Head-to-head: Should Ki67 proliferation index be included in the formal classification of pulmonary neuroendocrine neoplasms?

The reporting of lung neuroendocrine neoplasms (NENs) according to the 2021 World Health Organisation (WHO) is based on mitotic count per 2 mm2, necrosis assessment and a constellation of cytological and immunohistochemical details. Accordingly, typical carcinoid and atypical carcinoid are low- to intermediate-grade neuroendocrine tumours (NETs), while large-cell neuroendocrine carcinoma (NEC) and small-cell lung carcinoma are high-grade NECs. In small-sized diagnostic material (cytology and biopsy), the noncommittal term of carcinoid tumour/NET not otherwise specified (NOS) and metastatic carcinoid NOS have been introduced with regard to primary and metastatic diagnostic settings, respectively. Ki-67 antigen, a well-known marker of cell proliferation, has been included in the WHO classification as a non-essential but desirable criterion, especially to distinguish NETs from high-grade NECs and to delineate the provisional category of carcinoid tumours/NETs with elevated mitotic counts (> 10 mitoses per mm2) and/or Ki-67 proliferation index (≥ 30%). However, a wider use of this marker in the spectrum of lung NENs continues to be highly reported and debated, thus witnessing a never-subsided attention. Therefore, the arguments for and against incorporating Ki-67 in the classification and clinical practice of these neoplasms are discussed herein in detail.

An in-silico analysis reveals further evidence of an aggressive subset of lung carcinoids sharing molecular features of high-grade neuroendocrine neoplasms.

Little is known as to whether there may be any pathogenetic link between pulmonary carcinoids and neuroendocrine carcinomas (NECs). A gene signature we previously found to cluster pulmonary carcinoids, large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC), and which encompassed MEN1, MYC, MYCL1, RICTOR, RB1, SDHA, SRC and TP53 mutations or copy number variations (CNVs), was used to reclassify an independent cohort of 54 neuroendocrine neoplasms (NENs) [31 typical carcinoids (TC), 11 atypical carcinoids (AC) and 12 SCLC], by means of transcriptome and mutation data. Unsupervised clustering analysis identified two histology-independent clusters, namely CL1 and CL2, where 17/42 (40.5%) carcinoids and all the SCLC samples fell into the latter. CL2 carcinoids affected survival adversely, were enriched in T to G transversions or T > C/C > T transitions in the context of specific mutational signatures, presented with at least 1.5-fold change (FC) increase of gene mutations including TSC2, SMARCA2, SMARCA4, ERBB4 and PTPRZ1, differed for gene expression and showed epigenetic changes in charge of MYC and MTORC1 pathways, cellular senescence, inflammation, high-plasticity cell state and immune system exhaustion. Similar results were also found in two other independent validation sets comprising 101 lung NENs (24 carcinoids, 21 SCLC and 56 LCNEC) and 30 carcinoids, respectively. We herein confirmed an unexpected sharing of molecular traits along the spectrum of lung NENs, with a subset of genomically distinct aggressive carcinoids sharing molecular features of high-grade neuroendocrine neoplasms.

SMARCB1/INI1-deficient undifferentiated tumour of the thorax: a case report and review of the literature.

The 5th WHO classification of thoracic tumours includes thoracic SMARCA4-deficient undifferentiated tumour (SMARCA4-UT) among the "other epithelial tumours of the lung" chapter. Herein, we present a case of undifferentiated thoracic neoplasm with retention of SMARCA4 expression, lack of NUT fusion protein and loss of SMARCB1/INI1 expression. After presenting the clinical and pathological features of the tumour, we carried out a review of the literature on the same topic. Albeit very rare, we believe this entity should be included in the heterogeneous group of undifferentiated neoplasms of the thorax.

Biphenotypic lung carcinoma with coexpression of TTF-1 and ΔNP63/P40 within most of the same individual cells: a further case confirming poor prognosis and a review of literature.

The WHO Classification of Tumors, Thoracic Tumors, 5th edition, has outlined the use of TTF-1 and ΔNP63/P40 to discriminate between adenocarcinoma and squamous cell carcinoma. In 2015, the first description of a rare non-small cell lung carcinoma featuring co-expression of glandular and squamous differentiation within most of the same individual tumor cells was reported on, with ultrastructural and molecular demonstration of such a biphenotypic differentiation. We herein describe an additional case of this rare tumor entity, which is confirmed to be an aggressive neoplasm despite potential targets of therapy.

Metastatic mucinous ovarian carcinoma simulating lung primary: an integrated diagnostic lesson.

