Sarcomatoid carcinomas of the lung—are these histogenetically heterogeneous tumors?

Epidemiology, site-specific characteristics and survival of carcinosarcoma: a retrospective study based on SEER database

OBJECTIVES

Carcinosarcoma (CS) is a rare and biphasic malignancy characterised by a highly invasive biological nature and poor prognosis. This study explored the epidemiology, site-specific characteristics and survival outcome of CS.

DESIGN

We conducted a retrospective study in the Surveillance, Epidemiology and End Results (SEER) database (1975-2018) for primary CS.

SETTING AND PARTICIPANTS

SEER database includes publicly available information from regional and state cancer registries in the US centres. A total of 5042 CS patients were identified. We selected the top five anatomic CS (uterus, double adnexa, lung, bladder and breast) patients for further analysis.

PRIMARY OUTCOME MEASURES

Incidence was estimated by geographical region, age, sex, race, stage and primary site. Trends were calculated using joinpoint regression. The cancer-specific survival (CSS) rate and initial treatment were summarised.

RESULTS

Nearly 80% of CS occurred in the uterus and double adnexa, followed by lung, bladder and breast. The elderly and black population presented the highest age-adjusted rate of CS. The rates of distant metastasis in CS progressively increased from 1989 to 2018. Atlanta was the area with the highest incidence at 0.7 per 100 000. Pulmonary and bladder CS more frequently occurred in men and were diagnosed with regional stage. Distant metastasis was mostly found in ovary/fallopian tube CS. Radiotherapy was more commonly applied in uterine CS, while adnexa CS cases were more likely to receive chemotherapy. Multiple treatments were more used in breast CS. Pulmonary CS seemed to suffer worse CSS (median: 9.92 months), for which radiotherapy might not provide survival benefits (HR 0.60, 95% CI 0.42 to 0.86). Compared with the common histological types in each site, CS had the shortest survival.

CONCLUSIONS

CS has unique clinical features in each primary site. Substantial prognosis variances exist based on tumour locations. The aggressive course is the common feature in CS at all sites.

Pten and p53 Loss in the Mouse Lung Causes Adenocarcinoma and Sarcomatoid Carcinoma

Simple Summary

Lung cancer is the world leading cause of cancer death. Therefore, a better understanding of the disease is needed to improve patient survival. In this work, we have deleted the tumor suppressor genes Pten and Trp53 in adult mouse lungs to analyze its impact on tumor formation. Double mutant mice develop Adenocarcinoma and Pulmonary Sarcomatoid Carcinoma, two different types of Non-Small Cell Carcinoma whose biological relationships are a matter of debate. The former is very common, with various models described and some therapeutic options. The latter is very rare with very poor prognosis, no effective treatment and lack of models reported so far. Interestingly, this study reports the first mouse model of pulmonary sarcomatoid carcinoma available for preclinical research.

Abstract

Lung cancer remains the leading cause of cancer deaths worldwide. Among the Non-Small Cell Carcinoma (NSCLC) category, Adenocarcinoma (ADC) represents the most common type, with different reported driver mutations, a bunch of models described and therapeutic options. Meanwhile, Pulmonary Sarcomatoid Carcinoma (PSC) is one of the rarest, with very poor outcomes, scarce availability of patient material, no effective therapies and no models available for preclinical research. Here, we describe that the combined deletion of Pten and Trp53 in the lungs of adult conditional mice leads to the development of both ADC and PSC irrespective of the lung targeted cell type after naphthalene induced airway epithelial regeneration. Although this model shows long latency periods and incomplete penetrance for tumor development, it is the first PSC mouse model reported so far, and sheds light on the relationships between ADC and PSC and their cells of origin. Moreover, human ADC show strong transcriptomic similarities to the mouse PSC, providing a link between both tumor types and the human ADC.

Fascin as a useful marker for cancer-associated fibroblasts in invasive lung adenocarcinoma

Cancer-associated fibroblasts (CAFs) have been attracting attention in recent years, but their nature has not been fully elucidated. Although CAFs have been recognized as an important therapeutic target, therapeutic agents have not been developed to date. CAFs are characterized by their high migration rate and involvement in epithelial-to-mesenchymal transition with some displaying a dendritic morphology that is reminiscent of fascin expression.The present study was designed to immunohistochemically investigate fascin expression in lung adenocarcinoma including CAFs and compare the results with existing CAF markers.We immunohistochemically investigated fascin expression in not only cancer tissue but also CAFs from 26 autopsy cases of lung adenocarcinoma. Immunohistochemistry of α-smooth muscle actin and fibroblast activation protein was also performed.Fascin-positive staining in CAFs was observed in all cases, with a strong correlation observed with existing CAF markers α-smooth muscle actin and fibroblast activation protein (P < .001). In addition, the proportion of tumor cells showing fascin-positive staining was found to correlate with its expression in CAFs (P < .05).We propose that CAFs express fascin, and that fascin may mediate crosstalk between cancer tissue and CAFs. Fascin might be a novel therapeutic target for treatments that target the cancer stroma.

Anlotinib Combined With Chemotherapy for Recurrence of Pulmonary Sarcomatoid Cancer Previously Surgically Treated: A Case Report and Literature Review

Background

Pulmonary sarcomatoid cancer (PSC) is a very rare subtype of poorly differentiated non-small-lung-cancer (NSCLC) with very poor prognosis. To date, the optimal treatment for PSC has not been elucidated, and the efficacy of anlotinib in PSC has not been previously reported.

Case Presentation

A 77-year-old male patient was admitted with cough, expectoration, and blood-stained sputum for one month. CT showed a soft mass in the inferior lobe of the right lung, which was diagnosed as spindle cell carcinoma (PSC) by histopathology. A videothoracoscopic right lower lobectomy and mediastinal lymph node dissection procedure was performed on the patient, but the disease recurred one month after surgery. The patient was then given first-line chemotherapy with gemcitabine and albumin paclitaxel for one cycle, but the disease continued to progress. The patient then received anlotinib combined with second-line chemotherapy (dacarbazine and cis-platinum) for six cycles, and the response reached complete remission (CR). Then the patient was given maintenance therapy with anlotinib alone, and the disease was still stable at the most recent reexamination. Progression-free survival (PFS) has lasted for more than two years, without any intolerable toxicity.

Conclusion

This postoperative recurrent PSC patient achieved significant clinical benefits with anlotinib treatment. Our findings provide direct evidence of the efficacy of anlotinib in PSC. More studies are needed to confirm our observation.

