Alessandro Marchioni

Role of Chemotherapy and the Receptor Tyrosine Kinases KIT, PDGFRα, PDGFRβ, and Met in Large-Cell Neuroendocrine Carcinoma of the Lung

Purpose Pulmonary large-cell neuroendocrine carcinoma (LCNEC) is a relatively uncommon, high-grade neuroendocrine tumor sharing several features with small-cell lung carcinoma (SCLC) but currently considered as a variant of non-SCLC and accordingly treated with poor results. Little is known about the optimal therapy of LCNEC and the possible therapeutic molecular targets. Patients and Methods We reviewed 83 patients with pure pulmonary LCNEC to investigate their clinicopathologic features, therapeutic strategy, and immunohistochemical expression and the mutational status of the receptor tyrosine kinases (RTKs) KIT, PDGFRα, PDGFRβ, and Met. Results LCNEC histology predicted a dismal outcome (overall median survival, 17 months) even in stage I patients (5-year survival rate, 33%). LCNEC strongly expressed RTKs (KIT in 62.7% of patients, PDGFRα in 60.2%, PDGFRβ in 81.9%, and Met in 47%), but no mutations were detected in the exons encoding for the relevant juxtamembrane domains. Tumor stage and size (≥ 3 cm)...

Primary Mucinous (so-called Colloid) Carcinomas of the Lung: A Clinicopathologic and Immunohistochemical Study With Special Reference to cdx-2 Homeobox Gene and muc2 Expression

Herein we describe the clinicopathologic and immunohistochemical features of 13 primary mucinous (colloid) carcinomas (MCs) of the lung, an uncommon and controversial tumor. The patients, 7 males and 6 females, ranged in age from 50 to 79 years (mean, 64.5 years). All the tumors presented as a peripheral solitary nodule with gelatinous cut-surface and well circumscribed but lacking a complete fibrous wall. The size ranged from 1 to 5.5 cm. Microscopically, they consisted of neoplastic elements floating in large mucin pools and focally lining the alveolar spaces. Eleven cases were predominantly composed of tall, columnar goblet cells (goblet cell-type MC), while 2 consisted of signet-ring tumor cells (signet-ring cell-type MC). Five tumors were incidentally discovered by chest radiographs, while the others were symptomatic. All patients underwent complete surgical resection (six lobectomies and seven wedge resections). Postoperative chemotherapy was performed in 3 cases. Overall, the median follow-up was 26 months (mean 33 months; range 9–95 months). All patients with goblet cell-type MC were alive and well, while the 2 patients with signet-ring cell-type MC died of disease. Immunohistochemically, all the 11 goblet cell-type MCs were strongly stained with CDX-2 and MUC2, 8 reacted with TTF-1, 6 with cytokeratin 20 (CK20), 9 with cytokeratin 7 (CK7), and 2 with MUC-5AC. Conversely, the two signet-ring cell-type MCs were stained with TTF-1, CK7, and MUC5AC but were negative for CDX-2, MUC2, and CK20. Surfactant apoprotein-A (SP-A) was positive in four goblet cell-type and one signet-ring cell-type MC. When compared with 10 mucinous bronchioloalveolar carcinomas (m-BAC), the latter reacted with CK7, CK20, MUC5AC, TTF-1, SP-A, CDX-2, and MUC2 in 100%, 90%, 100%, 30%, 10%, 0%, and 0% of the cases, respectively. In summary, MC of the lung represents an entity with two distinct clinicopathologic and immunophenotypic variants: 1) the goblet cell-type, presenting a more indolent clinical behavior and frequently co-expressing markers of intestinal and pulmonary differentiation; and 2) the more aggressive signet-ring cell-type, which retains only markers of pulmonary origin. On morphologic and immunohistochemical grounds, MCs are easily distinguishable from m-BAC. Since goblet cell-type MC strongly stains with CDX2, MUC2, and CK20, differential diagnosis with metastatic colorectal carcinoma is very challenging and requires appropriate clinical correlation.

