Pathologic Grading of Malignant Pleural Mesothelioma: An Evidence-Based Proposal

INTRODUCTION

A pathologic grading system (PGS) for malignant pleural mesothelioma (MPM) is warranted to better identify different risk categories of patients, plan therapeutic options, and activate clinical trials.

METHODS

A series of 940 patients with MPM (328 in a training set and 612 in a validation set) that was diagnosed between October 1980 and June 2015 at the participant institutions was retrospectively assembled. A PGS was constructed by attributing to each histologic parameter, independent at multivariate analysis with excellent reproducibility (κ > 0.75), different scores based on the increase in corresponding hazard ratios. The relevant PGS score thus ranged from 0 to 8 points for individual patients with MPM.

CONCLUSIONS

The PGS was constructed by taking into consideration the histological subtyping of MPM (epithelioid/biphasic = 0 points; sarcomatoid = 2 points), necrosis (absent = 0 points versus present = 1 point), mitotic count per 1 mm² (cutoffs as follows: 1-2 = 0 points, 3-5 = 1 point, 6-9 = 2 points, or ≥10 = 4 points), and Ki-67 labeling index based on 2000 cells (<30% = 0 points versus ≥30 = 1 point), all of which are independent factors in both patient sets after adjustment for stage and age at diagnosis. No heterogeneity was seen across the validation centers (p = 0.19). Epithelioid/biphasic MPM patterning and biopsy versus resection did not affect survival, whereas the PGS outperformed mitotic count and Ki-67 LI in both the training (area under the curve receiver operating characteristic = 0.76) and validation sets (area under the curve receiver operating characteristic = 0.73) (p < 0.01). Patient survival progressively deteriorated from a score of 0 (median times of 26.3 and 26.9 months) to a score 1 to 3 (median times of 12.8 and 14.4 months) and a score of 4 to 8 (median times of 3.7 and 7.7 months) in both sets of patients, with the hazard ratio for a 1-point increase in score being 1.46 (95% confidence interval: 1.36-1.56) in the training set and 1.28 (95% confidence interval: 1.22-1.34) in the validation set (after adjustment for age and [when available] tumor stage). The PGS was effective even in subgroup analysis (epithelioid, biphasic, and sarcomatoid tumors).

DISCUSSION

A simple and reproducible multiparametric PGS effectively predicted survival in patients with MPM.

Abstract 121: Angiogenin and the mmp9-timp2 axis are strongly upregulated in pro-angigoenic dnk-like cells isolated from colorectal cancer patients

Natural Killer (NK) cells are effector lymphocytes involved in tumor immunosurveillance. In solid malignancies, tumor associated (TANK; peripheral blood) and tumor infiltrating (TINK) NK cells have compromised functions. We functionally and molecularly characterize TINK and TANKs from blood and tissue samples of colorectal cancer (CRC) patients, a tumor type where inflammation and angiogenesis have clinical relevance, compared to NK isolated from control and non-oncologic inflammatory bowel disease patients.

NK subset distribution and cytokine profiling were performed by multicolor flow cytometry, using peripheral blood and tissue samples from CRC patients, for surface antigen and cytokine profiling characterization. Conditioned media (CM) from FACS-sorted NKs were used either for secretomic profiling using antibody membrane arrays or in functional in vitro angiogenesis assays.

CRC TINKs/TANKs showed decreased activation marker NKG2D, impaired degranulation activity, a decidual-like NK polarization toward the CD56brightCD16dim/- CD9+CD49+ subset. TINKs and TANKs supernatants induced endothelial cell proliferation, migration, adhesion and formation of capillary-like structures in vitro. It has been reported that dNK release proangiogenic factors and metastasis-associated (MMP-9, TIMP1-2) proteins.

We describe for the first time the expression of angiogenin and MMP2, MMP9, TIMP1 and TIMP2 by CRC derived NK cells. This could be a phenotype relevant to their invasive capabilities and pro-angiogenic function. STAT-3/STAT-5 activation was observed in TANKs, and inhibition of the STAT5 pathway by pimozide, an antipsychotic drug, reduced proangiogenic factor VEGF and angiogenin production and capillary-like structure formation, but did not affect the levels of TIMP-1, TIMP-2 and MMP-9.

