Value of napsin A and thyroid transcription factor-1 in the identification of primary lung adenocarcinoma

Classification of NSCLC subtypes using lung microbiome from resected tissue based on machine learning methods

Classification of adenocarcinoma (AC) and squamous cell carcinoma (SCC) poses significant challenges for cytopathologists, often necessitating clinical tests and biopsies that delay treatment initiation. To address this, we developed a machine learning-based approach utilizing resected lung-tissue microbiome of AC and SCC patients for subtype classification. Differentially enriched taxa were identified using LEfSe, revealing ten potential microbial markers. Linear discriminant analysis (LDA) was subsequently applied to enhance inter-class separability. Next, benchmarking was performed across six different supervised-classification algorithms viz. logistic-regression, naïve-bayes, random-forest, extreme-gradient-boost (XGBoost), k-nearest neighbor, and deep neural network. Noteworthy, XGBoost, with an accuracy of 76.25%, and AUROC (area-under-receiver-operating-characteristic) of 0.81 with 69% specificity and 76% sensitivity, outperform the other five classification algorithms using LDA-transformed features. Validation on an independent dataset confirmed its robustness with an AUROC of 0.71, with minimal false positives and negatives. This study is the first to classify AC and SCC subtypes using lung-tissue microbiome.

Characterization of Nonsmall Cell Lung Carcinoma in Limited Biopsy Samples and Identifying Optimal Immunohistochemical Marker Combinations in Resource-Constrained Setup: An Institutional Experience

Background  The incorporation of immunohistochemical markers in the analysis of small biopsy samples, as outlined in the fourth edition of the World Health Organization Blue books, represents a noteworthy advancement in the diagnosis of advanced-stage lung carcinoma. This improved the histological classification for poorly differentiated nonsmall cell lung carcinomas (NSCLCs), especially in small biopsy specimens. Despite challenges in obtaining viable cells from diminutive tumor samples, a focused immunohistochemical panel effectively distinguishes histological types in most NSCLC. This preserves tissue for subsequent molecular testing. Material and Methods  This study examined 130 consecutive lung biopsy cases initially diagnosed as NSCLC, including various biopsy types (transbronchial, endobronchial, ultrasound-guided, computed tomography-guided). Carcinomas were categorized based on specific characteristics, such as glands and/or mucin for adenocarcinomas, keratinization and/or intercellular bridges for squamous cell carcinomas, and recognition of poorly differentiated NSCLC. Cases lacking clear morphological attributes underwent reclassification using immunohistochemical markers (TTF1, Napsin A, p63, and p40). Results  TTF1 exhibited superior sensitivity (97.56%) and specificity (96.77%) for adenocarcinoma compared with Napsin A, with sensitivity and specificity at 90.24 and 93.3%, respectively. p63 and p40 demonstrated 100% sensitivity for squamous cell carcinoma, with p40 being more specific than p63 (100% vs. 82.92%). Using TTF1 and p63 as a conventional panel, 87% of cases were subtyped. However, the combination of TTF1 and p40 achieved accurate classification in 94.66% (71/75) of cases, and all four markers allowed subtype identification in 97.2% (73/75) of cases. Conclusion  In a resource-constrained setting, subtyping NSCLC in small biopsy can be effectively accomplished using a minimal panel consisting of TTF1 and p40 immunohistochemical markers.

Evolving Precision First-Line Systemic Treatment for Patients with Unresectable Non-Small Cell Lung Cancer

First-line systemic therapy for patients with advanced or metastatic non-small cell lung cancer (NSCLC) has rapidly evolved over the past two decades. First, molecularly targeted therapy for a growing number of gain-of-function molecular targets has been shown to improve progression-free survival (PFS) and overall survival (OS) with favorable toxicity profiles compared to platinum-containing chemotherapy and can be given as first-line systemic therapy in ~25% of patients with NSCLC. Actionable genetic alterations include EGFR, BRAF V600E, and MET exon 14 splicing site-sensitizing mutations, as well as ALK-, ROS1-, RET-, and NTRK-gene fusions. Secondly, inhibitors of programmed cell death protein 1 or its ligand 1 (PD-1/L1) such as pembrolizumab, atezolizumab, or cemiplimab monotherapy have become a standard of care for ~25% of patients with NSCLC whose tumors have high PD-L1 expression (total proportion score (TPS) ≥50%) and no sensitizing EGFR/ALK alterations. Lastly, for the remaining ~50% of patients who are fit and whose tumors have no or low PD-L1 expression (TPS of 0-49%) and no sensitizing EGFR/ALK aberrations, platinum-containing chemotherapy with the addition of a PD-1/L1 inhibitor alone or in combination of a cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitor improves PFS and OS compared to chemotherapy alone. The objectives of this review are to summarize the current data and perspectives on first-line systemic treatment in patients with unresectable NSCLC and propose a practical algorithm for implementing precision biomarker testing at diagnosis.

