Histopathologic and molecular approach to staging of multiple lung nodules

Novel causes and assessments of intrapulmonary metastasis

Background

This study utilized next-generation sequencing (NGS) to analyze genetic information and gene mutation-related loci in ground glass nodules (GGN) with multiple (≥2) lesions. Pathological findings were then correlated to distinguish between multiple primary lung cancers (MPLC) and pulmonary metastasis (PM).

Methods

A cohort of 20 individuals who underwent surgical resection for ground glass nodules (GGN) was included. Final diagnosis and restaging were determined based on the analysis of clinical characteristics and NGS single-target genetic detection.

Results

Histopathological, immunohistochemical staining, and NGS analyses identified 48 tissue samples from 20 cases of multiple malignant nodules. A total of 66 gene mutations were identified, with four cases classified as PM. Notably, four patients with intrapulmonary metastases exhibited concurrent mutations in the epidermal growth factor receptor (EGFR) (50 %) and Kirsten ratsarcoma viral oncogene homolog (KRAS). Comparatively, the prevalence of EGFR mutations in PM patients was significantly higher than that in primary lesions.

Conclusion

Genomic analysis of multiple lung adenocarcinomas enables the determination of the clonal status of tumor cells across various lesions. When gene mutation sites in multiple lesions are identical and mutation abundance is significantly elevated, early intrapulmonary metastasis may be diagnosed.

Assessments of lung nodules by an artificial intelligence chatbot using longitudinal CT images

Large language models have shown efficacy across multiple medical tasks. However, their value in the assessment of longitudinal follow-up computed tomography (CT) images of patients with lung nodules is unclear. In this study, we evaluate the ability of the latest generative pre-trained transformer (GPT)-4o model to assess changes in malignancy probability, size, and features of lung nodules on longitudinal CT scans from 647 patients (547 from two local centers and 100 from a public dataset). GPT-4o achieves an average accuracy of 0.88 in predicting lung nodule malignancy compared to pathological results and an average intraclass correlation coefficient of 0.91 in measuring nodule size compared with manual measurements by radiologists. Six radiologists' evaluations demonstrate GPT-4o's ability to capture changes in nodule features with a median Likert score of 4.17 (out of 5.00). In summary, GPT-4o could capture dynamic changes in lung nodules across longitudinal follow-up CT images, thus providing high-quality radiological evidence to assist in clinical management.

Multiple primary lung cancer: Updates and perspectives

Management of multiple primary lung cancer (MPLC) remains challenging, partly due to its increasing incidence, especially with the significant rise in cases of multiple lung nodules caused by low-dose computed tomography screening. Moreover, the indefinite pathogenesis, diagnostic criteria, and treatment selection add to the complexity. In recent years, there have been continuous efforts to dissect the molecular characteristics of MPLC and explore new diagnostic approaches as well as treatment modalities, which will be reviewed here, with a focus on newly emerging evidence and future perspectives, hope to provide new insights into the management of MPLC and serve as inspiration for future research related to MPLC.

From Morphology to Molecules: Advances in the Distinction of Multiple Primary Lung Cancers From Intrapulmonary Metastases in Non-Small Cell Lung Cancer

The increasing incidence of multiple lung nodules underscores the need for precise differentiation between multiple primary lung cancers (MPLCs) and intrapulmonary metastases (IPMs). This distinction impacts patient prognosis and treatment strategies. The prevalence of multiple lung nodules, ranging from 19.7% to 55.5%, highlights the clinical significance of this challenge. Historically, the role of histopathology, particularly comprehensive histology assessment (CHA), has been pivotal in differentiating MPLCs and IPMs. However, CHA has significant limitations, resulting in a constant search for a better way to distinguish those lesions. The best strategy for delineating MPLCs from IPMs is a multidisciplinary approach combining clinical data, radiology, histology, and molecular methods. Histology provides architectural and cellular characteristics, radiology contributes anatomic context and lesion characterization, and molecular methods reveal molecular features critical for accurate differentiation. Incorporating clinical data further enhances diagnostic precision. This review presents current knowledge and current approaches to multiple lung tumors. It is clear that even with a combination of pathology, radiology, and molecular data, definitive classification of multifocal lung tumors is not always possible.