Genomic origin and intratumor heterogeneity revealed by sequencing on carcinomatous and sarcomatous components of pulmonary sarcomatoid carcinoma

Pulmonary sarcomatoid carcinoma (PSC) contains carcinomatous component (CaC) and sarcomatous component (SaC). Herein, we explored the genomic origin and intratumor heterogeneity (ITH) of PSC. We collected 31 resected PSC tumors and obtained CaC and SaC by laser capture microdissection for next-generation sequencing. The majority of PSCs (97%) had component-shared alterations. Driver mutations in EGFR, KRAS, MET, PIK3CA, and EML4-ALK fusion were mostly component-shared. Twenty-seven (87%) PSCs had component-private alterations. Compared with pure lung adenocarcinoma (LUAD), adenocarcinoma component of PSC showed lower EGFR incidence. Compared with other typical sarcomas, numerous genes of SaC exhibited significant differences. CaC and SaC had equivalent and proportional tumor mutation burden (TMB), as well as PD-L1 level. Compared with LUAD, SaC had significant higher TMB and more patients with high PD-L1 expression (tumor proportion score ≥50%). PSC with lower proportion of component-shared alterations (trunk-ratio) had a prolonged disease-free survival (DFS), regardless of the influence of clinical factors. We conclude that most PSCs originate from a monoclone accompanied by genomic ITH which is a potential independent prognostic factor, and more proportion of PSCs may be beneficial from immune checkpoint inhibitors.

Genetic heterogeneity and predictive biomarker for pulmonary sarcomatoid carcinomas

PURPOSE

The aim of this study is to investigate the genetic heterogeneity (carcinomatous vs. sarcomatous components) and predictive biomarkers in patients with pulmonary sarcomatoid carcinoma (PSC).

METHODS

Genetic alterations and biomarkers of immunotherapy were performed in a discovery set (n = 6) of PSC. Next-generation sequencing (NGS) on a pan-cancer gene panel was applied to detect the genetic alterations in each component, and the respective mutation profiling and tumor mutation burden (TMB) were compared as well. Immunohistochemistry (IHC) assay with SP263 antibody was used to detect the protein expression of programmed death-ligand 1 (PD-L1) in each component.

RESULTS

Comparative genetic analysis revealed that the separate carcinomatous and sarcomatous components shared strikingly common mutations. TP53 (4/6, 66.7%) was the most common genetic alteration in 6 PSC patients. MET exon 14 skipping was detected in one case, accounting for 16.7%. An EZR-ROS1 fusion (EZR: intron10-ROS1: intron32) was identified in one case. The TMB of the two components was similar. Nevertheless, significantly higher PD-L1 expression was found in carcinomatous components compared to sarcomatous components. MDM2 amplification was detected in 2/6 (33.3%) of cases and STK11 mutation in 1/6 (16.7%) of cases.

CONCLUSIONS

PSC containing carcinomatous and sarcomatous components had a mild heterogeneity; the two components may evolve from common ancestral cells. High PD-L1 expression suggests that immunotherapy could be used as a potential therapy for PSC patients, while patients with negative immune-responsive genes need to be screened out. Altogether, these findings further highlight that the detection of genetic alteration and PD-L1 expression plays an important role in treatment of patients with PSC.

Primary tumor and metastasis-sectioning the different steps of the metastatic cascade

Patients with lung cancer in the majority die of metastases. Treatment options include surgery, chemo- and radiotherapy, targeted therapy by tyrosine kinase inhibitors (TKIs), and immuno-oncologic treatment. Despite the success with these treatment options, cure of lung cancer is achieved in only a very small proportion of patients. In most patients’ recurrence and metastasis will occur, and finally kill the patient. Metastasis is a multistep procedure. It requires a change in adhesion of tumor cells for detachment from their neighboring cells. The next step is migration either as single cells [epithelial-mesenchymal transition (EMT)], or as cell clusters (hybrid-EMT or bulk migration). A combination of genetic changes is required to facilitate migration. Then tumor cells have to orient themselves along matrix proteins, detect oxygen concentrations, prevent attacks by immune cells, and induce a tumor-friendly switch of stroma cells (macrophages, myofibroblasts, etc.). Having entered the blood stream tumor cells need to adapt to shear stress, avoid being trapped by coagulation, but also use coagulation in small veins for adherence to endothelia, and express homing molecules for extravasation. Within a metastatic site, tumor cells need a well-prepared niche to establish a metastatic focus. Tumor cells again have to establish a vascular net for maintaining nutrition and oxygen supply, communicate with stroma cells, grow out and set further metastases. In this review the different steps will be discussed with a focus on pulmonary carcinomas. The vast amount of research manuscripts published so far are not easy to analyze: in most reports’ single steps of the metastatic cascade are interpreted as evidence for the whole process; for example, migration is interpreted as evidence for metastasis. In lung cancer most often latency periods are shorter, in between 1–5 years. In other cases, despite widespread migration occurs, tumor cells die within the circulation and do not reach a metastatic site. Therefore, migration is a requisite, but does not necessarily predict metastasis. The intention of this review is to point to these different aspects and hopefully provoke research directed into a more functional analysis of the metastatic process.

Integrated molecular characterization reveals potential therapeutic strategies for pulmonary sarcomatoid carcinoma

Pulmonary sarcomatoid carcinoma (PSC) is a rare subtype of lung cancer with poor prognosis. Here, we perform multi-omics analysis of 56 PSC samples, 14 of which are microdissected to analyze intratumoral heterogeneity. We report the mutational landscape of PSC. The epithelial and sarcomatoid components share numerous genomic alterations, indicating a common progenitor. We find that epithelial-mesenchymal transition (EMT) plays important roles in the carcinogenesis of PSC. The pan-cancer analysis reveals high tumor mutation burden and leukocyte fraction of PSC. Integrated molecular classification shows three subgroups with distinct biology, prognosis and potential therapeutic strategies. Actionable mutations are enriched in C1 and C2, patients in C3 have a significantly longer overall survival, and C1 and C2 exhibit T-cell inflamed microenvironments. The three subgroups show molecular similarities to specific subtypes of conventional lung cancer. In conclusion, our study reveals the molecular characteristics and provides entry points for the treatment of PSC.

Pulmonary sarcomatoid carcinoma (PSC) is a rare subtype of lung cancer with poor prognosis. Here the authors performed multi-omics analysis of human samples to investigate the mutational landscape of PSC and show three subgroups of PSC with distinct biology, prognosis and potential therapeutic strategies.

