Faculty Bibliography

INTRODUCTION: The two essential requirements for pathologic specimens in the era of personalized therapies for non-small cell lung carcinoma (NSCLC) are accurate subtyping as adenocarcinoma (ADC) versus squamous cell carcinoma (SqCC) and suitability for EGFR and KRAS molecular testing. The aim of this study was to comprehensively review the performance of cytologic specimens for the above two goals in a high-volume clinical practice. METHODS: Subtyping of primary lung carcinomas by preoperative cytology was correlated with subsequent resection diagnoses during a 1-year period (n = 192). The contribution of various clinicopathologic parameters to subtyping accuracy and utilization of immunohistochemistry (IHC) for NSCLC subtyping were analyzed. In addition, the performance of cytologic specimens submitted for EGFR/KRAS molecular testing during a 1-year period (n = 128) was reviewed. RESULTS: Of the 192 preoperative cytology diagnoses, tumor subtype was definitive versus favored versus unclassified in 169 (88%) versus 15 (8%) versus 8 (4%) cases, respectively. Overall accuracy of cytologic tumor subtyping (concordance with histology) was 93% and accuracy of definitive diagnoses 96%. For a group of patients with ADC and SqCC (n = 165), the rate of unclassified cytologic diagnoses was 3% and overall accuracy 96%. IHC was used for subtyping of 9% of those cases, yielding 100% accuracy. The strongest predictors of difficulty in subtyping of ADC and SqCC were poor differentiation (p = 0.0004), low specimen cellularity (p = 0.019), and squamous histology (p = 0.003). Of 128 cytologic specimens submitted for molecular testing, 126 (98%) were suitable for analysis, revealing EGFR and KRAS mutations in 31 (25%) and 25 (20%) cases, respectively. CONCLUSIONS: Cytologic subtyping of NSCLC is feasible and accurate, particularly when morphologic assessment is combined with IHC. Furthermore, routine cytologic specimens can be successfully used for EGFR/KRAS mutation analysis. Our data strongly support the suitability of cytologic specimens for the new therapeutic paradigms in NSCLC.

BACKGROUND: Because associations have been reported between inhaled ambient ultrafine particles and increased risk of cardiopulmonary disease, it has been suggested that inhaled engineered nanoparticles (NPs) may also induce adverse effects on the cardiovascular system. OBJECTIVE: We examined the long-term cardiovascular effects of inhaled nickel hydroxide NPs (nano-NH) using a sensitive mouse model. METHODS: Hyperlipidemic, apoprotein E-deficient (ApoE-/-) mice were exposed to nano-NH at either 0 or 79 mug Ni/m3, via a whole-body inhalation system, for 5 hr/day, 5 days/week, for either 1 week or 5 months. We measured various indicators of oxidative stress and inflammation in the lung and cardiovascular tissue, and we determined plaque formation on the ascending aorta. RESULTS: Inhaled nano-NH induced significant oxidative stress and inflammation in the pulmonary and extrapulmonary organs, indicated by up-regulated mRNA levels of certain antioxidant enzyme and inflammatory cytokine genes; increased mitochondrial DNA damage in the aorta; significant signs of inflammation in bronchoalveolar lavage fluid; changes in lung histopathology; and induction of acute-phase response. In addition, after 5-month exposures, nano-NH exacerbated the progression of atherosclerosis in ApoE-/- mice. CONCLUSIONS: This is the first study to report long-term cardiovascular toxicity of an inhaled nanomaterial. Our results clearly demonstrate that long-term exposure to inhaled nano-NH can induce oxidative stress and inflammation, not only in the lung but also in the cardiovascular system, and that this stress and inflammation can ultimately contribute to progression of atherosclerosis in ApoE-/- mice

New developments in the field of thoracic oncology have challenged the way pathologists approach the diagnosis of pulmonary carcinoma. Nonsmall cell carcinoma is no longer an adequate diagnostic category. Pathologists are required to further classify tumors into adenocarcinoma and squamous cell carcinoma since specific therapies are now recommended depending on the histological tumor type. This change occurred following the discovery of specific molecular alterations that predict response to certain drugs and now molecular testing of tumor cells is often requested to direct therapy. The vast majority of lung cancer is diagnosed in advanced clinical stages, where cytologic or small biopsy material is the only form of tissue diagnosis, thus placing cytology, especially fine needle aspiration biopsy in the front line for management of patients with lung cancer. In this paper we will review the current concepts in the suitability and accuracy of fine needle aspiration biopsy, including diagnosis, classification, prognostic markers, and use of ancillary techniques.

