Triplet chemotherapy with cisplatin, docetaxel, and irinotecan for patients with recurrent or refractory non-small cell lung cancer.

We examined the feasibility of triplet chemotherapy using cisplatin, docetaxel, and irinotecan for patients with recurrent or refractory non-small cell lung cancer (NSCLC), retrospectively. Twenty-five patients (21 men and 4 women) with NSCLC and good performance status who were < or = 70 years old were analyzed. The median age was 58 years. Most patients had performance status 1 (16/25), stage IV disease (18/25) and adenocarcinoma-histology (16/25). Cisplatin and docetaxel were given on day 1 and irinotecan on day 2; the cycle was repeated every 3 weeks. The objective response rate was 39.1% (95% confidence interval: 18.7-59.5%). The median survival time and actual 2-, 3-, and 5-year survival rates were 14.3 months, 32%, 20%, and 8%, respectively. Of note, only 6 patients were treated with gefitinib at the recurrence after triplet chemotherapy; of these, 4 (67%) achieved a partial response, which might result in favorable survival. Grade 3/4 toxicities consisted of neutropenia (100%), neutropenic fever (56%), nausea/vomiting (40%), and diarrhea (16%); no cases of treatment-related death occurred. Triplet chemotherapy showed impressive survival data in our clinical trial, but proved too toxic for use in treating patients with NSCLC in the clinical practice.

Sex difference in the influence of smoking status on the responsiveness to gefitinib monotherapy in adenocarcinoma of the lung: Okayama Lung Cancer Study Group experience.

BACKGROUND: Gefitinib is effective in patients with lung adenocarcinoma. Smoking status also affects the responsiveness to gefitinib, but it has not been fully evaluated whether a sex difference exists in the influence of smoking on the efficacy of gefitinib in patients with lung adenocarcinoma. METHODS: We reviewed the clinical records of 260 Japanese patients with lung adenocarcinoma who received gefitinib therapy (250 mg/day), and whose smoking status was known. Tumour response and survival were evaluated and stratified by smoking status and gender. RESULTS: Among the 260 patients, 157 were male (60%). Median pack-years was 40 (range 8-160) and 23 (range 1-74) in male and female smokers, respectively. Objective response was observed in 62 (23.8%) of the 260 patients, and 1-year overall survival and progression-free survival were 45.1 and 24.3%, respectively. Multivariate analysis revealed that smoking status (pack-years) was an independent predictive factor for response to gefitinib [odds ratio (OR) = 0.971, 95% confidence interval (CI) = 0.947-0.995; P = 0.0159] in male patients, but not in female patients (OR = 0.999, 95%CI = 0.957-1.042). Additionally, pack-years significantly influenced the overall survival in males (hazard ratio = 1.010; 95%CI = 1.002-1018, P = 0.0169), while differential survival of females was not significantly predicted by this factor (P = 0.7639). CONCLUSIONS: In male patients with lung adenocarcinoma, cumulative smoking significantly affected response and survival following gefitinib treatment, while in female patients, responsiveness to gefitinib was independent of smoking status. These results suggest that the influence of smoking habit on responsiveness to gefitinib is gender specific.

Epidermal growth factor receptor mutation, but not sex and smoking, is independently associated with favorable prognosis of gefitinib-treated patients with lung adenocarcinoma.

Epidermal growth factor receptor (EGFR) mutations have been reported as a predictive factor for favorable prognosis of gefitinib-treated patients with lung adenocarcinoma. However, its confounding with sex and smoking makes it unclear whether the EGFR mutation is independently associated with prolonged patient survival. In this study, we analyzed a large-scale database to discriminate the survival impact of EGFR mutations against those of sex and smoking after gefitinib therapy. EGFR mutations in exon19 and exon21 named drug-sensitive EGFR mutations were examined to investigate the impact of EGFR mutation, sex, and smoking status on survival of 362 gefitinib-treated patients with lung adenocarcinoma. Drug-sensitive EGFR mutations were detected in 169 patients (46.7%). The multivariate analysis including EGFR, sex, and smoking status showed that drug-sensitive EGFR mutations were significantly related to longer overall survival (OS) (P < 0.001) and progression-free survival (PFS) (P < 0.001). In addition, we investigated the impact of sex and smoking status according to EGFR mutation status, and the impact of EGFR mutation status according to sex and smoking status on survival. Sex and smoking status were not significantly associated with longer OS and PFS according to EGFR mutation status. Drug-sensitive EGFR mutations were significantly associated with longer OS and PFS according to sex or smoking status. Our results indicated that drug-sensitive EGFR mutations were the only independent factor for longer survival of patients treated with gefitinib, suggesting that patient selection based on EGFR mutation status for gefitinib therapy will lead to a better outcome for patients with lung adenocarcinoma.