Immunohistochemical evaluation of mismatch repair proteins and p53 expression in extrauterine carcinosarcoma/sarcomatoid carcinoma

Introduction

Carcinosarcoma (CS) is a tumor with components: epithelial (carcinomatous) and mesenchymal (sarcomatous), developing in the mechanism of epithelial-mesenchymal transition. It is known that the p53 defect is a frequent finding in a carcinosarcoma in different anatomical locations, additionally, in a subgroup of uterine CS MMR defect plays a role in the pathogenesis. The aim of this paper was to investigate the frequency of MMR and p53 aberrations in extrauterine CS.

Material and methods

Twenty eight extrauterine CS from the lung (n = 8), breast (n = 6), head and neck (n = 5), ovary (n = 3), urinary bladder (n = 3), adrenal gland (n = 1), skin (n = 1), and stomach (n = 1) were stained for hMLH1, PMS2, hMSH2, hMSH6 and p53. The pattern of expression was evaluated separately in carcinomatous and sarcomatous component.

Results

Immunostainings for hMLH1, PMS2, hMSH2 and hMSH6 were positive in all tumors. p53 defect was observed in 19 out of 28 samples (67.85%). In all cases except one (96.42%) there was a concordance between sarcomatoid and carcinomatous components.

Conclusions

MMR deficiency does not seem to play a role in the pathogenesis of extrauterine CS. p53 aberrant expression is frequent and almost always consistent in carcinomatous and sarcomatous component.

MLH1 promoter hypermethylation in uterine carcinosarcoma rarely coexists with TP53 mutation

Introduction

Carcinosarcoma (CS) is an infrequent neoplasm composed of a carcinomatous and a sarcomatous element. Its molecular pathogenesis is poorly understood. In this study, we investigated the disturbances in the immunohistochemical expression of p53 and mismatch repair (MMR) proteins, as well as their molecular background.

Material and methods

The study group consisted of 20 uterine CSs. We analysed their morphology and immunohistochemical expression of hMLH1, hPMS2, hMSH2, MSH6, and p53 as well as the presence of mutations in TP53 and promoter methylation of the hMLH1. Loss of hMLH1 and PMS2 was found in 3/20 tumours. All cases were positive for hMSH2 and hMSH6. The TP53 mutation was detected in 8/19 tumours (42.1%), whereas MLH1 promoter hypermethylation in 4/19 cases (21%), and one case with synchronous aberrations (5%). Agreement between the results of the genetic and immunohistochemical study was moderate for p53 (k = 0.615, p< 0.01) and strong for MLH1 (k = 0.826, p< 0.01).

Results and conclusions

We demonstrated MLH1 promoter hypermethylation in uterine CS, leading to loss of MLH1 immunostaining. Concomitant aberrations of p53 and hMLH1 are infrequent. It is likely that uterine CS may develop in two independent molecular pathways in association with either chromosomal or microsatellite instability.

An Epithelial-to-Mesenchymal Transcriptional Switch Triggers Evolution of Pulmonary Sarcomatoid Carcinoma (PSC) and Identifies Dasatinib as New Therapeutic Option

PURPOSE

Pulmonary sarcomatoid carcinoma (PSC) is a rare and aggressive form of NSCLC. Rarity and poor characterization have limited the development of PSC-tailored treatment protocols, leaving patients with inadequate therapeutic options. In this study, we investigated the gene expression profile of PSCs, with the aim to characterize the molecular mechanisms responsible for their evolution and to identify new drugs for their treatment.

EXPERIMENTAL DESIGN

A training set of 17 biphasic PSCs was selected and tested for the expression of a large panel of 770 genes related to cancer progression using NanoString technology. Computational analyses were used to characterize a PSCs-gene specific signature from which pathways and drivers of PSC evolution were identified and validated using functional assays in vitro. This signature was validated in a separate set of 15 PSCs and 8 differentiated NSCLC and used to interrogate the cMAP database searching for FDA-approved small molecules able to counteract PSC phenotype.

RESULTS

We demonstrated that the transcriptional activation of an epithelial mesenchymal transition (EMT) program drives PSC phylogeny in vivo. We showed that loss of the epithelial-associated transcription factor (TF) OVOL2 characterizes the transition to sarcomatoid phenotype triggering the expression of EMT promoting TFs, including TWIST and ZEB and the expression of the membrane kinase DDR2. Finally, using a drug repurposing approach, we identified dasatinib as potential inhibitor of the PSC-gene expression signature and we confirmed in vitro that this drug efficiently restrains proliferation and reverts the sarcomatoid-associated phenotype.

CONCLUSIONS

Our data provide new insights into PSC evolution and provide the rationale for further clinical studies with dasatinib.

Spindle Cell Carcinoma of the Lung/Pleura: An Incidental Finding

A 59-year-old male with a medical history of abdominal aortic dissection underwent a follow-up computed tomography (CT) scan abdomen, which showed an incidental pleural-based mass in the left lung base. The patient underwent an ultrasound (US)-guided biopsy and the histology was consistent with spindle cell carcinoma (SpCC). Staging workup was concerning for a metastatic lesion on the adrenal gland. The patient refused surgery and was subsequently started on chemotherapy. SpCC is a rare histological variant of sarcomatoid carcinoma. The prognosis is generally poor and treatment is the same as for other non-small cell lung cancers (NSCLC). The literature on disease progression and treatment is limited.

New therapeutic targets for pulmonary sarcomatoid carcinomas based on their genomic and phylogenetic profiles. Oncotarget. 2018;9:10635-10649. [PMID: 29535832 PMCID: PMC5828205 DOI: 10.18632/oncotarget.24365]

Objectives

Pulmonary sarcomatoid carcinomas are rare and generally aggressive tumors composed of carcinomatous and sarcomatous components; however, the evolution of sarcomatoid cancer has not been elucidated. Here, we aimed to evaluate the mutational profiles and phylogeny of sarcomatoid carcinomas using next generation sequencing and in-silico analysis to facilitate the development of novel therapies.

Methods

Four patients who underwent surgery for sarcomatoid cancer were enrolled. Cancer cells were collected from carcinomatous and sarcomatous components in each tumor by laser capture microdissection. Next-generation sequencing was performed in each component, and the mutation profiles were compared. For further inference of phylogenies, phylogenetic and PyClone analyses were performed. Mismatch repair disturbance and programmed death ligand-1 (PD-L1) expression were also evaluated.

Results

Comparative genetic analysis of different histological areas revealed that the separate components shared several common mutations, which showed relatively high cellular prevalence in the PyClone statistical inference. Phylogenetic analysis showed that the sarcomatous component had ramified from the carcinomatous component in the early phase of the evolution process and accumulated a number of mutations that were different from those of the carcinomatous component. Moreover, microsatellite instability was detected in a case of sarcomatoid cancer and PD-L1 was strongly positive (≥ 50%) in all sarcomatoid cancers.