Lung adenocarcinomas with isolated TP53 mutation: A comprehensive clinical, cytopathologic and molecular characterization

BACKGROUND

TP53 mutation is present in about 50.8% of lung adenocarcinomas, frequently in combination with other genetic alterations. However, a rare subset harbors the TP53 mutation alone.

METHODS

Next-generation sequencing was performed in 844 lung adenocarcinomas diagnosed by fine needle aspiration. Fourteen cases (1.7%) showed isolated TP53 alteration and were subjected to a comprehensive analysis.

RESULTS

The average age at diagnosis was 65.7 years (range 48-79); 9 males and 5 females. All were smokers with an average pack-year of 40.7 (range 10-70). Ten had metastases, mostly in the brain (n = 4) and pleura (n = 4). After a follow-up period of up to 102 months, 9 died, 3 were alive free of disease, 1 was alive with disease, and 1 was lost to follow-up. The median survival was 12.2 months. Most tumors exhibited poor differentiation, composed of solid sheets with moderate to severe atypia, increased mitotic activity, and necrotic background. Half were positive for TTF-1 and showed p53 overexpression. PD-L1 was positive in 5 cases. Most alterations were missense mutations in exons 5-8, and this mutation type was associated with p53 overexpression. Tumors with combined missense mutation and truncated protein had higher PD-L1 expression along with a trend towards an increase in tumor mutational burden (TMB). CEBPA deletion of undetermined significance was the most common copy number alteration.

CONCLUSION

Isolated TP53 mutation was seen in association with smoking, high-grade cytomorphologic features, adverse prognosis, and recurrent CEBPA deletions. These tumors tend to have strong PD-L1 expression and high TMB, suggesting potential benefit from immune checkpoint inhibitors. Hence, the recognition of this molecular group has prognostic and therapeutic implications.

Brain and Adrenal Metastasis From Unknown Primary Tumor: A Case Report

The clinical management of brain metastasis (BM) and adrenal metastasis (AM) of cancer of unknown primary (CUP) can be challenging. A 73-year-old man presented to the hospital with sudden-onset hemiplegia. His laboratory data were normal, except for elevated levels of carcinoembryonic antigen (CEA) (33.8 ng/mL). Contrast-enhanced magnetic resonance imaging revealed a 2-cm mass with ring enhancement in the right parietal lobe and extensive vasogenic edema around the tumor. The lesion was diagnosed as BM; however, we could not detect the primary origin by fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT). Stereotactic radiotherapy was then administered, resulting in reduced tumor size and relief of symptoms. Follow-up after one year revealed an elevated CEA level (148.6 ng/mL) and remarkable fluorodeoxyglucose (FDG) uptake in the right adrenal gland, with an area of enhancement of 20 mm, on FDG-positron emission tomography computed tomography, with normal findings in other distant organs. He underwent adrenalectomy, and the adrenal tumor was diagnosed as a poorly differentiated adenocarcinoma likely of lung origin based on the histopathologic and immunohistochemistry findings of cytokeratin (CK) 7 (+), CK 20 (-), thyroid transcription factor-1 (TTF-1) (+), inhibin (-), napsin A (+), prostate-specific antigen (PSA) (-), caudal type homeobox 2 (CDX-2) (-), synaptophysin (-), and p40 (-). Metastatic tumors of unknown primary origin remain latent. Aggressive treatment of these lesions can be beneficial for symptom relief, diagnosis, and prolongation of survival.

Role of immunohistochemistry markers in neoplastic lung lesions

Objectives

The objective of the evaluate was to study and determine the usefulness of immunohistochemistry (IHC) staining in neoplastic lung lesions.

Materials and Methods

We evaluated seven IHC stains in fifty lung cancers that included adenocarcinoma (AC), squamous cell carcinoma (SCC), small cell carcinoma, and carcinoid tumors.

Results

P63 was expressed in all the cases of SCCs and thyroid transcription factor-1 (TTF-1) was expressed in all cases of ACs. CK 5/6 was expressed in 77.77% of SCCs and CK 7 was expressed in 92.59% of ACs. Synaptophysin and chromogranin-A were expressed in 100% of neuroendocrine (NE) carcinomas.

Conclusion

P63 and TTF-1 are sensitive markers for SCCs and ACs. Synaptophysin and Chromogranin-A are sensitive markers for NE carcinomas.

Napsin A Expression in Human Tumors and Normal Tissues

Background: Novel aspartic proteinase of the pepsin family A (Napsin A, TAO1/TAO2) is a functional aspartic proteinase which is involved in the maturation of prosurfactant protein B in type II pneumocytes and the lysosomal protein catabolism in renal cells. Napsin A is highly expressed in adenocarcinomas of the lung and is thus commonly used to affirm this diagnosis. However, studies have shown that other tumors can also express Napsin A.

