Growth Factor Receptor Gene Mutations Research Articles

Erlotinib at a Dose of 25 mg Daily for Non-small Cell Lung Cancers with EGFR Mutations

The tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib are effective in non-small cell lung cancers (NSCLCs) with epidermal growth factor receptor (EGFR) gene mutations. The usual clinical dose of gefitinib (250 mg/d) is only one third of its maximum tolerated dose, whereas the dose of erlotinib (150 mg/d) is at its maximum tolerated dose. In NSCLC cell lines, both TKIs have similar micromolar inhibitory concentrations. We explored whether erlotinib at 25 mg/d (trough serum concentration similar to gefitinib 250 mg/d) would be efficacious in EGFR-mutated NSCLC. To study the inhibitory concentrations of gefitinib and erlotinib, we exposed EGFR-mutated cell lines (HCC827, H3255, PC-9, and H1975) to increasing concentrations of these TKIs. Further on, we performed a retrospective evaluation of seven patients with advanced EGFR-mutated (exon 19 deletions and L858R) NSCLC that were given erlotinib at 25 mg/d as their first EGFR TKI. Gefitinib and erlotinib generated similar inhibitory curves across our panel of EGFR-mutated NSCLC cell lines with overlapping mean 50% inhibitory concentration 95% confidence intervals for HCC827, PC-9, and H1975. Both drugs also displayed a high degree of correlation in mean 50% inhibitory concentration (Pearson's r = 0.99, p = 0.0417). Of the seven patients, five patients (71.5%) had partial responses to erlotinib 25 mg/d. Median progression-free survival was 17 months (95% confidence interval, 6-35 months). Toxicities were minimal, with only two (28.5%) patients having a rash and none experiencing (0%) diarrhea. In NSCLC cell lines, gefitinib and erlotinib have similar inhibitory profiles. In patients with NSCLC and EGFR-activating mutations, a dose of erlotinib 25 mg/d (equivalent to gefitinib 250 mg/d) leads to impressive response rates and progression-free survival similar to the growing experience with the approved doses of gefitinib (250 mg/d) and erlotinib (150 mg/d). Identifying prospectively the lowest and clinically active dose ranges of erlotinib and gefitinib will help further to personalize care for patients with tumors harboring EGFR mutations.

Erlotinib at a dose of 25 mg daily for non-small cell lung cancers with EGFR mutations.

7572 Background: The tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib are effective in non-small cell lung cancers (NSCLCs) with epidermal growth factor receptor (EGFR) gene mutations. The usual clinical dose of gefitinib (250 mg/day) is only one third of its maximum tolerated dose (MTD), while the dose of erlotinib (150 mg/day) is at its MTD. In NSCLC cell lines both TKIs have similar micromolar (μ M) inhibitory concentrations. We explored if erlotinib at 25 mg/day (trough serum concentration similar to gefitinib 250 mg/day) would be efficacious in EGFR mutated NSCLC. Methods: To study inhibitory concentrations of gefitinib and erlotinib, we exposed EGFR mutated cell lines (HCC827, H3255, PC-9, H1975) to increasing concentrations of these TKIs. Further on, we performed a retrospective evaluation of seven patients with advanced EGFR mutated (exon 19 deletions and L858R) NSCLC that were given erlotinib at 25 mg/day as their first EGFR TKI. Results: Gefitinib and erlotinib generated similar inhibitory curves across our panel of EGFR mutated NSCLC cell lines with overlapping mean IC50 95% confidence intervals (CI) for HCC827, PC-9 and H1975. Both drugs also displayed a high degree of correlation in mean IC50 (Pearson's r = 0.99, p = 0.0417). Of the 7 patients, 5 (71.5%) had partial responses to erlotinib 25 mg/day. Median progression-free survival (PFS) was 17 months (95% CI, 6 months – not reached). Toxicities were minimal with only 2 (28.5%) patients having a rash and none experiencing (0%) diarrhea. Conclusions: In patients with NSCLC and EGFR activating mutations, a dose of erlotinib 25 mg/day leads to impressive response rates and PFS similar to the growing experience with gefitinib 250 mg/day and erlotinib 150 mg/day. Identifying prospectively the clinically active dose ranges of erlotinib and gefitinib will help further personalize care for patients with tumors harboring EGFR mutations. Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration MolecularMD