Conclusions

Our data suggest that sarcomatoid carcinoma evolves from a common ancestral clone, and its phylogenetic features may reflect high-grade malignancy in pulmonary sarcomatoid carcinoma. High tumor mutation burden and strong PD-L1 staining may provide a rationale for the use of targeted immunotherapies in pulmonary sarcomatoid carcinomas.

Pulmonary sarcomatoid carcinoma: University of Cincinnati experience

Objectives

To review the outcomes of treatment in patients with pulmonary sarcomatoid carcinoma (PSC) treated at the University of Cincinnati Medical Center (UCMC).

Results

There was no significant difference in survival of patients treated with chemotherapy alone (median, 256 days) compared to patients not undergoing treatment (median, 205.5 days). Patients who underwent surgery and adjuvant chemotherapy showed a trend in improvement of survival (median, 457.6 days). Patients requiring only surgery had the longest OS of 713.5 days.

Conclusions

Systemic chemotherapy alone did not improve survival in patients with PSC. Surgery provides the greatest overall survival benefit and adjuvant chemotherapy may also improve survival.

Methods

From 2000 to 2014, twenty-five patients with pathologically confirmed PSC were treated at UCMC. The outcomes were retrospectively analyzed by treatment with overall survival (OS) as the endpoint.

The Successful Treatment of Pulmonary Pleomorphic Carcinoma with Pembrolizumab: A Case Report

Pulmonary pleomorphic carcinomas are rare malignant tumors, and no standard treatments have been established. We herein report the successful treatment of a patient with pulmonary pleomorphic carcinoma with pembrolizumab. A 51-year-old man who was a current smoker presented to our hospital due to dyspnea and hemosputum. Chest X-ray showed right-sided pneumothorax with pleural effusion; chest tube drainage was therefore performed. Computed tomography after chest tube drainage showed a cavitary nodule in the right upper lobe and right hilar and bilateral mediastinal lymphadenopathy. Surgery was performed for the diagnosis and treatment. He was eventually diagnosed with pulmonary pleomorphic carcinoma corresponding to clinical stage IVB (cT2aN2M1c [PLE, ADR, HEP]). The giant cells strongly expressed programmed death ligand-1, and the tumor proportion score was more than 50%. Therefore, pembrolizumab was introduced as the first-line therapy. After 3 cycles of pembrolizumab, his right hilar and bilateral mediastinal lymphadenopathy and pleural dissemination notably decreased. Pembrolizumab might be an effective therapy for pulmonary pleomorphic carcinoma.

Immunohistochemical analysis of NANOG expression and epithelial-mesenchymal transition in pulmonary sarcomatoid carcinoma

Pulmonary sarcomatoid carcinomas (PSCs) are defined as a group of poorly differentiated non-small cell lung cancers that demonstrate sarcoma-like differentiation. The mechanism of mesenchymal differentiation in PSC is epithelial-mesenchymal transition (EMT). The expression of homeobox protein NANOG (NANOG), which regulates the pluripotency of embryonic stem cells, is associated with the EMT process. Therefore, the present study aimed to assess the expression level of NANOG and the status of the EMT process in PSC. The data of patients with PSC were retrospectively reviewed and immunohistochemical analyses were performed on patient samples to examine the expression of NANOG and EMT-associated proteins. The comparator group included randomly selected patients with matched clinicopathological characteristics who had pulmonary adenocarcinoma (PA). In the present study, 12 patients with PSC (4 females and 8 males) were enrolled; their median age was 65 years (range, 36-79 years), and the number of patients with stage IB, IIB, IIIA, IIIB and IV disease were 1, 1, 1, 1 and 8, respectively. The immunoreactive score (IRS) for E-cadherin was significantly lower in the PSC group compared with the PA group (P<0.0001), whereas the IRS for vimentin was significantly higher in the PSC group compared with the PA group (P<0.0001). However, the IRS for NANOG was significantly decreased in the PSC group compared with the PA group (P<0.0001), which suggests that NANOG does not serve an essential role in EMT in PSC. In addition, the overall survival of patients with PSC was significantly lower compared with that of patients with PA (median survival time, 7.0 vs. 35.6 months, respectively; P=0.0256). However, no significant difference was observed in the OS of patients who expressed low compared with high levels of NANOG (P=0.4416). In conclusion, it was clearly demonstrated that cytoplasmic NANOG expression was significantly lower in PSC compared with PA, and that the EMT process in PSC was accelerated, compared with that in PA.

Progression and metastasis of lung cancer. Cancer Metastasis Rev. 2016;35:75-91. [PMID: 27018053 PMCID: PMC4821869 DOI: 10.1007/s10555-016-9618-0]

Metastasis in lung cancer is a multifaceted process. In this review, we will dissect the process in several isolated steps such as angiogenesis, hypoxia, circulation, and establishment of a metastatic focus. In reality, several of these processes overlap and occur even simultaneously, but such a presentation would be unreadable. Metastasis requires cell migration toward higher oxygen tension, which is based on changing the structure of the cell (epithelial-mesenchymal transition), orientation within the stroma and stroma interaction, and communication with the immune system to avoid attack. Once in the blood stream, cells have to survive trapping by the coagulation system, to survive shear stress in small blood vessels, and to find the right location for extravasation. Once outside in the metastatic locus, tumor cells have to learn the communication with the “foreign” stroma cells to establish vascular supply and again express molecules, which induce immune tolerance.

Sarcomatoid lung carcinomas show high levels of programmed death ligand-1 (PD-L1) and strong immune-cell infiltration by TCD3 cells and macrophages

OBJECTIVES

Pulmonary sarcomatoid carcinomas (SC) are rare tumors, associated with worse prognosis and resistant to platinum-based regimens. Therapies targeting the PD-1/PD-L1 pathway are an emerging treatment for lung cancer. By characterizing intra-tumoral immune infiltration and evaluating PD-L1 expression, it could be possible to predict the efficacy of these new treatments.

MATERIALS AND METHODS

From 1997 to 2013, data from all patients with SC who underwent lung resection was collected. Tumor-immune infiltration and PD-L1 expression were studied by immunochemistry tests, analyzing CD3 (clone SP7), CD4 (clone 1F6), CD8 (clone C8/144b), CD20 (clone L26), CD163 (clone 10D6), MPO (clone 59A5), and PD-L1 (clone 5H1). Results were compared to those of 54 NSCLC.