Myeloid‑derived suppressor cell accumulation induces Treg expansion and modulates lung malignancy progression

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous family of myeloid cells that suppress T cell immunity in tumor-bearing hosts. The present study aimed to examine roles of T and MDSC subsets in lung malignancy. The study analyzed 102 cases with lung malignancy and 34 healthy individuals. Flow cytometry was performed for identification of T cell and MDSC subsets and their phenotypic characteristics in peripheral blood. The lung malignancy cases exhibited lower frequencies of granulocyte-like MDSCs (G-MDSCs) expressing PD-L2 and PD-L1 than healthy controls (P=0.013 and P<0.001, respectively). Additionally, there was a higher frequency of monocyte-like MDSCs (M-MDSCs) expressing PD-L1 in the peripheral blood of patients with lung malignancy than healthy controls (P<0.001). The frequencies of G-MDSCs and M-MDSCs were positively correlated with proportions of PD-1+ and CTLA-4+ regulatory T cells (Tregs). In vitro co-culture assay demonstrated M-MDSCs of lung malignancy enhanced naive T cell apoptosis and promoted Treg subset differentiation compared with M-MDSCs of healthy controls. The findings suggested accumulation of MDSC subsets in lung malignancy and MDSCs expressing PD-L2 and PD-L1 induced Treg expansion by binding to PD-1 on the surface of Tregs.

Clinical and pathologic staging accuracy in patients with synchronous multiple primary lung cancers

Background

The incidence of synchronous multiple primary lung cancer (SMPLC) is increasing, occurring in up to 20% of lung cancer patients. Accurately identifying SMPLC can be challenging, and failure to recognize SMPLC results in poor outcomes. We sought to assess the staging accuracy of patients with SMPLC at our tertiary institution.

Methods

We retrospectively reviewed all patients who were evaluated for lung cancer resection between January 2018 to September 2019. Patients with SMPLC were identified using the modified Martini-Melamed criteria. Preoperative imaging, clinical assessment, and pathologic interpretation were reviewed and compared to the final staging assigned by a multidisciplinary lung cancer tumor board to determine accuracy.

Results

Out of 227 patients presenting for lung cancer resection, 47 patients with 119 SMPLC were identified, of which 38 (80.9%) were incorrectly staged by at least one report. Incorrect staging was most common by computed tomography (CT) reports (n=33/47, 70.2%), followed by positron emission tomography-CT (PET-CT) reports (n=28/45, 62.2%), surgeons' clinical assessment (n=10/47, 21.3%), and histopathology reports (n=8/47, 17.0%). CT reports, when incorrect, under-staged 97.0% (n=32) of patients. PET-CT reports, when incorrect, over-staged 25.0% (n=7) of patients by reporting the second primary nodule to be "consistent with metastasis". Histopathology reports, when incorrect, over-staged 87.5% (n=7) of patients despite lack of lymph node involvement.

Conclusions

Patients with SMPLC are at risk of receiving incorrect treatment based on radiographic and histopathologic staging reports alone. The observed staging inaccuracies are concerning, necessitating increased awareness among physicians caring for lung cancer patients.

Prevalence and Predictability of Occult Satellite Nodules in Clinical Stage Ia Non-small Cell Lung Cancer following Lobectomy

INTRODUCTION

We sought to assess the prevalence and clinical predictors of satellite nodules in patients undergoing lobectomy for clinical stage Ia disease.

PATIENTS AND METHODS

The National Cancer Database was queried for patients who underwent lobectomy for clinical stage cT1N0 NSCLC. Collaborative staging information was used to identify patients who were pathologically upstaged based on having separate tumor nodules in the same lobe as the primary tumor. Multivariable logistic regression was used to assess the association of clinical factors with the detection of separate nodules.

