Prevalence and Pattern of Lymph Node Metastasis in Malignant Pleural Mesothelioma

Lymphatic Drainage of Thoracic and Extrathoracic Malignancies

This review article details the lymphatic drainage pathways for both thoracic and extrathoracic cancers within the chest. The major lymphatic pathways into and through the thorax are reviewed, along with their impact on the spread of cancers. Defects or damage to lymphatic channels and variant anatomy may alter how cancer cells spread through the lymphatic system. Monitoring specific lymph node stations can help in the early detection of lymph node metastases. When an abnormal lymph node is detected without a known primary malignancy, understanding lymphatic drainage pathways can help target the search for the most likely origin of the abnormality.

Diagnostic role of internal mammary lymph node involvement in tuberculous pleurisy: a multicenter study

BACKGROUND AND OBJECTIVES

Diagnosis of tuberculous pleurisy (TP) may be challenging and it often requires pleural biopsy. A tool able to increase pre-test probability of TP may be helpful to guide diagnostic work-up and enlargement of internal mammary lymph node (IMLN) has been suggested to play a potential role. The aim of the present investigation was to assess role of IMLN involvement in TP in a multi-centric case-control study, by comparing its prevalence and test performance to those observed in patients with infectious, non-tuberculous pleurisy (NTIP), and in controls free from respiratory diseases (CP).

METHODS

A total of 419 patients, from 14 Pulmonology Units across Italy were enrolled (127 patients affected by TP, 163 affected by NTIP and 129 CP). Prevalence, accuracy and predictive values of ipsilateral IMLN involvement between cases and control groups were assessed, as well as concordance between chest computed tomography (CT scan) and thoracic ultrasound (TUS) measurements.

RESULTS

The prevalence of ipsilateral IMLN involvement in TP was significantly higher than that observed in NTIP and CP groups (respectively 77.2%, 39.3% and 14.7%). Results on test performance, stratified by age, revealed a high positive predictive value in patients aged ≤50 years, while a high negative predictive value in patients aged >50 years. The comparison between CT scan and ultrasound showed moderate agreement (Kappa=0.502).

CONCLUSIONS

Evaluation of IMLN involvement plays a relevant role in assessing the pre-test probability of TP. Considering the increasing global prevalence of mycobacterial infections, a tool able to guide diagnostic work-up of suspected TP is crucial, especially where local sources are limited.

Targeting AXL in Mesothelioma: from functional characterization to clinical implication

Malignant pleural mesothelioma (MM) is a highly aggressive and lethal cancer with a poor survival rate. Current treatment approaches primarily rely on chemotherapy and radiation, but their effectiveness is limited. Consequently, there is an urgent need for alternative treatment strategies, a comprehensive understanding of the molecular mechanisms underlying MM, and the identification of potential therapeutic targets. Extensive studies over the past decade have emphasized the role of Axl in driving tumor development and metastasis, while high levels of Axl expression have been associated with immune evasion, drug resistance, and reduced patient survival in various cancer types. Ongoing clinical trials are investigating the efficacy of Axl inhibitors for different cancers. However, the precise role of Axl in MM progression, development, and metastasis, as well as its regulatory mechanisms within MM, remain inadequately understood. This review aims to comprehensively investigate the involvement of Axl in MM. We discuss Axl role in MM progression, development, and metastasis, along with its specific regulatory mechanisms. Additionally, we examined the Axl associated signaling pathways, the relationship between Axl and immune evasion, and the clinical implications of Axl for MM treatment. Furthermore, we discussed the potential utility of liquid biopsy as a non-invasive diagnostic technique for early detection of Axl in MM. Lastly, we evaluated the potential of a microRNA signature that targets Axl. By consolidating existing knowledge and identifying research gaps, this review contributes to a better understanding of Axl's role in MM and sets the stage for future investigations and the development of effective therapeutic interventions.

Differentiating malignant pleural mesothelioma and metastatic pleural disease based on a machine learning model with primary CT signs: A multicentre study

Rationale and Objectives

It is still a challenge to make confirming diagnosis of malignant pleural mesothelioma (MPM), especially differentiating from metastatic pleural disease (MPD). The aim of this study was to develop a model to distinguish MPM with MPD based on primary CT signs.

Materials and methods

We retrospectively recruited 150 MPM patients and 147 MPD patients from two centers and assigned them to training (115 MPM patients and 113 MPD patients) and testing (35 MPM patients and 34 MPD patients) cohorts. The images were analyzed for pleural thickening, hydrothorax, lymphadenopathy, thoracic volume and calcified pleural plaque (CPP). The selected clinical characteristics and primary CT signs comprised the model by multivariate logistic regression in the training cohort. Then the model was tested on the external testing cohort. ROC curve and F1 score were used to validate the capability of the model in both two cohorts.