RESULTS

In total, 75 SC were included. Forty (53%) SC expressed PD-L1 vs 11 NSCLC (20%) (p<0.0001). CD3+ tumor-infiltrating lymphocytes and CD163+ tumor-associated macrophages were more important in SC than in NSCLC (median 23% [17-30] of tumoral surface vs 17% [7-27], p=0.011 and 23% [17-30] vs 20% [13-23], p=0.002, respectively). In SC, the presence of Kirsten Ras (KRAS) mutations, blood vessel invasion, and TTF1+ positivity were associated with PDL1 expression. On multivariate analysis, only CD163+ macrophages and blood-vessel invasion were associated with tumoral PD-L1 expression. High levels of tumor-infiltrating lymphocytes (CD3+ or CD4+ and not CD8+) constituted a factor of good prognosis on survival. Interestingly, PD-L1 expression distinguishes subpopulations within tumor-infiltrating lymphocytes (CD3+ or CD4+) with different prognosis

CONCLUSIONS

PD-L1 expression was higher in SC than in NSCLC as well as immune-cell infiltration by TCD3 cells and macrophages. This suggests that targeting the PD-1/PD-L1 pathway could represent a new potential therapy.

[Pulmonary sarcomatoid carcinoma]. Ann Pathol. 2016;36:44-54. [PMID: 26778815 DOI: 10.1016/j.annpat.2015.11.007]

Pulmonary sarcomatoid carcinomas are a rare group of tumors accounting for about one percent of non-small cell lung carcinoma (NSCLC). In 2015, the World Health Organization classification united under this name all the carcinomas with sarcomatous-like component with spindle cell or giant cell appearance, or associated with a sarcomatous component sometimes heterologous. There are five subtypes: pleomorphic carcinoma, spindle cell carcinoma, giant cell carcinoma, carcinosarcoma and pulmonary blastoma. Clinical characteristics are not specific from the other subtypes of NSCLC. Epithelial to mesenchymal transition pathway may play a key role. Patients, usually tobacco smokers, are frequently symptomatic. Tumors are voluminous more often peripherical than central, with strong fixation on FDG TEP CT. Distant metastases are frequent with atypical visceral locations. These tumors have poorer prognosis than the other NSCLC subtypes because of great aggressivity, and frequent chemoresistance. Here we present pathological description and a review of literature with molecular features in order to better describe these tumors and perhaps introduce new therapeutics.

Histomolecular profiling of pleomorphic, spindle cell, and giant cell carcinoma of the lung for targeted therapies

In pleomorphic, spindle cell, and giant cell carcinoma (PSCGC) of the lung, we wondered if an integrated diagnosis including morphological and immunohistochemical features could be related to molecular status. We performed immunohistochemistry on 35 PSCGCs against TTF1, napsin A, p40, ALK, ROS1, and c-MET. Mutational status regarding EGFR, KRAS, BRAF, HER2, and PIK3CA genes was established. Of 18 PSCGCs with adenocarcinomatous or "undifferentiated" carcinoma differentiation, 8 were mutated for EGFR (n = 1), KRAS (n = 2), BRAF (n = 1), HER2 (n = 3), and PIK3CA (n = 1). No PSCGC (0/4) with only squamous cell or adenosquamous (0/2) differentiation was mutated. c-MET overexpression was only seen in PSCGC with adenocarcinomatous or undifferentiated component (n = 5) without squamous cell component. ROS1 and ALK were negative. The presence of a "targetable mutation" was correlated to the presence of morphological or immunohistochemical adenocarcinomatous differentiation (P = .0137). Integrated diagnosis of an adenocarcinomatous component in PSCGC could be associated with the presence of targetable gene mutation. Because only PSCGC with adenocarcinomatous or undifferentiated carcinoma harbors mutations, whereas PSCGC with only squamous or adenosquamous differentiation does not in our study, this might represent a prescreening for patients with PSCGC to be tested for molecular targets. Our results emphasize that careful morphological examination and the use of immunohistochemistry might be useful for the selection of PSCGC tested for a mutational target.

Lung adenocarcinomas: comparison between mice and men

A few human tumor types have been modeled in mice using genetic or chemical tools. The final goal of these efforts is to establish models that mimic not only the location and cellular origin of human cancers but also their genetic aberrations and morphologic appearances. The latter has been neglected by most investigators, and comparative histopathology of human versus mouse cancers is not readily available. This issue is exacerbated by the fact that some human malignancies comprise a whole spectrum of cancer subtypes that differ molecularly and morphologically. Lung cancer is a paradigm that appears not only as non-small cell and small-cell lung cancer but comprises a plethora of subtypes with distinct morphologic features. This review discusses species-specific and common morphological features of non-small cell lung cancer in mice and humans. Potential inconsistencies and the need for refined genetic tools are discussed in the context of a comparative analysis between commonly employed RAS-induced mouse tumors and human lung cancers.

Pulmonary pleomorphic carcinoma with rapid progression

We describe a case of pleomorphic carcinoma showing a recurrent tumor with massive hemorrhage and myxoid change in the chest wall 2 months after complete resection. Whereas specimens from the initial surgery revealed both adenosquamous carcinoma and sarcomatous elements, the recurrent tumor predominantly consisted of a sarcomatous element. The recurrent tumor had stronger immunoreactivity for mesenchymal markers than the primary tumor, indicating that the sarcomatous element had more malignant potential than the epithelial element.

Brain metastases from lung cancer show increased expression of DVL1, DVL3 and beta-catenin and down-regulation of E-cadherin

The susceptibility of brain to secondary formation from lung cancer primaries is a well-known phenomenon. In contrast, the molecular basis for invasion and metastasis to the brain is largely unknown. In the present study, 31 brain metastases that originated from primary lung carcinomas were analyzed regarding over expression of Dishevelled-1 (DVL1), Dishevelled-3 (DVL3), E-cadherin (CDH1) and beta-catenin (CTNNB1). Protein expressions and localizations were analyzed by immunohistochemistry. Genetic alterations of E-cadherin were tested by polymerase chain reaction (PCR)/loss of heterozygosity (LOH). Heteroduplex was used to investigate mutations in beta-catenin. DVL1 and DVL3 showed over expression in brain metastasis in 87.1% and 90.3% of samples respectively. Nuclear staining was observed in 54.8% of cases for DVL1 and 53.3% for DVL3. The main effector of the Wnt signaling, beta-catenin, was up-regulated in 56%, and transferred to the nucleus in 36% of metastases. When DVL1 and DVL3 were up-regulated the number of cases with nuclear beta-catenin significantly increased (p=0.0001). Down-regulation of E-cadherin was observed in 80% of samples. Genetic analysis showed 36% of samples with LOH of the CDH1. In comparison to other lung cancer pathologies, the diagnoses adenocarcinoma and small cell lung cancer (SCLC) were significantly associated to CDH1 LOH (p=0.001). Microsatellite instability was detected in one metastasis from adenocarcinoma. Exon 3 of beta-catenin was not targeted. Altered expression of Dishevelled-1, Dishevelled-3, E-cadherin and beta-catenin were present in brain metastases which indicates that Wnt signaling is important and may contribute to better understanding of genetic profile conditioning lung cancer metastasis to the brain.