RESULTS

A separate tumor nodule was recorded in 2.8% (n = 1284) of 45,842 clinical stage Ia patients treated with lobectomy or bilobectomy. Female gender (3.1% vs. male 2.5%; P = .002) and non-squamous histology (adenocarcinoma 3.2% and large cell neuroendocrine 3.0% vs. squamous cell 1.9% tumors; P < .001) were associated with the presence of separate nodules. The frequency increased for tumors larger than 3 cm (≤ 3cm, 2.7% vs. > 3cm, 3.8%; P < .001). Other factors associated with separate nodules were upper lobe location, pleural and/or lymphovascular invasion and occult lymph node disease. The best predictive model for separate nodules based on the available clinical variables resulted in an area under the curve of 0.645 (95% CI 0.629-0.660).

CONCLUSION

Separate tumor nodules may be detected with a low but relatively consistent frequency across the spectrum of patients with clinical stage Ia NSCLC. The predictive ability using basic clinical factors in the database is limited.

Updates in pathology and molecular diagnostics to inform the evolving landscape of thoracic surgery and oncology

The pathologic assessment of lung cancers provides essential guidance to the surgeon and oncologist who are considering the best treatment strategies for patients with both early and advanced-stage disease. The management of patients with lung cancer is predicated first and foremost on access to an accurate diagnosis, even when the sample size is limited, as is often the case with use of modern, minimally invasive sampling techniques. Once the diagnosis and disease stage are established, predictive biomarker testing may be essential, particularly for those patients with nonsmall cell lung carcinoma (NSCLC) being considered for immunotherapy or genomic biomarker-driven targeted therapy. This review will discuss the best practices for the diagnosis of NSCLC using morphology and immunohistochemistry, thus providing the surgeon with needed information to understand and critically evaluate pathology reports. Controversial and evolving topics including tumor spread through airspaces, evaluation of multiple tumors, and staging based on invasive tumor size will be addressed. Clinical genomic profiling in NSCLC is driven by published guidelines and reflects evidence based on clinical trials and regulatory approvals. In this fast-moving space, surgeons should be aware of the critical immunohistochemical and genomic biomarkers that drive systemic therapy decisions and anticipate when such testing will be required, both to ensure adequate sampling and to advise the pathologist when tumor material will be required for biomarker analysis. The basic approaches to and sample requirements for molecular biomarker testing will be addressed. As biomarker testing moves exclusively from advanced-stage patients into earlier stage disease, the surgeon should be aware of the relevant markers and work with the pathologist and oncologist to ensure that this information is available to facilitate timely access to therapies not just in the advanced setting, but in consideration of neoadjuvant and adjuvant care.

EML4‑ALK fusion gene in non‑small cell lung cancer (Review)

Non-small cell lung cancer (NSCLC) is a malignant tumor with a high morbidity and mortality rate that is a threat to human health. With the development of molecular targeted research, breakthroughs have been made on the molecular mechanism of lung cancer. The echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) fusion gene is one of the most important pathogenic driver genes of NSCLC discovered thus far. Four generations of targeted drugs for EML4-ALK have been developed, with patients benefiting significantly from these drugs. Therefore, EML4-ALK has become a research hotspot in NSCLC. The aim of the present study is to introduce the current research progress of EML4-ALK and its association with NSCLC.

