Blood vessel invasion is a major feature and a factor of poor prognosis in sarcomatoid carcinoma of the lung

Preoperative Maximum Standardized Uptake Value Emphasized in Explainable Machine Learning Model for Predicting the Risk of Recurrence in Resected Non-Small Cell Lung Cancer

PURPOSE

To comprehensively analyze the association between preoperative maximum standardized uptake value (SUVmax) on 18F-fluorodeoxyglucose positron emission tomography-computed tomography and postoperative recurrence in resected non-small cell lung cancer (NSCLC) using machine learning (ML) and statistical approaches.

PATIENTS AND METHODS

This retrospective study included 643 patients who had undergone NSCLC resection. ML models (random forest, gradient boosting, extreme gradient boosting, and AdaBoost) and a random survival forest model were developed to predict postoperative recurrence. Model performance was evaluated using the receiver operating characteristic (ROC) AUC and concordance index (C-index). Shapley additive explanations (SHAP) and partial dependence plots (PDPs) were used to interpret model predictions and quantify feature importance. The relationship between SUVmax and recurrence risk was evaluated by using a multivariable Cox proportional hazards model.

RESULTS

The random forest model showed the highest predictive performance (ROC AUC, 0.90; 95% CI, 0.86 to 0.97). The SHAP analysis identified SUVmax as an important predictor. The PDP analysis showed a nonlinear relationship between SUVmax and recurrence risk, with a sharp increase at SUVmax 2-5. The random survival forest model achieved a C-index of 0.82. A permutation importance analysis identified SUVmax as the most important feature. In the Cox model, increased SUVmax was associated with a higher risk of recurrence (adjusted hazard ratio, 1.03 [95% CI, 1.00 to 1.06]).

CONCLUSION

Preoperative SUVmax showed significant predictive value for postoperative recurrence after NSCLC resection. The nonlinear relationship between SUVmax and recurrence risk, with a sharp increase at relatively low SUVmax values, suggests its potential as a sensitive biomarker for early identification of high-risk patients. This may contribute to more precise assessments of the risk of recurrence and personalized treatment strategies for NSCLC.

Dramatic response of advanced pulmonary sarcomatoid carcinoma to tislelizumab combined with anlotinib: a case report

Pulmonary sarcomatoid carcinoma (PSC) is a scarce pathologic type of lung cancer of non-small cell lung cancer (NSCLC) that exhibits resistance to conventional chemotherapy and radiotherapy, resulting in a poor prognosis. Herein, a 67-year-old man was admitted to the hospital in January 2022 with a diagnosis of PSC for over 6 months and a newly discovered brain metastasis for 4 days. He had previously undergone two unsuccessful chemotherapy regimens: bevacizumab combined with pemetrexed and loplatin, and albumin-bound paclitaxel combined with loplatin. Radiotherapy was performed for the brain and skull metastases, followed by treatment with tislelizumab combined with anlotinib, a programmed cell death protein 1 (PD-1) inhibitor with anti angiogenic drug, respectfully. The patient initially received nine cycles of treatment with tislelizumab and anlotinib, resulting in a significant shrinkage of the lung tumor. Subsequently, anlotinib was discontinued due to bleeding in the brain metastasis, and the patient received two additional cycles of tislelizumab. Following improvement in the hemorrhage from brain metastasis, the patient received two cycles of treatment with tislelizumab and anlotinib. Treatment was subsequently interrupted for 1 month due to the coronavirus disease 2019 (COVID-19) pandemic, which then resumed with two additional cycles of tislelizumab and anlotinib. Finally, the patient refused to continue treatment due to the progression of the brain metastasis and economic conditions, despite the stable condition. At this point, the patient has achieved over a year of progression-free survival, with overall survival exceeding 39 months. This case illustrates the efficacy and safety of combining antitumor immunotherapy with anlotinib, a targeted anti-angiogenic therapy.

Impact of the number of dissected lymph nodes on machine learning-based prediction of postoperative lung cancer recurrence: a single-hospital retrospective cohort study

BACKGROUND

The optimal number of lymph nodes to be dissected during lung cancer surgery to minimise the postoperative recurrence risk remains undetermined. This study aimed to elucidate the impact of the number of dissected lymph nodes on the risk of postoperative recurrence of non-small cell lung cancer (NSCLC) using machine learning algorithms and statistical analyses.

METHODS

We retrospectively analysed 650 patients with NSCLC who underwent complete resection. Five machine learning models were trained using clinicopathological variables to predict postoperative recurrence. The relationship between the number of dissected lymph nodes and postoperative recurrence was investigated in the best-performing model using Shapley additive explanations values and partial dependence plots. Multivariable Cox proportional hazard analysis was performed to estimate the HR for postoperative recurrence based on the number of dissected nodes.

RESULTS

The random forest model demonstrated superior predictive performance (area under the receiver operating characteristic curve: 0.92, accuracy: 0.83, F1 score: 0.64). The partial dependence plot of this model revealed a non-linear dependence of the number of dissected lymph nodes on recurrence prediction within the range of 0-20 nodes, with the weakest dependence at 10 nodes. A linear increase in the dependence was observed for ≥20 dissected nodes. A multivariable analysis revealed a significantly elevated risk of recurrence in the group with ≥20 dissected nodes in comparison to those with <20 nodes (adjusted HR, 1.45; 95% CI 1.003 to 2.087).

CONCLUSIONS

The number of dissected lymph nodes was significantly associated with the risk of postoperative recurrence of NSCLC. The risk of recurrence is minimised when approximately 10 nodes are dissected but may increase when >20 nodes are removed. Limiting lymph node dissection to approximately 20 nodes may help to preserve a favourable antitumour immune environment. These findings provide novel insights into the optimisation of lymph node dissection during lung cancer surgery.

Surgically resected sarcomatoid carcinoma of the lung: a nationwide retrospective study in 2010

BACKGROUND

Sarcomatoid carcinoma of the lung is a rare histological type of non-small cell lung cancer with a poor prognosis. We aimed to investigate the clinicopathological characteristics and prognostic factors of surgically resected sarcomatoid carcinoma of the lung.

METHODS

We retrospectively reviewed 14999 patients who underwent surgical resection for non-small cell lung cancer accumulated by the Japanese Joint Committee of Lung Cancer Registry in 2010. Clinicopathological characteristics and survival were compared between the sarcomatoid carcinoma and other non-small cell cancer groups. The prognostic factors in the sarcomatoid carcinoma group were identified using a multivariate Cox proportional hazard model.

RESULTS

Patients with sarcomatoid carcinoma comprised 1.4% of all patients. The sarcomatoid carcinoma group demonstrated a more aggressive pathology with presentation at more advanced stages, requiring more frequent extensive surgical resections. The sarcomatoid carcinoma group had remarkably poorer overall and recurrence-free survival than the other non-small cell lung cancer group. Adjuvant chemotherapy was associated with improved survival for pathological stage II-III sarcomatoid carcinoma cases rather than for pathological stage I disease. In the multivariate analysis, larger tumor size, lymphatic permeation, and no adjuvant chemotherapy were associated with the sarcomatoid carcinoma group's overall and recurrence-free survival.

CONCLUSIONS

Surgically resected sarcomatoid carcinoma of the lung has a higher aggressive and metastatic potential and a worse prognosis than other non-small cell lung cancers. Adjuvant chemotherapy, which was associated with enhanced survival in patients with pathological stage II-III of the disease, could be considered for treating patients with pathological stage II-III sarcomatoid carcinoma of the lung.

Pulmonary sarcomatoid carcinoma: A rare case report, diagnostic dilemma and review of literature

RATIONALE

Pulmonary sarcomatoid carcinoma (PSC), a rare tumor, comprises 0.1% to 0.4% of all malignant lung tumors. Given the rarity of PSC, its clinical course, therapeutic guidelines, and patient outcomes remain largely unknown. Therefore, it is imperative to alert clinicians to this extremely rare and instructive early-onset cancer.

PATIENT CONCERNS

This report describes a 28-year-old woman with PSC, who was initially misdiagnosed with Whipple's disease. A conclusive diagnosis of PSC was made following careful clinical examination, imaging, and histopathological evaluation of the patient's biopsy sample. Radiological imaging revealed multiple nodules and mass formations in the left upper lobe of the patient's lung, with the largest measuring of 5.4 × 3.2 cm.

DIAGNOSIS

Histopathological examination indicated the presence of a malignant neoplasm associated with necrosis suggestive of sarcoma, which was pathologically staged as cT4N1M1.

