Massimiliano Paci

Circulating plasma DNA as diagnostic biomarker in non-small cell lung cancer

OBJECTIVES The presence of circulating DNA in plasma of patients with malignant neoplasm has been a known fact for over 30 years. Since then, the concentration of free circulating plasma DNA has been studied as well as the genetic alterations and epigenetic alterations of tumour DNA of patients that suffer from various types of tumours. The analysis of circulating plasma DNA may be a useful marker to get an early diagnosis on malignant neoplasms. This study has been specifically designed to validate the quantification of circulating DNA in order to design a test useful for the early identification of non-small cell lung cancer patients and the monitoring of lung cancer progression. A second aim of this work is the sensibility and specificity evaluation of such method for future applications. METHODS The quantity of plasma DNA was determined using quantitative Real-Time PCR with amplification of the human telomerase reverse transcriptase (hTERT) gene in 151 patients that suffer from lung cancer and 79 healthy controls. The performance of the test was evaluated with a ROC curve. The relationship between the DNA concentration and main demographic, clinical and pathological variables was examined with logistic regression models as well as multiple linear regression models. RESULTS The concentration of circulating plasma DNA was about four times higher in patients with lung cancer with respect to the controls (12.8 vs 2.9 ng/mL). The area under the ROC curve was 0.79 (95% CI, 0.710-0.83). The concentration of circulating DNA proved to be an important risk factor for the presence of the illness and a prognostic index in the follow-up. CONCLUSIONS The use of quantitative Real-Time PCR revealed that higher values of circulating DNA can be found in patients with lung neoplasm compared to the healthy controls. This could have practical implications such as the use in screening programs and a possible prognostic significance in the follow-up.

Large cell carcinoma of the lung: clinically oriented classification integrating immunohistochemistry and molecular biology

This study aimed at challenging pulmonary large cell carcinoma (LLC) as tumor entity and defining different subgroups according to immunohistochemical and molecular features. Expression of markers specific for glandular (TTF-1, napsin A, cytokeratin 7), squamous cell (p40, p63, cytokeratins 5/6, desmocollin-3), and neuroendocrine (chromogranin, synaptophysin, CD56) differentiation was studied in 121 LCC across their entire histological spectrum also using direct sequencing for epidermal growth factor receptor (EGFR) and v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations and FISH analysis for ALK gene translocation. Survival was not investigated. All 47 large cell neuroendocrine carcinomas demonstrated a true neuroendocrine cell lineage, whereas all 24 basaloid and both 2 lymphoepithelioma-like carcinomas showed squamous cell markers. Eighteen out of 22 clear cell carcinomas had glandular differentiation, with KRAS mutations being present in 39 % of cases, whereas squamous cell differentiation was present in four cases. Eighteen out of 20 large cell carcinomas, not otherwise specified, had glandular differentiation upon immunohistochemistry, with an exon 21 L858R EGFR mutation in one (5 %) tumor, an exon 2 KRAS mutation in eight (40 %) tumors, and an ALK translocation in one (5 %) tumor, whereas two tumors positive for CK7 and CK5/6 and negative for all other markers were considered adenocarcinoma. All six LCC of rhabdoid type expressed TTF-1 and/or CK7, three of which also harbored KRAS mutations. When positive and negative immunohistochemical staining for these markers was combined, three subsets of LCC emerged exhibiting glandular, squamous, and neuroendocrine differentiation. Molecular alterations were restricted to tumors classified as adenocarcinoma. Stratifying LCC into specific categories using immunohistochemistry and molecular analysis may significantly impact on the choice of therapy.

Preoperative embolization in surgical treatment of mediastinal hemangiopericytoma

The case of a 47-year-old man with a tumor of the posterosuperior mediastinum is reported. Surgical biopsy sample revealed a hemangiopericytoma, but radical excision was impossible because of massive bleeding. Percutaneous embolization of mediastinal tumor was performed to reduce peroperative blood loss. It allowed uneventful complete removal of the lesion. We recommend preoperative embolization in cases of hypervascular mediastinal tumors.

PET/CT assessment of neuroendocrine tumors of the lung with special emphasis on bronchial carcinoids

Pulmonary neuroendocrine tumors (pNETs) arise from bronchial mucosal cells known as enterochromaffin cells which are part of the diffuse neuroendocrine system. The pathological spectrum of pNETs ranges from low-/intermediate-grade neoplasms such as bronchial carcinoids (BCs), also known as typical or atypical carcinoids, to high-grade neoplasms as large-cell neuroendocrine carcinoma and small-cell lung cancer. The tumor biology of pNETs still represents a matter of open debate. The distinct features among the different pNETs include not only their pathologic characteristics but also their clinical behavior, epidemiology, treatment, and prognosis. In this sense, a correct pathological identification in the preoperative setting is a key element for planning the best strategy of care in pNETs and especially in BCs. Controversial results have been reported on the diagnostic accuracy of fluorine-18-fluorodeoxyglucose positron emission tomography or positron emission tomography/computed tomography (F-18-FDG PET or PET/CT) in BCs. On the other hand, there is increasing evidence supporting the use of PET with somatostatin analogues (DOTA-TOC, DOTA-NOC, or DOTA-TATE) labeled with gallium-68 (Ga-68) in pNETs. Herein, we review the pertinent literature aiming to better define the current state of art of PET/CT in the detection and histological differentiation of pNETs with special emphasis on BCs.