TTF-1, Cytokeratin 7, 34βE12, and CD56/NCAM Immunostaining in the Subclassification of Large Cell Carcinomas of the Lung

We selected a 4-stain immunopanel including thyroid transcription factor (7ITF)-], cytokeratin (CK)7, 34betaE12, and CD56/neural cell adhesion molecule(NCAM) to subclassify a series of 45 pulmonary large cell carcinomas (LCCs) on bronchial biopsy. All cases consisted of a large tumor cell proliferation with abundant cytoplasm, vesicular nuclei, and prominent nucleoli. Immunohistochemically, 27 tumors (60%)were subclassified as adenocarcinoma (7TF-1 +/CK7+,24; CK7+ only, 3), 10 (22%) as squamous cell carcinoma (34betaE12+ only), and 4 (9%) as LCC with neuroendocrine differentiation (CD56+, variably stained with TTF-I and CK7, 34betaE12-). In 4 cases, the tumors coexpressed CK7 and 34betaE12 (3 cases) or were completely unstained (I case). Surgically resected tumors matched exactly with the corresponding original biopsy specimens in 21 of 23 cases; consistent CD56 expression was a reliable marker in confirming a diagnosis of large cell neuroendocrine carcinoma even on biopsy. Our results suggest that the proposed 4-stainset of commercially available markers might help subclassify LCC even in small biopsy material, validating expression-profiling studies aimed at lung cancer classification and permitting more consistent patient enrollment for trials with targeted treatments.

Primary Lung Cancer Presenting with Gastrointestinal Tract Involvement: Clinicopathologic and Immunohistochemical Features in a Series of 18 Consecutive Cases

Background: Lung cancer initially manifesting as gastrointestinal (GI)-tract metastasis is exceedingly rare, representing a diagnostic challenge and a late-stage disease sign. The clinicopathologic characteristics of the largest series of lung carcinomas initially presenting with GI involvement were described, focusing on differential diagnosis and therapeutic options. Methods: Eighteen consecutive cases of lung cancer (11 surgical specimens and 7 biopsies) initially diagnosed on GI histologic samples were identified during routine pathologist practice. All cases were immunostained with thyroid transcription factor-1 (TTF-1), caudal-related homeobox 2 (CDX2), and cytokeratins 7 (CK7) and 20 (CK20). Clinical and radiological data were obtained in all cases. Results: There were 10 women and 8 men with a mean age of 68.5 years. The small bowel was the most common GI involved site (12 cases), followed by the stomach (four) and large intestine (two). Only half of cases were correctly diagnosed on GI biopsies. Fourteen patients died shortly from disease (mean follow-up, 3 months); two are still alive with multiple metastases, and two patients with the GI tract as the unique site of metastasis underwent pulmonary lobectomy and chemotherapy and are alive without evidence of disease. At morphology, there were 10 large cell undifferentiated carcinomas and eight adenocarcinomas. All cases were immunostained for CK7 and 89% for TTF-1, whereas CK20 and CDX2 were completely negative. Conclusion: Lung cancer presenting as GI-tract metastasis is probably more frequent than expected, and pathologists should always keep in mind this possibility when dealing with undifferentiated GI carcinoma. Immunostaining with TTF-1, CDX2, CK7, and CK20 is helpful in highlighting lung primary. Although GI metastasis from lung cancer is associated with dismal outcomes, pulmonary resection coupled with chemotherapy might represent a therapeutic option in selected patients with a solitary GI-tract metastasis.

EGFR and K-ras Mutations Along the Spectrum of Pulmonary Epithelial Tumors of the Lung and Elaboration of a Combined Clinicopathologic and Molecular Scoring System to Predict Clinical Responsiveness to EGFR Inhibitors

We tested 418 neoplasms along the whole spectrum of primary lung tumor histotypes for epidermal growth factor receptor (EGFR) and K-ras mutations. Clinicopathologic data from 154 patients undergoing treatment with EGFR tyrosine kinase inhibitors (TKIs) were retrospectively studied. A scoring system assigning a score for each positive or negative characteristic (+1, female sex, nonsmoking status, adenocarcinoma histotype, Asian ethnicity, and EGFR mutation; -1, current smoker and K-ras mutation; and 0, male sex, ex-smoker, nonadenocarcinoma histotype, and no mutations) was elaborated and tested with EGFR-TKI response. Salivary gland-type, mucin-rich, and neuroendocrine tumors do not harbor EGFR mutations. A subset of nonmucinous adenocarcinomas, not necessarily of the bronchioloalveolar type, is related to EGFR mutations. Three probability groups significantly correlating with response to EGFR-TKIs were identified. Of note, the addition of molecular results did not significantly change the predictive value obtained by the combination of clinicopathologic characteristics alone in this scoring system. K-ras mutations, significantly associated with the mucin-secreting type of adenocarcinoma, consistently predict lack of response in white patients.

