Aubry, Marie‐Christine

7568 Background: The molecular events in the initiation and progression of invasive lung adenocarcinoma remain poorly characterized. These tumors are thought to develop through an adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), invasive adenocarcinoma (AD) sequence. The goal of our study was to assess lineage relationships between in situ and invasive components within adenocarcinomas with prominent lepidic growth patterns. Methods: Frozen tissue from fourteen lung adenocarcinomas with mixtures of AD together with an adjacent in situ component (AIS), varying in ratio between 40 to 80%, were selected from our Lung Specimen Registry. Laser capture microdissection (LCM) of each component was performed separately for each tumor. Genomic DNA was isolated using a direct in situ whole genome amplification (WGA) methodology, and Next Generation Sequencing performed using an Illumina Mate Pair (MP) library protocol. MP sequence reads were mapped to the human genome and primers spanning the fusion junctions were used in validation PCRs. Results: Genomic break points identical and unique to a specific patient were identified between the AIS and AD components in 13 (of 14) cases. The total number of events per case ranged from 4-215, and the number of identical events shared between the AIS and AD components ranged from 30 to 90%. Recurrent genomic breakpoints between cases were also observed, with the 2 most common involving 8q24.3 in 5 cases and FAM19A2 on chromosome 12 in 4 cases. PCR validation of selected genomic alterations confirmed the genomic break points identified from sequencing in both the AIS and AD in all cases. Interestingly, we also observed a limited number of genomic alterations present in a zonal distribution of surrounding normal lung around the tumor mass. Conclusions: Our study demonstrates unique chromosomal alterations present in both the AIS and AD components of individual lung tumors with features of lepidic growth. These data provide evidence for lineage relationship and clonal relatedness between the two components, and provide genomic evidence for a model of stepwise progression from AIS to invasive AD in this subset of lung adenocarcinomas.

7509 Background: NTX-010 is a naturally occurring replication-competent picornavirus with potent and selective tropism for SCLC tumor cells expressing neuroendocrine markers. A phase I study of NTX-010 showed evidence of antitumor activity in patients with SCLC. Methods: ES-SCLC patients (pts) with SD, PR or CR after at least 4 cycles of platinum-based chemotherapy were pre-registered to confirm diagnosis of SCLC with > 1 neuroendocrine marker by a central pathology review. Eligible pts were.randomized 1:1 to placebo (B) or NTX-010 (A). NTX-010 or placebo was administered intravenously as a 1-hour infusion in 100 mL normal saline as a single dose of 1 x1011vp/kg. Viral studies to determine distribution, clearance of the virus and the presence of neutralizing antibodies were done. The primary goal of this trial was to compare the progression-free survival (PFS) of arm A to B based on a sample size of 45 patients per arm to detect an improvement in median PFS from 3 to 5 months (m). A pre-planned interim futility analysis was done after 40 PFS events, and reported here. Results: The trial is permanently closed to accrual. One-hundred and twenty pts were pre-registered, of whom 58 were randomized. Baseline age, gender, ECOG performance status, and histology were balanced between arms. Median age was 63 (range: 44 - 82). 31% of pts had a PS of 0 and 69% of 1. Grade 4 adverse events were seen in 3 (12.5%) patients in arm A and none in arm B. Based on the interim futility analysis, PFS was 1.7 m (95% CI: 1.3-3.1) for arm A and 1.7 m (95% CI: 1.4-4.3) for arm B. Pts with viral RNA at 7 (7 pts) and 14 (6 pts) days had worse PFS compared to those with no detectable levels within arm A (1.0 vs 1.6 m, p=0.02; 0.9 vs. 1.2 m, p=0.06). Median follow-up in pts is 6.1 m. The 3-month OS estimates are 83% (95% CI: 69%-100%) and 85% (70%-100%) for arms A and B respectively. Conclusions: This phase II study showed no benefit in PFS for ES-SCLC patients receiving NTX-010. Pts with detectable virus at 7 and 14 days had worse PFS. Clinical trial information: NCT01017601.