Induction of lung adenocarcinoma in transgenic mice expressing activated EGFR driven by the SP-C promoter.

To investigate the role of an activating epidermal growth factor receptor (EGFR) mutation in lung cancer, we generated transgenic mice expressing the delE748-A752 mutant version of mouse EGFR driven by the SP-C promoter, which is equivalent to the delE746-A750 mutation found in lung cancer patients. Strikingly, the mice invariably developed multifocal lung adenocarcinomas of varying sizes at between 5 and 6 weeks of age, and they died from tumor progression approximately 2 months later if left untreated. Daily oral administration of the EGFR tyrosine kinase inhibitor (TKI) gefitinib (5 mg/kg/day) reduced the total and phosphorylation levels of EGFR to those in wild-type mouse lung tissue; in addition, it abrogated tumor growth within 1 week and prolonged survival to >30 weeks. Interestingly, phosphorylated ErbB2, ErbB3, and thyroid transcriptional factor-1 increased in the transgenic mice compared with those in wild-type mice. They might play some roles in tumors progression in the transgenic mice. This model will be useful for studying the mechanisms of carcinogenesis, chemoprevention, and acquired resistance to EGFR TKIs in lung cancer patients carrying activating EGFR mutations.

Association of the benefit from gefitinib monotherapy with smoking status in Japanese patients with non-small-cell lung cancer.

BACKGROUND: Gefitinib has been reported to be more effective in patients with non-small-cell lung cancer (NSCLC) who had low or never-smoking history than for heavier smokers. However, this has been criticized because the better survival in such subpopulation might be attributable simply to their favorable natural history, rather than any treatment effect. METHODS: We retrospectively reviewed the clinical records of 155 Japanese patients with relapsed NSCLC who received gefitinib (gefitinib-treated patients; n=83) and those who did not receive it, but were treated with other cytotoxic agents (gefitinib-untreated patients; n=72). A light smoker was defined as one with <20 pack-years. Survival was assessed stratified by gefitinib treatment and smoking status using stepwise proportional hazard modeling. RESULTS: Among the 155 relapsed patients, 58 (37%) had low or never-smoking history. The benefit from gefitinib monotherapy was associated with smoking status (test for interaction, p=0.01). Gefitinib monotherapy, as compared to the cytotoxic agents, significantly prolonged survival among patients with low or never-smoking history (hazard ratio [HR]=0.377; 95% confidence interval [CI]=0.181-0.785; p=0.01), but not among the heavier smokers. Additionally, among gefitinib-treated patients, those with low or never-smoking history survived longer than heavier smokers (HR=0.461; 95% CI=0.244-0.871; p=0.02), while the survival benefit of cytotoxic agents was comparable between those with low or never-smoking history and with heavy smoking habits among the gefitinib-untreated group. CONCLUSIONS: Patients with relapsed NSCLC and low or never-smoking habits appeared to benefit from gefitinib monotherapy, while patients with heavy smoking habits did not.

ERCC1 protein expression predicts the response of cisplatin-based neoadjuvant chemotherapy in non-small-cell lung cancer.

The excision repair cross-complementation group 1 (ERCC1) and BRCA1 have been identified as predictors of clinical outcomes among patients with non-small-cell lung cancer (NSCLC) treated with cisplatin-based chemotherapy. In this study, we immunohistochemically examined the ERCC1 and BRCA1 protein expression levels in 35 patients with metastatic mediastinal lymph nodes obtained prior to treatment as retrospective study. These patients had been enrolled in our studies on neoadjuvant chemotherapy with cisplatin and irinotecan (15 patients) or chemoradiotherapy with cisplatin and docetaxel plus concurrent thoracic radiation (20 patients). The relations between the ERCC1 or BRCA1 protein expression and the clinical outcomes of the patients were then examined. The rates of radiological response and pathological effectiveness were significantly higher among patients with ERCC1-negative tumors, compared with those with positive tumors in the neoadjuvant chemotherapy group (radiological response rates; 100% vs. 42.8%, P=0.013; pathological effectiveness; 100% vs. 47.1%, P=0.038), but no associations were observed in the neoadjuvant chemoradiotherapy group. Regarding survival, no significant differences in overall survival or disease-free survival were observed between patients with ERCC1-negative and positive tumors in both the neoadjuvant chemotherapy and chemoradiotherapy groups. In summary, we showed that a ERCC1-negative protein status was significantly related to tumor responsiveness to neoadjuvant chemotherapy with cisplatin and irinotecan, but such a status was not a clear prognostic predictor to cisplatin-based neoadjuvant therapy in NSCLC patients. Further study is needed to clarify the value of molecular predictors for customizing therapy for patients with NSCLC.