Multiple Primary Lung Tumors of Different Pathological Types Including Squamous Cell Carcinoma, Adenocarcinoma, and Mixed Squamous Cell and Glandular Papilloma: A Case Report

Multiple primary lung cancer (MPLC) is considered relatively rare. This report presents an unusual case of multiple pulmonary nodules in a 74-year-old man who presented with three independent synchronous tumors in the right upper lobe. The tumors were diagnosed as peripheral squamous cell carcinoma (SCC), adenocarcinoma, and pulmonary mixed squamous cell and glandular papilloma (mixed papilloma). Mixed papilloma is an extremely rare, benign pulmonary tumor with a typical papillary appearance, showing squamous and glandular epithelial differentiation. The histological and immunohistochemical features of each tumor were analyzed. In addition, molecular pathological examination for epidermal growth factor receptor (EGFR) showed no mutation in two primary cancers. Mixed papilloma showed no BRAF V600E mutation or HPV infection. The present case report provides a clinicopathological understanding of an instance in which three tumors of different pathological types are present in the same lung lobe. Furthermore, it provides a literature review regarding multiple lung nodules, focusing on the clinicopathological diagnosis, clinical treatment, and prognostic assessment of these nodules. This is the first case report of mixed papilloma arising in MPLC.

MTA1 Expression Can Stratify the Risk of Patients with Multifocal Non-Small Cell Lung Cancers ≤3 cm

Purpose

Currently, there is no uniform standard to guide postoperative adjuvant chemotherapy for patients with multifocal non-small cell lung cancers (NSCLCs) ≤3 cm. Therefore, there is an urgent need to explore prognostic molecular markers to identify high-risk patients with multifocal NSCLCs ≤3 cm. We aimed to explore the potential value of metastasis-associated protein 1(MTA1) expression in risk stratification of patients with multifocal NSCLCs ≤3 cm.

Methods

We retrospectively analyzed the clinical data and postoperative survival data of patients with multifocal NSCLCs ≤3 cm. Paraffin-embedded tissue sections were used for immunohistochemistry. Semiquantitative immunoreactivity scoring (IRS) system was used to evaluate the nuclear expression of MTA1. SPSS software (version 23.0) was used to analyze the data.

Results

The IRS of MTA1 nuclear expression in 259 lesions of 119 patients ranged from 2.2 to 11.7 (median: 5.6). Our results showed that MTA1 expression was highest in high-risk pathological subtypes of lung adenocarcinoma. MTA1 expression in multiple primary lung cancers (MPLCs) was lower than that in intrapulmonary metastases (IPMs). The median follow-up duration was 25.97 months. The disease-free survival (DFS) of patients with MPLCs was significantly better than that of patients with IPMs, and the DFS of patients with high MTA1 expression was significantly worse than that of patients with low MTA1 expression. Multivariate Cox analysis showed that high MTA1 expression (hazard ratio: 7.937, 95% confidence interval: 2.433–25.64, p =0.001) was a statistically significant predictor of worse DFS in patients with multifocal NSCLCs ≤3 cm.

Conclusion

MTA1 expression can stratify the risk in patients with multifocal NSCLCs ≤3 cm. Patients with MTA1 immunohistochemical score >5.6 are at a high risk of postoperative recurrence, and these patients may benefit from postoperative adjuvant chemotherapy.

Acetylcholinesterase and human cancers

The enzyme acetylcholinesterase (AChE) is a serine hydrolase whose primary function is to degrade acetylcholine (ACh) and terminate neurotransmission. Apart from its role in synaptic transmission, AChE has several "non-classical" functions in non-neuronal cells. AChE is involved in cellular growth, apoptosis, drug resistance pathways, response to stress signals and inflammation. The observation that the functional activity of AChE is altered in human tumors (relative to adjacent matched normal tissue) has raised several intriguing questions about its role in the pathophysiology of human cancers. Published reports show that AChE is a vital regulator of oncogenic signaling pathways involving proliferation, differentiation, cell-cell adhesion, migration, invasion and metastasis of primary tumors. The objective of this book chapter is to provide a comprehensive overview of the contributions of the AChE-signaling pathway in the growth of progression of human cancers. The AChE isoforms, AChE-T, AChE-R and AChE-S are robustly expressed in human cancer cell lines as well in human tumors (isolated from patients). Traditionally, AChE-modulators have been used in the clinic for treatment of neurodegenerative disorders. Emerging studies reveal that these drugs could be repurposed for the treatment of human cancers. The discovery of potent, selective AChE ligands will provide new knowledge about AChE-regulatory pathways in human cancers and foster the hope of novel therapies for this disease.