INTERVENTIONS AND OUTCOMES

A regimen of doxorubicin and ifosfamide was administered therapeutically, resulting in a stable disease state.

LESSONS

The rarity and tumor origin challenge the diagnosis, which emphasizes the imperative role of histological examination, immunohistochemistry, and flow cytometry in achieving an accurate diagnosis. This report summarizes the existing publications to provide a comprehensive overview of PSC, including its clinical manifestations, radiographic imaging, pathologic features, diagnostic challenges, treatment strategies, and prognosis, and aims to improve the understanding of PSC.

Nonlinear association between PD-L1 expression levels and the risk of postoperative recurrence in non-small cell lung cancer

Accurate prediction of postoperative recurrence is important for optimizing the treatment strategies for non-small cell lung cancer (NSCLC). Previous studies identified the PD-L1 expression in NSCLC as a risk factor for postoperative recurrence. This study aimed to examine the contribution of PD-L1 expression to predicting postoperative recurrence using machine learning. The clinical data of 647 patients with NSCLC who underwent surgical resection were collected and stratified into training (80%), validation (10%), and testing (10%) datasets. Machine learning models were trained on the training data using clinical parameters including PD-L1 expression. The top-performing model was assessed on the test data using the SHAP analysis and partial dependence plots to quantify the contribution of the PD-L1 expression. Multivariate Cox proportional hazards model was used to validate the association between PD-L1 expression and postoperative recurrence. The random forest model demonstrated the highest predictive performance with the SHAP analysis, highlighting PD-L1 expression as an important feature, and the multivariate Cox analysis indicated a significant increase in the risk of postoperative recurrence with each increment in PD-L1 expression. These findings suggest that variations in PD-L1 expression may provide valuable information for clinical decision-making regarding lung cancer treatment strategies.

Case report: Sintilimab combined with anlotinib as neoadjuvant chemotherapy for metastatic bone tumor resection in patients with PSC

Background

Pulmonary sarcomatoid carcinoma (PSC) is a rare subtype of non-small-cell lung cancer (NSCLC), which is resistant to chemotherapy and radiotherapy with a poor prognosis. PSC is highly malignant and is prone to recurrence even after surgery. The programmed death-ligand 1 (PD-L1) tumor cell proportion score (TPS) 5%, TERT and TP53 gene mutations were detected in this patient accompanied by multiple metastatic sites. The anlotinib is a novel multitarget tyrosine kinase inhibitor (TKI) that could be effective for advanced NSCLC and some sarcoma patients. Limited clinical trials and case reports have shown that PSC patients with gene mutations and PD-L1 expression have good responses to multitarget antiangiogenic drug and immune checkpoint inhibitors (ICIs). In this article, we reported a case with metastatic PSC diagnosed by Computed Tomography (CT)-guided needle biopsy treated with immunotherapy combined with antiangiogenic drugs as a neoadjuvant chemotherapy (NACT). PSC is controlled and the patient achieves successfully limb salvage treatment by surgical resection. Therefore, targeted therapy and immunotherapy can provide sufficient surgical opportunities for limb salvage in the treatment of metastatic PSC patients.

Case summary

A 69-year-old male diagnosed with malignant bone tumor in the proximal femur was admitted to our hospital in June 2022 with recurrent fever as well as swelling and pain in the left thigh for twenty days. The initial computed tomography (CT) scan of the chest showed a pulmonary cavity (20 mm × 30 mm) and scattered lung masses. Subsequently, he underwent a CT-guided needle biopsy to distinguish the essence of osteolytic bone destruction and soft tissue mass in the left proximal femur which showed metastatic sarcomatoid carcinoma histology. Genetic testing revealed TERT c.-124C mutation (abundance 8.81%), TP53 p.R342 mutation (abundance 11.35%), tumor mutational burden (TMB) 7.09 muts/Mb, microsatellite stability (MSS), and PD-L1 (SP263) TPS 5% were also detected. The patient was tentatively treated with a combination of antiangiogenic drug and PD-1 inhibitor. After one course, the tumor volume significantly reduced in magnetic resonance imaging (MRI) and pathological fracture occurred in the femur after combined treatment. The patient received proximal femoral tumor resection and prosthesis replacement after defervescence. Sequentially sintilimab with anlotinib were administered for over 1 year. Finally, the local tumor was well controlled, and no obvious drug-related adverse reactions were observed. The lesions in the lung remained in partial response (PR) for more than 16 months and complete response (CR) of metastatic tumor in the proximal femur was observed through imaging examinations.

Conclusion

This is the first reported case of a metastatic PSC in femur showing a favorable response to the treatment consisting of anlotinib combined with sintilimab. This case suggests that antiangiogenic therapy combined with immunotherapy may benefit patients with metastatic PSC in the preoperative adjuvant therapy for limb salvage.

Recording and classifying MET receptor mutations in cancers

Tyrosine kinase inhibitors (TKI) directed against MET have been recently approved to treat advanced non-small cell lung cancer (NSCLC) harbouring activating MET mutations. This success is the consequence of a long characterization of MET mutations in cancers, which we propose to outline in this review. MET, a receptor tyrosine kinase (RTK), displays in a broad panel of cancers many deregulations liable to promote tumour progression. The first MET mutation was discovered in 1997, in hereditary papillary renal cancer (HPRC), providing the first direct link between MET mutations and cancer development. As in other RTKs, these mutations are located in the kinase domain, leading in most cases to ligand-independent MET activation. In 2014, novel MET mutations were identified in several advanced cancers, including lung cancers. These mutations alter splice sites of exon 14, causing in-frame exon 14 skipping and deletion of a regulatory domain. Because these mutations are not located in the kinase domain, they are original and their mode of action has yet to be fully elucidated. Less than five years after the discovery of such mutations, the efficacy of a MET TKI was evidenced in NSCLC patients displaying MET exon 14 skipping. Yet its use led to a resistance mechanism involving acquisition of novel and already characterized MET mutations. Furthermore, novel somatic MET mutations are constantly being discovered. The challenge is no longer to identify them but to characterize them in order to predict their transforming activity and their sensitivity or resistance to MET TKIs, in order to adapt treatment.

Case report: Successful treatment of advanced pulmonary sarcomatoid carcinoma with BUBIB-ALK rearrangement and KRAS G12C mutation by sintilimab combined with anlotinib

Pulmonary sarcomatoid carcinoma (PSC) is a rare and aggressive subtype of non-small cell lung cancer (NSCLC) that is characterized by poor differentiation and invasiveness. According to the World Health Organization, PSC exhibits sarcoma or sarcomatoid differentiation and typically presents with an insidious onset, lacking specific symptoms and signs. It is associated with high malignancy, early metastasis, short survival time, and a poor prognosis. Treatment for PSC follows a similar approach to NSCLC; however, it presents significant challenges due to its high resistance to chemotherapy. Previous research has demonstrated the coexistence of two or more target mutations in PSC, and the presence of multiple mutations is correlated with higher mortality rates compared to single mutations. This is supported by our case study of a male patient with advanced BUBIB-ALK rearrangement and KRAS G12C missense mutation. There is currently no standard treatment protocol available for patients with this condition. The patient showed rapid progression after 1 month of alectinib treatment and was intolerant to paclitaxel + cisplatin chemotherapy. Following this, successful disease control was achieved with a combination therapy of sintilimab and anlotinib. The patient achieved a progression-free survival (PFS) of over 20 months, and long-term follow-up is still ongoing for the patient. Based on our clinical experience, the combination of anlotinib and programmed death-1 (PD-1) inhibitors may be a promising strategy for PSC patients, particularly those with multi-target mutations who do not respond to ALK-TKI and are resistant to chemotherapy.

Anlotinib combined with pembrolizumab as first-line treatment for advanced pulmonary sarcomatoid carcinoma: a case report and literature review

Pulmonary sarcomatoid carcinoma (PSC) is an uncommon variant of non-small cell lung cancer (NSCLC), known for its unfavorable prognosis. Previous studies have elucidated that PSC generally exhibits a significant expression of programmed death-ligand 1 (PD-L1), an elevated tumor mutation burden, and marked vascular invasion. These factors imply the possible effectiveness of treatments like immunotherapy and anti-angiogenic therapy. The subject of this case was a 65-year-old male diagnosed with advanced PSC, characterized by high PD-L1 expression and devoid of known driver gene mutations. Owing to the restrictions imposed by the COVID-19 pandemic, the patient initially underwent home-based treatment with anlotinib, which led to symptomatic improvement after a single treatment cycle. Subsequent hospitalization allowed for the administration of anlotinib plus Pembrolizumab, resulting in a partial response. Radiotherapy was necessitated due to local disease progression. But after 15 cycles of treatment with Pembrolizumab, hyperprogression was observed. The patient's overall survival spanned 14 months, with no evident adverse reactions to the medications. Genomic analysis revealed potential associations between treatment efficacy and mutations in the TP53, NF1, and MET genes. This case underscores the effectiveness and safety of a first-line treatment regimen combining pan-target anti-angiogenic therapy (anlotinib) with anti-tumor immunotherapy.