Elevated serum level of sialylated glycoprotein KL-6 predicts a poor prognosis in patients with non-small cell lung cancer treated with gefitinib.

PURPOSE: The factors affecting survival after gefitinib treatment in patients with non-small cell lung cancer (NSCLC) remain to be fully elucidated, although epidermal growth factor receptor (EGFR) mutation is a substantial prognostic factor. KL-6 has been studied as a useful indicator for interstitial lung diseases; however, it was first discovered as a lung cancer-related antigen. The aim of this study was to investigate the prognostic value of the serum KL-6 levels in advanced NSCLC patients treated with gefitinib and thus determine its association with the EGFR mutation status. PATIENTS AND METHODS: Between September 2002 and September 2005, 41 patients with NSCLC were treated with gefitinib after having their serum KL-6 levels measured at Okayama University Hospital. EGFR mutations were analyzed by direct sequence methods. RESULTS: The serum KL-6 levels ranged from 199 to 9080U/ml (median, 550U/ml), and 54% of 41 patients showed a level higher than the cut-off level of 500U/ml. The median progression-free survival (PFS) time and the median overall survival (OS) time were 4.7 months and 13.9 months, respectively. Multivariate analyses revealed that the elevated KL-6 level was an independent adverse prognostic factor for PFS (hazard ratio: 2.278, p=0.040) as well as OS (hazard ratio: 4.858, p=0.002) in NSCLC patients treated with gefitinib. The EGFR mutation status was analyzed in 22 patients (54%). Among those with wild-type EGFR, the patients with high serum KL-6 levels also had a worse survival than those within normal serum KL-6 levels (6.5 months versus 13.3 months, p=0.0194). CONCLUSION: Our data suggest that NSCLC patients with high serum KL-6 levels tended to have a poor clinical outcome when treated with gefitinib.

Being overweight influences the development of hepatic dysfunction in Japanese patients with non-small-cell lung cancer undergoing cytotoxic chemotherapy.

PURPOSE: The aim of this study was to identify risk factors for hepatic dysfunction during cytotoxic chemotherapy in Japanese patients with non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: We retrospectively reviewed the medical records of patients with NSCLC who received cytotoxic chemotherapy at Okayama University Hospital between January 2003 and March 2006. "Overweight" was defined as a body mass index (BMI) of 25 or more, according to the World Health Organization (WHO) criteria. We investigated the incidence and pattern of hepatic dysfunction during chemotherapy and evaluated the possible associations between hepatic dysfunction and several clinical factors, including BMI. RESULTS: Of the 155 Japanese patients enrolled in this study, 19 (12%) were overweight. Grade 2 or worse hepatic dysfunction was observed in 5 of the 19 overweight patients (26%) but in only 13 of the 136 non-overweight patients (10%). A multivariate analysis demonstrated that a higher BMI significantly increased the risk of grade 2 or worse hepatic dysfunction after the initiation of cytotoxic chemotherapy (odds ratio=4.04, 95% confidence intervals: 1.13-14.5, p=0.032). CONCLUSION: Our data suggest that being overweight can influence the development of hepatic dysfunction in Japanese patients receiving cytotoxic chemotherapy for the treatment of NSCLC, although further investigation is required.

Combination of SN-38 with gefitinib or imatinib overcomes SN-38-resistant small-cell lung cancer cells.