Citation Format: Antonino Bruno, Giuseppe Pelosi, Luigi Boni, Lorenzo Dominioni, Lorenzo Mortara, Douglas Noonan, Adriana Albini. Angiogenin and the mmp9-timp2 axis are strongly upregulated in pro-angigoenic dnk-like cells isolated from colorectal cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 121.

PD-L1 Immunohistochemistry Comparability Study in Real-Life Clinical Samples: Results of Blueprint Phase 2 Project

OBJECTIVES

The Blueprint (BP) Programmed Death Ligand 1 (PD-L1) Immunohistochemistry Comparability Project is a pivotal academic/professional society and industrial collaboration to assess the feasibility of harmonizing the clinical use of five independently developed commercial PD-L1 immunohistochemistry assays. The goal of BP phase 2 (BP2) was to validate the results obtained in BP phase 1 by using real-world clinical lung cancer samples.

METHODS

BP2 were conducted using 81 lung cancer specimens of various histological and sample types, stained with all five trial-validated PD-L1 assays (22C3, 28-8, SP142, SP263, and 73-10); the slides were evaluated by an international panel of pathologists. BP2 also assessed the reliability of PD-L1 scoring by using digital images, and samples prepared for cytological examination. PD-L1 expression was assessed for percentage (tumor proportional score) of tumor cell (TC) and immune cell areas showing PD-L1 staining, with TCs scored continuously or categorically with the cutoffs used in checkpoint inhibitor trials.

RESULTS

The BP2 results showed highly comparable staining by the 22C3, 28-8 and SP263 assays; less sensitivity with the SP142 assay; and higher sensitivity with the 73-10 assay to detect PD-L1 expression on TCs. Glass slide and digital image scorings were highly concordant (Pearson correlation >0.96). There was very strong reliability among pathologists in TC PD-L1 scoring with all assays (overall intraclass correlation coefficient [ICC] = 0.86-0.93), poor reliability in IC PD-L1 scoring (overall ICC = 0.18-0.19), and good agreement in assessing PD-L1 status on cytological cell block materials (ICC = 0.78-0.85).

CONCLUSION

BP2 consolidates the analytical evidence for interchangeability of the 22C3, 28-8, and SP263 assays and lower sensitivity of the SP142 assay for determining tumor proportion score on TCs and demonstrates greater sensitivity of the 73-10 assay compared with that of the other assays.

Angiogenin and the MMP9-TIMP2 axis are up-regulated in proangiogenic, decidual NK-like cells from patients with colorectal cancer

NK cells are effector lymphocytes involved in tumor immunosurveillance; however, in patients with solid malignancies, NK cells have compromised functions. We have previously reported that lung tumor-associated NK cells (TANKs; peripheral blood) and tumor-infiltrating NK cells (TINKs) show proangiogenic, decidual NK-like (dNK) phenotype. In this study, we functionally and molecularly investigated TINKs and TANKs from blood and tissue samples of patients with colorectal cancer (CRC), a neoplasm in which inflammation and angiogenesis have clinical relevance, and compared them to NK cells from controls and patients with nononcologic inflammatory bowel disease. CRC TINKs/TANKs showed decreased expression for the activatory marker NKG2D, impaired degranulation activity, a decidual-like NK polarization toward the CD56^brightCD16^dim/-CD9⁺CD49⁺ subset. TINKs and TANKs secreted cytokines with proangiogenic activities, and induce endothelial cell proliferation, migration, adhesion, and the formation of capillary-like structures in vitro. dNK cells release specific proangiogenic factors; among which, angiogenin and invasion-associated enzymes related to the MMP9-TIMP1/2 axis. Here, we describe, for the first time, to our knowledge, the expression of angiogenin, MMP2/9, and TIMP by TANKs in patients with CRC. This phenotype could be relevant to the invasive capabilities and proangiogenic functions of CRC-NK cells and become a novel biomarker. STAT3/STAT5 activation was observed in CRC-TANKs, and treatment with pimozide, a STAT5 inhibitor, reduced endothelial cell capability to form capillary-like networks, inhibiting VEGF and angiogenin production without affecting the levels of TIMP1, TIMP2, and MMP9, indicating that STAT5 is involved in cytokine modulation but not invasion-associated molecules. Combination of Stat5 or MMP inhibitors with immunotherapy could help repolarize CRC TINKs and TANKs to anti-tumor antimetastatic ones.-Bruno, A., Bassani, B., D'Urso, D. G., Pitaku, I., Cassinotti, E., Pelosi, G., Boni, L., Dominioni, L., Noonan, D. M., Mortara, L., Albini, A. Angiogenin and the MMP9-TIMP2 axis are up-regulated in proangiogenic, decidual NK-like cells from patients with colorectal cancer.