Methods: To comprehensively determine Napsin A expression in normal and tumor tissue, 11,957 samples from 115 different tumor types and subtypes as well as 500 samples of 76 different normal tissue types were evaluable by immunohistochemistry on tissue microarrays.

Results: Napsin A expression was present in 16 different tumor types. Adenocarcinoma of the lung (85.6%), clear cell adenocarcinoma of the ovary (71.7%), clear cell adenocarcinoma of the endometrium (42.8%), papillary renal cell carcinoma (40.2%), clear cell (tubulo) papillary renal cell carcinoma (16.7%), endometrial serous carcinoma (9.3%), papillary thyroid carcinoma (9.3%) and clear cell renal cell carcinoma (8.2%) were among the tumors with the highest prevalence of Napsin A positivity. In papillary and clear cell renal cell carcinoma, reduced Napsin A expression was linked to adverse clinic-pathological features (p ≤ 0.03).

Conclusion: This methodical approach enabled us to identify a ranking order of tumors according to their relative prevalence of Napsin A expression. The data also show that loss of Napsin A is linked to tumor dedifferentiation in renal cell carcinomas.

Clinicopathological and Prognostic Significance of the EML4-ALK Translocation and IGFR1, TTF1, Napsin A Expression in Patients with Lung Adenocarcinoma

OBJECTIVE

Patients with lung adenocarcinoma who harbor ALK gene rearrangements can demonstrate significant clinical benefit with ALK tyrosine kinase inhibitors. Insulin-like growth factor receptor 1 (IGFR1) is a cellular membrane receptor that is overexpressed in many tumors. It plays an important role in cancer progression and is associated with increased postoperative recurrence and poorer disease-free survival. The aim of this study was to determine the EML4-ALK mutation and IGFR1 expression in lung adenocarcinoma and analyze their prognostic value.

MATERIAL AND METHOD

In this study, we analyzed the EML4-ALK mutation using the FISH and IHC techniques in 251 lung adenocarcinoma (203 primary resections, 48 metastasectomies) cases. Correlative analyses were performed between the EML4-ALK mutation, the IGFR1, TTF1, and NapsinA expression, and the clinicopathologic factors in lung adenocarcinomas.

RESULTS

The EML4-ALK mutation was observed in 3.8% of the cases and it was associated with the solid pattern, signet ring cell morphology, and larger tumor size. IGFR1 expression was identified in 49% of the cases and most of the ALK-mutated cases were also expressing the IGFR1 protein (66%). IGFR1 expression frequency was increased in metastasectomy specimens.

CONCLUSION

A solid signet-ring cell pattern or mucinous cribriform pattern was present at least focally in all ALK-positive tumors, consistently with the literature. In addition, IGFR1 expression levels showed an increase in the EML4-ALK-mutated cases in our series, but the clinical significance of this finding should be supported by larger series and survival analysis. Our findings show that IGFR1 expression may be useful as a poor prognostic marker in patients with lung adenocarcinoma.

Expression of alpha-methylacyl-CoA racemase in vaginal gastric-type adenocarcinoma and uterine clear cell carcinoma

Background

Alpha-methylacyl-coenzyme A racemase (AMACR, P504S) is a commonly used marker in immunohistochemical diagnosis of prostate cancer. Recent studies identified P504S markers of the clear cell histotype in the ovary and/or endometrium. Gastric-type adenocarcinoma (GAS) is difficult to diagnose histologically, particularly when there is crossover with clear cell carcinoma (CCC). However, the significance of P504S for differentially diagnosing GAS and CCC is unclear.

Aim

To evaluate P504S as a potential diagnostic marker of GAS and CCC.

Settings and Design

We analyzed P504S expression in 48 cervical carcinomas (32 GAS and 16 CCC), as well as the expression of other markers including hepatocyte nuclear factor-1 beta (HNF-1β) and NapsinA.

Material and Methods

The expression differences of HNF-1β, NapsinA, and P504S in GAS and CCC were detected by immunohistochemistry. Immunohistochemical histoscores based on the intensity and extent of staining were calculated.

Results

The positive rates of HNF-1β in GAS and CCC were 90.32% and 75%, respectively. (χ2 = 2.251, P = 0.663). The positive rates of NapsinA in GAS and CCC were 19.36% and 81.25%, respectively. (χ2 = 47.332, P < 0.01). The positive rates of P504S in GAS and CCC were 16.13% and 81.25%, respectively. (χ2 = 41.420, P < 0.01). HNF-1β was frequently expressed in GAS and CCC, while NapsinA and P504S were frequently expressed in CCC, and reduced or lost in GAS.

Conclusion

NapsinA and P504S can be used to differentiate between GAS and CCC.