Irinotecan is one of the effective anticancer agents for small-cell lung cancer (SCLC) and 7-ethyl-10-hydroxy-campthothecin (SN-38) is an active metabolite of irinotecan. Gefitinib and imatinib are tyrosine kinase inhibitors which have clinical activities in several malignancies and they are also potent inhibitors of breast cancer resistance protein (BCRP) transporter, which confers the resistance of topoisomerase I inhibitors including SN-38 and topotecan. The cytotoxicity of SN-38, gefitinib and imatinib for the SN-38-resistant cells (SBC-3/SN-38) from human SCLC cells, SBC-3, was evaluated using AlamarBlue assay. The drug concentration required to inhibit the growth of tumor cells by 50% (IC50) for 96-h exposure was used to evaluate the cytotoxicity. BCRP expression was determined by Western blotting and immunofluorescence staining. Intracellular topotecan accumulation was evaluated by flow cytometry. No differences were observed in the IC50 values (mean +/- SD) of the tyrosine kinase inhibitors between the SBC-3 cells and the SBC-3/SN-38 cells: 15+/-1.6 and 12+/-2.8 microM of gefitinib, respectively; 15+/-0.51 and 14+/-3.9 microM of imatinib, respectively. The SBC-3/SN-38 was 9.5-fold more resistant to SN-38 than the parental SBC-3. The SBC-3/SN-38 restored sensitivity to SN-38 when combined with 8 microM gefitinib or 8 microM imatinib, even though the IC50 values of SN-38 combined with gefitinib or imatinib in the SBC-3 cells did not change. BCRP was equally overexpressed in the SBC-3/SN-38 with and without gefitinib or imatinib. In addition, the BCRP expression on the SBC-3/SN-38 cell membrane with and without gefitinib seemed to be equal. Gefitinib increased intracellular accumulation of topotecan in the SBC-3/SN-38 cells. Gefitinib or imatinib reversed SN-38-resistance in these SCLC cells, possibly due to intracellular accumulation of SN-38 without any change in BCRP quantity. Irinotecan with gefitinib or imatinib might be effective for SCLC refractory to irinotecan.

Role of early serial change in serum carcinoembryonic antigen levels as a predictive marker for radiological response to gefitinib in Japanese patients with non-small cell lung cancer.

BACKGROUND: There have been no reports evaluating the utility of monitoring early change in serum carcinoembryonic antigen (CEA) level as a predictor for subsequent radiological response to gefitinib in patients with non-small cell lung cancer. In this report, we investigated its role using the data from 110 non-small cell lung cancer (NSCLC) patients. METHODS: The daily rate of CEA change was defined as: (M0-Mx)/Dx/M0x100(%), using the baseline level (M0), the level on day X (Mx), and the number of days from day 1 to day X (Dx). RESULTS: The daily rate of CEA change until confirmation of an objective response was significantly higher in patients with an objective response or stable disease than progressive disease (PD) patients (p < 0.0001). Receiver operating characteristic analysis revealed that a cut-off level of 0.58% increase most accurately reflected tumor shrinkage, with sensitivity and specificity for disease control of 89.1% and 73.3%, respectively. In 41 (37%) patients, CEA was reassessed within the first two weeks after day 1. The daily rate of CEA change in this early phase tended to vary with the response (p = 0.0975), and reflected disease control less precisely, with sensitivity and specificity of 82.1% and 40.0%, respectively when a cut-off of 0.58% increase was used. CONCLUSION: The extent of CEA change until confirmation of an objective response correlated significantly with tumor burden. Monitoring an early CEA change, however, did not seem to be useful for detection of PD patients because of the low specificity. Considering the relatively high sensitivity, this model might be helpful for detecting those in whom subsequent disease control is likely.

Relationship between epidermal growth factor receptor gene mutations and the severity of adverse events by gefitinib in patients with advanced non-small cell lung cancer.

PURPOSE: Recent reports have demonstrated that mutation of epidermal growth factor receptor (EGFR) gene is predictive factor for tumor responsiveness to gefitinib suggesting the importance of EGFR status for the treatment of the patients with non-small cell lung cancer (NSCLC). However, the relationship between EGFR mutation and adverse events of gefitinib is still unknown. The aim of this study was to evaluate its correlation. PATIENTS AND METHODS: Twenty-six tumor samples from Japanese NSCLC patients who received gefitinib in Okayama University Hospital between November 2000 and October 2004 were examined exons 18-21 of EGFR using direct sequence method. We retrospectively reviewed the clinical records and compared EGFR mutation status with adverse events during gefitinib treatment. RESULTS: Of all 26 patients, EGFR mutation (exon 19 in-frame deletion, 6; exon 21 L858R, 5), were detected in 11 patients (42.3%). The principal adverse event was skin rash (89%), diarrhea (39%), and liver injury (39%). Grade 3 or more adverse events were not common. EGFR mutation status was correlated with neither its frequency nor severity of adverse events during gefitinib treatment including skin rash, diarrhea, liver injury, and interstitial lung disease. As expected, objective response rate of those with EGFR mutations was significantly higher than those without EGFR mutations (78% versus 21%, P<0.001). CONCLUSION: Our study did not demonstrate the presence of close relationships between EGFR mutation status and adverse events during gefitinib treatment.