Results

There were significant differences between two groups: (1) carcinoembryonic antigen (CEA); (2) nodular and mass pleural thickening; (3) the enhancement of pleura; (4) focal, diffuse and circumferential pleural thickening; (5) the thickest pleura; (6) thickening of diaphragmatic pleura; (7) multiple nodules and effusion of interlobar pleura; (8) hilar LN and ring enhancement of LN; (9) punctate and stipe CPP. The AUC and F1 score of the model were 0.970 and 0.857 in the training cohort, 0.955 and 0.818 in the testing cohort.

Conclusion

The model holds promise for use as a diagnostic tool to distinguish MPM from MPD.

Tumor-Derived Exosomes Modulate Primary Site Tumor Metastasis

Tumor-derived exosomes (TDEs) are actively produced and released by tumor cells and carry messages from tumor cells to healthy cells or abnormal cells, and they participate in tumor metastasis. In this review, we explore the underlying mechanism of action of TDEs in tumor metastasis. TDEs transport tumor-derived proteins and non-coding RNA to tumor cells and promote migration. Transport to normal cells, such as vascular endothelial cells and immune cells, promotes angiogenesis, inhibits immune cell activation, and improves chances of tumor implantation. Thus, TDEs contribute to tumor metastasis. We summarize the function of TDEs and their components in tumor metastasis and illuminate shortcomings for advancing research on TDEs in tumor metastasis.

Malignant Pleural Mesothelioma Nodal Status: Where Are We at?

Due to the lack of both prospective trial and high-volume retrospective studies, the management of clinical N+ malignant pleural mesothelioma (MPM) patients remains highly debated. Node positive patients show poor survival compared with node-negative ones; thus, lymph node staging appears crucial in determining treatment strategy. Notwithstanding the improvement in pre-treatment staging and the update on lymph node classification in the 8th edition of TNM, several open controversies remain on N parameter. How should we stage suspected N+ patients? How should we treat node positive patients? Which is the definition of a “resectable patient”? Is the site or the number the main prognostic factor for node positive patients? The aim of our narrative review is to analyse the existing relevant literature on lymph node status in MPM.

Impact of Detecting Occult Pathologic Nodal Disease During Resection for Malignant Pleural Mesothelioma

BACKGROUND

Lymph node (LN) involvement is a poor prognostic factor for malignant pleural mesothelioma (MPM). However, to our knowledge, postresection outcomes of node-negative (cN0/pN0), occult pathologic nodal disease (cN0/pN+), and clinical node-positive disease (cN+) have not been compared to date.

PATIENTS AND METHODS

The National Cancer Data Base was queried for newly diagnosed, resected MPM with known clinical/pathologic LN information. Three cohorts were compared: cN0/pN0, cN+, and cN0/pN+. Multivariable logistic regression examined predictors of pathologic nodal upstaging. Kaplan-Meier analysis with propensity matching assessed overall survival (OS); multivariate Cox proportional hazards modeling examined predictors thereof.

RESULTS

Of 1369 patients, 687 (50%) had cN0/pN0, 457 (33%) cN+, and 225 (16%) cN0/pN+ disease. Median follow-up was 29 months. In patients with cN0 disease, factors associated with pathologic nodal upstaging were younger age, greater number of examined LNs, and nonsarcomatoid histology (P < .05 for all). Relative to pN0 cases, occult LN involvement (65% being pN2) was associated with 51% higher hazard of mortality on multivariate analysis (P = .005). Following propensity matching, the OS of cN0/pN+ was similar to cN+ cases (P = .281). On multivariate analysis, the number of involved LNs (continuous variable, P = .013), but not nodal tumor, node, metastasis (TNM) classification or LN ratio (P > .05 for both), was associated with OS.

CONCLUSION

Detecting occult nodal disease during resection for cN0 MPM is associated with poorer prognosis, with similar survival as cN+ cases, underscoring the importance of routine preoperative pathologic nodal assessment for potentially resectable MPM. The number of involved LNs (rather than current location-based classification) may provide more robust prognostic stratification for future TNM staging.

Intra-abdominal recurrence from colorectal carcinoma: Differences and similarities between local and peritoneal recurrence

BACKGROUND

Peritoneal recurrences from colo-rectal cancer can be isolated (PR) or associated with local recurrences (LR). The purpose of this study was to analyze patterns and outcomes of LR and PR.