Individual risk and prognostic value prediction by machine learning for distant metastasis in pulmonary sarcomatoid carcinoma: a large cohort study based on the SEER database and the Chinese population

Background

This study aimed to develop diagnostic and prognostic models for patients with pulmonary sarcomatoid carcinoma (PSC) and distant metastasis (DM).

Methods

Patients from the Surveillance, Epidemiology, and End Results (SEER) database were divided into a training set and internal test set at a ratio of 7 to 3, while those from the Chinese hospital were assigned to the external test set, to develop the diagnostic model for DM. Univariate logistic regression was employed in the training set to screen for DM-related risk factors, which were included into six machine learning (ML) models. Furthermore, patients from the SEER database were randomly divided into a training set and validation set at a ratio of 7 to 3 to develop the prognostic model which predicts survival of patients PSC with DM. Univariate and multivariate Cox regression analyses have also been performed in the training set to identify independent factors, and a prognostic nomogram for cancer-specific survival (CSS) for PSC patients with DM.

Results

For the diagnostic model for DM, 589 patients with PSC in the training set, 255 patients in the internal and 94 patients in the external test set were eventually enrolled. The extreme gradient boosting (XGB) algorithm performed best on the external test set with an area under the curve (AUC) of 0.821. For the prognostic model, 270 PSC patients with DM in the training and 117 patients in the test set were enrolled. The nomogram displayed precise accuracy with AUC of 0.803 for 3-month CSS and 0.869 for 6-month CSS in the test set.

Conclusion

The ML model accurately identified individuals at high risk for DM who needed more careful follow-up, including appropriate preventative therapeutic strategies. The prognostic nomogram accurately predicted CSS in PSC patients with DM.

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.

Characteristics and Prognostic Analysis of 55 Patients With Pulmonary Sarcomatoid Carcinoma

Pulmonary sarcomatoid carcinoma (PSC) is a rare and aggressive subtype of non-small-cell lung cancer (NSCLC). Here, we present information on the clinicopathologic characteristics and clinical outcomes of this type of cancer. Clinicopathologic data from 55 patients treated at a single cancer center from January 2011 to December 2018 were retrospectively analyzed. The patients were mostly male (76.4%), with a median age of 66 years and a history of smoking (54.5%). Most had symptoms, and about 60% presented with locally advanced or metastatic disease at diagnosis. Of the 55 cases, 21 were diagnosed by surgical resection. Pleomorphic cancer was the most common subtype (58.1%). With a median follow-up period of 13.2 months, the average survival time of the patients was 16.1 months, and the median survival time was 12 months. The overall survival rates for 1, 2, and 3 years were 52.7%, 18.2%, and 9.1%, respectively. Univariate analysis showed that prognosis of the patients was influenced by tumor size, T stage, metastatic status, and surgery (p < 0.05). Multivariate analysis showed that T stage (p = 0.034) was an independent prognostic factor. There are few reports on the natural history of PSC, and its clinicopathological characteristics remain unclear. Herein, a retrospective review 55 individuals with PSC found that T stage was an independent predictor of survival. Surgical resection was associated with better prognosis.

Adjuvant chemotherapy for pulmonary sarcomatoid carcinoma: A retrospective analysis of the National Cancer Database

OBJECTIVES

Pulmonary sarcomatoid carcinoma (PSC) is a rarely occurring variant of non-small cell lung cancer with sarcoma-like features. Compared with traditional non-small cell lung cancer, PSC patients typically present later and have poorer prognoses, irrespective of stage. The standard of care is resection, but guidelines for the use of adjuvant chemotherapy have not been established. To advance the development of evidence-based management algorithms for PSC after resection, a statistical analysis on a nationwide representative sample of patients was performed.

METHODS

A retrospective cohort study was performed by querying the National Cancer Database for patients with a diagnosis of PSC between 2004 and 2015. Patients who received complete anatomical resection with or without adjuvant chemotherapy were included. Multivariable regression was used to detect factors associated with the receipt of adjuvant chemotherapy. Multivariable Cox regression of overall survival and Kaplan-Meier survival analysis on propensity-matched groups was conducted to study the association between adjuvant chemotherapy and prognosis.

RESULTS

We included 1497 patients with PSC in the final analysis. Factors associated with receiving adjuvant chemotherapy were age, histology, and receipt of adjuvant radiation. The results of multivariable Cox analysis and Kaplan-Meier analysis on propensity matched groups yielded similar trends: adjuvant chemotherapy was associated with improved 5-year overall survival for stage II and III disease, but not for stage I disease.

CONCLUSIONS

Multiple factors are associated with receipt of adjuvant chemotherapy for PSC, and this treatment appears to be associated with improved survival in stage II and stage III, but not stage I patients.

Multimodality Treatment of Pulmonary Sarcomatoid Carcinoma: A Review of Current State of Art

Pulmonary sarcomatoid carcinoma (PSC) is an unconventional non-small-cell lung cancer (NSCLC) that is currently managed under guidelines used for conventional NSCLC and has poor survival. Surgery is the optimal choice for resectable PSC, and the prevalence of mutations in this type of tumor laid the foundation for novel systemic therapies such as targeted therapy and immunotherapy. PSC is resistant to chemotherapy and radiotherapy, and the effects of the 2 therapies are controversial. Targeted therapies have been reported to confer survival benefits, and savolitinib, an oral selective MET tyrosine-kinase inhibitor, has been approved in metastatic patients with MET exon 14 skipping mutations. Expression and positive rate of programmed death ligand 1 in PSC are high; our previous research has also revealed a high mutational burden and a T-cell-inflamed microenvironment of PSC. Correspondingly, immune checkpoint inhibitors have shown preliminary antitumor effects (overall response rates of 40.5% (15/37) and 31.6% (6/19) in two retrospective studies, respectively) in PSC patients. In summary, patients should receive operations at an early stage and multimodality treatments are needed to maximize the benefits of patients with advanced disease.

The treatment of advanced pulmonary sarcomatoid carcinoma

Pulmonary sarcomatoid carcinoma (PSC) is a pathological subtype of non-small cell lung cancer. Although the incidence of PSC in lung cancer is very low, it is an aggressive cancer, leading to a poor prognosis. Currently, there is no standard treatment for advanced PSC. Targeted therapy can be used for patients with MET exon 14 mutations and patients with other driver gene mutations may also benefit from treatment. The emergence of immune checkpoint inhibitors also provides potential options for advanced PSC treatment, but more clinical data is needed. Additionally, more research may be warranted to explore the effects of chemotherapy, radiotherapy and antiangiogenic therapy. In this review, the authors summarize the research regarding the treatment of advanced PSC.

Rare cutaneous metastasis from sarcomatoid carcinoma of lung

We present the case of a 57-year-old woman diagnosed with stage 4 sarcomatoid carcinoma of the lung who concurrently developed a scalp lesion, thought to be a cyst, which continued to grow and ulcerate. Excision revealed a rare case, only four previously reported in the literature, of metastatic sarcomatoid carcinoma of the lung. While a very unusual case, we would like to emphasise the importance of considering skin metastases when presented with unusual skin lesions, and importantly listening to the patient's concerns, showing empathy and respecting their autonomy and referring to an appropriate specialist when considering the management of what may seem to be a minor skin report.

