Epidermal Growth Factor Receptor Mutation Analysis Research Articles

Never-smoking history predicts long-term survival in patients with non-small cell lung cancer with postoperative recurrence

20047 Background: Factors affecting long-term survival after postoperative recurrence in non-small cell lung cancer (NSCLC) patients have not been fully understood. Furthermore, molecular features of them also have remained undetermined. The aim of this study was to identify these possible factors and to investigate their association with epidermal growth factor receptor (EGFR) mutation. Methods: Fifty-eight patients with postoperative recurrent NSCLC treated at Okayama University Hospital between January 1999 and December 2003 were retrospectively analyzed. We defined those surviving for 2 years or longer after postoperative recurrence as long-term survivors. Tumor samples for EGFR mutation analysis were available in 32 (55%) patients and were examined in exons 18 to 21 of EGFR using direct sequence method. Results: Demographics of 58 patients were as follows: median age 65 years (range, 33–85 years), male/female, 69%/31%; adenocarcinoma/others, 69%/31%; ever/never-smokers, 66%/34% and local/local and distant/distant recurrence; 29%/10%/61%. Median survival time and 1-year survival rate for 58 patients were 22.7 months and 79%, respectively, with a minimum follow-up time of 2 years. Half of 28 long-term survivors did not have any smoking history, whereas only 6 never-smokers were included in the remaining 30 patients who died within 2 years, indicating that never-smoking history is significantly associated with long-term survival (p=0.016). In multivariate analysis, never-smoking history was a significant predictive factor for long-term survival (Odds ratio 4.90, 95% confidence interval: 1.26–19.00, p=0.022). Among 32 patients analyzed for EGFR mutation, patients harboring EGFR mutation in ever-smokers and in never-smokers were 10% and 82%, respectively. Seven (47%) of 15 long-term survivors analyzed had EGFR mutation; however, only 4 (24%) of 17 patients who died within 2 years did (p = 0.169). Conclusions: Our data suggest that never-smoking history might have a favorable effect on long-term survival in postoperative recurrent NSCLC patients, and long-term survivors tend to have EGFR mutation. No significant financial relationships to disclose.

Total blockade of the epidermal growth factor receptor with the combination of cetuximab and gefitinib: A phase I study for patients with recurrent non-small cell lung cancer (NSCLC)

17045 Background: Cetuximab and gefitinib inhibit the epidermal growth factor receptor (EGFR) through different mechanisms. Preclinical evidence suggests that the combination of cetuximab and Gefitinib is synergistic and has shown antitumor activity in vitro and in xenografts (Matar et al, Clin Cancer Res, 2004). We are conducting a phase I study to determine the doses of the two agents that can be administered in combination. Methods: Patients (pts) with advanced NSCLC were eligible upon progression following 1 or 2 prior chemotherapy regimens. Gefitinib was administered at a dose of 250 mg/day for all cohorts. The dose of cetuximab was escalated in sequential cohorts of patients ( table ) and there will be no dose escalation above the approved doses for both agents (dose level 3). Paraffin-embedded tissue samples of the primary cancer were collected from all patients for analysis of EGFR mutations, gene amplification and protein expression. Results: From March to December 2005, 11 patients have been entered to the 3 planned cohorts. Patient characteristics include: 3 women and 8 men, with a median age of 63 years (range 51–77) and ECOG performance status (PS) of: 0 = 50%, 1 = 50%. A total of 26 treatment cycles were administered to the 11 pts with a median of 2 cycles per pt (range 1–8). Other observed adverse events include grade 1/2 skin rash and diarrhea. Of 8 evaluable patients, 4 had stable disease. No DLT has been experienced so far at the projected recommended phase 2 dose (dose level 3). The results of correlative studies will be presented at the meeting. Conclusions: The novel combination of cetuximab and gefitinib is safe and is associated with promising anti-cancer activity in recurrent NSCLC. [Table: see text] [Table: see text]

Correlation of epidermal growth factor receptor (EGFR) mutation, immunohistochemistry (IHC), and fluorescence in situ hybridization (FISH) in esophageal squamous cell carcinoma (ESCC)

4085 Background: ESCC remains a devastating cancer in Southern Thailand and novel therapeutic approach needs to be explored. EGFR tyrosine kinase (TK) inhibitor is a potential therapeutic agent against EGFR-expression tumors including ESCC. Forty-nine percent of ESCC patients in our institution overexpressed EGFR protein and 15% had EGFR gene amplification as published previously. Mutations within EGFR TK domain, particularly in exon 19 and 21, EGFR amplification or polysomy, and EGFR overexpression on IHC have all been associated with sensitivity and benefit to EGFR inhibitor treatment. To our best knowledge, no data on EGFR mutations in ESCC have been reported. This prompted us to perform analysis of EGFR mutations and correlate the status of each of these characteristics in ESCC. Methods: We studied 35 patients with ESCC whose data on EGFR IHC and FISH were available. DNA extraction was performed using a QIAamp DNA Kit. PCR for EGFR detection, using the oligonucleotide primers for amplification of exon 19 and 21, was sequenced and analyzed, using ABI Prism 377 sequencing analysis system and the Big Dye Terminator V3.0 Ready Reaction Cycle Sequencing Kit (ABI Prism). Results: Among 35 ESCC specimens evaluated, no EGFR somatic mutations in exon 19 or 21 were detected. Conclusions: EGFR mutations in exon 19 and 21 of ESCC were not identified in this study. EGFR overexpression and amplification do not correlate with EGFR mutation in Thai patients with ESCC. A clinical study of an EGFR inhibitor in esophageal carcinoma has been going on in our institution and the molecular markers as predictive factors need to be further evaluated and correlated with treatment outcome. No significant financial relationships to disclose.