Correlations of Thin-Section Computed Tomographic, Histopathological, and Clinical Findings of Adenocarcinoma With a Bubblelike Appearance

We reported that adenocarcinomas with a bubblelike appearance (BLA) appear similar to old inflammation (J Comput Assist Tomogr 2009;33:42-48). The histopathological, clinical, and biological characteristics of adenocarcinomas with BLA need more investigation. We retrospectively reviewed the records of 26 patients who had undergone surgical resection between 1993 and 2008. We analyzed correlations between thin-section computed tomographic (TS-CT), histopathological, and clinical findings. We analyzed epidermal growth factor receptor and K-ras gene mutations. The TS-CT findings are unique with one pattern that was the same in all the 26 cases: (1) polygonal with straight and concave margins, (2) slight peripheral ground-glass opacity areas, (3) 3 or more dilated air bronchograms, and (4) clear pleural indentations. The histopathological findings were identical with our TS-CT findings. The mean tumor doubling time was 1165 days. Epidermal growth factor receptor mutations were observed in 17 cases. There were no K-ras mutations. After resection, the 5-year survival rate is 100%. The adenocarcinomas with BLA have unique TS-CT, histopathological, and clinical findings.

Clinical, biological, and molecular characteristics of clonal mast cell disorders presenting with systemic mast cell activation symptoms

Systemic mast cell activation disorders (MCADs) are characterized by severe and systemic mast cell (MC) mediators-related symptoms frequently associated with increased serum baseline tryptase (sBt). To analyze the clinical, biological, and molecular characteristics of adult patients presenting with systemic MC activation symptoms/anaphylaxis in the absence of skin mastocytosis who showed clonal (c) versus nonclonal (nc) MCs and to provide indication criteria for bone marrow (BM) studies. Eighty-three patients were studied. Patients showing clonal BM MCs were grouped into indolent systemic mastocytosis without skin lesions (ISMs(-); n = 48) and other c-MCADs (n = 3)-both with CD25(++) BM MCs and either positive mast/stem cell growth factor receptor gene (KIT) mutation or clonal human androgen receptor assay (HUMARA) tests-and nc-MCAD (CD25-negative BM MCs in the absence of KIT mutation; n = 32) and compared for their clinical, biological, and molecular characteristics. Most clonal patients (48/51; 94%) met the World Health Organization criteria for systemic mastocytosis and were classified as ISMs(-), whereas the other 3 c-MCAD and all nc-MCAD patients did not. In addition, although both patients with ISMs(-) and patients with nc-MCAD presented with idiopathic and allergen-induced anaphylaxis, the former showed a higher frequency of men, cardiovascular symptoms, and insect bite as a trigger, together with greater sBt. Based on a multivariate analysis, a highly efficient model to predict clonality before BM sampling was built that includes male sex (P = .01), presyncopal and/or syncopal episodes (P = .009) in the absence of urticaria and angioedema (P = .003), and sBt >25 microg/L (P = .006) as independent predictive factors. Patients with c-MCAD and ISMs(-) display unique clinical and laboratory features different from nc-MCAD patients. A significant percentage of c-MCAD patients can be considered as true ISMs(-) diagnosed at early phases of the disease.