Targeted Sequencing Facilitated Diagnosis of an Uncommon Patient Harboring Both Multiple Primary and Intrapulmonary Metastatic Lung Cancer: A Case Report

Estimated to comprise approximately 10% of lung cancer cases, multiple pulmonary lesions pose a diagnostic and therapeutic challenge in thoracic oncology. Distinction between multiple primary lung cancer (MPLC) and intrapulmonary metastasis (IPM) directly affects tumor staging and clinical management. In equivocal cases in which the lesions are histopathologically indistinguishable, targeted sequencing can provide key additional evidence for differential diagnosis. Herein, we describe an unusual patient who presented with seven lung lesions that consisted of primary tumors and metastatic lesions, each showing distinct clonality status based on histomolecular findings. Specifically, the 45-year-old female never-smoker underwent a surgery that removed one invasive lepidic predominant adenocarcinoma and five microinvasive adenocarcinomas. Next-generation sequencing revealed three of the lesions to carry a clonal driver mutation EGFR p.L858R, supporting an IMP diagnosis. EGFR p.L858R was not detected in two other surgical specimens, which instead harbored respective oncogenic BRAF p.G469A and an uncommon EGFR p.G779F. These results led to diagnosis of the two lesions as primary tumors of lineages different from that of the metastases. The patient had achieved a recurrence-free survival of 21 months as of the latest follow-up. In this rare case that presented with evidence of both MPLC and IPM, targeted sequencing proved valuable in facilitating the diagnostic workup.

Next-generation sequencing facilitates differentiating between multiple primary lung cancer and intrapulmonary metastasis: a case series

Background

In lung cancer management, differential diagnosis between multiple primary lung cancer (MPLC) and intrapulmonary metastasis (IMP) is a critical point that is of direct therapeutic and clinical importance. However, this process often suffers from absence of a gold standard, resulting in equivocal cases. Herein, we present a series of three cases, in which genomic alteration patterns revealed by next-generation sequencing (NGS) facilitated the differential diagnosis between MPLC and IMP.

Case presentation

Case 1 was a 57-year-old female with two separate lesions in the upper lobe and the lower lobe of left lung, which were both histopathologically determined as T2aN0M0 adenocarcinomas. NGS identified an EGFR L858R in one lesion and an EGFR 20 exon insertion in the other one, suggestive of double primary malignancies. The patient underwent wedge resections and received an adjuvant treatment of icotinib and chemotherapy. She had a disease-free survival (DFS) of 19 months and counting. Case 2 was a 55-year-old female with multiple small lesions in both lungs. Histopathological examinations of resected lesions from right upper lobe revealed three subtypes: atypical adenomatous hyperplasia of alveolar epithelium, adenocarcinomas in situ and minimally invasive adenocarcinoma. NGS identified two different BRAF driver mutations G466E and V600_K601delinsE in two lesions of adenocarcinoma in situ, and a BRAF K601E in a lesion of minimally invasive adenocarcinoma. Case 3, a 68-year-old male, had the right upper lobe lesion histophathologically classified as a stage T3NxM0 mixed adenoneuroendocrine carcinoma and the left upper lobe lesion as a stage T1aN0M0 adenocarcinoma. NGS performed with different loci of surgical tissues revealed a rare sensitizing EGFR mutation G719A shared by the right upper lobe lesion and lymph node, and two EGFR mutations L861Q and G719S in left upper lobe lesion. The patient received icotinib treatment postoperatively and achieved a stable disease with a progression-free survival of 5 months.

Conclusion

Our cases provide evidence for utility of NGS in facilitating diagnosis and treatment decisions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13000-021-01083-6.