Epidermal growth factor receptor gene mutation defines distinct subsets among small adenocarcinomas of the lung

Epidermal growth factor receptor (EGFR) gene mutations are frequently detected in lung cancer, especially in adenocarcinoma, in females, and non-smoking patients. EGFR mutations are closely associated with clinical response to EGFR tyrosine kinase inhibitor. Bronchioloalveolar carcinoma (BAC) appearance is a good predictor of response to this agent. Noguchi et al. subdivided small peripheral adenocarcinoma of the lung into two groups. One group was characterized with tumor cell growth replacing the normal alveolar cells with varying degree of fibrosis (types A-C), and the other shows non-replacing and destructive growth (types D-F). Using probes for the 13 mutations which have been previously described, we have genotyped the EGFR gene status in surgically resected atypical adenomatous hyperplasias (AAH) and small peripheral adenocarcinomas up to 2 cm in diameter using TaqMan PCR assay. In 95 small-sized adenocarcinomas, the EGFR mutations were detected in 37 patients (38.9%), and no mutations were found in five AAHs. In small peripheral adenocarcinomas, EGFR mutations were found 47.1% of types A, B, or C adenocarcinomas; it was less frequent (16%) in Noguchi's types D, E or F adenocarcinomas. These results suggest that type D, F adenocarcinomas are not derived from the less malignant types A-C adenocarcinomas; rather, they have arisen de novo by distinct mechanisms. Although types A and B adenocarcinomas are almost 100% cured by surgery, some type C adenocarcinoma show lymph node metastasis and relapse. EGFR mutation analysis may help identify patients who will respond to treatment with tyrosine kinase inhibitors, e.g., gefitinib.

Epidermal growth factor receptor mutations in needle biopsy/aspiration samples predict response to gefitinib therapy and survival of patients with advanced nonsmall cell lung cancer

Recently, mutations in the epidermal growth factor receptor (EGFR) gene in nonsmall cell lung cancer (NSCLC) patients were reported to correlate with gefitinib response. Less than 30% of NSCLC patients are surgically resectable; however, molecular analysis has to rely on nonsurgical diagnostic tissue samples. The objective of this study is to investigate EGFR mutation analysis on needle biopsy/aspiration samples and its correlations with gefitinib response and patients' survival. EGFR mutation was assessed from DNA of 63 paraffin-embedded small needle biopsy/aspiration specimens from 62 patients with NSCLC treated with gefitinib. The peripheral blood lymphocyte DNA of the patients was sequenced to verify the EGFR mutation. EGFR mutations were found in 47% of 62 patients (60% of 20 CT-guided biopsies, 44% of 18 ultrasound-guided biopsies, 31% of 16 endoscopic biopsies and 44% of 9 effusion cell blocks). EGFR mutations were frequently present in females (p = 0.006) and never smokers (p = 0.04). Patients with EGFR mutations had a significantly better response rate compared to that of the nonmutation group (p < 0.001). Multivariate analysis showed that EGFR mutation (p < 0.001) and PS 0-1 (p = 0.02) were independently associated with a better response rate. Cox regression analysis showed that EGFR mutation was the independent prognostic factor for progression-free survival (p = 0.008) and overall survival (p = 0.03). In conclusion, EGFR mutation analysis is feasible in needle biopsy/aspiration paraffin-fixed specimens. EGFR mutation is an independent predictor of gefitinib response and survival in patients of advanced NSCLC treated by gefitinib.

The status of epidermal growth factor receptor (EGFR) mutations at exon 19 and 21 in Chinese patients with NSCLC

7097 Background: Recently, two studies by Paez and Lynch show that somatic mutations in EGFR tyrosine kinase(TK) domain are associated with sensitivity of NSCLC to gefitinib. The mutations were clustered around ATP-biding pocket of the TK domain. Mutations were more frequent in women, adenocacinomas or bronchoalveolar carcinoma (BAC) and non-smoker patients. Interestingly, these studies showed the frequency of mutations is 2%–8% in Caucasian patient population compared to 26% in Japanese patients. Pao also report that 88% of these mutations are located at two “hotspots”(exon 19 and 21). This result also prompted us to perform analysis of EGFR mutations particularly on exon 19 and 21 in Chinese patients. Methods: All patients were pathologically confirmed NSCLC who had not been exposed to gefitinib. Fresh frozen tumor specimens and matched normal tissue were obtained from 56 consecutive patients during surgical operation. DNA was isolated by Proteinase K digestion, followed by traditional Phenol-chloroform extraction procedures. PCR was performed using the Takara Taq™ system (Takara Bio, Otsu, Japan). PCR amplification fragments were then sequenced and analyzed in both sense and antisense directions, using Beckman Coulter CEQ8000 Genetic analysis system and the CEQ™ DTCS Quick Start Kit (Beckman Coulter). Results: Somatic mutations in the TK domain of EGFR were identified from 9 of 56 (16.1%) patients. Among the 9 mutants, 6 showed in-frame deletions in exon 19 (delE746-A750 and delL747-S752). Another 3 showed substitutions leucine to arginine at position 858 (L858R) in exon 21. Mutations were more frequent in BAC (40%) and adenocarcinoma (28%) than in squamous carcinoma (0%), more frequent in women (21.4%) than in men (14.3%), and more frequent in non smokers (23.8%) than in smokers (11.4%). The highest fraction of mutations was detected in women with adenocarcinoma (42.9%). Conclusions: The status of EGFR mutations on exon 19 and exon 21 in Chinese patients with NSCLC are similar to Japanese patients, and the frequency of EGFR mutations in Chinese patients is higher than that in Caucasian patients (16.1% vs 2–8%). No significant financial relationships to disclose.