Lars Fjellbirkeland

Clinicopathological Characteristics of 11 NSCLC Patients with EGFR-Exon 20 Mutations

Introduction: The characteristics of different types of epidermal growth factor receptor (EGFR) gene mutations in non–small-cell lung cancer (NSCLC) are not extensively studied. The distribution of EGFR mutations is known, with the most frequent in exon 19 (deletions) or exon 21 (point mutations). Aberrations in exon 18 or 20 are infrequently found. Point mutations in exon 20 confer resistance against tyrosine kinase inhibitors (TKIs), whereas the effect of the rare exon 20 insertions is, to a lesser extent, known. We present clinicopathological characteristics of patients with EGFR mutations in the four exons, with emphasis on exon 20 positive patients. Methods: NSCLC patients who tested positively for EGFR mutations at the Oslo University Hospital, Oslo, Norway in the period between May 2010 and February 2012 were selected. Clinical information was collected for mutated patients, and response information for patients with exon 20 insertions treated with TKI is reported. Results: Of 119 patients with EGFR mutation, 62.2% were women. The median age was 66.0 years. The frequency of exon 18, 19, 20, and 21 was 7%, 45%, 7%, and 38%, respectively. Four patients (3.3%) had double mutations, and exon 20 was involved in three of these. Seven of 11 exon 20 positive patients were treated with TKI. All five single-mutated exon 20 positive TKI-treated patients had progressive disease at first evaluation, whereas both TKI-treated exon 20 involving double-mutated patients had partial response. Conclusion: Exon 20 mutations seem to confer insensitivity to TKI treatment.

Tumour fragment spheroids from human non-small-cell lung cancer maintained in organ culture.

Biopsy material from 17 human non-small-cell lung carcinomas (NSCLC) was maintained in agar overlay culture as tumour fragment spheroids for 40 days. A practical procedure for the formation of spheroids and organ culture is described. The mechanically dissociated tumour specimens showed a variation in their ability to generate spheroids that was not related to the ploidy or the histological differentiation of the biopsies. Light microscopic observations revealed a heterogeneous spheroid population with a mixture of tumour cells and stromal elements. Most of the histological elements normally found in human NSCLC could be seen in the spheroids. The cellular components in the spheroids varied between highly cellular to sparsely cellular, dominated by stromal elements. The squamous carcinomas were in general found to generate highly cellular spheroids more often than the adenocarcinomas. Spheroids with a different cellular content could be selected in vitro by using a morphometric technique. Diameter measurements showed a large variability in spheroid growth. Most of the spheroids decreased in size although bromodeoxyuridine labelling indicated active cell proliferation in the specimens. Frequent changes of medium did not affect spheroid growth. The culture system presented provides a model for studying the cellular heterogeneity as well as the biological characteristics of tumour tissue from individual patients in vitro.

Lung cancer treatment is influenced by income, education, age and place of residence in a country with universal health coverage.

Selection of lung cancer treatment should be based on tumour characteristics, physiological reserves and preferences of the patient. Our aims were to identify and quantify other factors associated with treatment received. Lung cancer patient data from 2002 to 2011 were obtained from the national population‐based Cancer Registry of Norway, Statistics Norway and the Norwegian Patient Register. Multivariable logistic regression examined whether year of diagnosis, age, sex, education, income, health trust, smoking status, extent of disease, histology and comorbidities were associated with choice of treatment; surgery or radical or palliative radiotherapy, within 1 year of diagnosis. Among the 24,324 lung cancer patients identified, the resection rate remained constant while the proportion of radical radiotherapy administered increased from 8.6 to 14.1%. Older patients, those with lower household incomes and certain health trusts were less likely to receive any treatment. Lower education and the male gender were identified as negative predictors for receiving surgery. Smoking history was positively associated with both radical and palliative radiotherapy, while comorbidity and symptoms were independently associated with receiving surgery and palliative radiotherapy. Although Norway is a highly egalitarian country with a free, universal healthcare system, this study indicates that surgery and radical and palliative radiotherapy were under‐used among the elderly, those with a lower socioeconomic status and those living in certain health trusts.

Lung cancer survival in Norway, 1997-2011: from nihilism to optimism.

We examine changes in survival and patient-, tumour- and treatment-related factors among resected and nonresected lung cancer patients, and identify subgroups with the largest and smallest survival improvements. National population-based data from the Cancer Registry of Norway, Statistics Norway and the Norwegian Patient Register were linked for lung cancer patients diagnosed during 1997–2011. The 1- and 5-year relative survival were estimated, and Cox proportional hazard regression, adjusted for selected patient characteristics, was used to assess prognostic factors for survival in lung cancer patients overall and stratified by resection status. We identified 34 157 patients with lung cancer. The proportion of histological diagnoses accompanied by molecular genetics testing increased from 0% to 26%, while those accompanied by immunohistochemistry increased from 8% to 26%. The 1-year relative survival among nonresected and resected patients increased from 21.7% to 34.2% and 75.4% to 91.5%, respectively. The improved survival remained significant after adjustment for age, sex, stage and histology. The largest improvements in survival occurred among resected and adenocarcinoma patients, while patients ≥80 years experienced the smallest increase. Lung cancer survival has increased considerably in Norway. The explanation is probably multifactorial, including improved attitude towards diagnostic work-up and treatment, and more accurate diagnostic testing that allows for improved selection for resection and improved treatment options. Lung cancer survival in Norway has improved due to improved attention towards diagnostic work-up and treatment http://ow.ly/S5L4j

