Solitary and multiple resected adenocarcinomas after CT screening for lung cancer: histopathologic features and their prognostic implications

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.

Pathologic Assessment and Staging of Multiple Non-Small Cell Lung Carcinomas: A Paradigm Shift with the Emerging Role of Molecular Methods

Non-small cell lung carcinomas (NSCLCs) commonly present as 2 or more separate tumors. Biologically, this encompasses 2 distinct processes: separate primary lung carcinomas (SPLCs), representing independently arising tumors, and intrapulmonary metastases (IPMs), representing intrapulmonary spread of a single tumor. The advent of computed tomography imaging has substantially increased the detection of multifocal NSCLCs. The strategies and approaches for distinguishing between SPLCs and IPMs have evolved significantly over the years. Recently, genomic sequencing of somatic mutations has been widely adopted to identify targetable alterations in NSCLC. These molecular techniques have enabled pathologists to reliably discern clonal relationships among multiple NSCLCs in clinical practice. However, a standardized approach to evaluating and staging multiple NSCLCs using molecular methods is still lacking. Here, we reviewed the historical context and provided an update on the growing applications of genomic testing as a clinically relevant benchmark for determining clonal relationships in multiple NSCLCs, a practice we have designated "comparative molecular profiling." We examined the strengths and limitations of the morphology-based distinction of SPLCs vs IPMs and highlighted pivotal clinical and pathologic insights that have emerged from studying multiple NSCLCs using genomic approaches as a gold standard. Lastly, we suggest a practical approach for evaluating multiple NSCLCs in the clinical setting, considering the varying availability of molecular techniques.

Long-term prognosis analysis of surgical therapy for bilateral synchronous multiple primary lung cancer: a follow-up of 293 cases

Background

Bilateral synchronous multiple primary lung cancer (BSMPLC) presents significant clinical challenges due to its unique characteristics and prognosis. Understanding the risk factors that influence overall survival (OS) and recurrence-free survival (RFS) is crucial for optimizing therapeutic strategies for BSMPLC patients.

Methods

We retrospectively analyzed clinical characteristics and treatment outcomes of 293 patients with BSMPLC who underwent surgical treatment between January 2010 and July 2017.

Results

The 10-year OS and RFS rates were 96.1% and 92.8%, respectively. Preoperative forced expiratory volume in 1 second (FEV1) ≥70% [hazard ratio (HR), 0.214; 95% confidence interval (CI): 0.053 to 0.857], identical pathology types (HR, 9.726; 95% CI: 1.886 to 50.151), largest pT1 (HR, 7.123; 95% CI: 2.663 to 19.055), and absence of lymphovascular invasion (LVI; HR, 7.021; 95% CI: 1.448 to 34.032) emerged as independent predictors of improved OS. Moreover, the sum of tumor sizes less than or equal to 3 cm (HR, 6.229; 95% CI: 1.411 to 27.502) and absence of pleural invasion (HR, 3.442; 95% CI: 1.352 to 8.759) were identified as independent predictors of enhanced RFS. The presence or absence of residual nodules after bilateral surgery did not influence patients' OS (P=0.987) and RFS (P=0.054).

Conclusions

Patients with BSMPLC who underwent surgery generally had a favorable prognosis. Whether or not to remove all nodules bilaterally does not affect the patient's long-term prognosis, suggesting the need for an individualized surgical approach.

Multimodal fusion of liquid biopsy and CT enhances differential diagnosis of early-stage lung adenocarcinoma

This research explores the potential of multimodal fusion for the differential diagnosis of early-stage lung adenocarcinoma (LUAD) (tumor sizes < 2 cm). It combines liquid biopsy biomarkers, specifically extracellular vesicle long RNA (evlRNA) and the computed tomography (CT) attributes. The fusion model achieves an impressive area under receiver operating characteristic curve (AUC) of 91.9% for the four-classification of adenocarcinoma, along with a benign-malignant AUC of 94.8% (sensitivity: 89.1%, specificity: 94.3%). These outcomes outperform the diagnostic capabilities of the single-modal models and human experts. A comprehensive SHapley Additive exPlanations (SHAP) is provided to offer deep insights into model predictions. Our findings reveal the complementary interplay between evlRNA and image-based characteristics, underscoring the significance of integrating diverse modalities in diagnosing early-stage LUAD.

Case report: Targeted sequencing facilitates the diagnosis and management of rare multifocal pure ground-glass opacities with intrapulmonary metastasis

Introduction

Treatments for multiple ground-glass opacities (GGOs) for which the detection rate is increasing are still controversial. Next-generation sequencing (NGS) may provide additional key evidence for differential diagnosis or optimal therapeutic schedules.

Case presentation

We first reported a rare case in which more than 100 bilateral pulmonary GGOs (91.7% of the GGOs were pure GGOs) were diagnosed as both multiple primary lung cancer and intrapulmonary metastasis. We performed NGS with an 808-gene panel to assess both somatic and germline alterations in tissues and plasma. The patient (male) underwent three successive surgeries and received osimertinib adjuvant therapy due to signs of metastasis and multiple EGFR-mutated tumors. The patient had multiple pure GGOs, and eight tumors of four pathological subtypes were evaluated for the clonal relationship. Metastasis, including pure GGOs and atypical adenomatous hyperplasia, was found between two pairs of tumors. Circulating tumor DNA (ctDNA) monitoring of disease status may impact clinical decision-making.

Conclusions

Surgery combined with targeted therapies remains a reasonable alternative strategy for treating patients with multifocal GGOs, and NGS is valuable for facilitating diagnostic workup and adjuvant therapy with targeted drugs through tissue and disease monitoring via ctDNA.

Detection of subsolid nodules on chest CT scans during the COVID-19 pandemic

OBJECTIVE

To investigate the detection of subsolid nodules (SSNs) on chest CT scans of outpatients before and during the COVID-19 pandemic, as well as to correlate the imaging findings with epidemiological data. We hypothesized that (pre)malignant nonsolid nodules were underdiagnosed during the COVID-19 pandemic because of an overlap of imaging findings between SSNs and COVID-19 pneumonia.