Abstract 1784: Erlotinib at a dose of 25 mg daily for non-small cell lung cancers with EGFR mutations

Abstract Introduction: The tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib are active in non-small-cell lung cancers (NSCLCs) with epidermal growth factor receptor (EGFR) gene mutations. The usual clinical dose of gefitinib (250 mg/day) is only one third of its maximum tolerated dose (MTD), while the dose of erlotinib (150 mg/day) is at its MTD. In NSCLC cell lines both TKIs have similar micromolar (μM) inhibitory concentrations. We explored if erlotinib at 25 mg/day (presumed trough serum concentration similar to gefitinib 250 mg/day at around 0.5 μM) would be active in EGFR mutated NSCLC. Methods and Patients: To study inhibitory concentrations of gefitinib and erlotinib, we studied EGFR mutated cell lines (HCC827, H3255, PC-9, H1975) exposed to increasing concentrations of these TKIs. Further on, we performed a retrospective evaluation of seven patients with advanced EGFR mutated (exon 19 deletions and L858R) NSCLC that were given erlotinib at 25 mg daily as their first EGFR TKI. Results: In EGFR mutated cell lines, both gefitinib and erlotinib had median IC50 inhibitory concentrations with similar values and statistical correlation (Pearson r = 0.9999, p < 0.0001). Concordance between the IC50 of gefitinib and erlotinib was confirmed using a separate published dataset of 8 EGFR-mutant NSCLC lines (r = 0.9919, p < 0.0001). These results indicate that both EGFR inhibitors have similar inhibitory concentrations in EGFR mutated cells. Of the 7 patients treated with erlotinib 25 mg/day, 5 (71.5%) had partial radiographic responses. Median progression-free survival (PFS) was 17 months, and individual PFS exceeds 6 months in most patients that have received drug for at least that period. Toxicities were minimal with only 2 (28.5 %) patients having a rash (grade 1) and none (0%) experiencing diarrhea. Conclusions: In patients with EGFR activating mutations, a dose of erlotinib 25 mg/day leads to impressive response rate and PFS similar to the growing experience with gefitinib 250 mg/day and erlotinib 150 mg/day. Identifying prospectively the clinically-active dose ranges of erlotinib and gefitinib will help further personalize care for patients with tumors harboring EGFR mutations. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1784.

Possible Delayed Cut-End Recurrence After Limited Resection for Ground-Glass Opacity Adenocarcinoma, Intraoperatively Diagnosed as Noguchi Type B, in Three Patients

In our limited resection trial of pulmonary peripheral ground-glass opacity (GGO) lesions from 1998 to 2002, limited resection of Noguchi type A and B carcinomas seemed to have a positive outcome. However, recently three of the 24 patients, with mixed GGO lesions intraoperatively diagnosed as type B, developed a solid lesion at the cut-end scar. Medical records and radiology and pathology findings of the three patients were reviewed. We also analyzed epidermal growth factor receptor gene mutations when possible. Radiologically, these three second tumors were clearly cut-end scar area recurrences. However, other pathologic and mutation findings suggest metachronous primary cancers developed in Case 1, cut-end recurrence in Case 2, and needle biopsy implantation in Case 3. It is difficult to definitively conclude whether the second tumors were recurrences or metachronous primaries. These second tumors have convinced us that our initial caution in concluding GGO lesions can be cured by limited resection was very appropriate. The recurrences definitely indicate that continuing follow-up attention for more than 5 years is needed after limited resection even for GGO bronchioloalveolar carcinomas.

Efficacy and safety of erlotinib as monotherapy for advanced non-small cell lung cancer

To explore the efficacy and safety of erlotinib monotherapy for advanced non-small cell lung cancer (NSCLC). Totally 50 patients with advanced NSCLC received oral erlotinib 150 mg/d treatment, and tumor specimen in 19 patients were collected for epidermal growth factor receptor (EGFR) gene mutation tests. Median survival (MS) was calculated using the Kaplan-Meier method. The most common adverse events (AEs) were skin rash (96%) and diarrhea (32%). The overall survival (OS) of all patients was 21.8 months 95% confidential interval (CI): 17.1-26.4 months and the median progression-free survival (PFS) of all patients was 7.0 months (95% CI: 3.9-10.1 months). EGFR mutation analysis showed gene mutation in 8 cases and wild type in 11 cases. The objective response rate in patients with or without EGFR gene mutations were 62.5% and 9.1%, respectively (chi(2)=6.631, P=0.036). PFS in patients with or without EGFR gene mutations were 16.330 (95% CI: 2.803-29.857 months) and 5.570 months (95% CI: 2.441-8.699 months), respectively (chi(2)=8.799, P=0.003). Erlotinib monotherapy is safe and effective for some Chinese NSCLC patients after failure of prior chemotherapy.