Progression-free survival and overall survival in phase III trials of molecular-targeted agents in advanced non-small-cell lung cancer.

BACKGROUND: We examined how crossover therapy might affect the association between progression-free survival (PFS) and overall survival (OS) in non-small cell lung cancer (NSCLC). METHODS: We extracted PFS- and OS-hazard ratios (HRs) in phase III trials of molecular-targeted agents for advanced NSCLC. Their relationship was modeled in a linear function with the coefficient of determination (R-squared) to assess the correlation between PFS and OS. RESULTS: Thirty-four trials with 35 pairs for the investigational and reference arms were identified (24,158 patients). Overall, there was little correlation between PFS- and OS-HRs (R-squared = 0.14), suggesting PFS-HR could account only for 14% of variation in OS-HR. The median proportion of crossover therapy per trial was 20%. If patients seldom crossed over (none or <1%), the association between PFS- and OS-HRs was strong (R-squared = 0.69). When the proportion of crossover was ≥1%, however, R-squared declined considerably (≥1% to <20% crossover, R-squared = 0.27; ≥20% to <40%, R-squared = 0.06; and ≥40%, R-squared = 0.27). CONCLUSIONS: A PFS advantage seldom is associated with an OS advantage any longer. Our analysis suggests this is due to a high level of crossover now that an increasing number of active agents are available for NSCLC.

Treatment-related death in patients with small-cell lung cancer in phase III trials over the last two decades.

INTRODUCTION: Treatment-related death (TRD) remains a serious problem in small-cell lung cancer (SCLC), despite recent improvements in supportive care. However, few studies have formally assessed time trends in the proportion of TRD over the past two decades. The aim of this study was to determine the frequency and pattern of TRD over time. METHODS: We examined phase 3 trials conducted between 1990 and 2010 to address the role of systemic treatment for SCLC. The time trend was assessed using linear regression analysis. RESULTS: In total, 97 trials including nearly 25,000 enrolled patients were analyzed. The overall TRD proportion was 2.95%. Regarding the time trend, while it was not statistically significant, it tended to decrease, with a 0.138% decrease per year and 2.76% decrease per two decades. The most common cause of death was febrile neutropenia without any significant time trend in its incidence over the years examined (p = 0.139). However, deaths due to febrile neutropenia as well as all causes in patients treated with non-platinum chemotherapy increased significantly (p = 0.033). CONCLUSIONS: The overall TRD rate has been low, but not negligible, in phase III trials for SCLC over the past two decades.

Role of survival post-progression in phase III trials of systemic chemotherapy in advanced non-small-cell lung cancer: a systematic review.

BACKGROUND: In advanced non-small-cell lung cancer (NSCLC), with the increasing number of active compounds available in salvage settings, survival after progression to first-line chemotherapy seems to have improved. A literature survey was conducted to examine whether survival post-progression (SPP) has improved over the years and to what degree SPP correlates with overall survival (OS). METHODS AND FINDINGS: Median progression-free survival (MPFS) time and median survival time (MST) were extracted in phase III trials of first-line chemotherapy for advanced NSCLC. SPP was pragmatically defined as the time interval of MST minus MPFS. The relationship between MPFS and MST was modeled in a linear function. We used the coefficient of determination (r(2)) to assess the correlation between them. Seventy trials with 145 chemotherapy arms were identified. Overall, median SPP was 4.7 months, and a steady improvement in SPP was observed over the 20 years (9.414-day increase per year; p<0.001) in parallel to the increase in MST (11.253-day increase per year; p<0.001); MPFS improved little (1.863-day increase per year). Overall, a stronger association was observed between MST and SPP (r(2) = 0.8917) than MST and MPFS time (r(2) = 0.2563), suggesting SPP and MPFS could account for 89% and 25% of the variation in MST, respectively. The association between MST and SPP became closer over the years (r(2) = 0.4428, 0.7242, and 0.9081 in 1988-1994, 1995-2001, and 2002-2007, respectively). CONCLUSIONS: SPP has become more closely associated with OS, potentially because of intensive post-study treatments. Even in advanced NSCLC, a PFS advantage is unlikely to be associated with an OS advantage any longer due to this increasing impact of SPP on OS, and that the prolongation of SPP might limit the original role of OS for assessing true efficacy derived from early-line chemotherapy in future clinical trials.