METHODS

This was a retrospective study including all chest CT scans performed in adult outpatients (> 18 years of age) in September of 2019 (i.e., before the COVID-19 pandemic) and in September of 2020 (i.e., during the COVID-19 pandemic). The images were reviewed by a thoracic radiologist, and epidemiological data were collected from patient-filled questionnaires and clinical referrals. Regression models were used in order to control for confounding factors.

RESULTS

A total of 650 and 760 chest CT scans were reviewed for the 2019 and 2020 samples, respectively. SSNs were found in 10.6% of the patients in the 2019 sample and in 7.9% of those in the 2020 sample (p = 0.10). Multiple SSNs were found in 23 and 11 of the patients in the 2019 and 2020 samples, respectively. Women constituted the majority of the study population. The mean age was 62.8 ± 14.8 years in the 2019 sample and 59.5 ± 15.1 years in the 2020 sample (p < 0.01). COVID-19 accounted for 24% of all referrals for CT examination in 2020.

CONCLUSIONS

Fewer SSNs were detected on chest CT scans of outpatients during the COVID-19 pandemic than before the pandemic, although the difference was not significant. In addition to COVID-19, the major difference between the 2019 and 2020 samples was the younger age in the 2020 sample. We can assume that fewer SSNs will be detected in a population with a higher proportion of COVID-19 suspicion or diagnosis.

Analysis of the correlation between clinical and imaging features of malignant lung nodules and pathological types

Introduction

To explore the correlation between clinical and imaging features of malignant lung nodules and pathology types.

Methods

Patients with lung nodules admitted to the Affiliated Hospital of Jiangsu University from January 1, 2020 to December 31, 2020 were collected as study subjects, and all of them underwent surgical treatment and were clearly diagnosed by pathology. The correlation between clinical and imaging features and pathological types of lung cancer patients was analyzed.

Results

Among them, The pathological types of malignant pulmonary nodules are correlated with age, gender, smoking history, ground glass sign, nodule size, solid to solid ratio, lobulation sign, pleural indentation sign, hair prick sign, CEA, SCCA. The imaging features of ground glass sign and nodule size are most significantly correlated with the pathological type.

Conclusion

It was found that, the clinical and imaging characteristics of patients with malignant lung nodules have a certain correlation with the pathological type, and gender, age, smoking history, nodule size, nodule nature, burr sign, pleural depression sign, and tumor markers are of great value for pathological typing.

A pairwise radiomics algorithm-lesion pair relation estimation model for distinguishing multiple primary lung cancer from intrapulmonary metastasis

Background

Distinguishing multiple primary lung cancer (MPLC) from intrapulmonary metastasis (IPM) is critical for their disparate treatment strategy and prognosis. This study aimed to establish a non-invasive model to make the differentiation pre-operatively.

Methods

We retrospectively studied 168 patients with multiple lung cancers (307 pairs of lesions) including 118 cases for modeling and internal validation, and 50 cases for independent external validation. Radiomic features on computed tomography (CT) were extracted to calculate the absolute deviation of paired lesions. Features were then selected by correlation coefficients and random forest classifier 5-fold cross-validation, based on which the lesion pair relation estimation (PRE) model was developed. A major voting strategy was used to decide diagnosis for cases with multiple pairs of lesions. Cases from another institute were included as the external validation set for the PRE model to compete with two experienced clinicians.

Results

Seven radiomic features were selected for the PRE model construction. With major voting strategy, the mean area under receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity of the training versus internal validation versus external validation cohort to distinguish MPLC were 0.983 versus 0.844 versus 0.793, 0.942 versus 0.846 versus 0.760, 0.905 versus 0.728 versus 0.727, and 0.962 versus 0.910 versus 0.769, respectively. AUCs of the two clinicians were 0.619 and 0.580.

Conclusions

The CT radiomic feature-based lesion PRE model is potentially an accurate diagnostic tool for the differentiation of MPLC and IPM, which could help with clinical decision making.

Solitary lung adenocarcinoma: follow-up CT, pathological-molecular characteristics, and surgical prognosis for different morphological classifications

OBJECTIVE

To investigate the dynamic changes during follow-up computed tomography (CT), histological subtypes, gene mutation status, and surgical prognosis for different morphological presentations of solitary lung adenocarcinomas (SLADC).

MATERIALS AND METHODS

This retrospective study compared dynamic tumor changes and volume doubling time (VDT) in 228 patients with SLADC (morphological types I-IV) who had intermittent growth during follow-ups. The correlation between the morphological classification and histological subtypes, gene mutation status, and surgical prognosis was evaluated.

RESULTS

Among the 228 patients, 66 (28.9%) were classified as type I, 123 (53.9%) as type II, 16 (7%) as type III, and 23 (10.1%) as type IV. Type I had the shortest VDT (254 days), followed by types IV (381 days) and III (501 days), and then type II (993 days) (p < 0.05 each). Type I had a greater proportion of solid/micropapillary-predominant pattern than type II, and the lepidic-predominant pattern was more common in type II and III than in type I (p < 0.05 each). Furthermore, type II and IV SLADCs were correlated with positive epidermal growth factor receptor mutation (p < 0.05 each). Lastly, the Kaplan-Meier curves showed that the disease-free survival was longest for patients with type II tumors, followed by those with type III and IV tumors, and then those with type I tumors (p < 0.001 each).

CONCLUSION

A good understanding of the natural progression and pathological-molecular characteristics of different morphological SLADC types can help make accurate diagnoses, develop individual treatment strategies, and predict patient outcomes.

CRITICAL RELEVANCE STATEMENT

A good understanding of the natural progression and pathological-molecular characteristics of different morphological solitary lung adenocarcinoma types can help make accurate diagnoses, develop individual treatment strategies, and predict patient outcomes.

KEY POINTS

• Type I-IV solitary lung adenocarcinomas exhibit varying natural progression on serial CT scans. • Morphological classification of solitary lung adenocarcinomas predicts histological subtype, gene status, and surgical prognosis. • This classification of solitary lung adenocarcinomas may help improve diagnostic, therapeutic, and prognosticating abilities.