PURPOSE: Recent evidence suggests that at least some sarcomas arise through aberrant differentiation of mesenchymal stromal cells (MSCs), but MSCs have never been isolated directly from human sarcoma specimens. EXPERIMENTAL DESIGN: We examined human sarcoma cell lines and primary adherent cultures derived from human sarcoma surgical samples for features of MSCs. We further characterized primary cultures as either benign or malignant by the presence of tumor-defining genetic lesions and tumor formation in immunocompromised mice. RESULTS: We show that a dedifferentiated liposarcoma cell line DDLS8817 posesses fat, bone, and cartilage trilineage differentiation potential characteristic of MSCs. Primary sarcoma cultures have the morphology, surface immunophenotype, and differentiation potential characteristic of MSCs. Surprisingly, many of these cultures are benign, as they do not form tumors in mice and lack sarcoma-defining genetic lesions. Consistent with the recently proposed pericyte origin of MSCs in normal human tissues, sarcoma-derived benign MSCs (SDBMSCs) express markers of pericytes and cooperate with endothelial cells in tube formation assays. In human sarcoma specimens, a subset of CD146-positive microvascular pericytes expresses CD105, an MSC marker, whereas malignant cells largely do not. In an in vitro coculture model, SDBMSCs as well as normal human pericytes markedly stimulate the growth of sarcoma cell lines. CONCLUSIONS: SDBMSCs/pericytes represent a previously undescribed stromal cell type in sarcoma that may contribute to tumor formation.

INTRODUCTION: Primary lung adenocarcinoma is extremely rare in the pediatric age group. There have been anecdotal reports of lesions that are histologically indistinguishable from adult-type pulmonary adenocarcinoma in young patients after treatment for nonpulmonary cancers. Herein, we present clinical, histopathologic, and molecular data on eight such cases. METHODS: Histopathologic evaluation of the tumors was performed according to the World Health Organization classification. Molecular studies for EGFR and KRAS mutations were performed on six patients with sufficient material. RESULTS: All eight patients were never smokers, four males and four females. Median age at nonpulmonary cancer diagnosis was 14 years (range, 3-23 years). Pulmonary adenocarcinomas were diagnosed at a median age of 15 years (range, 10-24 years); tumors were 0.1 to 2.0 cm in size and in some cases coexisted with metastases from the original cancer. Retrospective review showed that in at least three patients, the nodules were radiographically present before chemotherapy. Of six patients whose tumors were tested for common EGFR and KRAS mutations, two were positive for the former and one for the latter. At a median follow-up of 11 months (range, 2-29 months), six patients remained well without lung nodules and two had additional small, peripheral lung nodules that have not been biopsied. CONCLUSIONS: Pulmonary lesions found in young patients with pediatric cancers can be histologically indistinguishable from lung adenocarcinoma seen in adults, may display typical adenocarcinoma-associated mutations of EGFR and KRAS, and may precede the administration of cytotoxic chemotherapy.

Currently no objective grading system for pulmonary adenocarcinomas exists. To determine whether specific histologic patterns or combinations thereof could be linked to an objective grading system, the histologic patterns in metastatic tumor deposits was compared with the patterns seen in the corresponding 73 primary tumor to determine whether a specific pattern had higher propensity to metastasize. The concordance of the predominant histologic pattern in the primary tumor and the metastases was of 100% for micropapillary, 86% for solid, 42% for acinar, and 23% for papillary types of adenocarcinoma. Informed by these results, a 3-tier grading system based on the histologic subtypes was established. Grade I, a pattern with low metastatic potential (BAC); Grade II, patterns with intermediate metastatic potential (acinar and papillary); and Grade III, patterns with high metastatic potential (solid and micropapillary). These grades were combined into a number of different scoring systems, whose ability to predict recurrence or death from disease was tested in 366 stage 1 adenocarcinomas. A score based on the 2 most predominant grades was able to stratify patients into low-to-high risk for recurrence or death of disease (P=0.001). The 5-years disease-free survival for patients in the highest score group was of 0.73, compared with 0.84 and 0.92 in the intermediate and lowest score groups. Concordance probability estimate was 0.65 (95% confidence interval 0.57-0.73). Therefore, this scoring system provides valuable information in discriminating patients with different risk of disease-recurrence in a highly homogeneous population of patients with stage I cancer.