High-dose Chemotherapy in Small Cell Lung Cancer

Improvements in small cell lung cancer (SCLC) therapy with conventional doses of drugs with or without radiotherapy have been poor, and the 5-year survival is discouraging. Since SCLC is highly sensitive to radiotherapy and chemotherapy, some studies have tried to improve survival by increasing the dose of the drugs. Within conventional ranges, dose intensity can be increased with the support of hematopoietic growth factors (G/GM-CSF) and/or shortening treatment intervals (eg weekly regimens). However, dose intensity could be increased by only 20-30% and a survival advantage was not definitively obtained. Given its high chemosensitivity already two decades ago, SCLC was one of the first malignancies deemed suitable for maximizing dose and dose intensity with the support of autologous bone marrow transplantation (ABMT). On the whole, results were disappointing and the procedure was nearly abandoned. Nowadays, some interest is emerging again due to the improvements in supportive care such as the availability of hematopoietic growth factors and the peripheral blood progenitor cells (PBPC).

Thermal Balance and Dialysis Hypotension

Many Studies Have Confirmed Our Original Observation That Dialysate T Set At About 35° C Affords A Better Hemodynamic Protection Than The Standard Dialysate T Of 37-38° C. In This Review We Present Some New Data On The Hemodynamic Mechanism Of The Protective Effect Of Cold Dialysis On Blood Pressure. The Study Was Based On Serial Assessment Of The Percent Changes Occurring During Dialysis Treatment In Estimated Stroke Volume (Aortic Blood Flow Determined By Doppler Echocardiography), Blood Volume (Hemoglobinometry), Arterial Pressure (Dynamap), And Heart Rate (Ecg), From Which Cardiac Output (Co) Indexes And Total Peripheral Vascular Resistances (Tpvr) Were Derived. Of The 14 Pts Studied, 7 Showed A Drop In Mean Arterial Pressure (Map) Of 25° Or Greater During Standard Dialysis (Unstable Patients). Compared With The 7 Patients Having More Stable Intradialysis Map, Unstable Pts Showed Greater Reduction In Co Which Was Disproportionately Greater Than The Reduction In Blood Volume, And A Paradoxical Decrease In Tpvr, The Difference Being Highly Significant (P ≤ 0.01 For Both Changes). When Crossed-Over To Cold Dialysis, Along With A Significantly Lower Reduction In Map (P ≤ 0.01) The Unstable Pts Showed A Lower Decrease In Co Which Paralleled The Reduction In Blood Volume, And An Increase In Tpvr. These Changes Were Highly Significant (P ≤ 0.01). Data Suggest That Dialysis Hypotension Is Characterized By An Impaired Venous Return, Probably Due To The Peripheral Blood Pooling (Increased Ratio Between The ‘Unstressed’ And ‘Stressed’ Blood Volume) Associated With The Decrease In Tpvr. Exposure Of Extracorporeal Blood To Cold Dialysate Favours The Venous Return To The Heart By Increasing Tpvr And The ‘Stressed’ Blood Volume.

Author Correction: Establishment of patient derived xenografts as functional testing of lung cancer aggressiveness

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

5'-nucleotidase cN-II emerges as a new predictive biomarker of response to gemcitabine/platinum combination chemotherapy in non-small cell lung cancer