Pulmonary pleomorphic carcinoma with multiple metastases to the right posterior knee complicated by paraneoplastic hypercalcemia

In this report, we describe the case of a 46-year-old male who presented with a three-month history of progressive intermittent pain over the right posterior knee. Magnetic resonance imaging showed soft tissue masses over the right popliteal fossa. Surgery was performed, and histological examination revealed the mass to be a sarcomatoid carcinoma of poor differentiation. Fluorodeoxyglucose (FDG)-positron emission tomography showed FDG uptake in the lungs and in the right para-aortic and popliteal regions. On the basis of the morphological and immunohistochemical features of the specimens, the patient's condition was diagnosed as a pulmonary pleomorphic carcinoma with multiple metastases. Systemic chemotherapy was initiated with paclitaxel and cisplatin. The patient then developed paraneoplastic hypercalcemia and ultimately succumbed to healthcare-acquired pneumonia. The results of this rare case indicate that pulmonary pleomorphic carcinomas respond poorly to combination chemotherapy with paclitaxel and cisplatin. The firm mass in the popliteal fossa that was situated behind the knee was considered to be a Baker cyst; however, the possibility of malignant metastatic sarcomas, such as pulmonary sarcomatoid carcinoma, should be considered in the differential diagnosis. In conclusion, we emphasize that pretherapeutic examinations should be the basis for the diagnosis of a mass lesion at either an unusual or usual site.

Emerging evidence of epithelial-to-mesenchymal transition in lung carcinogenesis

The epithelial-to-mesenchymal transition (EMT) is a developmental programme that regulates embryonic morphogenesis and involves significant morphological and molecular changes in cells. Experimental models have revealed that EMT also contributes to various malignant features of cancer cells, including motile, invasive, anti-apoptotic and stem-like phenotypes. Clinically, correlative studies have indicated that mesenchymal-like features of tumour cells are associated with poor tumour differentiation as well as worse patient prognosis. Nevertheless, due to its transitory nature, demonstration of an actual occurrence of EMT during human carcinogenesis is challenging, and most of the evidence to date has been limited to breast and colorectal cancers. However, recent studies suggest that EMT may occur during lung cancer development, although such evidence is still limited. We propose three approaches for obtaining direct evidence of EMT in human cancers and use these criteria to review the available data. We suggest that multiple intrinsic and extrinsic factors cooperatively induce EMT in lung cancer. Intrinsic factors include oncogenic genetic changes such as mutant K-RAS. Extrinsic factors are associated with a tumour microenvironment that is inflammatory and hypoxic. The induction of EMT is primarily mediated by various EMT-inducing transcription factors that suppress E-cadherin expression, including SLUG and ZEB1. miR-200 family expression can reverse EMT by suppressing EMT- inducing transcription factors. Obviously, more data demonstrating the clinical relevance of EMT in lung cancer are required, and further elucidation of how EMT is regulated in lung cancer will enable us to develop novel therapeutics that specifically target molecules with critical roles in EMT.

[Pulmonary sarcomatoid carcinoma]

Pulmonary sarcomatoid carcinomas are a rare group of tumors accounting for about 1 % of non-small cell lung carcinoma (NSCLC). In 2004, World Health Organization classification united under this name all the carcinomas with sarcomatous or sarcomatous-like component with spindle cell or giant cell appearance. There are five subtypes: spindle cell carcinoma, giant cell carcinoma, pleomorphic carcinoma, carcino-sarcoma and pulmonary blastoma. Clinical characteristics are not specific from the others subtypes of NSCLC. Epithelial to mesenchymal transition pathway may play a key role. Patients are frequently symptomatic. Tumors are voluminous more often peripherical than central, with strong fixation on FDG TEP CT. Distant metastasis are frequent with atypical locations such as peritoneal or retroperitoneal sites. These tumors have poorer prognosis than the other NSCLC subtypes because of great aggressivity, and frequent chemoresistance. Here, we present a review of litterature in order to better describe these tumors.

Adenocarcinoma with sarcomatous dedifferentiation arising from mature cystic teratoma of the anterior mediastinum

Mediastinal teratoma with malignant transformation (TMT) is a very rare condition. A 44-year-old man presented with a large cystic mass of the anterior mediastinum. The tumor was surgically removed. The cystic mass was well demarcated, with an irregularly thickened wall. Histologically, the cystic wall was mainly lined by non-ciliated columnar epithelium and focally by squamous epithelium. A nodular part of the cystic wall revealed well-differentiated adenocarcinoma composed of tubulopapillary structures. Deep in the nodular tissue, neoplastic glands merged into undifferentiated sarcomatous cells. Immunohistochemically, CK7, CK19, and smad-4 were strongly and diffusely positive in adenocarcinoma. CD10 was focally positive on the luminal surface of the glands, and MUC5AC was also focally positive. TTF-1, cdx-2, and CK20 were negative in the adenocarinoma. Sarcomatous area showed diffuse strong positivity for vimentin, but was negative for the aforementioned epithelial markers. About 10 months postoperatively, a left pleural effusion had developed with multiple pleural nodules on computed tomography scan of the chest. The cytologic diagnosis from pleural fluid was metastatic adenocarcinoma. To our knowledge, in the English literature, this is the first case of adenocarcinoma with sarcomatous transformation that has developed in a mature cystic teratoma of the mediastinum and shows pleural metastasis.

Epithelial-mesenchymal transition in pulmonary carcinosarcoma: case report and literature review

Pulmonary carcinosarcoma is a rare and aggressive neoplasm that has both epithelial and mesenchymal components. We report on a 63-year-old woman who was found to have a right upper-lobe pulmonary carcinosarcoma with metastases to the liver and gastric fundus. There are currently no published guidelines on the treatment of pulmonary sarcomatoid carcinomas. However, with our expanding knowledge of cancer metastasis, cases of carcinosarcoma illustrate our current understanding of epithelial-mesenchymal transition in action. Here, we discuss the development and treatment of these biphasic tumors and the possible role of epithelial-mesenchymal transition.

Expression profiles of carcinosarcoma of the uterine corpus-are these similar to carcinoma or sarcoma?