Integrin-linked kinase pathway in heterogeneous pulmonary sarcomatoid carcinoma

Pulmonary sarcomatoid carcinoma (PSC) is classified as poorly differentiated, and non-small cell lung carcinomas that contained a component of sarcoma or sarcoma-like differentiation are rare. The underlying carcinogenetic mechanism governing PSC remains unclear. The current study investigated the underlying carcinogenetic mechanism of PSC based on the hypothesis that it involves the epithelial-mesenchymal transition (EMT) process. Mutation analysis of PSCs, including carcinosarcoma, pleomorphic carcinoma and epithelial carcinoma specimens, was performed using targeted deep sequencing, whole transcriptome analysis and digital spatial profiling (DSP). PSCs exhibit a distinct mutation profile, with TP53, SYNE1 and APC mutations. Therefore, clustering of the gene expression profiles allowed the PSCs to be distinguished from the epithelial carcinomas. Increased gene expression of fibronectin in PSC was an important contributor to differential profiles. Pathway analysis revealed enhanced activity of the integrin-linked kinase (ILK) signaling pathway in the PSCs. DSP analysis using 56 antibodies of marker proteins confirmed significantly higher expression of fibronectin in PSCs. Intratumor heterogeneity of fibronectin expression was observed in sarcoma components. In conclusion, epithelial-mesenchymal transition process mediated by ILK signaling may be associated with carcinogenetic mechanisms of PSC. Overexpression of fibronectin mediated by ILK signaling appears to serve a role in the EMT involved in the PSC transformation process.

Remarkable response to pembrolizumab with platinum-doublet in PD-L1-low pulmonary sarcomatoid carcinoma: A case report

Pulmonary sarcomatoid carcinoma (SC) is an aggressive subtype of lung cancer that exhibits resistance to cytotoxic chemotherapy. Although programmed cell death 1 (PD‐1) inhibitors have been reported to show antitumor effects in patients with high programmed death‐ligand 1 (PD‐L1) expressing SC, the efficacy of combined therapy with PD‐1 inhibitor plus cytotoxic chemotherapy has not previously been clarified. We herein report a case of SC with low expression of PD‐L1 and few pre‐existing tumor‐infiltrating lymphocytes which showed a remarkable response to pembrolizumab plus cytotoxic chemotherapy as first‐line treatment. Our findings suggest that combined treatment might enhance the immunogenic response, even in immunologically ignored SCs.

Clinicopathological features and prognostic analysis of metastatic pulmonary sarcomatoid carcinoma: a SEER analysis

Background

Pulmonary sarcomatoid carcinoma (PSC) is a rare type of non-small cell lung cancer (NSCLC). Metastases are often detected at the first diagnosis. Despite high rates of distant metastasis, there is insufficient data describing the characteristics of PSC metastasis.

Methods

We performed a Surveillance, Epidemiology, and End Results (SEER) database-based analysis of clinicopathological features and prognosis of distant metastasis in PSC patients. Data queried for this analysis included PSC patients in the database between 2010 and 2016.

Results

A total of 934 patients met the criteria for inclusion in the analysis and included, at the time of diagnosis, 512 (54.8%) patients with metastasis, including bone (n=152; 16.3%), brain (n=108; 11.6%), liver (n=70; 7.5%), lung (n=142; 15.2%) metastases. Binary logistic regression showed that patients with giant cell carcinoma [odds ratio (OR) 4.023, 95% confidence interval (CI): 2.113-7.661, P<0.001] and spindle cell carcinoma (OR 3.151, 95% CI: 1.699-5.843, P<0.001) were associated with metastasis. Log-rank test and Kaplan-Meier plots indicated poor prognosis in metastatic patients [the 1-, 3-, and 5-year overall survival (OS) rates were 14.1%, 5.5%, and 4.8%, respectively]. Multivariable analysis showed younger and chemotherapy as improved prognostic factors of PSC patients with single metastasis site.

Conclusions

The SEER database-based analysis revealed the clinical features of distant metastasis of PSC and showed that different histological types posed distinct metastasis potential. Besides, age and chemotherapy were the independent prognostic factors of PSC patients with single metastasis site.

The genomic and immunologic profiles of pure pulmonary sarcomatoid carcinoma in Chinese patients

PURPOSE

The distribution of genetic mutations differs between pure pulmonary sarcomatoid carcinoma (PSC) and biphasic PSC; however, most of the enrolled cases in previous studies are biphasic PSC. The current study aimed to investigate the genomic and immunologic profiles of pure PSC in the Chinese population.

MATERIALS AND METHODS

Next-generation sequencing analysis of a panel of 1021 genes was performed on surgical specimens of 58 pure PSCs. The tumor mutational burden (TMB) was calculated from 0.69 megabases (Mbs) of sequenced DNA. PD-L1 expression was evaluated by immunohistochemistry. Microsatellite instability (MSI) was evaluated by fluorescence-labeled microsatellite marker polymerase chain reaction followed by capillary electrophoresis fragment size analysis.

RESULTS

The top mutational genes of pure PSC were TP53 (74 %, 43/58), KRAS (24 %, 14/58), SMARCA4 (14 %, 8/58), MET (12 %, 7/58), EGFR (10 %, 6/58), MLL4 (10 %, 6/58), NF1 (10 %, 6/58), NOTCH4 (10 %, 6/58), and TERT (10 %, 6/58). The median TMB was 8.6 mutations/Mb; 37.9 % of cases (22/58) had a TMB > 10 mutations/Mb and 12.1 % of cases (7/58) had a TMB > 20 mutations/Mb. The median TMB was higher in TP53-mutant tumors than in wild-type tumors (10.1 versus 7.2 mutations/Mb, p = 0.019). Thirty-five patients had microsatellite-stable pure PSC, and four patients carried MSI-H tumors. The MSI status was independent of MET exon 14 status. Twenty-six patients (45 %) had PD-L1-positive tumors (≥1%) and 14 (24 %) had high PD-L1 expression (≥50 %).

CONCLUSION

In our cohort, 45 % of patients with pure PSC harbored at least one actionable alteration. More importantly, more than 60 % of patients (65.5 %, 38/58) had either MSI-H, PD-L1-positive, or high-TMB tumors, and these might derive survival benefits from immune checkpoint inhibitors.

Preoperative systemic immune-inflammation index predicts survival and recurrence in patients with resected primary pulmonary sarcomatoid carcinoma

Background

Pulmonary sarcomatoid carcinoma (PSC) is a rare lung cancer subtype. Studies concerning PSC are limited and controversial; therefore, we analyzed the treatment and outcomes of PSC utilizing a relatively large single-institution database.

Methods

From January 2003 to December 2018, 262 consecutive PSC patients treated at our institution were retrospectively reviewed. The clinical characteristics, treatments, and outcomes were analyzed.

Results

The median survival time (MST) was 22.0 months, with 1-, 3-, and 5-year overall survival (OS) rates of 59.9%, 40.1%, and 36.1%, respectively. Patients who underwent surgery had a significantly better prognosis than patients who received nonsurgical treatment (MST, 23.0 vs. 11.0 months, P=0.016). The use of surgery followed by adjuvant therapy significantly prolonged survival in stage III patients (MST, 17.0 vs. 8.0 months, P=0.003) but not in stage I and II patients. Multivariate analysis showed that a systemic inflammation-immune index (SII) value >430.8, TNM stage and necrosis were independent prognostic predictors of OS and disease-free survival (DFS) in radically resected PSC patients (P<0.05). In addition, SII and necrosis were independent risk factors for recurrence after the radical resection of PSC (P<0.05).

Conclusions

PSC is aggressive and has a poor prognosis. Surgery should be the mainstay treatment for operable cases, and adjuvant therapy is recommended for locally advanced disease. A novel potential biomarker, SII, which is an integrated parameter based on preoperative lymphocyte, neutrophil, and platelet counts, may be useful for prognostic prediction and the identification of resected PSC patients at high risk for recurrence.

Pulmonary sarcomatoid carcinoma: progress, treatment and expectations

Pulmonary sarcomatoid carcinoma (PSC) is a unique, highly invasive pulmonary malignancy with a poor prognosis, representing 0.1-0.4% of all malignant lung tumors. Because of its highly aggressive character and propensity for frequent metastasis, PSC shows low response rates to traditional treatments such as chemotherapy, radiotherapy, and neoadjuvant therapy. In recent years, considerable progress has been made in gene sequencing, targeted therapies, and immunotherapies. One of the most promising treatment approaches is the selection of mono-targeted or multi-targeted drugs according to tumor gene-mutation sites, such as epidermal growth factor receptor or vascular endothelial growth factor receptor 2 (EGFR/VEGFR2), anaplastic lymphoma kinase (ALK), and others. Another approach is the activation of therapeutic anti-tumor immunity via pathways including programmed cell-death protein-1/programmed cell-death ligand-1 (PD-1/PD-L1), which has been used in individual cases. In this review, we will introduce the clinicopathologic features, molecular typing, and traditional treatments. We will also review the biological characteristics and the latest therapies for PSC. These novel therapies show promise in the management of PSC, and the outcomes of investigative trials will hopefully reveal a variety of treatment options for patients with PSC.