An Algorithmic Immunohistochemical Approach to Define Tumor Type and Assign Site of Origin

Immunohistochemistry represents an indispensable complement to an epidemiology and morphology-driven approach to tumor diagnosis and site of origin assignment. This review reflects the state of my current practice, based on 15-years' experience in Pathology and a deep-dive into the literature, always striving to be better equipped to answer the age old questions, "What is it, and where is it from?" The tables and figures in this manuscript are the ones I "pull up on the computer" when I am teaching at the microscope and turn to myself when I am (frequently) stuck. This field is so exciting because I firmly believe that, through the application of next-generation immunohistochemistry, we can provide better answers than ever before. Specific topics covered in this review include (1) broad tumor classification and associated screening markers; (2) the role of cancer epidemiology in determining pretest probability; (3) broad-spectrum epithelial markers; (4) noncanonical expression of broad tumor class screening markers; (5) a morphologic pattern-based approach to poorly to undifferentiated malignant neoplasms; (6) a morphologic and immunohistochemical approach to define 4 main carcinoma types; (7) CK7/CK20 coordinate expression; (8) added value of semiquantitative immunohistochemical stain assessment; algorithmic immunohistochemical approaches to (9) "garden variety" adenocarcinomas presenting in the liver, (10) large polygonal cell adenocarcinomas, (11) the distinction of primary surface ovarian epithelial tumors with mucinous features from metastasis, (12) tumors presenting at alternative anatomic sites, (13) squamous cell carcinoma versus urothelial carcinoma, and neuroendocrine neoplasms, including (14) the distinction of pheochromocytoma/paraganglioma from well-differentiated neuroendocrine tumor, site of origin assignment in (15) well-differentiated neuroendocrine tumor and (16) poorly differentiated neuroendocrine carcinoma, and (17) the distinction of well-differentiated neuroendocrine tumor G3 from poorly differentiated neuroendocrine carcinoma; it concludes with (18) a discussion of diagnostic considerations in the broad-spectrum keratin/CD45/S-100-"triple-negative" neoplasm.

Napsin A Expression in Subtypes of Thyroid Tumors: Comparison with Lung Adenocarcinomas

Napsin A is widely used in the diagnosis of lung adenocarcinoma and has also been reported to be positive in cases of thyroid carcinomas. We investigated napsin A levels through immunohistochemistry on whole sections of 210 primary thyroid tumors of various subtypes and another 41 metastatic thyroid carcinomas, and compared these with 125 primary and 25 metastatic lung adenocarcinomas. The results showed that napsin A was expressed in 23.8% thyroid tumors and 30.3% papillary thyroid carcinomas. Most cases showed a focal and weak to moderate expression. In comparison, 80.8% primary lung adenocarcinomas expressed napsin A, with mostly diffused and strong expression. For metastatic carcinomas of thyroid and lung origin, napsin A was detected in 39.0% of thyroid carcinomas in contrast to 88.0% in cases of lung adenocarcinomas. Comparisons of additional markers, TTF-1, CK7, thyroglobulin, and Pax-8 in metastatic carcinomas showed the overlapping expression of immunomarkers of TTF-1 and CK7. Thyroglobulin and Pax-8 were useful for distinguishing between metastatic carcinomas; however, Pax-8 may be a superior marker due to its higher sensitivity. The clinicopathological analysis of papillary thyroid carcinomas showed that the expression of napsin A was positively correlated with lymph node metastasis (p = 0.030). Here, we focused on the expression of napsin A in thyroid tumors and compared it with that in lung adenocarcinomas. The expression of napsin A is common in thyroid tumors and the combined expression of napsin A and TTF-1 in a metastatic thyroid carcinoma is a cause for concern due to chances of misdiagnosis as lung adenocarcinoma.

Experimental study of peripheral-blood pro-surfactant protein B for screening non-small cell lung cancer

Purpose:

To evaluate the possibility of using peripheral-blood presurfactant protein B (Pro-SFTPB) for screening non-small cell lung cancer (NSCLC).

Methods:

A total of 873 healthy volunteers and 165 lung cancer patients hospitalized in the Fifth People's Hospital of Dalian were tested Pro-SFTPB once every half year from January 2014 to September 2015. The healthy volunteers were also conducted spiral computed tomography (CT) examination once every year. The data were then com-pared and statistically analyzed.

Results:

The positive expression rate of Pro-SFTPB in NSCLC was significantly higher than that in healthy volunteers, and significantly higher in lung adenocarcinoma than in squamous cell carcinoma; additionally, the expression rate was increased with the in-crease of smoking index, and the intergroup differences showed statistical signifi-cance (p≤0.05). The positive rate of newly diagnosed lung cancer was 29.55%, higher than healthy volunteers (22.34%), but there was no significant difference (p>0.05).