Uterine carcinosarcoma (CS) is usually classified as uterine endometrial carcinoma (EC). However, CS is more aggressive even compared with high grade EC. CS is also reported to undergo epithelial to mesenchymal transition (EMT). In this study, we compared the gene expression profiles of CS, EC, and uterine sarcoma (US) and evaluated the role of EMT and chromosomal aberrations in CS tumor formation. Frozen tissues of 46 patients (14 CS, 24 EC, and 8 US) were included. The similarity was examined by Gene Set Enrichment Analysis (GSEA), Fisher's exact test, and clustering using "intrinsic gene set". We examined the expression of 39 EMT-related genes and evaluated TGF-beta signaling by phospho-SMAD2/3 (p-SMAD2/3) staining. Chromosomal regions differing between CS and EC were identified by chromosomal GSEA and comparative genomic hybridization (CGH) microarrays. Three statistical methods confirmed that CS resembled US rather than EC. Acquired markers of EMT were upregulated and attenuated markers of EMT were downregulated in CS. Immunohistochemistry showed that carcinomatous region of CS have higher expression of p-SMAD2/3 than EC (P = 0.008). Chromosomal GSEA showed that genes located at 19q13 had higher expression in CS. Furthermore, CGH microarray indicated that the TGFB1 locus at 19q13.1 was amplified in 4 of 7 samples. Based on the expression profile, CS resembles US rather than EC. TGF-beta signaling is activated in CS and chromosomal gains at 19q13, which includes the TGFB1 locus, suggest that this may contribute to high expression of TGF-beta and thereby EMT phenotype of CS.

Molecular profiles of EGFR, K-ras, c-met, and FGFR in pulmonary pleomorphic carcinoma, a rare lung malignancy

BACKGROUND

Pulmonary pleomorphic carcinoma (PPC) is a rare type of lung cancer characterized by the poor response to conventional chemotherapy and subsequent disappointing outcomes. Therefore, it is paramount to delineate the molecular characteristics of this disease entity.

METHODS

In this study, we retrospectively examined the surgical specimens of 61 patients who underwent lung surgery. Mutational or gene amplification statuses of epidermal growth factor receptor (EGFR), k-ras, c-kit, c-met, and fibroblast growth factor receptor (FGFR) were examined using genomic DNA sequencing, real-time PCR and/or fluorescence in situ hybridization (FISH).

RESULTS

The median age was 61 years, and 50 patients were men and 11 were women. In the histologic review of epithelial component, adenocarcinoma were in 44 cases (72%), squamous cell carcinoma in 15 (25%) and large cell carcinoma in 2 patients (3%). Overall, 30 cases (49%) had any molecular alterations. Nine patients (15%) possessed EGFR deletion in exon 19 (n = 8) or L858R mutations in exon 21 (n = 1), while 3 other cases having atypical EGFR mutations. Six patients (9.8%) had k-ras mutations in exon 12, and 3 had c-kit mutations. High gene copy number of c-met was found in 11 patients (18.0%) and that of FGFR was in 6 patients (9.8%). No significant relationships were identified among the occurrence and type of mutations and patient survival or any other clinicopathological variables.

CONCLUSIONS

Given the diverse repertoire of mutational profiles observed in PPC samples, clinical trials based on accurate cancer-genotyping should be considered as a legitimate treatment scheme for this rare disease entity in the future.

The prognostic impact of TGF-β1, fascin, NF-κB and PKC-ζ expression in soft tissue sarcomas

Aims

Transforming growth factor-β (TGF-β), fascin, nuclear factor-kappa B (NF-κB) p105, protein-kinase C-zeta (PKC-ζ), partioning-defective protein-6 (Par-6), E-cadherin and vimentin are tumor promoting molecules through mechanisms involved in cell dedifferentiation. In soft tissue sarcomas, their expression profile is poorly defined and their significance is uncertain. We aimed to investigate the prognostic impact of TGF-β1, NF-κB p105, PKC-ζ, Par-6α, E-cadherin and vimentin in non-gastrointestinal stromal tumor soft tissue sarcomas (non-GIST STSs).

Patients and Methods

Tumor samples and clinical data from 249 patients with non-GIST STS were obtained, and tissue microarrays (TMAs) were constructed for each specimen. Immunohistochemistry (IHC) was used to evaluate marker expression in tumor cells.

Results

In univariate analysis, the expression levels of TGF-β1 (P = 0.016), fascin (P = 0.006), NF-κB p105 (P = 0.022) and PKC-ζ, (P = 0.042) were significant indicators for disease specific survival (DSS). In the multivariate analysis, high TGF-β1 expression was an independent negative prognostic factor for DSS (HR = 1.6, 95% CI = 1.1–2.4, P = 0.019) in addition to tumor depth, malignancy grade, metastasis at diagnosis, surgery and positive resection margins.

Conclusion

Expression of TGF-β1 was significantly associated with aggressive behavior and shorter DSS in non-GIST STSs.

Combined small-cell carcinoma of the lung with quadripartite differentiation of epithelial, neuroendocrine, skeletal muscle, and myofibroblastic type

The combined variant of small-cell lung carcinoma (SCLC) refers to the variable admixture of small cell and non-small cell carcinoma, whereas the association with sarcoma or sarcoma-like elements is exceedingly rare. A 76-year-old Caucasian man underwent right upper lobectomy with regional lymphadenectomy because of a symptomatic 7 cm-sized tumor mass. Formalin fixed-paraffin embedded material was used to highlight several differentiation cell lineages by means of immunohistochemistry, electron microscopy, and mutational assay. The tumor was discovered as being IIB stage (pT2b pN1(1/51) pM0) and featured biphasic appearance with close intermingling of SCLC (40%) and collagen-rich spindle cell sarcoma (60%). Epithelial (cytokeratins, TTF-1), neural (neurofilaments, GFAP), endocrine (chromogranin, synaptophysin, CD56), and skeletal muscle (desmin, sarcomeric actin, myogenin) markers were variably co-expressed by SCLC elements, whereas mesenchymal (vimentin), smooth muscle (actin, myosin, H-caldesmon, calponin), fibroblastic (CD10), and, more focally, skeletal muscle (desmin, sarcomeric actin and myogenin) markers were highlighted in the spindle cell sarcoma elements. TP53 codon V274F mutation in exon 8 was shared by either cell component. After undergoing adjuvant chemotherapy, the patient is currently alive and well at the 40-month follow-up. To the best of our knowledge, this is the first report of combined SCLC with quadripartite differentiation of epithelial, neuroendocrine, skeletal muscle, and myofibroblastic type, somewhere at the level of the same individual tumor cells. This tumor had probably derived for clonal evolution of a p53-mutated common ancestor lesion.