We herein document a rare instance of primary mucinous ovarian carcinoma metastatic to the left lung, whose deceptive secondary derivation was already envisaged according to the spectacular thromboembolism involving small pulmonary vessels, thereby realizing a centrifugal and centripetal metastatizing loop. This presentation was indicative of dismal prognosis. A multimodal biomarker key approach is herein emphasized, which included close clinico-pathologic data integration.

Improving Survival in Lymphangioleio-myomatosis: A 16-Year Observational Study in a Large Cohort of Patients.

BACKGROUND: Over the last 2 decades, great progress has been made in the understanding of the clinical aspects and pathogenesis of lymphangioleiomyomatosis (LAM), leading to publication of guidelines and approval of an effective therapy. OBJECTIVES: Aim of our study was to describe how the management and the natural history of this rare disease have changed after the publication of the ERS and American Thoracic Society/Japanese Respiratory Society guidelines and the introduction of sirolimus. METHODS: We examined 162 LAM patients followed at our center between 2001 and 2017, reporting clinical characteristics and diagnostic approach. Response to sirolimus in patients undergoing long-term treatment and mortality risk, estimated in terms of cumulative incidence taking into account organ transplantation as a competing cause of the event, were evaluated. The difference in the cumulative incidence between the patients admitted to the observation before 2011 and after 2011, year of the publication of the MILES trial for the efficacy of sirolimus, has also been estimated. RESULTS: Sixty-one patients had a histological diagnosis (22 from 2010 onward). 101 patients received a radiological diagnosis according to the guidelines criteria. Pulmonary function tests remained stable over a 3-year treatment period in patients who received sirolimus for over 12 months. The cumulative incidence of mortality after 10 years in the whole population was 25.5%. The cumulative incidence of mortality after 5 years was significantly lower in patients who entered the study since 2011 (after publication of the MILES trial) than in patients who entered the study before. CONCLUSIONS: We provide the data supporting the long-term efficacy of sirolimus therapy in a large cohort of patients with functional impairment and other manifestations of the disease. Our results also suggest that the advent of sirolimus and the publication of international guidelines changed the natural history of the disease lowering the mortality and reducing the need of invasive diagnostic techniques.

Recent advances and current controversies in lung neuroendocrine neoplasms✰.

In the lung, neuroendocrine tumors (NETs), namely typical and atypical carcinoids, and neuroendocrine carcinomas (NECs), grouping small cell carcinoma (SCLC) and large cell neuroendocrine carcinoma (LCNEC), make up for distinct tumor entities according to epidemiological, genetic, pathologic and clinical data. The proper classification is essential in clinical practice for diagnosis, prognosis and therapy purposes. Through an extensive literature survey, three perspectives on lung NENs have been revised: i) criteria and terminology on biopsy or cytology samples of primaries or metastases; ii) carcinoids with elevated mitotic counts and/or Ki-67 proliferation rates; iii) relevance of molecular landscape to identify new tumor entities and therapeutic targets. Furthermore, a dispute about lung NEN development has been raised according to emerging molecular models. We herein provide a pathology update on practical topics in the setting of lung NENs according to the current classification (recent advances). We have also reappraised the development of these tumors by modeling risk factors and natural history of disease (recent controversies). Combining recent advances and controversies may help clarify our biological understanding of lung NENs and give practical information for the clinical decision-making process.

The Ki-67 antigen in the new 2021 World Health Organization classification of lung neuroendocrine neoplasms.

Prof. Rosai's work has permeated the surgical pathology in many fields, including the 2017 World Health Organization classification on tumors of endocrine organs and pulmonary neuroendocrine cell pathology, with stimulating contributions which have also anticipated the subsequent evolution of knowledge. Among the many studies authored by Prof. Rosai, we would like to recall one of which whose topic has been encased in the new 2021 World Health Organization classification on lung tumors. This is an eminently practical paper dealing with the use of the proliferation antigen Ki-67 in lung neuroendocrine neoplasms. While these neoplasms are primarily ranked upon histologic features and Ki-67 labeling index does not play any role in classification, diagnostic dilemmas may however arise in severely crushed biopsy or cytology samples where this marker proves helpful to avoid misdiagnoses of carcinoids as small cell carcinoma. Another application of Ki-67 labeling index endorsed by the 2021 World Health Organization classification regards, alongside mitotic count, the emerging recognition of lung atypical carcinoids with increased mitotic or proliferation rates, whose biological boundaries straddle a subset of large cell neuroendocrine carcinoma.This article focuses on these two practical applications of the proliferation marker Ki-67 in keeping with the 2021 World Health Organization classification, which provides standards for taxonomy, diagnosis and clinical decision making in lung neuroendocrine neoplasm patients.