Soluble Epidermal Growth Factor Receptors (sEGFRs) in Cancer: Biological Aspects and Clinical Relevance

The identification of molecules that can reliably detect the presence of a tumor or predict its behavior is one of the biggest challenges of research in cancer biology. Biological fluids are intriguing mediums, containing many molecules that express the individual health status and, accordingly, may be useful in establishing the potential risk of cancer, defining differential diagnosis and prognosis, predicting the response to treatment, and monitoring the disease progression. The existence of circulating soluble growth factor receptors (sGFRs) deriving from their membrane counterparts has stimulated the interest of researchers to investigate the use of such molecules as potential cancer biomarkers. But what are the origins of circulating sGFRs? Are they naturally occurring molecules or tumor-derived products? Among these, the epidermal growth factor receptor (EGFR) is a cell-surface molecule significantly involved in cancer development and progression; it can be processed into biological active soluble isoforms (sEGFR). We have carried out an extensive review of the currently available literature on the sEGFRs and their mechanisms of regulation and biological function, with the intent to clarify the role of these molecules in cancer (and other pathological conditions) and, on the basis of the retrieved evidences, speculate about their potential use in the clinical setting.

The role of histology in idiopathic pulmonary fibrosis: An update

The diagnosis of idiopathic pulmonary fibrosis (IPF) currently requires an integrated clinical-radiological-pathological approach in which the histology plays a different role from in the past. The first reason for this change is that non-invasive diagnostic procedures, particularly pulmonary function tests and high resolution computed tomography, have become increasingly competitive with biopsy in providing prognostic information. The other reason is a better appreciation of the limitations of histology: sampling error and interobserver variation. In this review we analyze the reasons for this change of perspective, provide an update on the practical role of histology in the diagnosis of IPF and discuss some of its complications.

Bronchopulmonary Actinomycosis Associated With Hiatal Hernia

OBJECTIVES To describe clinicoradiologic and histopathologic features of bronchopulmonary actinomycosis and to determine whether hiatal hernia (HH) is a potential predisposing factor for bronchopulmonary actinomycosis. PATIENTS AND METHODS We reviewed the medical charts of 10 patients who had bronchopulmonary actinomycosis between November 1, 2002, and January 31, 2008. Complete clinical data, radiologic studies (chest radiographs and computed tomographic scans), and histopathologic features were assessed to investigate clinical manifestations and predisposing factors related to bronchopulmonary actinomycosis. RESULTS The series consisted of 6 men and 4 women, with a mean age of 63.5 years; 8 of the patients were smokers. Cough and fever were the most common symptoms. Chest imaging showed mass-like consolidation in 4 patients, bronchial thickening or lung atelectasis with pleural thickening in 2 patients each, and perihilar irregular mass or multiple bilateral nodules in 1 patient each. Primary or metastatic lung cancer was suspected clinically in 8 of the 10 patients. Foreign body-related endobronchial actinomycosis was diagnosed in 6 patients, 5 of whom had HH; only 1 had gastroesophageal reflux-related symptoms. Because of bronchial obstruction, rigid bronchoscopy was performed in 3 patients, lobectomy in 2, and atypical resection in 1. Antibiotic therapy with amoxicillin was given to all patients, with resolution of actinomycosis. CONCLUSION Bronchopulmonary actinomycosis is a rare condition that mimics pulmonary malignancy on clinical and radiologic grounds. Diagnosis relies on an accurate patient history and histopathologic examination. Although further confirmation is required, esophageal HH appears to be a potential predisposing factor.

The Histology of Pulmonary Sarcoidosis: A Review With Particular Emphasis on Unusual and Underrecognized Features

The pathologist is frequently involved in the diagnostic approach to the patient with suspected sarcoidosis. Although the histologic diagnosis is generally not difficult, atypical and underrecognized features may occasionally occur and may result in diagnostic problems. The authors review the histology of pulmonary sarcoidosis, focusing particularly on these unusual problematic findings.

Alveolar Adenoma of the Lung: A Clinicopathologic, Immunohistochemical, and Molecular Study of an Unusual Case

We describe an alveolar adenoma of the lung with 3 previously unreported findings, which expand both the clinical and the morphologic spectrum of this rare tumor: presentation as a cystic nodule, foci of mature adipocytes, and S-100 positivity of the mesenchymal cells. Furthermore, using a laser capture microdissection technique under microscope visualization, we analyzed multiple chromosomal loci in both the epithelial and mesenchymal components of the lesion, showing microsatellite alterations and loss of heterozygosity in the former but not in the latter.

Preliminary evidence on the diagnostic and molecular role of circulating soluble EGFR in non-small cell lung cancer

Assessment of biological diagnostic factors providing clinically-relevant information to guide physician decision-making are still needed for diseases with poor outcomes, such as non-small cell lung cancer (NSCLC). Epidermal growth factor receptor (EGFR) is a promising molecule in the clinical management of NSCLC. While the EGFR transmembrane form has been extensively investigated in large clinical trials, the soluble, circulating EGFR isoform (sEGFR), which may have a potential clinical use, has rarely been considered. This study investigates the use of sEGFR as a potential diagnostic biomarker for NSCLC and also characterizes the biological function of sEGFR to clarify the molecular mechanisms involved in the course of action of this protein. Plasma sEGFR levels from a heterogeneous cohort of 37 non-advanced NSCLC patients and 54 healthy subjects were analyzed by using an enzyme-linked immunosorbent assay. The biological function of sEGFR was analyzed in vitro using NSCLC cell lines, investigating effects on cell proliferation and migration. We found that plasma sEGFR was significantly decreased in the NSCLC patient group as compared to the control group (median value: 48.6 vs. 55.6 ng/mL respectively; p = 0.0002). Moreover, we demonstrated that sEGFR inhibits growth and migration of NSCLC cells in vitro through molecular mechanisms that included perturbation of EGF/EGFR cell signaling and holoreceptor internalization. These data show that sEGFR is a potential circulating biomarker with a physiological protective role, providing a first approach to the functional role of the soluble isoform of EGFR. However, the impact of these data on daily clinical practice needs to be further investigated in larger prospective studies.