Emerging MET tyrosine kinase inhibitors for the treatment of non-small cell lung cancer

Introduction MET aberrations, including MET exon 14 skipping mutation and amplification, are present in ~5% of non-small cell lung cancer (NSCLC) cases, and these levels are comparable to the frequency of ALK fusion. MET amplification also occurs as an acquired resistance mechanism in EGFR-mutated NSCLC after EGFR tyrosine kinase inhibitors (TKI) treatment failure. Therefore, the development of therapies for activated MET is urgently needed. Areas covered This review summarizes (1) the mechanisms and frequencies of MET aberrations in NSCLC, (2) the efficacies and toxicities of MET-TKIs under clinical development and (3) the mechanisms of inherent and acquired resistance to MET-TKIs. Expert opinion Type Ia, Ib and II MET-TKIs are currently under clinical development, and phase I/II studies have shown the potent activities of tepotinib, capmatinib and savolitinib; in fact, tepotinib and capmatinib were approved for use by health authorities. However, inherent and acquired resistance through on- and off-target mechanisms has been detected, and strategies to overcome this resistance are being developed.

Clinical Significance of PIK3CA Gene in Non-Small-Cell Lung Cancer: A Systematic Review and Meta-Analysis

Aim

To explore the clinicopathological and prognostic role of PIK3CA gene mutation and expression in non-small-cell lung cancer (NSCLC) patients.

Methods

A systematic and comprehensive literature search was conducted through EMBASE (via OVID), Web of Science, and PubMed. Relative risks (RRs) and hazard ratios (HRs) with 95% confidence intervals (CIs) were combined to evaluate the relationship of the PIK3CA gene with clinicopathological parameters and the survival of NSCLC patients, respectively.

Results

A total of 13 studies involving 3908 patients were analyzed in our study. Only lymph node metastasis status had an association with PIK3CA mutation (RR = 2.823; 95% CI: 1.128-7.065; P = 0.029). The results indicated that PICK3CA mutation was related with overall survival (OS) (HR = 1.55; 95% CI: 1.13-2.13; P = 0.007), progression-free survival (PFS) (HR = 1.48; 95% CI: 1.06-2.08; P = 0.023), and cancer-specific survival (CSS) (HR = 2.63; 95% CI: 1.00-6.92; P = 0.005). Furthermore, PIK3CA high expression was more prevalent in NSCLC patients with smoking history (RR = 2.42; 95% CI: 1.04-5.61; P = 0.040). However, no significant relation between PIK3CA expression and OS was found (HR = 0.80; 95% CI: 0.58-1.12; P = 0.193).

Conclusion

PIK3CA mutation may affect lymph node metastasis and serve as a promising prognostic factor, and smoking may be related with PIK3CA high expression in NSCLC patients. However, more well-designed prospective researches are needed to verify the abovementioned findings.

Analysis of targeted somatic mutations in pleomorphic carcinoma of the lung using next-generation sequencing technique

BACKGROUND

Pleomorphic carcinoma (PC) of the lung is a rare type of lung cancer with aggressive characteristics and a poor prognosis. Because it is rare, the molecular characteristics of PC remain unclear.

METHODS

A gene mutation analysis was performed using next-generation sequencing (NGS) in patients with PC of the lung who had undergone surgical resection.

RESULTS

A total of nine patients were enrolled in the study. All the patients were male and eight had a history of smoking. Eight tumors contained spindle cells and three contained giant cells. Mutations considered significant were found in eight of the nine patients: in TP53 in five patients, in MET in two patients, and in ALK, ERBB2, PIK3CA, APC, NF1, and CDKN2A in one patient each. No EGFR mutation was detected in our analysis. Co-mutations were detected in three patients: TP53 with MET and NF1, TP53 with ERBB2, and PIK3CA with CDKN2A.

CONCLUSIONS

TP53 mutations were detected most frequently in PC of the lung with NGS analysis. Different co-mutations were seen in several specimens.

KEY POINTS

Significant findings of the study This study demonstrates that mutations in the TP53 gene are frequently found and co-mutations are sometimes found in pleomorphic carcinoma of the lung using genomic profiling analysis. What this study adds Our results will help to analogize the genetic characteristics and potential target of molecular-targeted agents of pleomorphic carcinoma of the lung.

Significant benefits of pembrolizumab in treating refractory advanced pulmonary sarcomatoid carcinoma: A case report

BACKGROUND

Pulmonary sarcomatoid carcinoma (PSC), a rare subtype of non-small cell lung cancer (NSCLC), is poorly differentiated and highly aggressive. Treatment is limited, and the prognosis is poor. Pembrolizumab is an anti-programmed death (PD)-1 antibody with good efficacy in NSCLC. Recent studies have demonstrated that PD-ligand 1 (PD-L1) overexpression is common in PSCs, which suggests that anti-PD-L1 treatment is an ideal option. However, the response to pembrolizumab in PSC has not been studied.

CASE SUMMARY

We present a PSC case with PD-L1 overexpression that significantly benefited from pembrolizumab. A 73-year-old Chinese male was detected with a right lung lesion. Pathological analysis of the right upper lobectomy confirmed PSC. The PD-L1 test revealed overexpression (TPS: 90%). Multiple metastases occurred 1 mo after surgery, representing stage IV PSC. Neither first-line chemotherapy nor second-line antiangiogenic agents showed any benefit. Radiotherapy (1200 cGy) was administered to relieve chest wall pain. The patient received the PD-1 inhibitor pembrolizumab (100 mg) as third-line therapy; however, because of fever and severe infection, he refused to receive immunotherapy any longer. Thus, only one dose of pembrolizumab was administered. Deep sustained remission of most of the metastases was achieved except for lesions in the right adrenal gland, which first shrank and then progressed. The patient died because of disease progression in the right adrenal gland. He achieved a progression-free survival time of 8 mo and an overall survival time of 9 mo with third-line pembrolizumab.

CONCLUSION

Our findings highlight and offer direct evidence of the efficacy of pembrolizumab in PD-L1-overexpressing PSCs. Combined radiotherapy and immunotherapy may enhance treatment efficacy.

First-line albumin-bound paclitaxel/carboplatin plus apatinib in advanced pulmonary sarcomatoid carcinoma: A case series and review of the literature

RATIONALE

Pulmonary sarcomatoid carcinoma (PSC) is an uncommon type of non-small cell lung cancer, exhibiting aggressive behavior and resistance to the conventional chemoradiotherapy. To date, the optimal treatment for PSC has not been elucidated.

PATIENT CONCERNS

Three male patients including a 69-year-old smoker (Case 1), a 45-year-old non-smoker (Case 2), and a 69-year-old smoker (Case 3) were admitted because of cough, back pain, and loss of body weight respectively.

DIAGNOSES

Radiographical examinations in these patients showed bulky intrathoracic lesions, which were pathologically diagnosed as PSC staging III-IV by computed tomography-guided percutaneous biopsy and endoscopy.

INTERVENTIONS

Immunotherapy was not covered by their health insurance and they refused immune checkpoint inhibitors for financial reasons. In addition, a radical resection was not appropriate due to the advanced staging of these lesions. Therefore, first-line albumin-bound paclitaxel (nab-paclitaxel, 260 mg/m of the body surface area) and carboplatin (area under curve 5) combined with oral apatinib (425 mg, daily) were administered empirically.

OUTCOMES

Two patients achieved a partial response and the other case showed stable disease lasting for more than 6 months. However, 1 of them indicated progression on the 7-month follow up.

LESSONS

Nab-paclitaxel/carboplatin plus apatinib showed limited short-term efficacy in advanced, unresectable PSC. The rapid resistance of PSC to the current therapeutic regimen necessitates further researches, as more effective agents are urgently needed.

Efficacy of Immune Checkpoint Inhibitors in Lung Sarcomatoid Carcinoma

INTRODUCTION

Immune checkpoint inhibitors (ICIs) have improved cancer prognosis but have not been evaluated specifically in sarcomatoid carcinoma (SC), a rare lung cancer subtype with poor prognosis. As such, our study sought to retrospectively assess the efficacy of ICI in SC.

METHODS

All consecutive patients with centrally confirmed SC treated using ICI as a second-line treatment or beyond between 2011 and 2017 were enrolled. Programmed death-ligand 1 (PD-L1) tumor expression was assessed using immunohistochemistry (SP263 clone) and the tumor mutational burden (TMB) with the Foundation One panel. TMB was considered high if it was greater than or equal to 10 mutations per megabase.