Application of large-scale targeted sequencing to distinguish multiple lung primary tumors from intrapulmonary metastases

The effective differentiation between multiple primary lung tumors (MPs) and intrapulmonary metastases (IMs) in patients is imperative to discover the exact disease stage and to select the most appropriate treatment. In this study, the authors was to evaluate the efficacy and validity of large-scale targeted sequencing (LSTS) as a supplement to estimate whether multifocal lung cancers (MLCs) are primary or metastatic. Targeted sequencing of 520 cancer-related oncogenes was performed on 36 distinct tumors from 16 patients with MPs. Pairing analysis was performed to evaluate the somatic mutation pattern of MLCs in each patient. A total of 25 tumor pairs from 16 patients were sequenced, 88% (n = 22) of which were classified as MPs by LSTS, consistent with clinical diagnosis. One tumor pair from a patient with lymph node metastases had highly consistent somatic mutation profiles, thus predicted as a primary-metastatic pair. In addition, some matched mutations were observed in the remaining two paired ground-glass nodules (GGNs) and classified as high-probability IMs by LSTS. Our study revealed that LSTS can potentially facilitate the distinction of MPs from IMs. In addition, our results provide new genomic evidence of the presence of cancer invasion in GGNs, even pure GGNs.

Genetic features and application value of next generation sequencing in the diagnosis of synchronous multifocal lung adenocarcinoma

The present study aimed to elucidate the genetic features of multiple lung cancer (MLC) and identify effective molecular markers for diagnosis using next generation sequencing (NGS). The present data may also inform patient treatment and prognosis. A total of 35 lesions were obtained from 17 patients with MLC. Based on lesion histology and NGS, 13 cases of multiple primary lung cancer (MPLC) were identified and 4 cases were classified as intrapulmonary metastasis (IPM). All 4 patients with IPM exhibited an epidermal growth factor receptor (EGFR) mutation and synchronous mutation of at least one tumor suppressor gene. The frequency and percentage of EGFR mutations, accompanied with tumor suppressor genes, were significantly higher in patients with IPM compared with MPLC. Furthermore, a high EGFR-heterogeneity score and male sex were risk factors of IPM occurrence. There were significant differences in mean EGFR mutation abundance alone, mutations of tumor suppressor genes and mutations of EGFR combined with tumor suppressor genes between patients with adenocarcinoma (ADC) and adenocarcinoma in situ (AIS). In conclusion, histological characteristics combined with genetic alterations may be an effective method for the diagnosis of MPLC and IPM, and NGS may serve as a useful diagnostic tool. MLC exhibited unique molecular characteristics, including higher rates of EGFR mutations, EGFR driver mutations accompanied with tumor suppressor gene mutations and the absence of anaplastic lymphoma kinase mutations, which may help distinguish between patients with MPLC or IPM. The present study hypothesized that the mean frequency of EGFR mutations, mutations of tumor suppressor genes and mutations of both EGFR and tumor suppressor genes may serve an important role in the development of AIS to ADC. The results of the present study highlight the potential underlying mechanisms of lung ADC development, which may assist with future elucidation of effective treatments to prevent the progression of lung cancer.

[Progress in Basic Research and Clinical Treatment of Multiple Pulmonary Nodules]

肺癌是世界上发病率和死亡率最高的肿瘤。随着多层螺旋计算机断层扫描（computed tomography, CT）技术的发展和肺癌筛查的广泛开展，越来越多的肺结节被发现, 其中不少是多发肺结节，这些结节在病理学上常被诊断为多原发肺腺癌。对于具有不同影像学特征的多发结节，首选处理方法不尽相同，且每个肺结节的处理方法仍存在很大争议。近年来多发肺结节各病灶的演进及病灶间的相互影响机制，病灶内和病灶间肿瘤细胞在基因组学方面的同质性和异质性也备受关注。本文从组织病理学、基因组学、外科处理等多方面综合论述多发肺结节的研究进展。