Accurate and non-invasive localization of multi-focal ground-glass opacities via electromagnetic navigation bronchoscopy assisting video-assisted thoracoscopic surgery: a single-center study

Background

Accurate localization of multi-focal ground-glass opacities (GGOs) is crucial for successful video-assisted thoracoscopic surgery (VATS). Electromagnetic navigation bronchoscopy (ENB) provides a minimally invasive and dependable approach for precise localization. This study assessed the accuracy and safety of ENB-guided localization in cases involving multi-focal GGOs.

Methods

This retrospective study presents a single-center investigation into ENB-guided localization, utilizing methylene blue, for multi-focal GGOs assisting VATS. Clinical, surgical, and pathological data were collected from patients who underwent ENB-guided localization between 23 December 2019 and 31 August 2022.

Results

The study examined 57 patients with multi-focal GGOs who underwent ENB-guided localization and VATS. A total of 150 GGOs were treated, with ENB-guided localization taking a median time of 65 min. Following localization, all patients proceeded to VATS, with a median duration of 170 min. The median lesion size measured 7.8 mm, with a 5-mm distance between GGO and pleura or fissure. When the distance between GGO and pleura/fissure exceeded 1 cm, an additional location point was introduced below the pleura or fissure based on GGO location. No complications related to localization were observed. The overall malignancy rate stood at 66%. Location precision was confirmed by measuring the marker-to-GGO lesion distance, resulting in a 94% (141/150) accuracy rate for GGO localization.

Conclusion

ENB-guided methylene blue injection is a safe and precise method to treat multi-focal GGOs, potentially minimizing operation time and simplifying lesion detection.

Progress in genome-inspired treatment decisions for multifocal lung adenocarcinoma

INTRODUCTION

Multifocal lung adenocarcinoma (MFLA) is becoming increasingly recognized as a distinct subset of lung cancer, with unique biology, disease course, and treatment outcomes. While definitions remain controversial, MFLA is characterized by the development and concurrent presence of multiple independent (non-metastatic) lesions on the lung adenocarcinoma spectrum. Disease progression typically follows an indolent course measured in years, with a lower propensity for nodal and distant metastases than other more common forms of non-small cell lung cancer.

AREAS COVERED

Traditional imaging and histopathological analyses of tumor biopsies are frequently unable to fully characterize the disease, prompting interest in molecular diagnosis. We highlight some of the key questions in the field, including accurate definitions to identify and stage MLFA, molecular tests to stratify patients and treatment decisions, and the lack of clinical trial data to delineate best management for this poorly understood subset of lung cancer patients. We review the existing literature and progress toward a genomic diagnosis for this unique disease entity.

EXPERT OPINION

Multifocal lung adenocarcinoma behaves differently than other forms of non-small cell lung cancer. Progress in molecular diagnosis may enhance potential for accurate definition, diagnosis, and optimizing treatment approach.

Surgical resection versus radiotherapy for clinical stage IA lung cancer ≤1 cm in size: A population-based study

OBJECTIVE

With the increasing incidence of stage IA lung cancer ≤1 cm in size, the optimal primary treatment remains to be controversial, and thus, we compared the survival of these patients treated with radiotherapy, wedge resection, segmentectomy, or lobectomy in a large population.

METHODS

We identified patients with stage IA lung cancer ≤1 cm in size between 2004 and 2015 in the Surveillance, Epidemiology, and End Results (SEER) database. We compared the overall survival (OS) via Kaplan-Meier analysis and conducted Cox regression analysis via propensity score matching (PSM) method to identify the relative hazard ratio (HR) and difference of OS among these treatments in the subgroup stratified by four variables (age, total number of tumors, pathological grade, and histology).

RESULTS

A total of 5435 patients were included with a median age of 68 years (range, 6-94 years), of which 2131 (39.2%) were male, and 3510 (64.6%) were adenocarcinoma. The 5-year OS rate was 67.1%, 34.5%, 61.6%, 72.1%, and 75.0% for the entire study population, radiotherapy, wedge resection, segmentectomy, and lobectomy, respectively. In PSM analysis, wedge resection and segmentectomy were all superior to radiotherapy (P < 0.001), and segmentectomy was superior to wedge resection (P = 0.043), while segmentectomy was comparable with lobectomy (P = 0.058). In patients with multiple tumors, radiotherapy brought similar survival to surgery (wedge resection versus radiotherapy, P = 0.323; segmentectomy versus radiotherapy, P = 0.170; lobectomy versus radiotherapy, P = 0.796).

CONCLUSIONS

Among stage IA lung cancer with ≤1 cm, segmentectomy and lobectomy were identified as the potential effective treatments, with segmentectomy more preferred, while radiotherapy would be recommended in those with multiple tumors, which requires further verification.

Osimertinib showed efficacy on contralateral multiple ground-glass nodules after segmentectomy for lung adenocarcinoma harboring primary EGFR-T790M mutation: a case report and review of the literature

BACKGROUND

Multiple ground-glass nodules (mGGNs) in the lung has been defined as synchronous multiple primary lung cancer (SMPLC), it is has been very difficult challenging to differentiate SMPLC from intrapulmonary metastases, and its treatment remains controversial.

CASE PRESENTATION

We report a case simultaneously involving mGGNs and lung adenocarcinoma harboring primary EGFR-T790M mutation, in which the patient underwent the radical resection of lesions in the left upper lung, and continued the osimertinib treatment for the residual mGGNs in all lobes of the right lung. These mGGNs displayed different responses to osimertinib.

CONCLUSIONS

We reported a successful strategy on the postoperative treatment for mGGNs. For those that cannot be completely resected, the chemotherapy, radiotherapy, stereotactic body radiation therapy, immunotherapy and targeted therapy have been performed instead. The EGFR-TKI therapy strategy showed significant advantages, but how to achieve even better therapeutic effect needs more researches.

Small nodules (≤ 6 mm in diameter) of multiple primary lung cancers: prevalence and management

Background

Synchronous multiple primary lung cancers associated with small non-dominant nodules are commonly encountered. However, the incidence, follow-up, and treatment of small non-dominant tumors have been but little studied. We explored the prevalence and management of small non-dominant tumors and factors associated with interval growth.

