Kevin Matar

Pleural fluid cell-free DNA integrity index to identify cytologically negative malignant pleural effusions including mesotheliomas

BackgroundThe diagnosis of malignant pleural effusions (MPE) is often clinically challenging, especially if the cytology is negative for malignancy. DNA integrity index has been reported to be a marker of malignancy. The aim of this study was to evaluate the utility of pleural fluid DNA integrity index in the diagnosis of MPE.MethodsWe studied 75 pleural fluid and matched serum samples from consecutive subjects. Pleural fluid and serum ALU DNA repeats [115bp, 247bp and 247bp/115bp ratio (DNA integrity index)] were assessed by real-time quantitative PCR. Pleural fluid and serum mesothelin levels were quantified using ELISA.ResultsBased on clinico-pathological evaluation, 52 subjects had MPE (including 16 mesotheliomas) and 23 had benign effusions. Pleural fluid DNA integrity index was higher in MPE compared with benign effusions (1.2 vs. 0.8; p<0.001). Cytology had a sensitivity of 55% in diagnosing MPE. If cytology and pleural fluid DNA integrity index were considered together, they exhibited 81% sensitivity and 87% specificity in distinguishing benign and malignant effusions. In cytology-negative pleural effusions (35 MPE and 28 benign effusions), elevated pleural fluid DNA integrity index had an 81% positive predictive value in detecting MPEs. In the detection of mesothelioma, at a specificity of 90%, pleural fluid DNA integrity index had similar sensitivity to pleural fluid and serum mesothelin (75% each respectively).ConclusionPleural fluid DNA integrity index is a promising diagnostic biomarker for identification of MPEs, including mesothelioma. This biomarker may be particularly useful in cases of MPE where pleural aspirate cytology is negative, and could guide the decision to undertake more invasive definitive testing. A prospective validation study is being undertaken to validate our findings and test the clinical utility of this biomarker for altering clinical practice.

Phenotypes and Karyotypes of Human Malignant Mesothelioma Cell Lines

Background Malignant mesothelioma is an aggressive tumour of serosal surfaces most commonly pleura. Characterised cell lines represent a valuable tool to study the biology of mesothelioma. The aim of this study was to develop and biologically characterise six malignant mesothelioma cell lines to evaluate their potential as models of human malignant mesothelioma. Methods Five lines were initiated from pleural biopsies, and one from pleural effusion of patients with histologically proven malignant mesothelioma. Mesothelial origin was assessed by standard morphology, Transmission Electron Microscopy (TEM) and immunocytochemistry. Growth characteristics were assayed using population doubling times. Spectral karyotyping was performed to assess chromosomal abnormalities. Authentication of donor specific derivation was undertaken by DNA fingerprinting using a panel of SNPs. Results Most of cell lines exhibited spindle cell shape, with some retaining stellate shapes. At passage 2 to 6 all lines stained positively for calretinin and cytokeratin 19, and demonstrated capacity for anchorage-independent growth. At passage 4 to 16, doubling times ranged from 30–72 hours, and on spectral karyotyping all lines exhibited numerical chromosomal abnormalities ranging from 41 to 113. Monosomy of chromosomes 8, 14, 22 or 17 was observed in three lines. One line displayed four different karyotypes at passage 8, but only one karyotype at passage 42, and another displayed polyploidy at passage 40 which was not present at early passages. At passages 5–17, TEM showed characteristic features of mesothelioma ultrastructure in all lines including microvilli and tight intercellular junctions. Conclusion These six cell lines exhibit varying cell morphology, a range of doubling times, and show diverse passage-dependent structural chromosomal changes observed in malignant tumours. However they retain characteristic immunocytochemical protein expression profiles of mesothelioma during maintenance in artificial culture systems. These characteristics support their potential as in vitro model systems for studying cellular, molecular and genetic aspects of mesothelioma.

Idiopathic Chylothorax and Chylopericardium Resistant to Conservative and Surgical Management

Simultaneous idiopathic collection of chyle in the pericardial and pleural cavities is a rare phenomenon and to our knowledge it has been reported twice before [Torrington KG, Youkey JR. Simultaneous Idiopathic chylothorax and chylopericardium. South Med J 1981;74(March(3)):357-9; Kozielski J, Chylopericardium and chylothorax of unknown etiology. 1996]. There have been very few reported cases of chylopericardium presenting cardiac tamponade [Mehrotra S, Peeran NA, Bandyopadhyay A. Tex Heart Inst J 2006;33(2):249-53]. We report two cases of idiopathic pericardial and pleural effusions presenting cardiac tamponade resistant to conservative and surgical management.

Telomere length in pleural fluid is not different between malignant and benign effusions

