor (EGFR-TKI) therapy in nonsmoking NSCLC patients. However, few studies directly focus on the relationship between EGFR-TKI's efficacy and smoking history in NSCLC EGFR-mutant patients.

METHODS

Electronic databases were searched for eligible literatures. Data on objective response rates, disease control rates, and progression-free survival (PFS) stratified by smoking status were extracted and synthesized on the basis of a random-effect model. Subgroup and sensitivity analyses were conducted.

RESULTS

A total of 9 studies that involved a total of 1029 EGFR-mutant advanced NSCLC patients after EGFR-TKI treatment were included. In overall, nonsmoking was associated with significant prolonged PFS (HR, 0.73, 0.60 to 0.88; P = .001) compared to ever smokers. However, only marginal improvements without statistical significance in objective response rates (odds ratio, 1.11; 95% confidence interval, 0.85 to 1.46; P = .433) and disease control rate (odds ratio, 1.04; 95% confidence interval, 0.82 to 1.33; P = .740) were observed. Subgroup analyses showed that the benefits of PFS in nonsmokers were predominantly presented in pooled results of studies enrolling patients with active EGFR mutations, studies involving previously treated patients, and retrospective studies. Additionally, we failed to observe any significant benefit from nonsmokers in every subgroup for objective response rates and disease control rate.

CONCLUSION

For advanced NSCLC patients with EGFR mutations, nonsmoking is associated with longer PFS than ever smoking after EGFR-TKIs treatment. Smoking history should be considered an essential factor in studies regarding EGFR-targeted agents toward EGFR-mutant patients.

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.

Second-line treatment in advanced non-small-cell lung cancer in the epidermal growth factor receptor wild-type population: review of patient profile

After progression during first-line treatment in advanced non-small-cell lung cancer (NSCLC), a large percentage of patients are candidates for second-line treatment. The majority do not have epidermal growth factor receptor-activating mutations (EGFRwt). This article reviews the treatment options available for this subpopulation of patients, which includes essentially docetaxel, pemetrexed and erlotinib. These drugs all have similar efficacy, both in terms of objective response rates and overall survival, although with different toxicity profiles. In view of the similar efficacy of the three agents (docetaxel, pemetrexed and erlotinib) in the second-line treatment of NSCLC in the EGFRwt population, and although there are no prospective studies on predictive variables or new molecular markers available, selection of the treatment will depend on the histological type (pemetrexed); patient preference (oral as opposed to intravenous formulation); the presence of comorbid conditions; quality of life; previous or residual toxicities; the risk of neutropenia; response to and the duration of the first-line chemotherapy; and history of smoking.

Prevalence of cigarette smoking and associated factors among secondary school teachers in Malaysia

OBJECTIVE

The smoking prevalence in Malaysia is high, especially among men and adolescents. This study aimed to determine the prevalence and associated factors towards cigarette smoking among school teachers in Malaysia.

METHODOLOGY

This study was a school-based cross-sectional study conducted among 495 secondary school teachers. The questionnaire used in this study consisted of 29 questions categorized into two sections: socio-demographic characteristics and smoking behaviour. Data were analyzed using the Statistical Package for the Social Sciences (SPSS) program 13.0. ANOVA; t-tests were used in univariate analysis; multiple linear regression was applied for multivariate analysis.

RESULTS

The majority of the participants were female (81.6%), in the age group ranged between 30-39 years (44%), Malay (90.1%), married (89.7%), degree holders (85.1%), with monthly income ranged between 3000-3999 Ringgit Malaysia (33.5%), from urban areas (94.7%), their specialty is social studies (33.9%) and with no family history of cancer (83.6%). The prevalence of smoking among school teachers in Malaysia was found to be 7.8%. Regarding reasons to start smoking among school teachers: the major reason was found to be relaxation (33.3%), followed by stress-relief (28.2%). Univariate analysis showed that sex, educational status, monthly income and residency were significantly associated with smoking among school teachers (p<0.001, p=0.004, p=0.031, p=0.010; respectively). Multivariate analysis showed that gender and marital status were significantly associated with smoking among school teachers (p<0.001, p=0.033; respectively).

CONCLUSION

The prevalence of smoking among school teachers in Malaysia was found to be relatively low. Sex, marital status, educational status, monthly income and residency were significantly associated with smoking among school teachers.

Src mediates cigarette smoke-induced resistance to tyrosine kinase inhibitors in NSCLC cells

The EGF receptor (EGFR) is a proto-oncogene commonly dysregulated in several cancers including non-small cell lung carcinoma (NSCLC) and, thus, is targeted for treatment using tyrosine kinase inhibitors (TKI) such as erlotinib. However, despite the efficacy observed in patients with NSCLC harboring oncogenic variants of the EGFR, general ineffectiveness of TKIs in patients with NSCLC who are current and former smokers necessitates identification of novel mechanisms to overcome this phenomenon. Previously, we showed that NSCLC cells harboring either wild-type (WT) EGFR or oncogenic mutant (MT) L858R EGFR become resistant to the effects of TKIs when exposed to cigarette smoke, evidenced by their autophosphorylation and prolonged downstream signaling. Here, we present Src as a target mediating cigarette smoke-induced resistance to TKIs in both WT EGFR- and L858R MT EGFR-expressing NSCLC cells. First, we show that cigarette smoke exposure of A549 cells leads to time-dependent activation of Src, which then abnormally binds to the WT EGFR causing TKI resistance, contrasting previous observations of constitutive binding between inactive Src and TKI-sensitive L858R MT EGFR. Next, we show that Src inhibition restores TKI sensitivity in cigarette smoke-exposed NSCLC cells, preventing EGFR autophosphorylation in the presence of erlotinib. Furthermore, we show that overexpression of a dominant-negative Src (Y527F/K295R) restores TKI sensitivity to A549 exposed to cigarette smoke. Importantly, the TKI resistance that emerges even in cigarette smoke-exposed L858R EGFR-expressing NSCLC cells could be eliminated with Src inhibition. Together, these findings offer new rationale for using Src inhibitors for treating TKI-resistant NSCLC commonly observed in smokers.