Dose effect of cigarette smoking on frequency and spectrum of epidermal growth factor receptor gene mutations in Korean patients with non-small cell lung cancer

This study aimed to determine the dose effect of smoking on the mutational frequency and spectrum of epidermal growth factor receptor (EGFR) gene in Korean non-small cell lung cancer (NSCLC). Detailed smoking histories were obtained from 324 consecutively enrolled Korean NSCLC patients. Mutational status of EGFR (exon 18-21) was determined using nested polymerase chain reaction amplification. A total of 108 EGFR mutations (33.3%) were identified in 107 patients. Decreased EGFR mutation rate with increased smoking dose was observed, with 48.0% (82 of 171) in never smokers, 23.1% (15 of 65) in former smokers, and 11.4% (10 of 88) in current smokers. The incidence of EGFR mutation was significantly lower in patients who smoked for more than 25 pack-years (P < 0.0001) or who stopped smoking cigarettes less than 10 years ago (P < 0.0001). Mutations in exon 19 or 21 were associated with fewer total smoke years (5.0 vs. 25.0 years in exon 20, P = 0.024), fewer total pack-years (6.3 vs. 38.9 pack-years in exon 20, P = 0.079), and more smoke-free years (11.1 vs. 3.6 years in exon 20, P = 0.027), compared with those in exon 20. Mutations in exon 19 or 21 were associated with female (P < 0.0001), never smoker (P < 0.0001), and adenocarcinoma (P < 0.0001), whereas those in exon 20 were not. Smoking dosage affects the incidence of EGFR mutations. EGFR mutations in exon 19 or 21 are associated with low exposure to cigarette smoke, whereas EGFR mutation in exon 20 is more common in smokers.

Personalized cancer therapy coming of age: clinical highlights in 2009 and future directions.

Brigette BY Ma Author for correspondence: LKS Specialist Clinic, Department of Clinical Oncology, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR, China Tel.: +852 2632 2118 Fax: +852 2648 7097 brigette@clo.cuhk.edu.hk and State Key Laboratory in Oncology in South China, Hong Kong SAR, China and Sir YK Pao Centre for Cancer, Hong Kong SAR, China and Hong Kong Cancer Institute, Hong Kong SAR, China and Chinese University of Hong Kong, Hong Kong SAR, China

Mast cells from different molecular and prognostic subtypes of systemic mastocytosis display distinct immunophenotypes

Systemic mastocytosis (SM) is a heterogeneous group of disorders with distinct clinical and biological behavior. Despite this, little is known about the immunophenotypic features of the distinct diagnostic categories of SM. To analyze the immunophenotypic characteristics of bone marrow (BM) mast cells (MCs) of different subtypes of SM. Bone marrow samples from 123 patients with different subtypes of SM and 92 controls were analyzed for a broad panel of immunophenotypic markers by flow cytometry. Three clearly different maturation-associated immunophenotypic profiles were found for BMMCs in SM. These different profiles were associated with both genetic markers of the disease and its clinical behavior. BMMCs from poor-prognosis categories of SM (aggressive SM and MC leukemia) typically showed an immature phenotype with clonal involvement of all myeloid lineages by the D816V stem cell growth factor receptor gene (KIT) mutation. In turn, a mature activated versus resting BMMC immunophenotype was commonly found among patients with good-prognosis subtypes of SM depending on whether they carried (indolent SM and clonal MC activation disorders) or not (well differentiated SM) the D816V KIT mutation. Bone marrow MCs from SM show 3 different maturation-related immunophenotypic profiles that are associated with both the genetic markers of the disease and its clinical behavior.