068-P12 LUNG ADENOCARCINOMA BIOMARKER SCREENING IN AN AUSTR`ALIAN POPULATION Ainge Allen H, Stone E, Plit Ml, Havryk A, Goldrick A, Field A, Mead S, Qiu M, Chou A, Morey A Department of Respiratory Medicine, St Vincent’s Hospital, Sydney, New South Wales/AUSTRALIA; Department of Anatomical Pathology, Sydpath, St Vincent’s Hospital, Sydney, New South Wales/AUSTRALIA Aims: The emergence of new targeted therapies and clinical trials in lung adenocarcinoma suggest that routine molecular biomarker testing is warranted to detected subtypes of adenocarcinoma which will benefit from new therapies. Australian data is still emerging. We aim to detect the incidence of treatment specific molecular subtypes of lung adenocarcinoma in the Australian population. Methods: This is a single centre prospective pilot study of patients with a histopathological diagnosis of adenocarcinoma who have been presented at a Lung Cancer multidisciplinary meeting. Formalin fixed paraffin embedded tissue of 22 tumour samples were submitted for targeted PCR-based EGFR and KRAS mutation analysis; and EGFR amplification, MET amplification and EML4-ALK rearrangement testing by in-situ hybridization. one sample had insufficient tissue for analysis. Results: So far 22 patients received a definite tissue diagnosis of lung adenocarcinoma, 8/22 with Stage III and 10/22 with Stage IV disease. 4/22 (19%) are positive for an EGFR mutation, with activating EGFR mutations in 3/22 (14%) and an EGFR mutation of uncertain clinical significance in one patient (5%). EGFR amplification was detected in 2/22 patients (9%), KRAS mutations were detected in 5/22 patients (23%) patients, of which none carried EGFR mutations. EML4-ALK translocation was seen in 2/22 patients (9%) and MET amplification in 1/22 (5%) patients. Conclusions: Preliminary results indicate that treatment specific molecular subtypes of lung adenocarcinoma occur more commonly in the Australia population than other Western populations. Though further investigation is required, routine molecular biomarker testing is warranted. Disclosure: This study was funded by an unrestricted grant from Roche.

Pleural fluid cell-free dna integrity index and mesothelin to identify cytologically negative malignant pleural effusions including mesotheliomas

068-P12 LUNG ADENOCARCINOMA BIOMARKER SCREENING IN AN AUSTR`ALIAN POPULATION Ainge Allen H, Stone E, Plit Ml, Havryk A, Goldrick A, Field A, Mead S, Qiu M, Chou A, Morey A Department of Respiratory Medicine, St Vincent’s Hospital, Sydney, New South Wales/AUSTRALIA; Department of Anatomical Pathology, Sydpath, St Vincent’s Hospital, Sydney, New South Wales/AUSTRALIA Aims: The emergence of new targeted therapies and clinical trials in lung adenocarcinoma suggest that routine molecular biomarker testing is warranted to detected subtypes of adenocarcinoma which will benefit from new therapies. Australian data is still emerging. We aim to detect the incidence of treatment specific molecular subtypes of lung adenocarcinoma in the Australian population. Methods: This is a single centre prospective pilot study of patients with a histopathological diagnosis of adenocarcinoma who have been presented at a Lung Cancer multidisciplinary meeting. Formalin fixed paraffin embedded tissue of 22 tumour samples were submitted for targeted PCR-based EGFR and KRAS mutation analysis; and EGFR amplification, MET amplification and EML4-ALK rearrangement testing by in-situ hybridization. one sample had insufficient tissue for analysis. Results: So far 22 patients received a definite tissue diagnosis of lung adenocarcinoma, 8/22 with Stage III and 10/22 with Stage IV disease. 4/22 (19%) are positive for an EGFR mutation, with activating EGFR mutations in 3/22 (14%) and an EGFR mutation of uncertain clinical significance in one patient (5%). EGFR amplification was detected in 2/22 patients (9%), KRAS mutations were detected in 5/22 patients (23%) patients, of which none carried EGFR mutations. EML4-ALK translocation was seen in 2/22 patients (9%) and MET amplification in 1/22 (5%) patients. Conclusions: Preliminary results indicate that treatment specific molecular subtypes of lung adenocarcinoma occur more commonly in the Australia population than other Western populations. Though further investigation is required, routine molecular biomarker testing is warranted. Disclosure: This study was funded by an unrestricted grant from Roche.

Screening lung Tumour tissue for whole genome sequencing

068-P12 LUNG ADENOCARCINOMA BIOMARKER SCREENING IN AN AUSTR`ALIAN POPULATION Ainge Allen H, Stone E, Plit Ml, Havryk A, Goldrick A, Field A, Mead S, Qiu M, Chou A, Morey A Department of Respiratory Medicine, St Vincent’s Hospital, Sydney, New South Wales/AUSTRALIA; Department of Anatomical Pathology, Sydpath, St Vincent’s Hospital, Sydney, New South Wales/AUSTRALIA Aims: The emergence of new targeted therapies and clinical trials in lung adenocarcinoma suggest that routine molecular biomarker testing is warranted to detected subtypes of adenocarcinoma which will benefit from new therapies. Australian data is still emerging. We aim to detect the incidence of treatment specific molecular subtypes of lung adenocarcinoma in the Australian population. Methods: This is a single centre prospective pilot study of patients with a histopathological diagnosis of adenocarcinoma who have been presented at a Lung Cancer multidisciplinary meeting. Formalin fixed paraffin embedded tissue of 22 tumour samples were submitted for targeted PCR-based EGFR and KRAS mutation analysis; and EGFR amplification, MET amplification and EML4-ALK rearrangement testing by in-situ hybridization. one sample had insufficient tissue for analysis. Results: So far 22 patients received a definite tissue diagnosis of lung adenocarcinoma, 8/22 with Stage III and 10/22 with Stage IV disease. 4/22 (19%) are positive for an EGFR mutation, with activating EGFR mutations in 3/22 (14%) and an EGFR mutation of uncertain clinical significance in one patient (5%). EGFR amplification was detected in 2/22 patients (9%), KRAS mutations were detected in 5/22 patients (23%) patients, of which none carried EGFR mutations. EML4-ALK translocation was seen in 2/22 patients (9%) and MET amplification in 1/22 (5%) patients. Conclusions: Preliminary results indicate that treatment specific molecular subtypes of lung adenocarcinoma occur more commonly in the Australia population than other Western populations. Though further investigation is required, routine molecular biomarker testing is warranted. Disclosure: This study was funded by an unrestricted grant from Roche.