Methods

This observational, consecutive, retrospective single-center study enrolled patients diagnosed with synchronous multiple primary lung cancers and small non-dominant tumors (≤ 6 mm in diameter) who underwent resection of the dominant tumor. The incidence, follow-up, and management of small non-dominant tumors and predictors of nodule growth were analyzed.

Results

There were 88 patients (12% of all lung cancer patients) with pathological diagnoses of synchronous multiple primary lung cancers. A total of 131 (18%) patients were clinically diagnosed with at least one small (≤ 6 mm in diameter) multiple primary lung cancer non-dominant tumor. 94 patients with 125 small-nodule non-dominant tumors clinically diagnosed as multiple primary lung cancers were followed-up for at least 6 months. A total of 29 (29/125, 23.2%) evidenced small pulmonary nodules (≤ 6 mm in diameter) that exhibited interval growth on follow-up computed tomography (CT). On multivariate analysis, a part-solid nodule (compared to a pGGN) (OR 1.23; 95% CI 1.08–1.40) or a solid nodule (compared to a pGGN) (OR 3.50; 95% CI 1.94–6.30) predicted small nodule interval growth.

Conclusion

We found a relatively high incidence of multiple primary lung cancers with small non-dominant tumors exhibiting interval growth on follow-up CT, suggesting that resection of non-dominant tumors at the time of dominant tumor resection, especially when the nodules are part-solid or solid, is the optimal treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-022-02022-2.

Multiple Primary Lung Cancers With ALK Rearrangement: A Case Report and Literature Review

Multiple primary lung cancers (MPLCs) are that patients with lung cancer may present with two primary tumors at the same time (synchronous multiple primary lung cancer, SMPLC) or may develop a second, metachronous primary lung cancer after treatment of the initial lesion. Currently, there are no definitive guidelines for the diagnosis and treatment of multiple primary lung cancers. Herein, we report a case of double primary lung cancers with ALK rearrangement. The patient was treated with chemotherapy, targeted therapy, and radiotherapy. After these treatments, the patient was free of locally recurrent or distant disease at 2 years.

Radiological classification, gene-mutation status, and surgical prognosis of synchronous multiple primary lung cancer

OBJECTIVE

To investigate the radiological classification, gene-mutation status, and surgical prognosis of synchronous multiple primary lung cancer (sMPLC).

METHODS

From January 2013 to October 2019, 192 consecutive patients with sMPLC were investigated. The clinical, CT, molecular, and pathological features of all patients were analyzed. Furthermore, the prognosis of 89 patients who only underwent surgical resection was evaluated.

RESULTS

Among 192 patients, all lesions pathologically confirmed or highly suspected as tumors based on radiological findings were retrospectively analyzed, and the CT findings of sMPLC were classified into three types: (I) all lesions manifested as solid nodules/masses (14.06%, 27/192), (II) all lesions manifested as subsolid nodules/masses (43.23%, 83/192), and (III) tumor lesions manifested as a combination of ≥ 2 of the following patterns: solid nodules/masses, subsolid nodules/masses, cystic airspace, and focal consolidation (42.71%, 82/192). For 252 tumors undergoing epidermal growth factor receptor (EGFR)-mutation testing, the EGFR-mutation rate was higher in subsolid tumors than that in solid tumors (p < 0.05). Among 19 patients with all tumors undergoing surgery and driver-gene testing, genetic heterogeneity was prevalent among the multiple tumors (63.16%,12/19). The highest clinical stage of non-I, ipsilateral distribution of tumors, and CT classification of I indicated a poor prognosis for patients with sMPLC (all p < 0.05).

CONCLUSION

Subsolid lesions are the most common presentation of sMPLC. Genetic heterogeneity in driver mutations among sMPLC may be present. Prognosis in patients with sMPLC is determined by the highest clinical TNM stage, distribution, and radiological classification among the multiple tumors.

KEY POINTS

• Synchronous multiple primary lung cancer (sMPLC) has three types of CT findings. • Genetic heterogeneity may be prevalent among the multiple tumors. • Prognosis in patients with sMPLC is associated with the highest clinical TNM stage, distribution, and radiological classification among the multiple tumors.

Pearls and Pitfalls in Lung Cancer CT Screening

Annual LDCT lung cancer screening is recommended by the United States Preventive Services Task Force (USPSTF) for high-risk population based on the results from the National Lung Cancer Screening Trial (NLST) that showed a significant (20%) reduction in lung cancer-specific mortality rate with the use of annual low-dose computed tomography (LDCT) screening. More recently, the benefits of lung cancer screening were confirmed by the Dutch- Belgian NELSON trial in Europe. With the implementation of lung screening in large scale, knowledge of the limitations related to false positive, false negative and other potential pitfalls is essential to avoid misdiagnosis. This review outlines the most common potential pitfalls in the characterization of screen-detected lung nodules that include artifacts in LDCT, benign nodules that mimic lung cancer, and causes of false negative evaluations of lung cancer with LDCT and PET/CT studies. Awareness of the spectrum of potential pitfalls in pulmonary nodule detection and characterization, including equivocal or atypical presentations, is important for avoiding misinterpretation that can alter patient management.

Advances in lung cancer screening and early detection

Lung cancer is associated with a heavy cancer-related burden in terms of patients' physical and mental health worldwide. Two randomized controlled trials, the US-National Lung Screening Trial (NLST) and Nederlands-Leuvens Longkanker Screenings Onderzoek (NELSON), indicated that low-dose CT (LDCT) screening results in a statistically significant decrease in mortality in patients with lung cancer, LDCT has become the standard approach for lung cancer screening. However, many issues in lung cancer screening remain unresolved, such as the screening criteria, high false-positive rate, and radiation exposure. This review first summarizes recent studies on lung cancer screening from the US, Europe, and Asia, and discusses risk-based selection for screening and the related issues. Second, an overview of novel techniques for the differential diagnosis of pulmonary nodules, including artificial intelligence and molecular biomarker-based screening, is presented. Third, current explorations of strategies for suspected malignancy are summarized. Overall, this review aims to help clinicians understand recent progress in lung cancer screening and alleviate the burden of lung cancer.