Efficacy of Gefitinib for Elderly Patients with Advanced Non-Small Cell Lung Cancer Harboring Epidermal Growth Factor Receptor Gene Mutations: A Retrospective Analysis

To retrospectively evaluate the efficacy and safety of gefitinib in elderly patients with advanced non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor mutations. Nine patients aged 70 years or older who had advanced NSCLC with mutations of the epidermal growth factor receptor gene were treated with gefitinib, 250 mg daily. Clinical data, types of epidermal growth factor receptor mutations, efficacy and toxicity of gefitinib were evaluated in these patients. Tumor responses were assessed by computed tomography scan using the Response Evaluation Criteria in Solid Tumors. Six patients showed a partial response, and the other three exhibited stable disease. The overall response rate was 66.7%. The median progression-free survival was 396 days, whereas the median over all survival was 523 days. No serious toxicities were observed. Gefitinib is very efficacious and safe for elderly patients with adenocarcinoma of the lung harboring an EGFR tyrosine kinase mutation. The present data support the use of gefitinib in this particular subgroup.

Clinical outcomes of advanced non-small cell lung cancer patients screened for epidermal growth factor receptor gene mutations

To evaluate the relationship between the epidermal growth factor receptor (EGFR) mutation status and the effectiveness of gefitinib monotherapy or chemotherapy in patients with advanced non-small cell lung cancer (NSCLC). We retrospectively analyzed a cohort of 100 patients with stage IIIB/IV NSCLC screened for two major EGFR mutations (exon 19 deletions and L858R mutation). Forty-six out of 48 EGFR mutation-positive patients (96%) received gefitinib, whereas only 3 out of 52 EGFR mutation-negative patients (6%) received gefitinib. Favorable objective response rates to gefitinib as first- and second-line treatment (87 and 80%, respectively) were observed in EGFR mutation-positive patients. Overall response rate to chemotherapy as first-line treatment did not differ significantly between patients with EGFR mutations and those without mutation (32 vs. 28%, respectively; P = 0.7198). As to first-line treatment, EGFR mutation-positive patients treated with gefitinib experienced significantly longer progression-free survival (PFS) than did patients who received chemotherapy (median survival, 7.8 months vs. 5.1 months, respectively; P = 0.0323). Similarly, as to second-line treatment, EGFR mutation-positive patients treated with gefitinib had significantly longer PFS than did patients who received chemotherapy (median survival, 6.5 months vs. 4.0 months, respectively; P = 0.0048). Patients with EGFR mutations survived longer than those without EGFR mutations after first-line treatment (median, 24.3 vs. 12.6 months, respectively; P = 0.0029). EGFR mutation-positive patients benefit from either first- or second-line gefitinib monotherapy. Further large-scale prospective studies to confirm this finding are needed.

Four kinds of hypothyroidism and the cancers of breast and lung found in cases of Japanese rheumatoid arthritis (RA), arthritis deformans, or bone fracture