RESULTS

Overall, 37 patients with SC were evaluated, predominantly men (73%) with a median age of 63.2 years (36.8-79.7) and who were current or former smokers (94.6%). Immunotherapy (nivolumab, 86.5% of cases) was given as a second-line treatment in 54% of the patients and as third-line treatment or beyond in 46% of the patients. The objective response rate was 40.5% and disease control rate was 64.8%, regardless of PD-L1 status. Median overall survival was 12.7 months (range: 0.3-45.7). One-third of patients exhibited early progression. The median PD-L1 expression was 70% (0-100). There was a trend toward higher PD-L1 expression in responsive diseases, with an objective response rate of 58.8% in patients with PD-L1+ and 0% in the one patient with PD-L1- (p = 0.44). The median TMB was 18 (4-39) mutations per megabase, with 87.5% of the cases displaying a high TMB. There was a trend toward higher TMB in responders versus stable or progressive diseases (p = 0.2).

CONCLUSIONS

Patients with SC exhibited high response rates and prolonged overall survival under ICI treatment. These data support the prospective investigation of ICI in patients with SC who are under first-line treatment.

Frequent Mutations of POT1 Distinguish Pulmonary Sarcomatoid Carcinoma From Other Lung Cancer Histologies

INTRODUCTION

Pulmonary sarcomatoid carcinoma (PSC) is a rare subtype of non-small-cell lung cancer (NSCLC) harboring mutations in many canonical NSCLC-driver genes (eg, TP53, KRAS, MET). Protection of telomeres 1 (POT1) mutations are observed in angiosarcoma and chronic lymphocytic leukemia, but their frequency in other solid tumors, including NSCLC subtypes, has not been rigorously explored.

MATERIALS AND METHODS

We analyzed next-generation sequencing data from 62,368 tumors, including 11,134 NSCLCs and 100 PSCs. We performed logistic regression to identify associations between POT1 mutation frequency and tumor histology across 184 tumor categories, adjusting for tumor mutational burden. We further explored co-occurring gene mutations in genes previously reported to underlie PSC tumorigenesis.

RESULTS

Across 184 tumor categories, POT1 mutations were most frequent in PSC and were 14 times more common in PSC (28%) than in other tumor types (P = 1.23 × 10^-31) and 6.7 times more common in PSC than other NSCLCs (P = 5.1 × 10^-17). PSCs harboring KRAS mutations were significantly more likely to harbor POT1 mutations (P = 1.3 × 10^-3), whereas those with TP53 mutations were less likely to harbor POT1 mutations (P = .037). One-fourth of POT1-mutated PSCs harbored a second POT1 mutation. Across all PSCs, 83% of POT1 mutations were in the OB1/OB2 (DNA-binding) domain (P = 1.5 × 10^-5), an enrichment not observed in other tumor types.

CONCLUSION

We report an unanticipated association between POT1 mutation and PSC. Unlike other molecular alterations that are frequent across NSCLC subtypes, POT1 mutations are largely unique to PSC. This finding may help to develop disease-defining molecular subgroups within PSC and presents opportunities for molecularly stratified prognostication and therapy.

The characteristic of tumor immune microenvironment in pulmonary carcinosarcoma

Pulmonary carcinosarcoma (PCS) is a rare but aggressive neoplasm, due to late diagnosis and early metastasis. Surgery combined with radiotherapy is a standard treatment. However, PCS features an easy relapse after surgery resection and resistance to chemotherapy and radiotherapy. Tumor immune microenvironment reflects tumor immunophenotyping and affects immunotherapy efficiency. This review summarized current studies on the characteristic of tumor immune microenvironment in PCS and discussed the potential of immunotherapy combined with other regimes strategy as a candidate for treatments in PCS.

Approaches to Tumor Classification in Pulmonary Sarcomatoid Carcinoma

Pulmonary sarcomatoid carcinoma (PSC) is a heterogeneous category of primary lung cancer accounting from 0.3% to 3% of all primary lung malignancies. According to the most recent 2015 World Health Organization (WHO) classification, PSC includes several different variants of malignant epithelial tumors (carcinomas) histologically mimicking sarcomas showing or entirely lacking a conventional component of non-small cell lung cancer (NSCLC). Thus, this rare subheading of lung neoplasms includes pleomorphic carcinoma, spindle cell carcinoma, giant cell carcinoma, pulmonary blastoma, and carcinosarcoma. A diagnosis of PSC may be suspected on small biopsy or cytology, but commonly requires a surgical resection to reach a conclusive definition. The majority of patients with PSC consists of elderly, smoking men with a large, peripheral mass characterized by well-defined margins. However, presentation with a central, polypoid endobronchial lesion is well-documented, particularly in pleomorphic carcinoma and carcinosarcoma showing a squamous cell carcinoma component. As expected, PSC may pose diagnostic problems and immunohistochemistry is largely used when pathologists deal these tumors in routine practice. Indeed, PSC tends to overexpress molecules associated with the epithelial-to-mesenchymal transition, such as vimentin, but the panel of immunostains also includes epithelial markers (cytokeratins, EMA), TTF-1, p40 and negative markers (e.g., melanocytic, mesothelial and sarcoma-related primary antibodies). Although rare, PSC has increased their interest among oncologist community for different reasons: a. identification of the epithelial-to-mesenchymal phenomenon as a major mechanism of secondary resistance to tyrosine kinase inhibitors; b. over-expression of PD-L1 and effective treatment with immunotherapy; c. identification of c-MET exon 14 skipping mutation representing an effective target to crizotinib and other specific inhibitors. In this review, the feasibility of the diagnosis of PSC, its differential diagnosis and novel molecular findings characterizing this group of lung tumor are discussed.

PD-L1 and CD47 co-expression in pulmonary sarcomatoid carcinoma: a predictor of poor prognosis and potential targets of future combined immunotherapy

PURPOSE

Combined immunotherapy with anti-programmed cell death-ligand 1 (PD-L1) and an inhibitor of cluster of differentiation 47 (CD47) have exhibited preliminary anti-tumor effect. Our study attempted to describe the PD-L1/CD47 expression status in pulmonary sarcomatoid carcinoma (PSC), and explore its survival impact and relevance with cytotoxic T lymphocytes and macrophages infiltration.

METHODS

148 patients with PSC who underwent surgeries were retrospectively reviewed. Tissue microarrays were conducted for immunohistochemistry (IHC) of PD-L1, CD47, CD8 and CD68.

RESULTS

54 (36.5%) and 78 (52.7%) cases were positive for PD-L1 and CD47, respectively, and 36 (24.3%) of them demonstrated PD-L1/CD47 co-expression. There was a significant correlation between PD-L1 and CD47 expression (P = 0.011). The median overall survival (OS) was 22.5 months (range 0.9-102.4 months). The univariate analysis demonstrated a significantly worse OS in cases with CD47 expression (hazard ratio [HR], 1.66; 95% CI, 1.14-2.42, P = 0.008) and PD-L1/CD47 co-expression (HR, 1.75; 95% CI, 1.15-2.67, P = 0.009). The multivariate analysis demonstrated PD-L1/CD47 co-expression (HR, 1.83; 95% CI, 1.17-2.87, P = 0.008), T stage, M stage, completeness of resection and adjuvant therapy were independent prognostic factors for OS. There was a significant relevance between PD-L1 expression and PD-L1/CD47 co-expression with higher densities of CD8-positive T lymphocytes (P = 0.004, 0.012, respectively) and CD68-positive macrophages (P = 0.026, 0.034, respectively).

CONCLUSION

We demonstrated the PD-L1/CD47 co-expression status in PSC. PD-L1 expression correlated with CD47 expression, and PD-L1/CD47 co-expression correlated with poorer prognosis and may serve as a predictive biomarker for combined dual-targeting immunotherapy in PSC patients.

Uncommon Types of Lung Carcinoma With Mixed Histology: Sarcomatoid Carcinoma, Adenosquamous Carcinoma, and Mucoepidermoid Carcinoma

CONTEXT

- Lung tumors are histologically heterogeneous, but classification of lung carcinoma has prognostic impact and increasingly, specific molecular correlates.

OBJECTIVE

- To update the gross, microscopic, and molecular pathology of unusual lung carcinomas to assure accurate classification. In entities with mixed histology, the recognition of specific features or rare patterns is critical to diagnosis. These diagnoses can identify tumors with aggressive clinical behavior, and diagnostic pitfalls can therefore result in underdiagnosis of these already rare entities. Incorrect classification of more indolent tumors into the more aggressive categories can also occur. In the area of molecular pathology, these unusual tumors have a specific spectrum of molecular alterations.