Trends in lung cancer incidence by gender, histological type and stage at diagnosis in Japan, 1993-2015: A multiple imputation approach

Continued decrease in smoking prevalence and increasing use of sensitive diagnostic procedures necessitate updated monitoring of trends in lung cancer incidence in Japan. We analyzed histology- and stage-specific trends in 1993-2015 using data from 62,870 diagnosed cases from the Monitoring of Cancer Incidence in Japan project. After applying a multiple imputation approach to impute missing/unknown values of stage and histology, we estimated age-standardized incidence rates and applied joinpoint regression analyses. We observed long-term growth trends in adenocarcinoma (ADC) and localized cancer among both genders, long-term declining trends among men and leveling-off trends among women in small-cell carcinoma (SMC) and squamous cell carcinoma (SQC). Stratifying by gender, we observed an increase in localized ADC with average annual percentage changes (AAPC) of 4.5 (95% confidence interval: 3.9 to 5.0) and 5.7 (5.0 to 6.4), a decrease in regional ADC with AAPC of -1.5 (-2.5 to -0.6) and -2.3 (-4.6 to 0.0), but an increase in distant ADC with AAPC of 1.5 (1.1 to 1.9) and 1.6 (0.9 to 2.3) among males and females, respectively. Additionally, increasing trends in female-to-male incidence rate ratios were observed in localized ADC with significantly above one in the most recent diagnosis period. Our results revealed evidence for a partial shift from advanced to early cancer stage, which may suggest the modest effectiveness of nationwide organized screening programs. The observed increasing localized and distant ADC may be linked to improved diagnostic procedures, especially for metastasis detection. Further investigation is needed for more accurate quantification of these factors.

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.

Clinicopathologic Characteristics and Outcomes of Simultaneous Multiple Primary Lung Cancer

Background

Simultaneous multiple primary lung cancer has been detected increasingly nowadays with the development of image technology. However, the clinicopathologic characteristics and outcomes are not clear.

Methods

All consecutive patients diagnosed as simultaneous multiple primary lung cancer according to Martini–Melamed and American College of Chest Physicians criteria from June 2010 to June 2019 in our center were enrolled. The clinicopathologic characteristics and outcomes were compared between patients with the same histological type and different histological types.

Results

A total of 336 patients were enrolled, consisting of 297 (88.4%) patients with the same histological type and 39 (11.6%) patients with different histological types. Compared to patients with the same histological type, patients with different histological types were more commonly males (87.2% vs. 34.0%; p < 0.001) with an older age (65 [62–69] vs. 59 [52–65] yrs; p < 0.001) at diagnosis. Also, patients with different histological types showed worse respiratory function and more advanced stage according to TNM staging. The 1-, 2-, and 3-year overall survival of overall patients was 97.7%, 96.1%, and 92.2%, and the 1-, 2-, and 3-year recurrence-free survival of overall patients was 96.8%, 92.9% and 85.7%, respectively. Importantly, patients with different histological types showed worse overall survival (p < 0.001) and recurrence-free survival (p=0.002) than patients with same histological type. The multivariable Cox proportional hazard model revealed that presence of different histological types was significant predictor for worse overall survival (adjusted hazard ratio: 10.00; 95% confidence interval: 2.92–34.48; p < 0.001) and recurrence-free survival (adjusted hazard ratio: 2.59; 95% confidence interval: 1.14–5.88; p=0.023).

Conclusions

Although relatively less common in simultaneous multiple primary lung cancer, patients with different histological types showed worse clinical characteristics and outcomes.

Recent Advances in the Diagnosis and Management of Multiple Primary Lung Cancer

With the wide application of computed tomography in lung cancer screening, the incidence of multiple primary lung cancer (MPLC) has been increasingly reported. Despite the established criteria, the differentiation between MPLC and intrapulmonary metastasis remains challenging. Although histologic features are helpful in some circumstances, a molecular analysis is often needed. The application of next-generation sequencing could aid in distinguishing MPLCs from intrapulmonary metastasis, decreasing ambiguity. For MPLC management, surgery with lobectomy is the main operation method. Limited resection does not appear to negatively affect survival, and it is a reasonable alternative. Stereotactic ablative radiotherapy (SABR) has become a standard of care for patients refusing surgery or for those with medically inoperable early-stage lung cancer. However, the efficacy of SABR in MPLC management could only be found in retrospective series. Other local ablation techniques are an emerging alternative for the control of residual lesions. Furthermore, systemic therapies, such as targeted therapy for oncogene-addicted patients, and immunotherapy have shown promising results in MPLC management after resection. In this paper, the recent advances in the diagnosis and management of MPLC are reviewed.

The Role of Whole Exome Sequencing in Distinguishing Primary and Secondary Lung Cancers

Non-small cell lung cancer (NSCLC) that presents with multiple lung tumors (MLTs) poses a challenge to accurate staging and prognosis. MLTs that arise as clonally related secondary metastases from a common primary are higher stage and often require adjuvant chemotherapy or may in fact be incurable stage IV lesions. Conversely, MLTs that represent distinct primaries have a better prognosis and may be overtreated if inappropriately classified as related secondaries. Historically, pathologic and radiographic criteria were used to distinguish between primary and secondary MLTs; however, the advent of genomic profiling has demonstrated limitations to these historic classification systems. In this review, we discuss the use of molecular profiling to distinguish between primary and secondary lung cancers, with a focus on the insights gleaned from whole exome sequencing (WES) analyses. While WES is not yet feasible in routine clinical practice, WES studies have helped elucidate the clonal relationship between primary and secondary lung cancers and provide important context for the application of targeted sequencing panel-based analyses.

Biglycan, tumor endothelial cell secreting proteoglycan, as possible biomarker for lung cancer

OBJECTIVES

In lung cancer, surgery remains the most curative treatment and limited resection is beneficial for patients with low cardiopulmonary function and low malignancy tumors. However, there are no biomarkers of low malignancy to select candidates for limited resection without compromising the outcome of treatments. Recently we identified biglycan (BGN) as a tumor endothelial cell (TEC) marker that is associated with tumor progression in various cancers. In this study, we analyzed the association between BGN expression in TECs in lung cancer and cancer progression in patients.