Neuroendocrine neoplasms of the biliary tree, liver and pancreas: a pathological approach.

Neuroendocrine neoplasms of the pancreatobiliary tract and liver are a heterogeneous group that encompass a spectrum of entities with distinct morphological, biological and clinical features. Although in the various anatomical sub-sites of this region they show specific characteristics, these tumors, as a whole, share several etiological and clinical aspects. This review systematically addresses NENs arising in the extrahepatic bile ducts, gallbladder, liver and pancreas, with the principal aim of pinpointing essential diagnostic and classification issues. In addition, the section on hepatic NENs has been expanded to include metastatic disease of unknown primary site.

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 CD56brightCD16dim/-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.

Lung Cryobiopsy for the Diagnosis of Interstitial Lung Diseases: A Series Contribution to a Debated Procedure.

Introduction: Transbronchial cryobiopsy is an alternative to surgical biopsy for the diagnosis of fibrosing interstitial lung diseases, although the role of this relatively new method is rather controversial. Aim of this study is to evaluate the diagnostic performance and the safety of transbronchial cryobiopsy in patients with fibrosing interstitial lung disease. Materials and methods: The population in this study included patients with interstitial lung diseases who underwent cryobiopsy from May 2015 to May 2018 at the Division of Pneumology of San Giuseppe Hospital in Milan and who were retrospectively studied. All cryobiopsy procedures were performed under fluoroscopic guidance using a flexible video bronchoscope and an endobronchial blocking system in the operating room with patients under general anaesthesia. The diagnostic performance and safety of the procedure were assessed. The main complications evaluated were endobronchial bleeding and pneumothorax. All cases were studied with a multidisciplinary approach, before and after cryobiopsy. Results: Seventy-three patients were admitted to this study. A specific diagnosis was reached in 64 cases, with a diagnostic sensitivity of 88%; 5 cases (7%) were considered inadequate, 4 cases (5%) were found to be non-diagnostic. Only one major bleeding event occurred (1.4%), while 14 patients (19%) experienced mild/moderate bleeding events while undergoing bronchoscopy; 8 cases of pneumothorax (10.9%) were reported, of which 2 (2.7%) required surgical drainage. Conclusions: When performed under safe conditions and in an experienced center, cryobiopsy is a procedure with limited complications having a high diagnostic yield in fibrotic interstitial lung disease.

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.

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.

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.

An open-label, single-arm, phase 2 study of the Aurora kinase A inhibitor alisertib in patients with advanced urothelial cancer.

BACKGROUND: Progress in developing effective salvage therapies for UC is warranted. Alisertib is an orally available, selective inhibitor of the aurora kinase A. METHODS: A single-group, phase 2 trial was conducted with alisertib 50 mg orally BID for 7 days, with 14d rest until disease progression (PD) (NCT02109328). The primary endpoint (EP) was RECIST 1.1 objective response-rate (ORR, H0 ≤ 5%, H1 ≥ 20%, α = 10% and ß = 20%). Eligibility included failure of at least one platinum-based regimen. RESULTS: From 10/2014 to 04/2015, 22 patients were enrolled (20 evaluable for response), 8 (36.4%) in second-line and 14 (63.6 %) beyond the second-line. Eight (36.4%) had an ECOG-performance status 1-2. Two partial responses (PR, ORR: 9.1%), 7 stable disease (SD) and 11 PD were obtained. Median follow-up was 8.3 months (IQR: 7-10.3), 6-month progression-free survival (PFS) was 13.6% (95%CI: 4.8-39.0). Two SD are still receiving treatment after 11.5 and 6.3 months. Median overall survival (OS) was not reached (6-month OS: 59.1%, 95%CI: 41.7-83.7). Hb < 10 g/dl was significantly associated with shorter PFS and OS multivariably (p = 0.031 and p = 0.033). Tissue of the case with 11.5 month SD harbored a missense mutation of mTOR (E1813D), the nonsense mutation Q527STOP of TSC1, HER3 and TAF1L missense mutations. Grade 3-4 adverse events (AE) were: 40.9% mucositis, 36.4% fatigue, 18.2% neutropenia (13.6% febrile neutropenia). There were 2 treatment-related deaths. CONCLUSIONS: The study did not meet the primary EP, yet sustained disease control was obtained in about 14% of patients. The incidence of AE and the issue of patient selection are two major concerns.