DATA SOURCES

- PubMed searches for lung and sarcomatoid carcinoma, pleomorphic carcinoma, blastoma, carcinosarcoma, and adenosquamous and mucoepidermoid carcinoma were undertaken and this information was integrated with clinical experience of the author.

CONCLUSIONS

- These uncommon carcinomas have specific clinicopathologic features, and attention to their gross and microscopic pathology leads to classification with important associated molecular findings.

A High PD-L1 Expression in Pulmonary Pleomorphic Carcinoma Correlates with Parietal-pleural Invasion and Might Predict a Poor Prognosis

Objective Pleomorphic carcinoma (PC) is a rare pulmonary epithelial malignant tumor with a poor prognosis. The objective of the present study was to investigate the programmed death-ligand 1 (PD-L1) expression in PC and its correlation between the clinicopathological factors and prognosis. Methods Clinical and pathological data of 35 patients with surgically resected PC encountered from 2002 to 2016 at our institution were collected. The PD-L1 expression on tumor cells was evaluated via immunohistochemistry (clone 22C3). We examined the correlation between the PD-L1 expression and patients' clinicopathological factors and their prognosis. Results A high PD-L1 expression (≥50%) was seen in 21 (60%) patients, and parietal-pleural invasion was significantly correlated with a high PD-L1 expression (p=0.012). The 5-year overall survival and relapse-free survival were 68.2% and 43.2%, respectively. Tumor size ≥50 mm (p=0.021), lymph node metastasis (p=0.023), and a high PD-L1 expression (p=0.047) were correlated with a short relapse-free survival. Since lymph node metastasis was an independent risk factor of a poor overall survival (p=0.012), patients with a high PD-L1 expression also tended to have a worse overall survival than those with low levels (p=0.081). Conclusion A high PD-L1 expression is frequently seen in PC. The PD-L1 expression is associated with parietal-pleural invasion and might indicate a poor prognosis.

[Current Status of Diagnosis and Treatment of Pulmonary Sarcomatoid Carcinoma]

Pulmonary sarcomatoid carcinoma (PSC) is a rare, poorly differentiated, subtype of non-small cell lung carcinoma (NSCLC) and constitutes approximately 0.1% to 0.5% of all lung malignancies. PSC can be divided into five subtypes based on the 2015 World Health Organization (WHO) classification of lung tumors: pleomorphic carcinoma, spindle cell carcinoma, giant cell carcinoma, carcinosarcoma, and pulmonary blastoma. Some imaging characteristics can be found for PSC although no special symptoms. The accurate pathological diagnosis of PSC can be a significant challenge, which depends on pathology and immunohistochemistry. PSC should be managed similar to other NSCLC, surgical resection is the standard management for early stage cases, moreover, multimodal treatment should be considered. However, PSC is insensitive to radiotherapy and chemotherapy, and has high rate of local and metastatic recurrence and poor prognosis. With the development of molecular pathology, targeted therapy and immunotherapy may have broad prospects.
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Pulmonary Sarcomatoid Carcinomas: A Review

Pulmonary sarcomatoid carcinomas belong to a group of neoplasms that remain incompletely understood. They are rare tumors of the bronchopulmonary system that incorporate a wide range of neoplasms that by definition contain a sarcomatoid component characterized by spindle or giant cells. Such classification has led to a heterogenous tumor category that includes neoplasms with different clinical, morphologic, and prognostic features. To date, the histopathologic diagnosis of pulmonary sarcomatoid carcinomas does not require the use of ancillary testing and is based on light microscopic criteria alone. However, with recent advances in immunohistochemical and molecular methods, it is becoming increasingly clear that pulmonary sarcomatoid carcinomas represent poorly differentiated or "dedifferentiated" variants of conventional non-small cell carcinomas with similar immunophenotype and molecular signatures. This review summarizes the latest insights and concepts of these unusual tumors and outlines future directions with emphasis on tumor classification and patient management.

[MET exon 14 splicing sites mutations: A new therapeutic opportunity in lung cancer]

The mutations leading to MET exon 14 skipping represent a new class of molecular alterations described in various cancers. These alterations are observed in 2 to 3 % of cases of non-small cell lung cancer (NSCLC). Several cases of NSCLC carrying such alterations and achieving objective response to MET tyrosine kinase inhibitorshave recently been published. This review summarizes the molecular mechanisms responsible for MET exon 14 skipping as well as the consequences of the loss of this exon on receptor activity. We also describe the clinical characteristics of patients with METΔ14 mutations. Finally, we address the issues related to the detection of these mutations in lung cancer, and the need to anticipate resistance to MET inhibitors.

KRAS mutation is predictive of outcome in patients with pulmonary sarcomatoid carcinoma

AIMS

Pulmonary sarcomatoid carcinoma (PSC) is a poorly differentiated non-small-cell lung carcinoma (NSCLC) with aggressive behaviour. This study aimed to evaluate the prognostic clinicopathological and genetic characteristics of PSCs.

METHODS AND RESULTS

Fifty-three cases of surgically treated PSCs were selected, 23 of which were subjected to mutation and copy number variation analysis using the 50-gene Ion AmpliSeq Cancer Panel. The majority of the patients were male (32 of 53, 60.3%) and smokers (51 of 53, 96.2%). Overall, 25 (47.1%) patients died within 2-105 months (mean = 22.7 months, median = 15 months) after diagnosis, and 28 were alive 3-141 months (mean = 38.7 months, median = 21.5 months) after diagnosis. Five-year overall survival was 12.5%. KRAS codon 12/13 mutation in adenocarcinomas (P = 0.01), age more than 70 years (P = 0.008) and tumour size ≥4.0 cm (P = 0.02) were associated strongly with worse outcome. TP53 (17 of 23, 74.0%) and KRAS codon 12 of 13 mutations (10 of 23, 43.4%) were the most common genetic alterations. Potentially actionable variants were identified including ATM (four of 23, 17.3%), MET, FBXW7 and EGFR (two of 23, 8.7%), AKT1, KIT, PDGFRA, HRAS, JAK3 and SMAD4 (one of 23, 4.3%). MET exon 14 skipping and missense mutations were identified in two (11.1%) cases with adenocarcinoma histology. Copy number analysis showed loss of RB1 (three of 23, 13%) and ATM (two of 23, 8.7%). Copy number gains were seen in EGFR (two of 23, 13.0%) and in one (4.3%) of each PIK3CA, KRAS, MET and STK11.

CONCLUSIONS

Potentially targetable mutations can be identified in a subset of PSC, although most tumours harbour currently untargetable prognostically adverse TP53 and KRAS mutations.

MET exon 14 mutations as targets in routine molecular analysis of primary sarcomatoid carcinoma of the lung

MET exon 14 splicing mutations are new targetable oncogenic drivers reported in 3% of non-small cell lung cancer (NSCLC) cases and have been shown to be more common in pulmonary sarcomatoid carcinomas (PSCs). This study sought to screen mutations affecting MET exon 14 splice sites in a large SC cohort of Caucasian patients, with a large adenocarcinoma cohort as internal control.

We tested 81 patients with SC and 150 with adenocarcinoma for splice site DNA mutations leading to RNA splicing-based skipping of MET exon 14. To this end, we employed a mass spectrometry-based custom-designed PCR assay for routine analysis of whole MET exon 14 and flanking intronic regions using formalin-fixed paraffin-embedded (FFPE) tumor samples.

Our results revealed a 4.9% mutation rate for MET exon 14 mutations in Caucasian SC patients, which is, though highly variable, within the usual range reported in NSCLC. Discrepancies with previous results reported in SC could be accounted for the small number of cases, ethnicity, epithelial component, and percentage of other driver mutations, such as KRAS, in the patient populations studied. Based on our study findings, SC patients should be screened for MET exon 14 mutations in the same manner as adenocarcinoma patients.

The multiple paths towards MET receptor addiction in cancer

Targeted therapies against receptor tyrosine kinases (RTKs) are currently used with success on a small proportion of patients displaying clear oncogene activation. Lung cancers with a mutated EGFR provide a good illustration. The efficacy of targeted treatments relies on oncogene addiction, a situation in which the growth or survival of the cancer cells depends on a single deregulated oncogene. MET, a member of the RTK family, is a promising target because it displays many deregulations in a broad panel of cancers. Although clinical trials having evaluated MET inhibitors in large populations have yielded disappointing results, many recent case reports suggest that MET inhibition may be effective in a subset of patients with unambiguous MET activation and thus, most probably, oncogene addiction. Interestingly, preclinical studies have revealed a particularity of MET addiction: it can arise through several mechanisms, and the mechanism involved can differ according to the cancer type. The present review describes the different mechanisms of MET addiction and their consequences for diagnosis and therapeutic strategies. Although in each cancer type MET addiction affects a restricted number of patients, pooling of these patients across all cancer types yields a targetable population liable to benefit from addiction-targeting therapies.