Japanese patients were selected from 875 patients who had undergone an orthopedic operation. Seventy-two cases of rheumatoid arthritis (RA) and 17 cases of suspected RA were analyzed. In parallel with high levels of rheumatoid factor (RF), Sjoegren syndrome, finger and toe deformans, and knee and hip arthritis deformans were observed at high frequencies. The arthritis deformans of 51 patients displayed a mean serum iron levels of 50 ± 33 (SD) μg/dl and transferrin saturation (TS) of 18 ± 11%. The hypothyroidisms diagnosed in the 12 patients were caused by autoimmune, hypopituitary, and papillary thyroid cancer (PTC). Two of the insulinoma cases had hypothyroidism due to down-regulated transcription of genes related to insulin. Two PTC, four breast ductal carcinomas, and three lung adenocarcinomas, which were observed in patients with bone diseases, were assumed to be caused by epidermal growth factor receptor (EGFR) gene mutations. One lung cancer with gefitinib-sensitive EGFR mutations, a breast cancer that expressed human epidermal growth factor receptor 2 (HER2), and a lung-metastasized popliteal epitheloid sarcoma showed disseminated bone and/or intra-lung metastases. When an HER2-positive breast cancer metastasized to the bones, TS was elevated to 73.4–81.4% with anemic attacks and high levels (12.4–16.8 ng/ml) of pyridinoline cross-linked carboxy-terminal telopeptide type I. In the other six cancer patients with noninvasive phenotypes, the metastases became cysts. One noninvasive lung cancer was confirmed to express thyroid transcription factor-1 (TTF-1). Polyps, varix, and multiple thromboses were found to be clinical signs of pre-EGFR cancers.

MiR-21 is an EGFR-regulated anti-apoptotic factor in lung cancer in never-smokers

Fifteen percent of lung cancer cases occur in never-smokers and show characteristics that are molecularly and clinically distinct from those in smokers. Epidermal growth factor receptor (EGFR) gene mutations, which are correlated with sensitivity to EGFR-tyrosine kinase inhibitors (EGFR-TKIs), are more frequent in never-smoker lung cancers. In this study, microRNA (miRNA) expression profiling of 28 cases of never-smoker lung cancer identified aberrantly expressed miRNAs, which were much fewer than in lung cancers of smokers and included miRNAs previously identified (e.g., up-regulated miR-21) and unidentified (e.g., down-regulated miR-138) in those smoker cases. The changes in expression of some of these miRNAs, including miR-21, were more remarkable in cases with EGFR mutations than in those without these mutations. A significant correlation between phosphorylated-EGFR (p-EGFR) and miR-21 levels in lung carcinoma cell lines and the suppression of miR-21 by an EGFR-TKI, AG1478, suggest that the EGFR signaling is a pathway positively regulating miR-21 expression. In the never-smoker-derived lung adenocarcinoma cell line H3255 with mutant EGFR and high levels of p-EGFR and miR-21, antisense inhibition of miR-21 enhanced AG1478-induced apoptosis. In a never-smoker-derived adenocarcinoma cell line H441 with wild-type EGFR, the antisense miR-21 not only showed the additive effect with AG1478 but also induced apoptosis by itself. These results suggest that aberrantly increased expression of miR-21, which is enhanced further by the activated EGFR signaling pathway, plays a significant role in lung carcinogenesis in never-smokers, as well as in smokers, and is a potential therapeutic target in both EGFR-mutant and wild-type cases.

Prognosis in adult indolent systemic mastocytosis: A long-term study of the Spanish Network on Mastocytosis in a series of 145 patients

Indolent systemic mastocytosis is a group of rare diseases for which reliable predictors of progression and outcome are still lacking. Here we investigate the prognostic impact of the clinical, biological, phenotypic, histopathological, and molecular disease characteristics in adults with indolent systemic mastocytosis, who were followed using conservative therapy. A total of 145 consecutive patients were prospectively followed between January 1983 and July 2008; in addition, from 1967 to 1983, 20 patients were retrospectively studied. Multivariate analysis showed that serum beta2-microglobulin (P = .003) together with the presence of mast/stem cell growth factor receptor gene (KIT) mutation in mast cells plus myeloid and lymphoid hematopoietic lineages (P = .02) was the best combination of independent parameters for predicting disease progression (cumulative probability of disease progression of 1.7% +/- 1.2% at 5-10 years and of 8.4% +/- 5.0% at 20-25 years). Regarding overall survival, the best predictive model included age >60 years (P = .005) and development of an associated clonal hematological non-mast cell disorder (P = .03) with a cumulative probability of death of 2.2% +/- 1.3% at 5 years and of 11% +/- 5.9% at 25 years. Indolent systemic mastocytosis in adults has a low disease progression rate, and the great majority of patients have a normal life expectancy, with the presence of KIT mutation in all hematopoietic lineages and increased serum beta2-microglobulin the most powerful independent parameters for predicting transformation into a more aggressive form of the disease.