Conclusion:

Pro-SFTPB is over expressed in non-small cell lung cancer, especially in lung adeno-carcinoma, but it can't be used as a clinical screening tool for lung cancer.

Novel urease-negative Helicobacter sp. 'H. enhydrae sp. nov.' isolated from inflamed gastric tissue of southern sea otters

A total of 31 sea otters Enhydra lutris nereis found dead or moribund (and then euthanized) were necropsied in California, USA. Stomach biopsies were collected and transected with equal portions frozen or placed in formalin and analyzed histologically and screened for Helicobacter spp. in gastric tissue. Helicobacter spp. were isolated from 9 sea otters (29%); 58% (18 of 31) animals were positive for helicobacter by PCR. The Helicobacter sp. was catalase- and oxidase-positive and urease-negative. By electron microscopy, the Helicobacter sp. had lateral and polar sheathed flagella and had a slightly curved rod morphology. 16S and 23S rRNA sequence analyses of all 'H. enhydrae' isolates had similar sequences, which clustered as a novel Helicobacter sp. closely related to H. mustelae (96-97%). The genome sequence of isolate MIT 01-6242 was assembled into a single ~1.6 Mb long contig with a 40.8% G+C content. The annotated genome contained 1699 protein-coding sequences and 43 RNAs, including 65 genes homologous to known Helicobacter spp. and Campylobacter spp. virulence factors. Histological changes in the gastric tissues extended from mild cystic degeneration of gastric glands to severe mucosal erosions and ulcers. Silver stains of infected tissues demonstrated slightly curved bacterial rods at the periphery of the gastric ulcers and on the epithelial surface of glands. The underlying mucosa and submucosa were infiltrated by low numbers of neutrophils, macrophages, and lymphocytes, with occasional lymphoid aggregates and well-defined lymphoid follicles. This is the second novel Helicobacter sp., which we have named 'H. enhydrae', isolated from inflamed stomachs of mustelids, the first being H. mustelae from a ferret.

The Utility of Thyroid Transcription Factor 1 (TTF-1), Napsin A, Excision Repair Cross-Complementing 1 (ERCC1), Anaplastic Lymphoma Kinase (ALK) and the Epidermal Growth Factor Receptor (EGFR) Expression in Small Biopsy in Prognosis of Patients with Lung Adenocarcinoma - A Retrograde Single-Center Study from Croatia

Background

The present study was carried out in order to evaluate our institutional experience with small biopsy in diagnosis and molecular testing of lung adenocarcinoma. Few specific and predictive markers have been evaluated and correlated with clinicopathologic characteristics and survival in patients with lung adenocarcinoma who received platinum-based chemotherapy. There have not been such reports from Croatia.

Material/Methods

A total of 142 cases of lung adenocarcinoma were retrospectively investigated in small biopsies for the immunohistochemical expression of TTF-1, napsin A, ERCC1, ALK, and the EGFR mutation by real-time polymerase chain reaction (rtPCR).

Results

TTF-1, napsin A, and ERCC1 expression was found in 81%, 78%, and 69% of patients, respectively, and the expressions were not significantly associated with subtype. Expression of ALK was found in 4% and EGFR mutation in 10% of patients. Exon 19 deletions were the most common. Longer survival was significantly associated with TTF-1 positivity (p=0.007) and napsin A positivity (p=0.026). Higher relative risk of death significantly correlated with positive expression of ERCC1 (p=0.041).

Conclusions

Positive TTF-1 and napsin A expressions in lung adenocarcinoma tissues were useful diagnostic and favorable prognostic parameters. Positive ERCC1 expression was identified as a negative prognostic marker in patients treated with platinum-based chemotherapy. The percentages of EGFR and ALK mutations corresponded to those in previously published reports for Caucasians.

Negative Thyroid Transcription Factor 1 Expression Defines an Unfavorable Subgroup of Lung Adenocarcinomas

INTRODUCTION

Thyroid transcription factor 1 (TTF1) is a master regulator of pulmonary differentiation that is downregulated in a subset of lung adenocarcinoma, of which the clinicopathologic characteristics were not fully clarified.

METHODS

One thousand forty-two lung adenocarcinoma patients who underwent surgery were investigated for clinic characteristics, histologic subtyping, and spectrum of well-identified driver mutations. TTF1 expression was correlated with these clinicopathologic factors and survival.