A number of pharmacogenetic studies have been carried out in non-small-cell lung cancer (NSCLC) to identify and characterize genes involved in chemotherapy activity. However, the results obtained so far are controversial and no reliable biomarker is currently used to predict clinical benefit from platinum-based chemotherapy, which represents the cornerstone of treatment of advanced NSCLC. This study investigated the expression levels of ERCC1 and of six genes (RRM1, RRM2, hENT1, dCK, cN-II and CDA) involved in gemcitabine metabolism in locally/advanced NSCLC patients treated with gemcitabine/platinum combination. Gene expression was assessed by quantitative-PCR in laser-microdissected specimens and correlated with tumor response. Frequency distribution of responses above and below the median expression level of biomarkers was compared using a two-sided Fisher’s test. 5′-nucleotidase (cN-II) was the only gene differently expressed (p = 0.016) in the responders (complete/partial-response) compared to non-responders (stable/progressive disease). In the multivariate analysis, overexpression of this catabolic enzyme of gemcitabine remained a significant negative predictive factor. Patients with low cN-II had a modest trend toward increased survival, while both survival and progression-free survival were significantly longer in a more homogenous validation cohort of 40 advanced NSCLC (8.0 vs. 5.1 months, p = 0.026). Moreover, in vitro studies showed that silencing or pharmacological inhibition of cN-II increased the cytotoxicity of gemcitabine. This is the first study demonstrating the role of cN-II as a predictor of response to gemcitabine/platinum combinations in NSCLC. Its validation in prospective studies may improve clinical outcome of selected patients.

Pulmonary Resections: Cytostructural Effects of Different-Wavelength Lasers versus Electrocautery

Aims and Background

There are few papers on the cytostructural effects of surgical instruments used during pulmonary resections. The aim of the present study was to evaluate the parenchymal damage caused by different surgical instruments: a new generation electrosurgical scalpel and two different-wavelength lasers.

Methods

Six surgical procedures of pulmonary resection for nodules were performed using a new generation electrosurgical scalpel, a 1318 nm neodymium (Nd:YAG) laser or a 2010 nm thulium laser (two procedures for each instrument). Specimens were analyzed using optical microscopy and scansion electronic microscopy.

Results

Severe cytostructural damage was found to be present in an average of 1.25 mm in depth from the cutting surface in the patients treated using electrosurgical cautery. The depth of this zone dropped to less than 1 mm in patients treated by laser, being as small as 0.2 mm using the laser with a 2010 nm-wavelength and 0.6 mm with the 1318 nm-wavelength laser.

Discussion

These preliminary findings support the use of laser to perform conservative pulmonary resections (i.e., metastasectomies), since it is more likely to avoid damage to surrounding structures. Controlled randomized trials are needed to support the clinical usefulness and feasibility of new types of lasers for pulmonary resections.

Serum Steroid Ratio Profiles in Prostate Cancer: A New Diagnostic Tool Toward a Personalized Medicine Approach

BACKGROUND

Serum steroids are crucial molecules altered in prostate cancer (PCa). Mass spectrometry (MS) is currently the elected technology for the analysis of steroids in diverse biological samples. Steroids have complex biological pathways and stoichiometry and it is important to evaluate their quantitative ratio. MS applications to patient hormone profiling could lead to a diagnostic approach.

METHODS

Here, we employed the Surface Activated Chemical Ionization-Electrospray-NIST (SANIST) developed in our laboratories, to obtain quantitative serum steroid ratio relationship profiles with a machine learning Bayesian model to discriminate patients with PCa. The approach is focused on steroid relationship profiles and disease association.

RESULTS

A pilot study on patients affected by PCa, benign prostate hypertrophy (BPH), and control subjects [prostate-specific antigen (PSA) lower than 2.5 ng/mL] was done in order to investigate the classification performance of the SANIST platform. The steroid profiles of 71 serum samples (31 controls, 20 patients with PCa and 20 subjects with benign prostate hyperplasia) were evaluated. The levels of 10 steroids were quantitated on the SANIST platform: Aldosterone, Corticosterone, Cortisol, 11-deoxycortisol, Androstenedione, Testosterone, dehydroepiandrosterone, dehydroepiandrosterone sulfate (DHEAS), 17-OH-Progesterone and Progesterone. We performed both traditional and a machine learning analysis.

CONCLUSION

We show that the machine learning approach based on the steroid relationships developed here was much more accurate than the PSA, DHEAS, and direct absolute value match method in separating the PCa, BPH and control subjects, increasing the sensitivity to 90% and specificity to 84%. This technology, if applied in the future to a larger number of samples will be able to detect the individual enzymatic disequilibrium associated with the steroid ratio and correlate it with the disease. This learning machine approach could be valid in a personalized medicine setting.