MATERIALS AND METHODS

First, we performed immunohistochemistry of BGN with resected lung tumor tissues of 155 patients who had undergone thoracic surgery and analyzed the correlation between BGN-positive vessel density in primary lung tumors and clinicopathological factors. Second, we measured the BGN levels in preoperative serum of other 46 patients with lung cancer by ELISA, and analyzed the correlation between BGN expression in tumor tissues and blood BGN levels.

RESULTS

High BGN expression in the TECs was significantly associated with T factor, and was a significant negative predictor. BGN levels in preoperative serum of 46 patients with lung cancer was significantly correlated with BGN expression in the TECs. Preoperative serum BGN level was significantly lower in healthy volunteers and less invasive adenocarcinoma than in invasive adenocarcinoma and other lung carcinomas. These results suggest that low BGN level in preoperative serum in patients with lung cancer might indicate low malignancy.

CONCLUSIONS

BGN can be a potential biomarker for lung cancer.

Clinical features and outcomes of patients with stage I multiple primary lung cancers

The number of patients with multiple primary lung cancers (MPLC) is rising. We studied the clinical features and factors related to outcomes of MPLC patients using the database of surgically resected lung cancer (LC) cases compiled by the Japanese Joint Committee of Lung Cancer Registry. From the 18 978 registered cases, 9689 patients with clinical stage I non‐small‐cell lung cancer who achieved complete resection were extracted. Tumors were defined as synchronous MPLC when multiple LC was simultaneously resected or treatment was carried out within 2 years after the initial surgery; metachronous MPLC was defined as second LC treated more than 2 years after the initial surgery. Of these cases, 579 (6.0%) were synchronous MPLC and 477 (5.0%) metachronous MPLC, with 51 overlapping cases. Female sex, nonsmoker, low consolidation‐tumor ratio (CTR), and adenocarcinoma were significantly more frequent in the synchronous MPLC group, whereas patients with metachronous MPLC had higher frequencies of male sex, smoker, chronic obstructive pulmonary disease (COPD), and nonadenocarcinoma. There was no significant difference in survival rate between patients with and without synchronous or metachronous MPLC. Age, gender, CTR for second LC, and histological combination of primary and second LC were prognostic indicators for both types of MPLC. Logistic regression analysis showed that female sex, history of malignant disease other than LC, and COPD were risk factors for MPLC incidence. The present findings could have major implications regarding MPLC diagnosis and identification of independent prognostic factors, and provide valuable information for postoperative management of patients with MPLC.

3D deep learning based classification of pulmonary ground glass opacity nodules with automatic segmentation

Classifying ground-glass lung nodules (GGNs) into atypical adenomatous hyperplasia (AAH), adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and invasive adenocarcinoma (IAC) on diagnostic CT images is important to evaluate the therapy options for lung cancer patients. In this paper, we propose a joint deep learning model where the segmentation can better facilitate the classification of pulmonary GGNs. Based on our observation that masking the nodule to train the model results in better lesion classification, we propose to build a cascade architecture with both segmentation and classification networks. The segmentation model works as a trainable preprocessing module to provide the classification-guided 'attention' weight map to the raw CT data to achieve better diagnosis performance. We evaluate our proposed model and compare with other baseline models for 4 clinically significant nodule classification tasks, defined by a combination of pathology types, using 4 classification metrics: Accuracy, Average F1 Score, Matthews Correlation Coefficient (MCC), and Area Under the Receiver Operating Characteristic Curve (AUC). Experimental results show that the proposed method outperforms other baseline models on all the diagnostic classification tasks.

The effectiveness of three-dimensional reconstruction in the localization of multiple nodules in lung specimens: a prospective cohort study

Background

The detection rate of multiple pulmonary nodules in computed tomography (CT) screening has increased significantly in recent years. In cases with multiple nodules within the same lung lobe or segment, it is often difficult for thoracic surgeons and pathologists to accurately locate all lesions in the surgically resected specimens. Therefore, the objective of our study was to use three-dimensional (3D) reconstruction in conjunction with 3D printing as an auxiliary method for localizing multiple small nodules in specimens after surgery and to evaluate its effectiveness.

Methods

A single-center prospective cohort study was conducted between September 2019 and September 2020 at the National Cancer Center (Beijing, China). In total, 43 surgical candidates with multiple nodules were recruited to undergo lobectomy or segmentectomy and 40 patients were ultimately enrolled in this study. With the assistance of 3D reconstruction/printing models, the obtained specimens were marked and then identified by a pathologist. The primary outcome was the success rate of nodule localization in the resected specimens, and the secondary outcome was the agreement rate between the pathological results of the samples and CT images.

Results

In the 40 patients enrolled, 126 nodules were detected by preoperative imaging, of which 124 nodules (positive rate: 98.4%) were successfully located in the resected specimens using 3D reconstruction/printing. For the 124 nodules, the agreement rate of the pathological results of samples and CT images with the assistance of 3D reconstruction/printing models was 100.0%.

Conclusions

The results show that 3D reconstruction/printing models allow for the rapid and accurate localization of nodules in resected specimens. Also, the pathological results of lesions show good agreement with the results of preoperative CT imaging, which is of great significance for further study into the clinicopathological characteristics and radiomics of multiple pulmonary nodules.

Solid Components in the Mediastinal Window of Computed Tomography Define a Distinct Subtype of Subsolid Nodules in Clinical Stage I Lung Cancers

BACKGROUND

We aimed to validate the clinicopathologic characteristics and prognostic value of the presence of solid components in the mediastinal window of computed tomography scan in clinical stage I pulmonary subsolid nodules (SSNs).

METHODS

We retrospectively evaluated patients with pulmonary SSNs resected between 2011 and 2016. We classified SSNs into heterogeneous ground-glass nodules (HGGNs) (solid component detected only in lung window) and part-solid nodules (PSNs) (solid component detected both in lung/mediastinal windows).