Tyrosine Phosphorylation of the Human Glutathione S-Transferase P1 by Epidermal Growth Factor Receptor

Epidermal growth factor receptor (EGFR) gene amplification, mutations, and/or aberrant activation are frequent abnormalities in malignant gliomas and other human cancers and have been associated with an aggressive clinical course and a poor therapeutic outcome. Elevated glutathione S-transferase P1 (GSTP1), a major drug-metabolizing and stress response signaling protein, is also associated with drug resistance and poor clinical outcome in gliomas and other cancers. Here, we provide evidence that GSTP1 is a downstream EGFR target and that EGFR binds to and phosphorylates tyrosine residues in the GSTP1 protein in vitro and in vivo. Mass spectrometry and mutagenesis analyses in a cell-free system and in gliomas cells identified Tyr-7 and Tyr-198 as major EGFR-specific phospho-acceptor residues in the GSTP1 protein. The phosphorylation increased GSTP1 enzymatic activity significantly, and computer-based modeling showed a corresponding increase in electronegativity of the GSTP1 active site. In human glioma and breast cancer cells, epidermal growth factor stimulation rapidly increased GSTP1 tyrosine phosphorylation and decreased cisplatin sensitivity. Lapatinib, a clinically active EGFR inhibitor, significantly reversed the epidermal growth factor-induced cisplatin resistance. These data define phosphorylation and activation of GSTP1 by EGFR as a novel, heretofore unrecognized component of the EGFR signaling network and a novel mechanism of tumor drug resistance, particularly in tumors with elevated GSTP1 and/or activated EGFR.

Epidermal growth factor receptor gene mutations in papillary thyroid carcinoma

Recent studies have indicated that somatic mutations in the epidermal growth factor receptor (EGFR) gene have been identified in a subset of patients with nonsmall-cell lung cancer (NSCLC) and are associated with sensitivity to the EGFR-tyrosine-kinase inhibitors. These mutations have been reported to be almost exclusively found in a pulmonary adenocarcinoma subgroup of NSCLC, with a low frequency in other solid tumors. We describe a patient with advanced-stage papillary thyroid carcinoma (PTC) whose disease had been diagnosed as pulmonary adenocarcinoma at first, and who had a marked response to the EGFR-tyrosine-kinase inhibitor, gefitinib. An in-frame deletion in exon 19 that eliminated 4 amino acids at positions 746 through 750, which is one of the common drug-sensitive mutations in pulmonary adenocarcinoma, and a serine-to-proline substitution at codon 752, were found in a tumor specimen of the patient. We subsequently searched for mutations in the EGFR tyrosine kinase domain in primary tumors from 23 patients with PTC, and drug-sensitive mutations commonly observed in pulmonary adenocarcinoma were found in 7 of these patients. Our observation of a high frequency of the EGFR-activating mutations in PTC suggests that the EGFR mutation may be an important event in the development of PTC. EGFR gene amplification, also considered to be a predictor of response to EGFR-tyrosine-kinase inhibitors, was evaluated by fluorescence in situ hybridization (FISH); however, only 1 FISH-positive tumor was detected. Our data suggest that EGFR-tyrosine-kinase inhibitors may deserve consideration in the treatment of a subset of patients with PTC, just as with pulmonary adenocarcinoma.