Interobserver Variation among Pathologists and Refinement of Criteria in Distinguishing Separate Primary Tumors from Intrapulmonary Metastases in Lung

Multiple tumor nodules are seen with increasing frequency in clinical practice. On the basis of the 2015 WHO classification of lung tumors, we assessed the reproducibility of the comprehensive histologic assessment to distinguish second primary lung cancers (SPLCs) from intrapulmonary metastases (IPMs), looking for the most distinctive histologic features. An international panel of lung pathologists reviewed a scanned sequential cohort of 126 tumors from 48 patients and recorded an agreed set of histologic features, including tumor typing and predominant pattern of adenocarcinoma, thereby opining whether the case was SPLC, IPM, or a combination thereof. Cohen κ statistics of 0.60 on overall assessment of SPLC or IPM indicated a good agreement. Likewise, there was good agreement (κ score 0.64, p < 0.0001) between WHO histologic pattern in individual cases and SPLC or IPM status, but the proportions diversified for histologic pattern and SPLC or IPM status (McNemar test, p < 0.0001). The strongest associations for distinguishing between SPLC and IPM were observed for nuclear pleomorphism, cell size, acinus formation, nucleolar size, mitotic rate, nuclear inclusions, intraalveolar clusters, and necrosis. Conversely, the associations for lymphocytosis, mucin content, lepidic growth, vascular invasion, macrophage response, clear cell change, acute inflammation keratinization, and emperipolesis did not reach significance with tumor extent. Comprehensive histologic assessment is recommended for distinguishing SPLC from IPM with good reproducibility among lung pathologists. In addition to main histologic type and predominant patterns of histologic subtypes, nuclear pleomorphism, cell size, acinus formation, nucleolar size, and mitotic rate strongly correlate with pathologic staging status.

The role of multimodal treatment in patients with advanced lung neuroendocrine tumors

Lung neuroendocrine tumors (NETs) comprise typical (TC) and atypical carcinoids (AC). They represent the well differentiated (WD) or low/intermediate grade forms of lung neuroendocrine neoplasms (NENs). Unlike the lung poorly differentiated NENs, that are usually treated with chemotherapy, lung NETs can be managed with several different therapies, making a multidisciplinary interaction a key point. We critically discussed the multimodal clinical management of patients with advanced lung NETs. Provided that no therapeutic algorithm has been validate so far, each clinical case should be discussed within a NEN-dedicated multidisciplinary team. Among the systemic therapies available for metastatic lung NETs everolimus is the only approved drug, on the basis of the results of the phase III RADIANT-4 trial. Another phase III trial, the SPINET, is ongoing comparing lanreotide with placebo. Peptide receptor radionuclide therapy and chemotherapy were not studied within phase III trials for lung NETs, and they have been reported to be active within retrospective or phase II prospective studies. Temozolomide and oxaliplatin are two interesting chemotherapeutic agents in lung NETs. While some European Institutions were certificated as Centers of Excellence for gastroenteropancreatic NENs by the European Neuroendocrine Tumor Society (ENETS), an equivalent ENETS certification for lung NENs does not exist yet. Ideally a lung NEN-dedicated multidisciplinary tumor board should include NEN-dedicated medical oncologists, thoracic medical oncologist, thoracic surgeons, pathologists, interventional radiologists, endocrinologists, radiotherapists, interventional pneumologists, nuclear physician.