Time to progression as a surrogate marker for overall survival in patients with advanced non-small cell lung cancer.

PURPOSE: With the increasing number of active compounds available for advanced non-small cell lung cancer, it is useful to evaluate whether surrogate end points can replace survival in randomized trials for the rapid and efficient assessment of efficacy. We examined the association between differences in overall survival and time to progression (TTP) using a literature survey. METHODS: We used median TTP (MTTP) and median survival time (MST) from 54 phase III trials of first-line chemotherapy involving 23,457 advanced non-small cell lung cancer patients in a multiple linear regression analysis. The MST ratio in each trial was defined as the ratio of MST in the investigational arm to that in the reference arm. The MTTP ratio was defined similarly. RESULTS: The degree of the association between the MST and MTTP ratios was only moderate both in the overall cohort (R(2) = 0.33) and various trial settings (R(2) = 0.16-0.51), although the MTTP ratio was an independent factor influencing the MST ratio in the multiple regression model (p < 0.01). This means that the MTTP ratio could account for less than half of the variance in the MST ratio. CONCLUSIONS: The TTP potentially acts as a surrogate marker, but may not be still a definitive alternative in the first-line setting.

Twenty-seven years of phase III trials for patients with extensive disease small-cell lung cancer: disappointing results.

BACKGROUND: Few studies have formally assessed whether treatment outcomes have improved substantially over the years for patients with extensive disease small-cell lung cancer (ED-SCLC) enrolled in phase III trials. The objective of the current investigation was to determine the time trends in outcomes for the patients in those trials. METHODS AND FINDINGS: We searched for trials that were reported between January 1981 and August 2008. Phase III randomized controlled trials were eligible if they compared first-line, systemic chemotherapy for ED-SCLC. Data were evaluated by using a linear regression analysis. RESULTS: In total, 52 trials were identified that had been initiated between 1980 and 2006; these studies involved 10,262 patients with 110 chemotherapy arms. The number of randomized patients and the proportion of patients with good performance status (PS) increased over time. Cisplatin-based regimens, especially cisplatin and etoposide (PE) regimen, have increasingly been studied, whereas cyclophosphamide, doxorubicin, and vincristine-based regimens have been less investigated. Multiple regression analysis showed no significant improvement in survival over the years. Additionally, the use of a PE regimen did not affect survival, whereas the proportion of patients with good PS and the trial design of assigning prophylactic cranial irradiation were significantly associated with favorable outcome. CONCLUSIONS AND SIGNIFICANCE: The survival of patients with ED-SCLC enrolled in phase III trials did not improve significantly over the years, suggesting the need for further development of novel targets, newer agents, and comprehensive patient care.

Comprehensive analysis of EGFR signaling pathways in Japanese patients with non-small cell lung cancer.

PURPOSE: Translational approach is essentially needed to return the achievement of basic researches to oncological practice. The molecular associations among EGFR mutation and the components of EGFR signaling pathways have been extensively studied in laboratory experiments, although were still controversial. Moreover, the impact of downstream signaling of EGFR on clinical features in patients with non-small cell lung cancer (NSCLC) remains undetermined. PATIENTS AND METHODS: A total of 93 surgically resected NSCLC patients were recruited the study. EGFR mutation status was analyzed by direct sequence method. The protein expression levels of EGFR, phosphorylated EGFR (pEGFR), phosphorylated Akt (pAkt), and phosphorylated MAPK (pMAPK) were determined by immunohistochemistry. RESULTS: There were 37 (40%) patients whose tumor harboring EGFR mutations (1 in exon 18, 22 in exon 19, and 14 in exon 21). Protein expression of EGFR, pEGFR, pAkt, and pMAPK was detected in 61 (66%), 27 (29%), 58 (62%), and 41 (44%) patients, respectively. The expression of pAkt was significantly associated with female gender and never-smoking history, and it was frequently upregulated in tumors harboring EGFR mutations (p<0.05, each). Phosphorylation of EGFR was closely correlated with the EGFR protein expression (p<0.05), but not with the EGFR mutations. In regard to patient survival, none of the molecular biomarkers was predictive for survival after surgical resection, but pMAPK expression was predictive for poor prognosis after gefitinib treatment in patients with postoperative recurrence (p<0.05), suggesting the strong linkage between pMAPK expression and survival benefit from gefitinib. CONCLUSION: Our result could provide new insight into MAP kinase signaling when we treat NSCLC patients with gefitinib.