Invasiveness by lacZ transfected non-small cell lung cancer cells into human bronchial tissues in vitro

To facilitate the detection of invading tumor cells in a three dimensional coculture assay in vitro, the reporter gene Escherichia coli beta-galactosidase (lacZ), was transfected into a human large-cell lung carcinoma cell line GaL23. Multicellular spheroids initiated from the transfected cell line, GaL23LZ, were confronted with fragments of human bronchial tissue differing in their surface composition. While an intact surface epithelium was found to obstruct both adhesion and invasion of tumor cells, an exposed basal lamina augmented adhesion, migration and invasion of tumor cells into the normal tissue. Tumor cells, migrating on the surface of the bronchial fragments, were found to migrate between the epithelial cells and the basal lamina. Fibroblast covered stromal fragments, derived from resected non-small cell lung cancers, were found to be more edible to the invading tumor cells than subepithelial stromal fragments from normal bronchi. The lacZ transfection made it possible to quantitatively analyze the invasive process. While the transfection neither changed the invasive ability of the tumor cells in vitro or in vivo nor their growth pattern in monolayers, three dimensional growth represented by spheroid morphology and clonogenicity in soft agar was significantly changed. This model offers an in vitro system to study qualitative and quantitative aspects of tumor-host relationships in a complex microenvironment which has several similarities to the in vivo situation.

Non-small-cell lung carcinoma cells invade human bronchial mucosa in vitro.

SummaryTo study invasion of lung cancer in vitro a novel three-dimensional coculture assay consisting of living human tissues has been developed. Multicellular spheroids initiated from a new large-cell lung carcinoma cell line (GaL23), found to be invasive in immunodeficient mice, were confronted with precultured bronchial fragments derived from mucosal biopsies obtained during routine fiberoptic bronchoscopy. The bronchial fragments consist of a stromal core with scattered fibroblasts covered by a continuous surface epithelium resting on a basal lamina. During the first 2 wk of confrontation, a gradual retraction of the bronchial epithelium with subsequent adhesion of the tumor cells to the underlying basal lamina occurred. The following week, a limited invasion of tumor cells into the bronchial stroma was seen. To facilitate the entrance of tumor cells through the mucosal surface, the surface epithelium was removed prior to coculture by ethylenediaminetetraacetic acid (EDTA) buffer treatment. Upon confrontation, GaL23 cells then rapidly attached to and migrated on the exposed basal lamina and an increasing number of tumor cells was seen in the stroma during the first week of culture. This model offers opportunities for studying mechanisms of lung cancer adhesion, migration, and invasion using human bronchial mucosa as the natural target tissue.

EGFR mutation testing of lung cancer patients – Experiences from Vestfold Hospital Trust

Background. Patients with advanced stage lung cancer and somatic mutations in the epithelial growth factor receptor (EGFR) gene are currently treated with tyrosine-kinase inhibitors. The Norwegian Lung Cancer Group (NLCG) recommended EGFR testing of all patients with non-small cell lung carcinoma (NSCLC) from June 2010. From March 2013, testing of squamous cell carcinomas was terminated. We have analysed how these recommendation were followed at a medium-sized Norwegian hospital and we present data on mutation frequency, retesting and possible explanations for missing test results. Material and methods. All pathology reports for patients diagnosed with NSCLC at Vestfold Hospital Trust were examined for the period June 2010 to December 2013. Mutation analyses were done at the Department of Pathology, Oslo University Hospital. Results. Material was sent for EGFR analysis for 256 of the 304 eligible patients diagnosed in the period. Material from 48 patients was never sent for EGFR testing, of which five samples consisted of too few tumour cells. For the rest, no obvious reason for omitting EGFR mutation analyses was identified. During the first six months of our study period, material from 25 of 66 NSCLC patients (38%) was not tested, whereas only six of the 118 patients (5%) in 2013 were not tested. For 34 patients, the first tissue specimen contained too few tumour cells and a new sample was sent for EGFR analyses for 11 of these. EGFR mutation was detected in 7.1% of the analysed NSCLC and in 9.4% of adenocarcinomas. Discussion. Especially for patients with advanced stages of NSCLC, EGFR mutation status is necessary for treatment stratification. Our results show that the guidelines were followed increasingly over time for patients diagnosed with NSCLC at the Vestfold Hospital Trust. The establishment of interdisciplinary meetings has improved the diagnostic routines.