Histoculture drug response assay for gefitinib in non-small-cell lung cancer

There are many predictive factors for gefitinib sensitivity, including epidermal growth factor receptor (EGFR) gene mutation, EGFR copy number, and k-ras mutation. To investigate all of them is too expensive. We evaluated the chemosensitivity for gefitinib in non-small-cell lung cancer (NSCLC) using a histoculture drug response assay (HDRA). Surgically resected fresh tumor specimens from 22 patients with NSCLC were used. There were 13 male and 9 female patients, ranging in age from 49 to 84 (average 70) years old. Sixteen patients (73%) were smokers. Sixteen adenocarcinomas, four squamous cell carcinomas, and two other histological types were included. Small pieces of viable cancer tissue were placed on the collagen gel and then cultured for 7 days in the presence of gefitinib. The HDRA was successful in all specimens. A dose-response relation was observed between inhibition rates and gefitinib concentration (p = 0.016). The inhibition rate at 20 microg/ml (IR(20)) in adenocarcinoma without smoking (39.2% +/- 35.1%, n = 6) was higher than that with smoking (2.2% +/- 5.0%, n = 10, P = 0.001) and that of nonadenocarcinoma (16.9% +/- 23.6%, n = 6, P = 0.09). Gene mutation analysis was performed in two of three adenocarcinomas without smoking, which showed especially high IR(20) values, and sensitizing mutations were observed in these specimens. A cutoff inhibition rate of approximately 40%-50% appeared to be suitable for a concentration of 20 microg/ml. HDRA appears to be applicable for evaluating sensitivity to gefitinib in NSCLC. It provides a convenient method for predicting the response to gefitinib in patients with NSCLC whose fresh tumor specimens are available.

Bisphosphonate zoledronic acid enhances the inhibitory effects of gefitinib on EGFR-mutated non-small cell lung carcinoma cells

Patients with non-small cell lung carcinoma (NSCLC) bearing epidermal growth factor receptor (EGFR) gene mutations are good responders to gefitinib (Iressa), an EGFR tyrosine kinase inhibitor (EGFR-TKI), yet these patients may eventually develop acquired resistance to all available EGFR-TKIs. Nitrogen-containing bisphosphonates (N-BPs) are inhibitors of farnesyl diphosphate (FPP) synthase as well as chelators of divalent cations. This study was undertaken to examine if the N-BP zoledronic acid (zoledronate) possessing antitumor activity could enhance the antitumor effect of gefitinib on the HCC827 NSCLC cell line expressing mutated EGFR. Both gefitinib and zoledronate were cytotoxic to HCC827 cells when treated alone. Combined treatment with gefitinib (0.025 μM) that induced G 0/ G 1 arrest and zoledronate (50 μM) that caused S/ G 2/ M accumulation generated an additive induction in cell cytotoxicity, sub- G 1 cell population, and apoptosis. Gefitinib suppressed EGF-activated phosphorylation of ERK1/2 and Akt, while zoledronate seemed to impose its pharmacological effect independent of ERK1/2 and Akt phosphorylation. The volumes of xenografted tumors in nude mice co-administered with gefitinib (1 mg/kg/day, five days a week, p.o.) and zoledronate (10 μg/kg, twice weekly, i.p.) were significantly smaller than those of tumors in mice treated with gefitinib alone at the last stage of a 6-week in vivo study. Severe peri-tumoral fat loss frequently observed in gefitinib-treated mice disappeared in mice receiving the combined treatment. Hence, combined treatment of gefitinib with zoledronate may form a basis to develop a more effective and less toxic therapy for NSCLC with EGFR gene mutations.

Successful Treatment of Lung Cancer with Gefitinib and EGFR Mutation Status Determination Using EBUS-TBNA Samples in an Extremely Old Patient

We report a 90-year-old woman who had complained of bloody sputum and for whom a chest CT showed a nodular lesion on the right lower lobe. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) was performed and adenocarcinoma was revealed in both a subcarinal lymph node (#7) and in the primary lung tumor. Epidermal growth factor receptor (EGFR) gene mutation status was evaluated, and an exon 21 point mutation (L858R) was identified by direct sequencing. Two weeks after administration of gefitinib, the tumor size decreased and bloody sputum disappeared. The patient has remained in good condition for 6 months.