Classification of pulmonary neuroendocrine tumors: new insights

Neuroendocrine tumors of the lung (Lu-NETs) embrace a heterogeneous family of neoplasms classified into four histological variants, namely typical carcinoid (TC), atypical carcinoid (AC), large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC). Defining criteria on resection specimens include mitotic count in 2 mm2 and the presence or absence of necrosis, alongside a constellation of cytological and histological traits including cell size and shape, nuclear features and overall architecture. Clinically, TC are low-grade malignant tumors, AC intermediate-grade malignant tumors and SCLC/LCNEC high-grade malignant full-blown carcinomas with no significant differences in survival between them. Homologous tumors arise in the thymus that occasionally have some difficulties in differentiating from the lung counterparts when presented with large unresectable or metastatic lesions. Immunohistochemistry (IHC) helps refine NE diagnosis at various anatomical sites, particularly on small-sized tissue material, in which only TC and small cell carcinoma categories can be recognized easily on hematoxylin & eosin stain, while AC and LCNEC can only be suggested on such material. The Ki-67 labeling index effectively separates carcinoids from small cell carcinoma and may prove useful for the clinical management of a metastatic disease to help the therapeutic decision-making process. Although carcinoids and high-grade neuroendocrine carcinomas in the lung and elsewhere make up separate tumor categories on molecular grounds, emerging data supports the concept of secondary high-grade NETs arising in the preexisting carcinoids, whose clinical and biological relevance will have to be placed into the proper context for the optimal management of these patients. In this review, we will discuss the selected, recent literature with a focus on current issues regarding Lu-NET nosology, i.e., classification, derivation and tumor evolution.

Increased frequency of bronchiolar histotypes in lung carcinomas associated with idiopathic pulmonary fibrosis

AIMS

The association between lung cancer and idiopathic pulmonary fibrosis (IPF) is well known, but the significance of this association is poorly understood. Bronchiolar honeycomb cysts have been proposed as possible precursors for the development of carcinoma, but limited evidence in support of this hypothesis is available. The aim of this study was to investigate this hypothesis analysing a series of carcinomas arising in IPF by immunohistochemistry.

METHODS AND RESULTS

Thirty-three lung carcinomas arising in patients with IPF were analysed with a panel of immunohistochemical markers. The antibodies included those against pneumocyte markers [thyroid transcription factor 1 (TTF1), napsin-A, and surfactant protein A], the goblet cell marker mucin 5AC, markers of basal/squamous cell differentiation [cytokeratin (CK) 5/6 and ΔN-p63], and markers related to enteric differentiation (CDX2, mucin 2, CK20, and villin). A series of 100 consecutive lung adenocarcinomas arising in smokers without IPF were investigated as controls. All carcinomas arising in IPF patients were peripherally located on imaging analysis. The diagnoses were: eight squamous cell carcinomas, 20 adenocarcinomas, three small-cell carcinomas (including one composite small-cell carcinoma and adenocarcinoma), and two large-cell carcinomas. Among adenocarcinomas, a 'pneumocyte' profile (TTF1/napsin-A/SPA1-triple-positive) was observed in seven of 20 (35% versus 84% in non-IPF controls, P = 0.0001). The remaining 13 adenocarcinomas (65%) showed rare histotypes: four invasive mucinous adenocarcinomas (20% in IPF patients versus 1% in non-IPF controls, P = 0.002), seven tumours (35%) that were characterized by variable expression of markers of enteric differentiation, and two tumours (10%) that showed a peculiar basaloid component.

CONCLUSIONS

The immunohistochemical characterization of carcinomas arising in IPF patients shows striking divergence from that in non-IPF smokers. The prevalence of rare entities showing bronchiole-related markers is in line with the hypothesis that these tumours arise from transformed small airways in honeycomb lung areas where abnormal bronchiolar proliferation takes place.

Establishment of patient derived xenografts as functional testing of lung cancer aggressiveness

Despite many years of research efforts, lung cancer still remains the leading cause of cancer deaths worldwide. Objective of this study was to set up a platform of non-small cell lung cancer patient derived xenografts (PDXs) faithfully representing primary tumour characteristics and offering a unique tool for studying effectiveness of therapies at a preclinical level. We established 38 PDXs with a successful take rate of 39.2%. All models closely mirrored parental tumour characteristics although a selective pressure for solid patterns, vimentin expression and EMT was observed in several models. An increased grafting rate for tumours derived from patients with worse outcome (p = 0.006), higher stage (p = 0.038) and higher CD133⁺/CXCR4⁺/EpCAM⁻ stem cell content (p = 0.019) was observed whereas a trend towards an association with SUV_max higher than 8 (p = 0.084) was detected. Kaplan Meier analyses showed a significantly worse (p = 0.0008) overall survival at 5 years in patients with grafted vs not grafted PDXs also after adjusting for tumour stage. Moreover, for 63.2% models, grafting was reached before clinical recurrence occurred. Our findings strengthen the relevance of PDXs as useful preclinical models closely reflecting parental patients tumours and highlight PDXs establishment as a functional testing of lung cancer aggressiveness and personalized therapies.