RESULTS

A total of 487 patients (216 PSNs) were included. PSNs were associated with higher frequencies of micropapillary or solid pathologic patterns (18.1% vs. 3.3%; P < .001), epidermal growth factor receptor gene mutation (39.4% vs. 32.8%), and other types of gene mutations (2.3% vs. 1.1%; P = .043). Logistic regression analysis revealed that male sex (odds ratio [OR], 2.58; 95% confidence interval [CI], 1.20-5.57; P = .016) and higher consolidation tumor ratio (CTR) (OR, 110.04; 95% CI, 8.56-1414.39; P < .001) remained independent for invasive adenocarcinomas with poor differentiation. Receiver operating characteristic analyses revealed that solid component size in the mediastinal window (area under the curve [AUC], 0.731; 95% CI, 0.653-0.808; P < .0001) showed a better predictive ability to poor differentiation compared with solid component size in the lung window and CTR. The 5-year recurrence-free survival (RFS) rate of PSNs was worse than that of HGGNs (94.6% vs. 99.1%; P = .019). Multivariate Cox regression revealed that positive lymph node status (hazard ratio, 22.99; 95% CI, 4.52-116.86; P < .001) indicated worse RFS for PSNs.

CONCLUSION

SSNs with solid components in mediastinal window demonstrated clinicopathologic and prognostic features different from those without in clinical stage I lung cancer. Solid components in mediastinal window was a strong predictor of poor differentiation.

Are there imaging characteristics that can distinguish separate primary lung carcinomas from intrapulmonary metastases using next-generation sequencing as a gold standard?

OBJECTIVES

Distinguishing separate primary lung carcinomas (SPLCs) from intrapulmonary metastases (IPMs) in non-small cell lung cancer (NSCLC) patients is a challenging dilemma in clinical practice. Next-generation sequencing (NGS) was recently shown to represent a robust molecular method for clonal discrimination in this setting. In this study, using clonal relationships established by comprehensive NGS as the ground truth, we investigated whether NSCLC patients with SPLCs versus IPMs exhibit distinct imaging characteristics.

MATERIAL AND METHODS

This retrospective study included patients who underwent pre-treatment computed tomography (CT) and/or positron emission tomography/CT (PET/CT) imaging followed by surgical resection for >1 NSCLC. Nodular, parenchymal, pleural, and ancillary CT features, as well as maximum standardized uptake values (SUVs) on PET/CT were recorded. Rao-Scott chi-square, Wilcoxon rank-sum, and Fisher's exact tests were used in patient- and lesion-level comparisons.

RESULTS

This study included 60 patients (median age = 69 years, 68 % female) with 127 individual tumors comprising 51 SPLC vs 23 IPM tumor pairs based on NGS profiling. SPLCs were associated with subsolid consistency (P = 0.005) and spiculated contours (P <  0.001), while IPMs were associated with greater difference of size between lesions (P = 0.017) or pure solid consistency of the smaller lesion (P = 0.011). Lymph node involvement was more frequent in IPMs than SPLCs (P = 0.036). SUV measurements were not useful for differentiation (P > 0.05).

CONCLUSION

Selected preoperative CT features are distributed differentially in SPLCs and IPMs, suggesting that imaging may have a role in distinguishing clonal relationships of tumors in patients with >1 NSCLC.

Increased VEGF-A in solid type of lung adenocarcinoma reduces the patients' survival

The histological classification of lung adenocarcinoma includes 5 types: lepidic, acinar, papillary, micropapillary and solid. The complex gene interactions and anticancer immune response of these types are not well known. The aim of this study was to reveal the survival rates, genetic alterations and immune activities of the five histological types and provide treatment strategies. This study reviewed the histological findings of 517 patients with lung adenocarcinoma from The Cancer Genome Atlas (TCGA) database and classified them into five types. We performed gene set enrichment analysis (GSEA) and survival analysis according to the different types. We found six oncogenic gene sets that were higher in lung adenocarcinoma than in normal tissues. In the survival analysis of each type, the acinar type had a favorable prognosis, and the solid subtype had an unfavorable prognosis; however, the survival differences between the other types were not significant. Our study focused on the solid type, which had the poorest prognosis. The solid type was related to adaptive immune resistance associated with elevated CD8 T cells and high CD274 (encoding PD-L1) expression. In the pathway analyses, the solid type was significantly related to high vascular endothelial growth factor (VEGF)-A expression, reflecting tumor angiogenesis. Non-necrosis/low immune response affected by high VEGF-A was associated with worse prognosis. The solid type associated with high VEGF-A expression may contribute to the development of therapeutic strategies for lung adenocarcinoma.

The Regimen of Computed Tomography Screening for Lung Cancer: Lessons Learned Over 25 Years From the International Early Lung Cancer Action Program

We learned many unanticipated and valuable lessons since we started planning our study of low-dose computed tomography (CT) screening for lung cancer in 1991. The publication of the baseline results of the Early Lung Cancer Action Project (ELCAP) in Lancet 1999 showed that CT screening could identify a high proportion of early, curable lung cancers. This stimulated large national screening studies to be quickly started. The ELCAP design, which provided evidence about screening in the context of a clinical program, was able to rapidly expand to a 12-institution study in New York State (NY-ELCAP) and to many international institutions (International-ELCAP), ultimately working with 82 institutions, all using the common I-ELCAP protocol. This expansion was possible because the investigators had developed the ELCAP Management System for screening, capturing data and CT images, and providing for quality assurance. This advanced registry and its rapid accumulation of data and images allowed continual assessment and updating of the regimen of screening as advances in knowledge and new technology emerged. For example, in the initial ELCAP study, introduction of helical CT scanners had allowed imaging of the entire lungs in a single breath, but the images were obtained in 10 mm increments resulting in about 30 images per person. Today, images are obtained in submillimeter slice thickness, resulting in around 700 images per person, which are viewed on high-resolution monitors. The regimen provides the imaging acquisition parameters, imaging interpretation, definition of positive result, and the recommendations for further workup, which now include identification of emphysema and coronary artery calcifications. Continual updating is critical to maximize the benefit of screening and to minimize potential harms. Insights were gained about the natural history of lung cancers, identification and management of nodule subtypes, increased understanding of nodule imaging and pathologic features, and measurement variability inherent in CT scanners. The registry also provides the foundation for assessment of new statistical techniques, including artificial intelligence, and integration of effective genomic and blood-based biomarkers, as they are developed.