Carcinomas may arise as a disorder of regeneration, so that a malignant cell may represent a failure to fully attain the characteristics of differentiated tissue. We hypothesized that there is a differential distribution of progenitor cell markers among different histological types of lung cancers, with poorly differentiated tumors being more likely to express progenitor stem cell markers. The study was limited to paraffin-embedded archival material of resected untreated pulmonary carcinomas, including adenocarcinoma, squamous cell carcinoma, large cell carcinoma, and small cell carcinoma. The sections were stained for putative stem cells markers (Musashi-1, Musashi-2, CD34, CD21, KIT, CD133, p63, and OCT-4). Positivity was read as isolated, focal, or diffuse staining. Stem cell markers were detected in all histological types of pulmonary carcinomas. There was a difference in the expression of markers among the histological types. Small cell carcinoma showed diffuse positivity for most of the markers; in contrast to focal or negative staining in other histological groups. An inverse relationship between CD21 and Musashi-1 was observed. No staining for OCT-4 and CD34 was seen in any of the tumor types. Hierarchical clustering based on marker expression separated tumors into two groups, with one group marked by high expression of Musashi-1 and KIT, contained most of the poorly differentiated adenocarcinomas and small cell carcinomas. Therefore, stem cell markers are expressed in lung cancers with different patterns seen for different histological types and degrees of differentiation.

Short and long-term pulmonary response to inhaled nickel hydroxide nanoparticles (nano-Ni(OH)(2), CMD = 40 nm) in C57BL/6 mice was assessed using a whole body exposure system. For short-term studies mice were exposed for 4 h to nominal concentrations of 100, 500, and 1000 mg/m(3). For long-term studies mice were exposed for 5 h/d, 5 d/w, for up to 5 months (m) to a nominal concentration of 100 mg/m(3). Particle morphology, size distribution, chemical composition, solubility, and intrinsic oxidative capacity were determined. Markers of lung injury and inflammation in bronchoalveolar lavage fluid (BALF); histopathology; and lung tissue elemental nickel content and mRNA changes in macrophage inflammatory protein-2 (Mip-2), chemokine ligand 2 (Ccl2), interleukin 1-alpha (Il-1alpha), and tumor necrosis factor-alpha (Tnf-alpha) were assessed. Dose-related changes in BALF analyses were observed 24 h after short-term studies while significant changes were noted after 3 m and/or 5 m of exposure (24 h). Nickel content was detected in lung tissue, Ccl2 was most pronouncedly expressed, and histological changes were noted after 5 m of exposure. Collectively, data illustrates nano-Ni(OH)(2) can induce inflammatory responses in C57BL/6 mice

The most recent WHO classification of lung cancer defines bronchioloalveolar carcinoma (BAC) as a noninvasive carcinoma or adenocarcinoma in situ. However, the use of this terminology is not uniform and does not reflect standardized criteria. As a result, the diagnosis of BAC has been used in association with small, solitary, and well-differentiated adenocarcinoma as well as tumors with advanced clinical stage. At present, there is a growing consensus among specialists in thoracic oncology that BAC or adenocarcinoma in situ is a rare tumor, and the term should be restricted to adenocarcinomas that show a pure lepidic pattern of growth. The amount of invasive component present in a tumor with a predominant lepidic growth pattern has also been under intense scrutiny. The concept of minimally invasive adenocarcinoma is developing in order to differentiate a pure BAC from an invasive adenocarcinoma that still carries an excellent prognosis.