METHODS

Analyze from a prospective database of 108 patients treated with CCS plus HIPEC at two cancer centers between 2008 and 2015.

RESULTS

The population was divided into an LPR group (presence of LR with or without PR, n = 56) and a PR group (isolated PR, n = 52). The patients characteristics (age, sex, Charlson score, PCI) or perioperative treatments were comparable between the groups. The median number of resected organs for tumor involvement (respectively, 2 vs 1; p < 0.001), the percentage of patients with metastatic lymph nodes (LN+) from the resected specimen (respectively, 25% vs 7%; p = 0.016) and the mortality rate (respectively, 9% vs 0%; p = 0.023) were significantly higher in the LPR group. After a median follow-up of 32 (1-108) months, median overall survival was comparable between the two groups (respectively, 46 vs 42 months; p = 0.262).

CONCLUSIONS

LR is associated with a higher incidence of organ invasion, LN involvement (25%) and postoperative mortality. Optimal surgical resection of LR with systematic lymphadenectomy of invaded organs seems mandatory.

Progress and challenges in Mesothelioma: From bench to bedside

Malignant Pleural Mesothelioma (MPM) is currently an incurable cancer with a typical survival of 1 year from the time of diagnosis. The recent genomic and transcriptomic characterization of MPM presents new opportunities and challenges for MPM researchers. Recent advances in clinical and laboratory diagnostics, and proposals for an updated, data-driven, staging system, also present new challenges for clinicians and hospital services involved in MPM care. The aim of this review is first to introduce the reader to the topic of MPM, a disease that is causally linked to prior, typically occupational, exposure to asbestos fibres. Secondly, we will discuss MPM from the clinical and laboratory perspectives, including reviews of current and evolving therapies and our present understanding of the molecular basis of the disease. Finally, we will attempt to identify critical knowledge gaps that currently prevent more effective treatment, including the challenges involved in early detection and chemoprophylaxis.

The IASLC Mesothelioma Staging Project: Proposals for Revisions of the N Descriptors in the Forthcoming Eighth Edition of the TNM Classification for Pleural Mesothelioma

INTRODUCTION

Nodal categories for malignant pleural mesothelioma are derived from the lung cancer staging system and have not been adequately validated. The International Association for the Study of Lung Cancer developed a multinational database to generate evidence-based recommendations to inform the eighth edition of the TNM classification of malignant pleural mesothelioma.

METHODS

Data from 29 centers were entered prospectively (n = 1566) or by transfer of retrospective data (n = 1953). Survival according to the seventh edition N categories was evaluated using Kaplan-Meier survival curves and Cox proportional hazards regression analysis. Survival was measured from the date of diagnosis.

RESULTS

There were 2432 analyzable cases: 1603 had clinical (c) staging, 1614 had pathologic (p) staging, and 785 had both. For clinically staged tumors there was no separation in Kaplan-Meier curves between cN0, cN1 or cN2 (cN1 versus cN0 hazard ratio [HR] = 1.06, p = 0.77 and cN2 versus cN1 HR = 1.04, p = 0.85). For pathologically staged tumors, patients with pN1 or pN2 tumors had worse survival than those with pN0 tumors (HR = 1.51, p < 0.0001) but no survival difference was noted between those with pN1 and pN2 tumors (HR = 0.99, p = 0.99). Patients with both pN1 and pN2 nodal involvement had poorer survival than those with pN2 tumors only (HR = 1.60, p = 0.007) or pN0 tumors (HR = 1.62, p < 0.0001).

CONCLUSIONS

A recommendation to collapse both clinical and pN1 and pN2 categories into a single N category comprising ipsilateral, intrathoracic nodal metastases (N1) will be made for the eighth edition staging system. Nodes previously categorized as N3 will be reclassified as N2.

Multidetector CT Findings and Differential Diagnoses of Malignant Pleural Mesothelioma and Metastatic Pleural Diseases in Korea

Objective

To compare the multidetector CT (MDCT) features of malignant pleural mesothelioma (MPM) and metastatic pleural disease (MPD).

Materials and Methods

The authors reviewed the MDCT images of 167 patients, 103 patients with MPM and 64 patients with MPD. All 167 cases were pathologically confirmed by sonography-guided needle biopsy of pleura, thoracoscopic pleural biopsy, or open thoracotomy. CT features were evaluated with respect to pleural effusion, pleural thickening, invasion of other organs, lung abnormality, lymphadenopathy, mediastinal shifting, thoracic volume decrease, asbestosis, and the presence of pleural plaque.