Small bowel intussusception due to metastatic intestinal carcinosarcoma from a pulmonary primary

Metastatic small bowel tumors are rarely encountered. They usually present with small bowel obstruction, perforation, bleeding, or, rarely, intestinal intussusception. Only a few case reports have mentioned bowel symptoms due to metastatic malignancies. We report a seldom encountered clinical condition of intestinal intussusception from metastatic lung malignancy. Pathology demonstrated both epithelial and mesenchymal content, and the final diagnosis was carcinosarcoma. This case report indicates that intestinal metastases should be considered in the differential diagnosis for patients with lung malignancy and abdominal symptoms.

A systems view of epithelial-mesenchymal transition signaling states

Epithelial–mesenchymal transition (EMT) is an important contributor to the invasion and metastasis of epithelial-derived cancers. While considerable effort has focused in the regulators involved in the transition process, we have focused on consequences of EMT to prosurvival signaling. Changes in distinct metastable and ‘epigentically-fixed’ EMT states were measured by correlation of protein, phosphoprotein, phosphopeptide and RNA transcript abundance. The assembly of 1167 modulated components into functional systems or machines simplified biological understanding and increased prediction confidence highlighting four functional groups: cell adhesion and migration, metabolism, transcription nodes and proliferation/survival networks. A coordinate metabolic reduction in a cluster of 17 free-radical stress pathway components was observed and correlated with reduced glycolytic and increased oxidative phosphorylation enzyme capacity, consistent with reduced cell cycling and reduced need for macromolecular biosynthesis in the mesenchymal state. An attenuation of EGFR autophosphorylation and a switch from autocrine to paracrine-competent EGFR signaling was implicated in the enablement of tumor cell chemotaxis. A similar attenuation of IGF1R, MET and RON signaling with EMT was observed. In contrast, EMT increased prosurvival autocrine IL11/IL6-JAK2-STAT signaling, autocrine fibronectin-integrin α5β1 activation, autocrine Axl/Tyro3/PDGFR/FGFR RTK signaling and autocrine TGFβR signaling. A relatively uniform loss of polarity and cell–cell junction linkages to actin cytoskeleton and intermediate filaments was measured at a systems level. A more heterogeneous gain of ECM remodeling and associated with invasion and migration was observed. Correlation to stem cell, EMT, invasion and metastasis datasets revealed the greatest similarity with normal and cancerous breast stem cell populations, CD49f^hi/EpCAM^-/lo and CD44^hi/CD24^lo, respectively.

Sarcomatoid neoplasms of the lung and pleura

Sarcomatoid neoplasms of the lung and pleura are rare tumors that present a complex differential diagnosis, making them challenging for surgical pathologists. In the lung, the main tumors are the sarcomatoid carcinomas, including pleomorphic carcinoma, spindle cell carcinoma, giant cell carcinoma, carcinosarcoma, and pulmonary blastoma. They are characterized by histologic heterogeneity; molecular data support their origin from a pluripotent stem cell that undergoes neoplastic transformation with divergent epithelial and sarcomatous differentiation. Diagnosis is difficult in small biopsy specimens and typically requires a resection specimen. Despite the presence of sarcomatoid features, these tumors are classified as lung carcinomas. Pulmonary blastomas must be distinguished from pleuropulmonary blastomas, which are a unique type of thoracic sarcoma typically occurring in young children. In the pleura, the main tumors to consider are the sarcomatoid and desmoplastic types of malignant mesothelioma, solitary fibrous tumor, and desmoid tumor. While light microscopy is sufficient to diagnose most of these tumors, immunohistochemistry can be useful in selected settings. In particular, it can aid to confirm epithelial differentiation in spindle cell carcinomas and the presence of rhabdomyosarcoma in sarcomatoid carcinomas, mesotheliomas, or pleuropulmonary blastomas. For sarcomatoid and desmoplastic mesothelioma, keratin is the most useful stain because it can highlight invasive growth and mesothelial markers are positive in only the minority of cases. Clinical and radiologic correlation is needed to separate some pleomorphic carcinomas with pleural involvement from sarcomatoid malignant mesothelioma, since these poorly differentiated tumors may not express the usual immunohistochemical markers for carcinoma or mesothelioma.

Adult jejunojejunal intussusception caused by metastasized pleomorphic carcinoma of the lung: report of a case

Adult small-intestinal intussusception is rare and very different from childhood intussusception. Both benign and malignant pathologies can underlie small intestinal intussusception in adults, but malignancy is much less frequent. We report a case of jejunojejunal intussusception caused by an intestinal metastasis of the sarcomatoid component of pleomorphic carcinoma of the right lung. The patient, a 61-year-old man, underwent successful segmental jejunal resection. Adult small bowel intussusception, though an unusual cause of acute abdomen, requires early diagnosis and timely management. To our knowledge, this is the first report of adult jejunojejunal double intussusception caused by metastatic sarcomatoid carcinoma of the lung.

Sarcomatoid lung carcinomas: a case series

We report on three Caucasian Greeks 2 males and 1 female (67, 54 and 62 years old) that were operated with sarcomatoid carcinoma of the lung, an uncommon tumor that sometimes is referred as pleomorphic carcinoma (spindle and giant cell carcinomas). These tumors are encountered in the thorax far more often than true sarcomas. There are many erroneous reports of pulmonary sarcomas made before the advent of adjunctive pathologic screening, including immunohistochemical studies. Pulmonary Sarcomatoid Carcinomas represent 0.2-1% of all lung cancers in different series and they are considered that they are not significantly aggressive than ordinary lung carcinoma.

Review article: pulmonary sarcomatoid carcinomas: a practical overview

Pulmonary sarcomatoid carcinomas (PSCs) are currently defined as poorly differentiated non-small-cell carcinomas containing a component with sarcoma or sarcoma-like (spindle and/or giant cell) features. They consist of 5 major histological variants, namely pleomorphic carcinoma, spindle cell carcinoma, giant cell carcinoma, carcinosarcoma, and pulmonary blastoma. The segregation of PSCs into a distinct clinicopathologic entity seems justified on the basis of morphologic, behavioral, and genotypic/phenotypic attributes. As a group, PSCs generally run an aggressive clinical course and may cause major difficulties in the differential diagnosis with other primary and secondary malignancies of the lung. At present, PSCs are believed to represent a family of carcinomas "in transition," in which diverse pathways of clonal evolution account for histological differences of a common ancestor lesion. The sarcomatous or sarcomatoid component of these tumors is thought to derive from carcinoma cells during the progression of carcinogenesis through the activation of an epithelial-mesenchymal transition program leading to sarcomatous transformation or metaplasia (conversion paradigm). Conceivably, targeting the epithelial-mesenchymal transition program could become a valid therapeutic strategy for these life-threatening tumors, whose sensitivity to current medical manipulation is disappointing.