Sarcomatoid Carcinoma of the Lung: The Mayo Clinic Experience in 127 Patients

BACKGROUND

Pulmonary sarcomatoid carcinoma (PSC) is an unusual form of non-small-cell lung cancer (NSCLC). Because of its rarity and heterogeneity, the treatment and prognosis of PSC have not been clearly described.

METHODS AND MATERIALS

We retrospectively evaluated all patients with a diagnosis of PSC from 1997 to 2015 at the Mayo Clinic (Rochester, MN). The clinical characteristics, treatment details, and outcomes were collected. The survival rates of the PSC patients were compared with those for other subtypes of NSCLC. We used propensity score matching to minimize the bias resulting from to imbalanced comparison groups.

RESULTS

The study included 127 PSC patients. The median age at diagnosis was 68 years (range, 32-89 years), most of whom were men (61%) and smokers (82%). The clinical stage was I, II, III, and IV in 15.9%, 20.6%, 22.2%, and 41.3%, respectively. The median survival time was 9.9 months (95% confidence interval [CI], 7.6-12.6 months). The 1-, 2-, and 5-year survival rates were 42%, 23%, and 15%, respectively. Most patients received multimodality treatment. Of the 3 patients who received neoadjuvant chemotherapy, a partial response was demonstrated in 2. Twenty-five patients who underwent palliative chemotherapy were evaluated for tumor response: 52% experienced progression, 40% stable disease, 8.0% a partial response, and 0% a complete response. Multivariate analysis showed T stage, M stage, and treatment with surgery plus neoadjuvant chemotherapy or surgery plus adjuvant therapy were independent prognostic factors (P < .05). In matched analysis, multivariate models revealed worse overall survival for PSC compared with adenocarcinoma (hazard ratio, 2.38; 95% CI, 1.61-2.53) and squamous cell carcinoma (hazard ratio, 2.20; 95% CI, 1.44-2.34).

CONCLUSION

We found the outcome of PSC to be significantly worse than that of adenocarcinoma and squamous cell carcinoma. Neoadjuvant or adjuvant chemotherapy, in addition to surgical resection, should be considered.

Clinical Significance and Next-Generation Sequencing of Chinese Pulmonary Sarcomatoid Carcinoma

Pulmonary Sarcomatoid Carcinoma (PSC) constitutes a heterogeneous group of non-small-cell lung carcinomas (NSCLCs) with a poor prognosis. In this study, a group of 7 patients with PSC was studied. Microscope analysis of all 7 cases revealed a pleomorphic carcinoma subtype. Moreover, 5 cases (71.4%) were composed entirely of malignant sarcomatoid-like elements, and 2 cases (28.6%) were composed of malignant sarcomatoid-like elements and at least 10% adenocarcinoma-like elements. Immunohistochemically, the PSC components of all 7 cases were positive for vimentin and cytokeratins, including cytokeratin (CK) and cytokeratin 7 (CK7). Next-Generation Sequencing (NGS) was performed, and a total of 136 putative somatic variants and one gene fusion were identified, of which 16 variants were considered hot spot mutations, including the genes EGFR, EML4-ALK, MET, BRAF, PIK3CA, and TP53. Of these hot spot mutations, one sample expressing an EML4-ALK fusion was further confirmed by Ventana IHC, and one sample containing an EGFR exon 19 deletion was also confirmed. The NGS results imply that TP53 mutations occur often in PSCs and that EML4-ALK fusion events and EGFR exon deletions also occur in these rare tumors. Molecular targeted therapy may be a useful treatment strategy for these rare lung tumors.

Sarcomatoid Adrenal Carcinoma: Case Report with Contribution to Pathogenesis

A tumor in the adrenal region with two metastases in the liver was classified as poorly differentiated sarcoma on the base of extensive immunostainings (expression of vimentin, desmin, myogenin, and CD31, no expression of inhibin, melan A). Four years later in a second examination with molecular methods for a study of adrenal sarcomas, this diagnosis must be revised due to the lack of MDM-2 gene amplification and FKHR translocation which exclude sarcoma. Further immunostainings of many other parts of the tumor showed in one area more mature tumor tissue expressing synaptophysin, SF-1, and melan A. From these findings we classified an adrenal cortical cancer with predominant dedifferentiation into a sarcomatoid adrenal carcinoma. The properties of this very rare cancer type are presented and discussed.

Pulmonary Sarcomatoid Carcinomas Commonly Harbor Either Potentially Targetable Genomic Alterations or High Tumor Mutational Burden as Observed by Comprehensive Genomic Profiling

INTRODUCTION

Pulmonary sarcomatoid carcinoma (PSC) is a high-grade NSCLC characterized by poor prognosis and resistance to chemotherapy. Development of targeted therapeutic strategies for PSC has been hampered because of limited and inconsistent molecular characterization.

METHODS

Hybrid capture-based comprehensive genomic profiling was performed on DNA from formalin-fixed paraffin-embedded sections of 15,867 NSCLCs, including 125 PSCs (0.8%). Tumor mutational burden (TMB) was calculated from 1.11 megabases (Mb) of sequenced DNA.

RESULTS

The median age of the patients with PSC was 67 years (range 32-87), 58% were male, and 78% had stage IV disease. Tumor protein p53 gene (TP53) genomic alterations (GAs) were identified in 74% of cases, which had genomics distinct from TP53 wild-type cases, and 62% featured a GA in KRAS (34%) or one of seven genes currently recommended for testing in the National Comprehensive Cancer Network NSCLC guidelines, including the following: hepatocyte growth factor receptor gene (MET) (13.6%), EGFR (8.8%), BRAF (7.2%), erb-b2 receptor tyrosine kinase 2 gene (HER2) (1.6%), and ret proto-oncogene (RET) (0.8%). MET exon 14 alterations were enriched in PSC (12%) compared with non-PSC NSCLCs (∼3%) (p < 0.0001) and were more prevalent in PSC cases with an adenocarcinoma component. The fraction of PSC with a high TMB (>20 mutations per Mb) was notably higher than in non-PSC NSCLC (20% versus 14%, p = 0.056). Of nine patients with PSC treated with targeted or immunotherapies, three had partial responses and three had stable disease.

CONCLUSION

Potentially targetable GAs in National Comprehensive Cancer Network NSCLC genes (30%) or intermediate or high TMB (43%, >10 mutations per Mb) were identified in most of the PSC cases. Thus, the use of comprehensive genomic profiling in clinical care may provide important treatment options for a historically poorly characterized and difficult to treat disease.

"Sarcomatoid" carcinomas of the lung: a clinicopathological study of 86 cases with a new perspective on tumor classification

Pulmonary sarcomatoid carcinoma includes a heterogenous group of tumors difficult to diagnose and treat. We report the clinicopathological features of 86 such tumors, including 74 pleomorphic and 12 spindle cell carcinomas, and propose a novel approach to the classification of these neoplasms in an attempt to better guide patient management. The patients were 47 men and 39 women aged 36 to 87 years (mean, 63 years) who primarily presented with shortness of breath, cough, and chest pain. Eighty-six percent of patients had a smoking history. Histologically, the pleomorphic carcinomas consisted of spindle and/or giant cells with varying proportions of conventional non-small cell carcinoma in the form of adenocarcinoma (n=29), squamous cell carcinoma (n=10), or large cell carcinoma (n=18); 17 cases contained a mix of spindle and giant cells only. The 12 spindle cell carcinomas consisted of spindle cells only. Based on the combined histopathologic and immunohistochemical features of these tumors, we were able to reanalyze the spectrum of these lesions and reclassify them accordingly. Statistical analysis revealed an overall survival at 3, 5, and 10 years of 42.9%, 34.6%, and 23.5%, respectively, and a median survival of 15 months. Log-rank test showed that in multivariate analysis, only pathological T stage was a factor associated with prognosis. The current classification of pulmonary sarcomatoid carcinomas precludes optimal triaging of these tumors with the risk of denying patients access to novel treatment. Our proposal for a reclassification of these tumors would more accurately guide patient management and facilitate targeted therapies.