Results

Pleural thickening was the most common CT finding in MPM (96.1%) and MPD (93.8%). Circumferential pleural thickening (31.1% vs. 10.9%, odds ratio [OR] 3.670), thickening of fissural pleura (83.5% vs. 67.2%, OR 2.471), thickening of diaphragmatic pleura (90.3% vs. 73.4%, OR 3.364), pleural mass (38.8% vs. 23.4%, OR 2.074), pericardial involvement (56.3% vs. 20.3%, OR 5.056), and pleural plaque (66.0% vs. 21.9%, OR 6.939) were more frequently seen in MPM than in MPD. On the other hand, nodular pleural thickening (59.2% vs. 76.6%, OR 0.445), hilar lymph node metastasis (5.8% vs. 20.3%, OR 0.243), mediastinal lymph node metastasis (10.7% vs. 37.5%, OR 0.199), and hematogenous lung metastasis (9.7% vs. 29.2%, OR 0.261) were less frequent in MPM than in MPD. When we analyzed MPD from extrathoracic malignancy (EMPD) separately and compared them to MPM, circumferential pleural thickening, thickening of interlobar fissure, pericardial involvement and presence of pleural plaque were significant findings indicating MPM than EMPD. MPM had significantly lower occurrence of hematogenous lung metastasis, as compared with EMPD.

Conclusion

Awareness of frequent and infrequent CT findings could aid in distinguishing MPM from MPD.

Extrapleural and cardiophrenic lymph nodes: prevalence, clinical significance and diagnostic value

PURPOSE

The aim of this study was to evaluate the prevalence, clinical meaning and diagnostic value of extrapleural and cardiophrenic nodes occasionally observed on computed tomography (CT) scans of the chest.

MATERIALS AND METHODS

We included 750 consecutive patients who underwent CT of the chest for different clinical purposes (340 nonneoplastic patients, 270 with extrathoracic neoplasms, 120 with intrathoracic neoplasms, 20 with pleural metastasis) and 91 patients with histologically proven malignant pleural mesothelioma (MPM). For each group of patients, we analysed the presence of extrapleural and cardiophrenic nodes, their number (single or multiple) and their size.

RESULTS

The prevalence of cardiophrenic nodes between 6 and 10 mm and >10 mm was significantly higher in patients with MPM (28.6 and 26.4 %, respectively) than in all other categories of patients, except for patients with pleural metastasis (30 and 25 %, respectively). The prevalence of extrapleural nodes, independently from their size, was significantly higher in patients with MPM (68 %) compared with all other groups, including patients with pleural metastasis (5 %; p < 0.0001).

CONCLUSIONS

Cardiophrenic nodes >5 mm and extrapleural nodes of any size have a significant diagnostic value in malignant pleural disease, either primary or secondary, whereas they are extremely rare in other neoplastic or nonneoplastic diseases.

Lymph node involvement and metastatic lymph node ratio influence the survival of malignant pleural mesothelioma: a French multicenter retrospective study

Malignant pleural mesothelioma (MPM) is a rare tumor with disastrous evolution. The prognostic value of nodal involvement is still debated. We analyzed the impact of nodal involvement on overall survival (OS) in patients treated by multimodal therapy including extra pleural pneumonectomy (EPP). We evaluated the role, as a prognostic factor, of the metastatic lymph node ratio (LNR), corresponding to the number of involved nodes out of the total number of removed nodes. In this retrospective multicentric study, we reviewed the data of 99 MPM patients. Information regarding lymph node involvement was assessed from the final pathology reports. N1-N3 patients were pooled as N+ group. The OS, calculated by the Kaplan-Meier method, was compared using the log-rank test. A multivariate Cox proportional hazards model was used to identify independent prognostic factors. For the whole cohort, median OS was 18.3 months and 5-year survival was 17.5%. N+ status reduced significantly the median survival (22.4 months for N0 patients vs 12.7 months for N+ patients, P=0.002). A lower metastatic LNR (≤13%) was associated with a significantly improved median survival (19.9 vs. 11.7 months, P=0.01). OS was not related to the number of involved or total removed lymph nodes. In multivariate analysis, only adjuvant radiotherapy (P=0.001) was identified as an independent positive prognostic factor. Metastatic LNR is a more reliable prognostic factor than the number of involved lymph nodes or the total number of removed nodes. However, it could not be identified as an independent prognostic factor.