Distinctive pathological and clinical features of lung carcinoids with high proliferation index

Typical (TCs) and atypical carcinoids (ACs) are defined based on morphological criteria, and no grading system is currently accepted to further stratify these entities. The 2015 WHO classification restricts the Ki-67 role to biopsy or cytology samples, rather than for prognostic prediction. We aimed to investigate whether values and patterns of Ki-67 alone would allow for a clinically meaningful stratification of lung carcinoids, regardless of histological typing. Ki-67 proliferation index and pattern (homogeneous versus heterogeneous expression) were assessed in a cohort of 171 TCs and 68 ACs. Cases were subdivided into three Ki-67 ranges (<4/4–9/≥10%). Correlations with clinicopathological data, univariate and multivariate survival analyses were performed. The majority of cases (61.5%) belonged to the <4% Ki-67 range; 25.1 and 13.4% had a proliferation index of 4–9% and ≥10%, respectively. The <4% Ki-67 subgroup was significantly enriched for TCs (83%, p < 0.0001); ACs were more frequent in the subgroup showing Ki-67 ≥ 10% (75%, p < 0.0001). A heterogeneous Ki-67 pattern was preferentially seen in carcinoids with a Ki-67 ≥10% (38%, p < 0.02). Mean Ki-67 values ≥4 and ≥10% identified categories of poor prognosis both in terms of disease-free and overall survival (p = 0.003 and <0.0001). At multivariate analysis, the two thresholds did not retain statistical significance; however, a Ki-67 ≥ 10% identified a subgroup of dismal prognosis even within ACs (p = 0.03) at univariate analysis. Here, we describe a subgroup of lung carcinoids showing brisk proliferation activity within the necrosis and/or mitotic count-based categories. These patients were associated with specific clinicopathological characteristics, to some extent regardless of histological subtyping.

Alpha-fetoprotein elevation in NUT midline carcinoma: a case report

Background

Nuclear protein in testis (NUT) midline carcinoma is a rarely diagnosed and potentially under-recognized type of squamous carcinoma that is considered one of the most aggressive human solid tumors. Alpha-fetoprotein elevation has been associated with chronic liver diseases and a limited number of cancers. In particular, in presence of a mediastinal mass in a young man, alpha-fetoprotein elevation is considered nearly pathognomonic of a non-seminoma germ-cell tumor.

Case presentation

A 22-year old man without any comorbidity was diagnosed with a large mediastinal mass with skeletal and lymph node metastases. The clinical picture was dominated by a life-threatening superior vena cava syndrome with elevated alpha-fetoprotein and lactate dehydrogenase that supported the diagnostic suspicion of mediastinal germ-cell tumor. However, a biopsy showed a poorly-differentiated and diffusely necrotic carcinoma. We eventually reached the diagnosis of the peculiar entity of NUT midline carcinoma, but the differential diagnosis was quite challenging also because alpha-fetoprotein is not reported as a marker of NUT midline carcinoma. Notably, alpha-fetoprotein levels correlated with disease course.

Conclusions

The life-threatening aggressiveness of NUT midline carcinoma mandates to reach the right diagnosis in the shortest possible time. In this regard, poorly differentiated carcinomas lacking glandular differentiation mandate testing for NUT expression by immunohistochemistry. Awareness of a potentially misleading tumor marker elevation can help to broaden the differential diagnosis and establish the most appropriate treatment.

Pulmonary adenocarcinoma with mucin production modulates phenotype according to common genetic traits: a reappraisal of mucinous adenocarcinoma and colloid adenocarcinoma