43 Background: Human leukocyte antigens (HLA) are crucial for cytotoxic T cell responses to cancer. Loss of HLA expression is a mechanism of tumor immune escape and may contribute to resistance to immunotherapy. In patients with non-small cell lung cancer (NSCLC) treated with immune checkpoint inhibitors we have observed discordant responses between brain metastases and extracranial disease and reported on differential PD-L1 expression and clonal T cell infiltration between paired primary lung lesions and brain metastases. In this project we sought to evaluate whether HLA expression was retained in metastatic NSCLC. Methods: Adult patients with paired primary NSCLC and brain metastases were identified from our institution’s tissue registry. HLA-A cell membrane expression on tumor cells was determined by immunohistochemistry with an anti-HLA-A antibody. Tumors with greater than 10% HLA expression were considered positive. Agreement statistics (κ) and Fisher’s exact test were used for analysis. Results: 51 patients with paired primary NSCLC and brain lesions were identified. The median HLA expression was 20% in the primary tumors (IQR 0-65%) and 10% in the brain metastases (IQR 5-40%). 27 primary tumors and 24 brain metastases were positive for HLA expression. There was disagreement in HLA positivity between paired lesions in 11 patients (22%, 95% CI 12-35%)(κ = 0.57, 95% CI 0.35-0.79)(p = 0.0001). There was no significant difference in the time between the primary tumor and brain metastasis resections in patients with HLA expression disagreement compared to those with HLA expression agreement. None of the patients received immune checkpoint inhibitors for treatment of these lesions. Conclusions: We found significant differences in HLA-A expression on tumor cells in nearly one quarter of paired primary lung cancers and brain metastases. Differences in HLA expression may help explain the discrepancies in response to immune checkpoint inhibitors at different sites of disease and warrants further study.

AimsPulmonary chondromas, which are rare cartilaginous neoplasms that often arise in the setting of Carney triad, are morphologically similar to pulmonary hamartomas, which are much more common. There is evidence that succinate dehydrogenase (SDH) deficiency drives neoplasia in patients with Carney triad, and SDHB immunohistochemistry can be used as a surrogate marker to detect SDH deficiency. The aim of this study was to investigate the utility of SDHB immunohistochemistry in distinguishing pulmonary chondromas from hamartomas.Methods and resultsImmunohistochemistry for SDHB (clone 21A11AE7) was performed on histological sections from six cases of pulmonary chondroma and 33 cases of pulmonary hamartoma. SDHB expression was retained in all 33 pulmonary hamartomas, and lost in the majority of evaluable chondromas (five of six). Of the five patients with chondromas showing SDHB loss, four had definitive Carney triad. Most patients with pulmonary hamartomas were older males with small solitary masses, whereas chondromas often presented as multiple masses in young females.ConclusionLoss of SDHB immunohistochemical expression can be useful for differentiating pulmonary chondromas from hamartomas, and potentially identifying patients with Carney triad.

Transthoracic fine needle aspiration (TFNA)/core needle biopsy (CNB) under computed tomography (CT) guidance has proved useful in the assessment of pulmonary nodules. We sought to determine the TFNA false‐negative (FN) rate at our institution and identify potential causes of FN diagnoses. Medical records were reviewed from 1,043 consecutive patients who underwent CT‐guided TFNA with or without CNB of lung nodules over a 5‐year time period (2003–2007). Thirty‐seven FN cases of “negative” TFNA/CNB with malignant outcome were identified with 36 cases available for review, of which 35 had a corresponding CNB. Cases were reviewed independently (blinded to original diagnosis) by three pathologists with 15 age‐ and sex‐matched positive and negative controls. Diagnosis (i.e., nondiagnostic, negative or positive for malignancy, atypical or suspicious) and qualitative assessments were recorded. Consensus diagnosis was suspicious or positive in 10 (28%) of 36 TFNA cases and suspicious in 1 (3%) of 35 CNB cases, indicating potential interpretive errors. Of the 11 interpretive errors (including both suspicious and positive cases), 8 were adenocarcinomas, 1 squamous cell carcinoma, 1 metastatic renal cell carcinoma, and 1 lymphoma. The remaining 25 FN cases (69.4%) were considered sampling errors and consisted of 7 adenocarcinomas, 3 nonsmall cell carcinomas, 3 lymphomas, 2 squamous cell carcinomas, and 2 renal cell carcinomas. Interpretive and sampling error cases were more likely to abut the pleura, while histopathologically, they tended to be necrotic and air‐dried. The overall FN rate in this patient cohort is 3.5% (1.1% interpretive and 2.4% sampling errors). Diagn. Cytopathol. 2014;42:1063–1068;. © 2014 Wiley Periodicals, Inc.

Abstract Pulmonary lymphangioleiomyomatosis (LAM) is an uncommon disease reported to occur exclusively in women. We describe a phenotypically normal man with pulmonary LAM. Fluorescence in situ hybridization (FISH) studies performed on the lung biopsy confirmed a normal XY genotype. Our patient also had stigmata of tuberous sclerosis complex (TSC), including facial angiofibromas and renal angiomyolipoma. Immunohistochemical stains of both LAM and renal angiomyolipoma showed positive immunoreactivity for hamartin (TSC1) and loss of immunoreactivity for tuberin (TSC2). Loss of heterozygosity (LOH) for TSC2 was further demonstrated in the renal angiomyolipoma. Coupled with the results of immunostains, these findings are consistent with TSC2 mutation.

Abstract 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 LB-186.