Primary intrahepatic malignant mesothelioma with multiple lymphadenopathies due to non-tuberculous mycobacteria: A case report and review of the literature

Primary intrahepatic malignant mesothelioma (PIHMM) is an extremely rare tumor with clinicopathological characteristics that remain to be elucidated. The current study presents the case of a 68-year-old female with PIHMM and multiple lymphadenopathies due to non-tuberculous mycobacteria. The patient presented with an intrahepatic tumor, 70 mm in diameter, in the right lobe of the liver. An ultrasound-guided fine-needle aspiration biopsy of the liver tumor revealed findings that were consistent with an intrahepatic malignant mesothelioma. The systemic lymph node swellings were due to epithelioid granulomas that were caused by non-tuberculous mycobacteria. However, a hepatic rupture occurred due to the rapid growth of the liver tumor and consequently, a surgical resection was not performed. A review of the literature revealed that the clinicopathological characteristics of PIHMM are similar to those of non-occupational mesothelioma. However, PIHMM is usually a solitary tumor and is rarely associated with cavity effusion in contrast with conventional mesothelioma. Therefore, surgical resection with curative intent is often recommended for patients with PIHMM.

Perineal and colonic metastases in two cases of malignant mesothelioma

Two patients with rare sites of metastatic pleural mesothelioma are presented and the literature on similar cases is examined. One patient developed colonic metastases from a sarcomatoid mesothelioma. Another patient with epithelioid mesothelioma developed perineal metastases.

Expert opinions of the first italian consensus conference on the management of malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a very important public health issue. A large amount of data indicates a relationship between mesothelioma and asbestos exposure. The incidence has both considerably and constantly increased over the past 2 decades in the industrialized countries and is expected to peak in 2010-2020. In Italy, a standardized-rate incidence in 2002 among men was 2.98 per 100,000 and 0.98 per 100,000 among women, with wide differences from one region to another. Stage diagnosis and definition may be difficult. Management of patients with MPM remains complex, so an optimal treatment strategy has not yet been clearly defined. The First Italian Consensus Conference on Malignant Pleural Mesothelioma was held Bologna (Italy) in May 20, 2008. The Consensus Conference was given the patronage of the Italian scientific societies AIOM, AIRO, AIPO, SIC, SICO, SICT, SIAPEC-IAP, AIOT, GOAM, and GIME. This Consensus did not answer all of the unresolved questions in MPM management, but the Expert Opinions have nonetheless provided recommendations, presented in this report, on MPM management for clinicians and patients.

[Surgical treatment of primary pleural tumours in our department]

AIM

The authors analyzed the results and outcome of surgical treatment of primary pleural tumors in patients treated in the last 11 years.

METHODS

31 operations were performed for primary pleural tumors in 25 patients (17 males, 8 females). The tumors were classified into the following groups: benign local fibrous tumors (benign LFTP; n = 15), recurrent malignant fibrous tumors (recurrent malignant LFTP; n = 2) and malignant mesotheliomas (MPM; n = 12). 40% of patients with MPM were exposed to asbestos. Complete resections of benign LFTPs were performed, with additional resection of the chest wall and lobectomy in two cases. Completion pneumonectomy and lobectomy were done in recurrent malignant LFTP cases. Five biopsies and pleurodesis, and one open decortication were performed. In four cases, after the biopsy, two pleurectomies and decortications (P/D) and two pleuropneumonectomies (PPN)/extra-pleural pneumonectomies (EPP) were carried out.

RESULTS

There was no operative mortality. Pathological examination revealed seven epithelial, two sarcomatous and one biphasic malignant mesotheliomas. Survival was one (currently alive) and 49 months after malignant recurrent LFTP. Survival in MPM cases was 9,7 months (3-17) without resection and 17,3 months (5 (currently alive) - 29) in P/D or PPN (EPP) cases.

CONCLUSIONS

The PPN (EPP) and P/D are safe procedures providing relatively good survival when it is done as part of complete oncological treatment. In cases of recurrent LFTP, anatomical resections recommended with completion pneumonectomy or lobectomy.

Benign and Malignant Mesothelial Proliferation

Malignant mesothelioma (MM) is a rare primary malignant tumor of the surface serosal cells. The diagnosis of MM is challenging with a broad differential diagnosis. For many decades, studies have focused on distinguishing MM from other types of cancer; however, benign mesothelial cell hyperplasia, especially in small biopsies, has emerged as a major problem. The features of pleural lesions are somewhat different from peritoneal diseases, and this article primarily focuses on pleural diseases. Thorough interpretation and correlation of clinical, radiologic, and pathologic findings are essential for a correct diagnosis.