RESULTS

Compared with TTF1 positive (TTF1+) patients, the 133 negative individuals (12.8%, TTF1-) were more likely to be male (p = 0.006) and heavy smokers (p = 0.002) who had larger tumor size (p < 0.001) and more advanced disease stage (p < 0.001). TTF1- presented more in solid and invasive mucinous-predominant carcinomas (both p < 0.001), whereas TTF1+ was identified in 100% patients with adenocarcinoma in situ, minimally invasive and lepidic-predominant adenocarcinomas. The TTF1- tumors harbored the known driver mutations in significantly low frequency compared with TTF1+ adenocarcinomas (57.8% versus 78.1%, p < 0.001), especially in epidermal growth factor receptor (EGFR) mutations (37.6% versus 60.7%, p < 0.001). There was no significant difference in recurrence-free survival between the TTF1- and TTF1+ patients, either for the whole cohort or stratified by pathologic stage, or among the driver mutation-defined subsets. However, recurrence of multiple metastases was more likely to occur in patients with TTF1- adenocarcinomas (88.1% versus 32.4%, p < 0.001). Multivariate analysis revealed that TTF1- independently predicted both poor postrecurrence survival (hazard ratio = 1.664; 95% confidence interval , 1.097-2.524; p = 0.017) and unfavorable overall survival (hazard ratio = 1.553; 95% confidence interval , 1.013-2.381; p = 0.043).

CONCLUSIONS

TTF1- correlated with solid and invasive mucinous subtypes of lung adenocarcinoma and lower frequency of EGFR mutations. It defines a subgroup of lung adenocarcinomas with unfavorable outcomes.

Prognostic analysis of primary mucin-producing adenocarcinoma of the lung: a comprehensive retrospective study

Although primary mucin-producing adenocarcinoma of the lung is uncommon, each subtype has distinct clinical, pathological, molecular, and prognostic characteristics. This study aimed to determine correlations between clinical and pathological features and genetic phenotypes with the prognosis. We immunohistochemically examined the protein levels of thyroid transcription factor 1 (TTF-1), Napsin A, and anaplastic lymphoma kinase (ALK) and genetically examined epidermal growth factor receptor (EGFR) and KRAS mutations in these mucin-producing tumors. A total of 75 cases of mucin-producing adenocarcinoma of the lung were examined. ALK protein positivity was 33.3 % (25/75), and primarily occurred in solid predominant with mucin production subtype (SA). KRAS mutations occurred in 22.7 % (17/75) of patients, predominantly in invasive mucinous adenocarcinoma (IMA). Positive TTF-1 and Napsin A expression was more common in SA, while they were both negative in IMA. The 1-, 3-, and 5-year progression-free survival rates of mucin-producing lung adenocarcinoma were 85, 64, and 38 %, respectively; the overall survival rates were 90, 67, and 50 %, respectively. Larger tumors, advanced stage, and lymph node metastasis were associated with poor prognosis. Mucinous minimally invasive adenocarcinoma (m-MIA) had the best prognosis, followed by IMA, SA, and acinar or papillary predominant adenocarcinoma with mucin production (A/P). KRAS mutations were an independent positive prognostic factor for postoperative progress.

Trefoil factor 3 as a novel biomarker to distinguish between adenocarcinoma and squamous cell carcinoma

In carcinoma, such as of the lung, the histological subtype is important to select an appropriate therapeutic strategy for patients. However, carcinomas with poor differentiation cannot always be distinguished on the basis of morphology alone nor on clinical findings. Hence, delineation of poorly differentiated adenocarcinoma and squamous cell carcinoma, the 2 most common epithelial-origin carcinomas, is pivotal for selection of optimum therapy. Herein, we explored the potential utility of trefoil factor 3 (TFF3) as a biomarker for primary lung adenocarcinoma and extrapulmonary adenocarcinomas derived from different organs. We observed that 90.9% of lung adenocarcinomas were TFF3-positive, whereas no expression of TFF3 was observed in squamous cell carcinomas. The subtype of lung carcinoma was confirmed by four established biomarkers, cytokeratin 7 and thyroid transcription factor 1 for adenocarcinoma and P63 and cytokeratin 5/6 for squamous cell carcinoma. Furthermore, expression of TFF3 mRNA was observed by quantitative PCR in all of 11 human lung adenocarcinoma cell lines and highly correlated with markers of the adenocarcinomatous lineage. In contrast, little or no expression of TFF3 was observed in 4 lung squamous cell carcinoma cell lines. By use of forced expression, or siRNA-mediated depletion of TFF3, we determined that TFF3 appeared to maintain rather than promote glandular differentiation of lung carcinoma cells. In addition, TFF3 expression was also determined in adenocarcinomas from colorectum, stomach, cervix, esophagus, and larynx. Among all these extrapulmonary carcinomas, 93.7% of adenocarcinomas exhibited TFF3 positivity, whereas only 2.9% of squamous cell carcinomas were TFF3-positive. Totally, 92.9% of both pulmonary and extrapulmonary adenocarcinomas exhibited TFF3 positivity, whereas only 1.5% of squamous cell carcinomas were TFF3-positive. In conclusion, TFF3 is preferentially expressed in adenocarcinoma and may function as an additional biomarker for distinguishing adenocarcinoma from squamous cell carcinoma.