Osteopontin, E-cadherin, and ß-catenin expression as prognostic biomarkers in patients with radically resected gastric cancer.

A correlation between osteopontin, E-cadherin, ß-catenin, and cyclooxygenase 2 overexpression and poor clinicopathological features and prognosis has been previously suggested in gastric cancer. This translational study was aimed at assessing the correlation of these immunohistochemical biomarkers with outcome in patients with radically resected gastric cancer. We analyzed osteopontin, E-cadherin, ß-catenin, and cyclooxygenase 2 expression by immunohistochemistry in 346 primary gastric tumor tissue samples from patients enrolled in the ITACA-S trial. This phase III study randomized patients with radically resected gastric cancer to receive adjuvant chemotherapy with either 5-fluorouracil and leucovorin or a sequential regimen of infusional 5-fluorouracil and leucovorin plus irinotecan followed by cisplatin and docetaxel. High expression of osteopontin was correlated with high histological grade, diffuse histotype, and peritoneal relapse, but not with TNM stage. Moreover, osteopontin overexpression was associated with higher risk of tumor recurrence and metastases, and was an independent prognostic factor for both relapse-free and overall survival of gastric cancer patients following adjuvant chemotherapy. Abnormal E-cadherin expression and abnormal ß-catenin expression were correlated with more advanced disease stage, and as a consequence, with poor outcome. Our results suggest that osteopontin overexpression is a valuable independent predictor of tumor recurrence and survival in patients with radically resected gastric cancer.

Inference on germline BAP1 mutations and asbestos exposure from the analysis of familial and sporadic mesothelioma in a high-risk area.

Inherited loss-of-function mutations in the BAP1 oncosuppressor gene are responsible for an inherited syndrome with predisposition to malignant mesothelioma (MM), uveal and keratinocytic melanoma, and other malignancies. Germline mutations that were inherited in an autosomal dominant fashion were identified in nine families with multiplex MM cases and 25 families with multiple melanoma, renal cell carcinoma, and other tumors. Germline mutations were also identified in sporadic MM cases, suggesting that germline mutations in BAP1 occur frequently. In this article, we report the analysis of BAP1 in five multiplex MM families and in 103 sporadic cases of MM. One family carried a new truncating germline mutation. Using immunohistochemistry, we show that BAP1 is not expressed in tumor tissue, which is in accordance with Knudson's two hits hypothesis. Interestingly, whereas the three individuals who were possibly exposed to asbestos developed MM, the individual who was not exposed developed a different tumor type, that is, mucoepidermoid carcinoma. This finding suggests that the type of carcinogen exposure may be important for the cancer type that is developed by mutation carriers. On the contrary, the other families or the 103 sporadic patients did not show germline mutations in BAP1. Our data show that BAP1 mutations are very rare in patients with sporadic MM, and we report a new BAP1 mutation, extend the cancer types associated with these mutations, and suggest the existence of other yet unknown genes in the pathogenesis of familial MM.

Germline polymorphisms and survival of lung adenocarcinoma patients: a genome-wide study in two European patient series.

In lung cancer, the survival of patients with the same clinical stage varies widely for unknown reasons. In this two-phase study, we examined the hypothesis that germline variations influence the survival of patients with lung adenocarcinoma. First, we analyzed existing genotype and clinical data from 289 UK-resident patients with lung adenocarcinoma, identifying 86 single nucleotide polymorphisms (SNPs) that associated with survival (p < 0.01). We then genotyped these candidate SNPs in a validation series of 748 patients from Italy that resulted genetically compatible with the UK series based on principal component analysis. In a Cox proportional hazard model adjusted for age, sex and clinical stage, four SNPs were confirmed on the basis of their having a hazard ratio (HR) indicating the same direction of effect in the two series and p < 0.05. The strongest association was provided by rs2107561, an intronic SNP of PTPRG, protein tyrosine phosphatase, receptor type, G; the C allele was associated with poorer survival in both patient series (pooled analysis loge HR = 0.31; 95% CI: 0.15-0.46, p = 8.5 × 10(-5) ). PTPRG mRNA levels in 43 samples of lung adenocarcinoma were 40% of those observed in noninvolved lung tissue from the same patients. PTPRG overexpression significantly inhibited the clonogenicity of A549 lung carcinoma cells and the anchorage-independent growth of the NCI-H460 large cell lung cancer line. These four germline variants represent promising candidates that, with further study, may help predict clinical outcome. In addition, the PTPRG locus may have a role in tumor progression.