PDGFR expression in differential diagnosis between KIT-negative gastrointestinal stromal tumours and other primary soft-tissue tumours of the gastrointestinal tract

Aims : To investigate the value of platelet‐derived growth factor receptors (PDGFRs) by immunohistochemistry in discriminating KIT‐negative gastrointestinal stromal tumours (GISTs) from other soft‐tissue neoplasms of the digestive tract.

Kit Expression in Small Cell Carcinomas of the Lung: Effects of Chemotherapy

A significant number of small cell lung carcinomas shows overexpression of the proto-oncogene c-kit product, a tyrosine kinase known as Kit or CD117. This molecular pathway seems somewhat implicated in promoting the neoplastic growth of small cell lung carcinoma. The current pharmacological availability of its selective inhibitor, together with the promising clinical results in the management of CD117-positive neoplasms such as advanced gastrointestinal stromal tumors, aroused great interest among oncologists in also adopting this therapeutic strategy in other CD117-positive tumors. We evaluated a series of 27 small cell lung carcinomas, comparing the expression of CD117 of the primary naïve tumor (before first-line chemotherapy) with the expression of the same neoplasm after postchemotherapy relapse. All the patients underwent similar chemotherapeutic regimens (cisplatin/carboplatin plus etoposide). At diagnosis, 21 of 27 cases (78%) showed strong immunoreactivity for CD117. Among these 21 originally positive tumors, CD117 remained overexpressed in 10 after relapse (48%), whereas the other 11 cases became negative. No originally CD117-negative small cell carcinomas displayed immunoreactivity after chemotherapy. CD117 expression was not statistically correlated with overall survival, occurrence of chemoresistance, or clinical response to chemotherapy. We also evaluated CD117 expression in a series of 46 surgically resected non-small cell lung carcinomas (8 squamous cell carcinomas, 10 adenocarcinomas, 5 pleomorphic carcinomas, 10 typical and 3 atypical carcinoids, and 10 large cell neuroendocrine carcinomas). Apart from small cell carcinomas, CD117 overexpression was observed in 6 of 10 large cell neuroendocrine carcinomas, whereas all the other histotypes resulted unstained. We speculate that loss of CD117 expression after chemotherapy in a high proportion of SCLC indicates that in this tumor, Kit unlikely represents the product of a constitutive mutation, as instead shown in gastrointestinal stromal tumors. Keeping this finding in mind, oncologists could re-test CD117 expression in relapsing small cell lung carcinomas in order to establish the best candidates for enrollment in ongoing clinical trials with Kit inhibitors. Practically speaking, CD117 may be helpful in discriminating between pulmonary high-grade neuroendocrine tumors and other histotypes, but pathologists should be aware that treated small cell lung carcinomas may remain unstained in a not insignificant number of cases.

A Single Institution-Based Retrospective Study of Surgically Treated Bronchioloalveolar Adenocarcinoma of the Lung: Clinicopathologic Analysis, Molecular Features, and Possible Pitfalls in Routine Practice

Introduction: Prognostic evaluation of bronchioloalveolar carcinoma (BAC) from a homogenous population of Caucasian patients. Methods: Retrospective analysis of resected BAC reclassified according to the 2004 World Health Organization classification of lung tumors. Analyzed variables are clinicoradiologic presentation, histologic subtypes, stage, epidermal growth factor receptor (EGFR) and HER2/neu immunohistochemical expression, EGFR exons 18, 19, and 21 mutations, K-RAS exon 2 mutation. Univariate and multivariate analyses of survival were performed. Results: Of 40 patients analyzed, EGFR and HER2/neu expression were detected in 72% and 20%, respectively. HER2/neu expression significantly characterized mucinous BAC (46% versus 7%; p = 0.014). EGFR mutations were identified in 17% (30% in nonmucinous BAC and none in mucinous BAC; p = 0.083). K-RAS mutations were found in 42.5% (92% in mucinous BAC versus 18% in other types; p < 0.0001). Early stages (IA+IB) nonmucinous BAC had excellent prognosis: 5 years overall survival of 91% (100% for stage IA). Sixty six percent (4 of 6) of patients with multifocal disease died (two mucinous BAC and one nonmucinous BAC with recurrent disease). Seventy one percent (5 of 7) of patients with pneumonic-like tumor (all mucinous BAC) died of recurrent/progressive disease. Stage (p = 0.004) and histologic classifications (p = 0.035) resulted as independent prognostic factors at multivariate analysis. Conclusions: Early stage nonmucinous BAC has excellent prognosis, whereas mucinous BAC presents a poor prognosis. Locally advanced nonmucinous BAC has a poor prognosis: the diagnosis of nonmucinous BAC in large tumors should be interpreted with caution given the possible presence of invasive areas in incompletely sampled tumor. Coexpression of EGFR and HER2/neu in mucinous BAC could be considered for future trials on target therapies even in Caucasian population.