Utility of five commonly used immunohistochemical markers TTF-1, Napsin A, CK7, CK5/6 and P63 in primary and metastatic adenocarcinoma and squamous cell carcinoma of the lung: a retrospective study of 246 fine needle aspiration cases

BACKGROUND

Fine needle aspiration (FNA) biopsy plays a critical role in the diagnosis and staging of lung primary and metastatic lung carcinoma. Accurate subclassification of adenocarcinoma (ADC) and/or squamous cell carcinoma (SqCC) is crucial for the targeted therapy. However, the distinction between ADC and SqCC may be difficult in small FNA specimens. Here, we have retrospectively evaluated the utility of TTF-1, Napsin A, CK7, P63 and CK5/6 immunohistochemical (IHC) markers in the distinguishing and subclassification of ADC and SqCC.

METHODS

A total of 246 FNA cases were identified by a computer search over a two-year period, including 102 primary NSCLC and 144 primary NSCLC which had metastasized to other sites. The immunostaining patterns of TTF-1, Napsin A, CK7, P63 and CK5/6 were correlated with the histological diagnosis of the tumor.

RESULTS

In 72 primary ADCs, TTF-1, Napsin A and CK7 showed a sensitivity and specificity of 84.5%/96.4%, 92.0%/100%, and 93.8%/50.0%. In 30 primary SqCCs, CK5/6 and P63 showed a sensitivity and specificity of 100%/77.8% and 91.7%/78.3%. In 131 metastatic ADCs, Napsin A showed the highest specificity (100%), versus TTF-1 (87.5%) and CK7 (25%) but decreased sensitivity (67.8% versus 86.9% and 100%); whereas in 13 metastatic SqCCs, CK5/6 and P63 showed a sensitivity/specificity of 100%/84.6% and 100%/68.4%. Bootstrap analysis showed that the combination of TTF-1/CK7, TTF-1/Napsin A and TTF-1/CK7/Napsin A had a sensitivity/specificity of 0.960/0.732, 0.858/0.934, 0.972/0.733 for primary lung ADCs and 0.992/0.642, 0.878/0.881, 0.993/0.618 for metastatic lung ADCs.

CONCLUSIONS

Our study demonstrated that IHC markers had variable sensitivity and specificity in the subclassification of primary and metastatic ADC and SqCC. Based on morphological findings, an algorithm with the combination use of markers aided in the subclassification of NSCLCs in difficult cases.

The functional and pathologic relevance of autophagy proteases

Autophagy is a well-conserved catabolic process essential for cellular homeostasis. First described in yeast as an adaptive response to starvation, this pathway is also present in higher eukaryotes, where it is triggered by stress signals such as damaged organelles or pathogen infection. Autophagy is characterized at the cellular level by the engulfment of portions of the cytoplasm in double-membrane structures called autophagosomes. Autophagosomes fuse with lysosomes, resulting in degradation of the inner autophagosomal membrane and luminal content. This process is coordinated by complex molecular systems, including the ATG8 ubiquitin-like conjugation system and the ATG4 cysteine proteases, which are implicated in the formation, elongation, and fusion of these autophagic vesicles. In this Review, we focus on the diverse functional roles of the autophagins, a protease family formed by the four mammalian orthologs of yeast Atg4. We also address the dysfunctional expression of these proteases in several pathologic conditions such as cancer and inflammation and discuss potential therapies based on their modulation.

Napsin A is a specific marker for ovarian clear cell adenocarcinoma

Ovarian clear cell adenocarcinoma has a relatively poor prognosis among the ovarian cancer subtypes because of its high chemoresistance. Differential diagnosis of clear cell adenocarcinoma from other ovarian surface epithelial tumors is important for its treatment. Napsin A is a known diagnostic marker for lung adenocarcinoma, and expression of napsin A is reported in a certain portion of thyroid and renal carcinomas. However, napsin A expression in ovarian surface epithelial tumors has not previously been examined. In this study, immunohistochemical analysis revealed that in 71 of 86 ovarian clear cell adenocarcinoma patients (83%) and all of the 13 patients with ovarian clear cell adenofibroma, positive napsin A staining was evident. No expression was observed in 30 serous adenocarcinomas, 11 serous adenomas or borderline tumors, 19 endometrioid adenocarcinomas, 22 mucinous adenomas or borderline tumors, 10 mucinous adenocarcinomas, or 3 yolk sac tumors of the ovary. Furthermore, expression of napsin A was not observed in the normal surface epithelium of the ovary, epithelia of the fallopian tubes, squamous epithelium, endocervical epithelium, or the endometrium of the uterus. Therefore, we propose that napsin A is another sensitive and specific marker for distinguishing ovarian clear cell tumors (especially adenocarcinomas) from other ovarian tumors.