Whether invasive mucinous adenocarcinoma (IMA) and colloid adenocarcinoma (ICA) of the lung represent separate tumour entities, or simply lie within a spectrum of phenotypic variability, is worth investigating. Fifteen ICA, 12 IMA, 9 ALK‐rearranged adenocarcinomas (ALKA), 8 non‐mucinous KRAS‐mutated adenocarcinomas (KRASA) and 9 mucinous breast adenocarcinomas (MBA) were assessed by immunohistochemistry for alveolar (TTF1, cytoplasmic MUC1), intestinal (CDX‐2, MUC2), gastric (membrane MUC1, MUC6), bronchial (MUC5AC), mesenchymal (vimentin), neuroendocrine (chromogranin A, synaptophysin), sex steroid hormone‐related (oestrogen and progesterone receptors), pan‐mucinous (HNF4A) and pan‐epithelial (keratin 7) lineage biomarkers and by targeted next generation sequencing (TNGS) for 50 recurrently altered cancer genes. Unsupervised clustering analysis using molecular features identified cluster 1 (IMA and ICA), cluster 2 (ALKA and KRASA) and cluster 3 (MBA) (p < 0.0001). Cluster 1 showed four histology‐independent sub‐clusters (S1 to S4) pooled by HFN4A and MUC5AC but diversely reacting for TTF1, MUC1, MUC2, MUC6 and CDX2. Sub‐cluster S1 predominantly featured intestinal‐alveolar, S2 gastrointestinal, S3 gastric and S4 alveolar differentiation. In turn, KRASA and ALKA shared alveolar lineage alongside residual MUC5AC expression, with additional focal CDX2 and diffuse vimentin, respectively. A proximal‐to‐distal scheme extending from terminal (TB) and respiratory (RB) bronchioles to alveolar cells was devised, where S3 originated from distal TB (cellular mucinous adenocarcinoma), S2 from proximal RB (secreting mucinous adenocarcinoma), S1 from intermediate RB (mucin lake‐forming colloid adenocarcinoma), S4 from distal RB (colloid alveolar adenocarcinoma), KRASA from juxta‐alveolar RB (KRAS‐mutated non‐mucinous adenocarcinoma) and ALKA from juxta‐bronchial alveolar cells (ALK‐translocated adenocarcinoma). TNGS analysis showed KRAS, LKB1, TP53, APC and CDKN2A mutation predominance. In conclusion, IMA and ICA are basket categories, which likely originate from distinct domains of stem/progenitor cells spatially distributed along bronchioles upon common molecular features and genetic alterations.

Lung neuroendocrine tumours: deep sequencing of the four World Health Organization histotypes reveals chromatin-remodelling genes as major players and a prognostic role for TERT, RB1, MEN1 and KMT2D

Next-generation sequencing (NGS) was applied to 148 lung neuroendocrine tumours (LNETs) comprising the four World Health Organization classification categories: 53 typical carcinoid (TCs), 35 atypical carcinoid (ACs), 27 large-cell neuroendocrine carcinomas, and 33 small-cell lung carcinomas. A discovery screen was conducted on 46 samples by the use of whole-exome sequencing and high-coverage targeted sequencing of 418 genes. Eighty-eight recurrently mutated genes from both the discovery screen and current literature were verified in the 46 cases of the discovery screen, and validated on additional 102 LNETs by targeted NGS; their prevalence was then evaluated on the whole series. Thirteen of these 88 genes were also evaluated for copy number alterations (CNAs). Carcinoids and carcinomas shared most of the altered genes but with different prevalence rates. When mutations and copy number changes were combined, MEN1 alterations were almost exclusive to carcinoids, whereas alterations of TP53 and RB1 cell cycle regulation genes and PI3K/AKT/mTOR pathway genes were significantly enriched in carcinomas. Conversely, mutations in chromatin-remodelling genes, including those encoding histone modifiers and members of SWI-SNF complexes, were found at similar rates in carcinoids (45.5%) and carcinomas (55.0%), suggesting a major role in LNET pathogenesis. One AC and one TC showed a hypermutated profile associated with a POLQ damaging mutation. There were fewer CNAs in carcinoids than in carcinomas; however ACs showed a hybrid pattern, whereby gains of TERT, SDHA, RICTOR, PIK3CA, MYCL and SRC were found at rates similar to those in carcinomas, whereas the MEN1 loss rate mirrored that of TCs. Multivariate survival analysis revealed RB1 mutation (p = 0.0005) and TERT copy gain (p = 0.016) as independent predictors of poorer prognosis. MEN1 mutation was associated with poor prognosis in AC (p = 0.0045), whereas KMT2D mutation correlated with longer survival in SCLC (p = 0.0022). In conclusion, molecular profiling may complement histology for better diagnostic definition and prognostic stratification of LNETs. © 2016 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.