A subset of lung adenocarcinomas and atypical adenomatous hyperplasia-associated foci are genotypically related: an EGFR, HER2, and K-ras mutational analysis.

Atypical adenomatous hyperplasia (AAH) is considered the preinvasive lesion of pulmonary adenocarcinoma, and mutations of EGFR, HER2, and K-ras are involved in the early stage of lung adenocarcinoma carcinogenesis, also predicting clinical response to anti-EGFR small molecule inhibitors. We analyzed 18 cases of primary lung adenocarcinoma with concomitant AAH foci from 13 patients for mutations of EGFR (exons 18-21), HER2 (exons 19-20), and K-ras (exon 2) by direct sequencing polymerase chain reaction. Among mutated cases, concordant mutations of EGFR or K-ras in adenocarcinoma and related AAH were observed in 5 (63%) of 8 cases. In particular, 3 of 4 adenocarcinomas with EGFR mutations (all L858R point mutations in women, never or former smokers) had a concomitant and identical mutation in AAH, and 2 of 4 adenocarcinomas with K-ras mutations (both at codon 12 in women, a never and a current smoker) showed the same mutation in concomitant AAH. All cases were wild-type for HER2. Mutations of EGFR and K-ras genes represent an early event in lung adenocarcinomagenesis, and AAH convincingly seems to be a precursor lesion in a subset of cases of adenocarcinoma.

Endobronchial metastasis: An epidemiologic and clinicopathologic study of 174 consecutive cases

PURPOSE Endobronchial metastases from extrapulmonary solid tumors are a rare event and currently available epidemiological and clinico-pathological data mainly derive from anecdotal case reports. METHODS A series of 174 consecutive cases of endobronchial metastases from extrathoracic solid tumors were collected over a period of 18 years. Immunohistochemistry was performed in 115 cases. Complete imaging features were available in 81 patients, and analysis of the latency period between primitive tumor diagnosis and occurrence of endobronchial metastasis was obtained. RESULTS Among all bronchoscopic examinations performed in the same period for malignancy, a mean of 5.6 cases per year consisted of endobronchial metastases (range 2-17 cases), with a statistically significant increase when comparing the periods 1992-2000 (65 cases, 37%) and 2001-2009 (109 cases, 63%) (p = 0.05). Overall, 4% of endobronchial biopsies for suspected malignancy disclosed an endobronchial metastasis from extrapulmonary tumor. Breast (52 cases, 30%), colorectal (42 cases, 24%), renal (14%), gastric (6%) and prostate (4.5%) cancers and melanoma (4.5%) were the most common metastatic neoplasms presenting as endobronchial mass. One-hundred fifty-four cases were identified after the primitive tumor diagnosis (metachronous cases, 89%), 11 cases were simultaneously evidenced in extrapulmonary and endobronchial sites (synchronous cases, 6%), while 9 occult metastatic cases (5%) first presented as endobronchial mass (anachronous cases). Overall, mean latency from extrapulmonary tumor diagnosis and endobronchial metastasis was 136 months (range, 1-300 months). The most frequent symptoms were dyspnea (23%), cough (15%) and haemoptysis (12%), while 26% of patients were totally asymptomatic. At radiology, 53% presented as multiple pulmonary nodules, while other cases presented as hilar and mediastinal mass, single peripheral nodule, atelectasis or pleural effusion. CONCLUSIONS Endobronchial metastases from extrapulmonary tumors account for about 4% of all bronchoscopic biopsies performed for suspected malignancy and in 5% of the cases the metastasis is the first manifestation of the neoplasm.