Polyclonal Napsin A Expression: A Potential Diagnostic Pitfall in Distinguishing Primary From Metastatic Mucinous Tumors in the Lung

Context.—Napsin A is a useful marker for distinguishing primary from metastatic lung tumors. Mucinous lung tumors may be difficult to distinguish from metastatic mucinous tumors.

Objectives.—To evaluate napsin A expression in lung and extrapulmonary mucinous tumors on both histology and cytology specimens and to determine napsin A's utility in differentiating primary from metastatic mucinous tumors.

Design.—Napsin A immunohistochemistry was performed using a rabbit polyclonal antibody on formalin-fixed, paraffin-embedded surgical and fine-needle aspiration biopsy–derived, paraffin-embedded cell block specimens. Positive expression was defined as coarse, granular, cytoplasmic staining in 10% or more of tumor cells.

Results.—Sixteen of 32 mucinous lung tumors (50%) and 16 of 33 extrapulmonary mucinous tumors (48%), including 15 of 18 of gastrointestinal origin (83%), expressed napsin A. Positivity was concordant between surgical and cell block specimens in 5 of 9 cases (56%). In 3 of 4 discordant cases, napsin A expression was detected on the surgical specimen but not the cell block. The cell block material in these cases was paucicellular.

Conclusions.—Napsin A shows decreased sensitivity and specificity for mucinous lung tumors and is unlikely to be reliable as a sole immunohistochemical marker of lung origin for such tumors (52% specificity in this study). The high frequency of napsin A expression in gastrointestinal mucinous tumors makes it particularly unreliable in distinguishing metastatic gastrointestinal from primary lung mucinous tumors. However, napsin A expression analysis may facilitate distinguishing mucinous tumors of pulmonary from those of nongastrointestinal origin. Interpretation of napsin A staining may be problematic in mucinous tumor specimens of low cellularity such as cell blocks.

The high diagnostic accuracy of combined test of thyroid transcription factor 1 and Napsin A to distinguish between lung adenocarcinoma and squamous cell carcinoma: a meta-analysis

Background

Accurate classification of non-small cell lung cancer (NSCLC) using morphological features has several limitations. However, the use of thyroid transcription factor 1 (TTF-1) and Napsin A as markers for the identification of various subtypes of NSCLC has shown promise. This meta-analysis was designed to evaluate the diagnostic value of combined TTF-1 and Napsin A test to distinguish lung adenocarcinoma from squamous cell carcinoma.

Methods

The Medline, EMBASE and Web of Science databases were searched, along with the reference lists of relevant articles (up to May 4, 2014). Ten studies containing 1,446 subjects were identified. The sensitivity, specificity, diagnostic odds ratio (DOR) and area under the summary receiver operating characteristics curve (AUC) were calculated to estimate the combined diagnostic value of TTF-1 and Napsin A.

Results

The pooled sensitivity and specificity were 0.76 (95% CI: 0.69–0.83) and 1.00 (95% CI: 0.92–1.00), respectively. The positive and negative likelihood ratios were 877.60 (95% CI: 8.40–91533.40) and 0.24 (95% CI: 0.18–0.32). The DOR was 3719 (95% CI: 33–414884). The AUC was 0.92 (95%CI: 0.89–0.94). The patient's location was a source of heterogeneity for sensitivity. The patient's location, the study's sample size and the threshold used to determine positive staining were consistently found to be sources of heterogeneity for specificity in subgroup analyses and meta-regression.

Conclusions

The combined test of TTF-1 and Napsin A presents a promising alternative method, useful to distinguish between lung adenocarcinoma and squamous cell carcinoma.

Ten cases of resected solitary pulmonary metastases arising from gastric cancer

BACKGROUND

Because carcinomatous lymphangitis and carcinomatous pleuritis are the usual forms of metastasis associated with gastric cancer, resection of solitary pulmonary metastases arising from gastric cancer is rarely performed. To clarify the characteristics of pulmonary metastases from gastric cancer, we investigated patients who underwent resection of metastatic solitary lung tumors arising from gastric cancer.

METHODS

Between October 2003 and October 2012, 10 patients underwent pulmonary metastasectomy for metastatic gastric cancer at our institution. We retrospectively evaluated features of the primary gastric cancer and the clinicopathological features of the pulmonary metastases in these cases.

RESULTS

70% of the patients had stage II disease. Lymphatic invasion was observed in all cases of primary gastric cancer. The method of pulmonary resection was partial resection in 5 cases, segmentectomy in 1, and lobectomy in 4. On histopathological examination, immunohistochemical staining was negative for thyroid transcription factor-1 and napsin A in all cases. Patients who underwent resection of pulmonary metastases arising from gastric cancer had a good prognosis: the 4-year survival rate was 75%.

CONCLUSIONS

Carefully chosen patients have a good opportunity to obtain benefits from resection of pulmonary metastases arising from gastric cancer.