Surgical Prognosis of Synchronous Multiple Primary Lung Cancer: Systematic Review and Meta-Analysis

BACKGROUND

We evaluated the long-term prognosis of synchronous multiple primary lung cancer (SMPLC) patients after surgical treatment and explored prognostic factors for overall survival (OS).

MATERIALS AND METHODS

A systematic review and meta-analysis was performed regarding the surgical prognosis of SMPLC. A literature search was performed using online databases. All studies were rigorously categorized following the 8th edition of the tumor, node, metastasis classification (TNM) staging rules for multiple lung cancers: SMPLC and multifocal ground-glass/lepidic (GG/L) lung cancers. Five-year OS after surgery was pooled, and hazard ratios (HRs) for prognostic factors were synthesized. Specific subgroup analysis and sensitivity analysis were conducted (PROSPERO registration CRD42019142420).

RESULTS

An analysis of 26 studies including 1788 patients was performed. The pooled 5-year OS was 45% (95% confidence interval [CI], 37-53) of true SMPLC patients and 62% (95% CI, 57-67) of patients with pathologic stage I disease, which was different from the 5-year OS of 93% (95% CI, 85-100) of patients with multifocal GG/L lung cancers. Poor prognostic factors for SMPLC were lymph node metastasis (HR = 2.36; 95% CI, 1.75-3.20; P < .001) and pneumonectomy (HR = 2.96; 95% CI, 1.36-6.45; P = .006], whereas histology (HR = 1.11; 95% CI, 0.82-1.50; P = .508), laterality (HR = 1.16; 95% CI, 0.93-1.44, P = .190), sublobar resection (HR = 1.29; 95% CI, 0.90-1.84; P = .159), and adjuvant therapy (HR = 1.07; 95% CI, 0.64-1.80; P = .791) were not found to influence the outcome.

CONCLUSION

The long-term prognosis of SMPLC patients after surgery is acceptable, especially in patients with early-stage disease. Sublobar resection can be applied, although pneumonectomy should be avoided. Advanced criteria are needed to diagnose SMPLC and distinguish it from multifocal GG/L lung cancer to perform accurate surgical evaluation.

Distinguishing multiple lung primaries from intra-pulmonary metastases and treatment implications

INTRODUCTION

The distinction between multiple primary lung cancers and intra-pulmonary metastases has been extensively investigated because of its important clinical and therapeutic implications.

AREAS COVERED

Rapidly improving imaging technology and genomic analysis has led to a finer discrimination between multiple primary lung tumors and pulmonary metastases. However, over the past few decades, standardized criteria for the identification of multiple lung tumors have been lacking. Therefore, in 2017 a multidisciplinary international committee composed of the Union for International Cancer Control (UICC), American Joint Committee on Cancer (AJCC) and International Association for the Study of Lung Cancer (IASLC) addressed this problem when drawing up the 8th edition of TMN stage classification, that now represents a specific consensus on this topic. The most advanced diagnostic strategies associated with screening allow for the detection of early stage synchronous lung cancers.

EXPERT OPINION

Although diagnostic confirmation relies on pathologic and clinical examination, new molecular analyses help in the discrimination between primary and secondary tumors. The treatment of multiple primary lung tumors remains, whenever possible, a local treatment based on surgical resection, providing the absence of distant or local (lymph node) metastases.

A comprehensive algorithm to distinguish between MPLC and IPM in multiple lung tumors patients

Background

Diagnosis of multiple lung nodules has become convenient and frequent due to the improvement of computed tomography (CT) scans. However, to distinguish intrapulmonary metastasis (IPM) from multiple primary lung cancer (MPLC) remains challenging. Herein, for the accurate optimization of therapeutic options, we propose a comprehensive algorithm for multiple lung carcinomas based on a multidisciplinary approach, and investigate the prognosis of patients who underwent surgical resection.

Methods

Patients with multiple lung carcinomas who were treated at West China Hospital of Sichuan University from April, 2009 to December, 2017, were retrospectively identified. A comprehensive algorithm combining histologic assessment, molecular analysis, and imaging information was used to classify nodules as IPM or MPLC. The Kaplan-Meier method was used to estimate survival rates, and the relevant factors were evaluated using the log-rank test or Cox proportional hazards model.

Results

The study included 576 patients with 1,295 lung tumors in total. Significant differences were observed between the clinical features of 171 patients with IPM and 405 patients with MPLC. The final classification consistency was 0.65 and 0.72 compared with the criteria of Martini and Melamed (MM) and the American College of Chest Physicians (ACCP), respectively. Patients with independent primary tumors had better overall survival (OS) than patients with intra-pulmonary metastasis (HR =3.99, 95% CI: 2.86–5.57; P<0.001). Nodal involvement and radiotherapy were independent prognostic factors.

Conclusions

The comprehensive algorithm was a relevant tool for classifying multifocal lung tumors as MPLC or IPM, and could help doctors with precise decision-making in routine clinical practice. Patients with multiple lesions without lymph node metastasis or without radiotherapy tended to have a better prognosis.

The value of microRNA-21 as a biomarker for the prognosis of lung cancer: A protocol for systematic review and meta-analysis

BACKGROUD

More and more studies are investigating the influence of the expression of MicroRNA-21 (miRNA-21) on prognosis and clinical significance in patients with lung cancer, but the results are contradictory and uncertain. A meta-analysis was conducted with controversial data to accurately assess the issue.

METHODS

A detailed search of relevant research in Wanfang, Chinese Biomedical Literature Database, Chinese National Knowledge Infrastructure (CNKI), the Chongqing VIP Chinese Science and Technology Periodical Database, PubMed, Embase, Web of Science and other databases. Two reviewers independently conducted data extraction and literature quality evaluation. Odd ratio and its 95% confidence intervals were used to evaluate the relationship between miRNA-21 and clinicopathological characteristics of lung cancer patients. Hazard ratios and its 95% confidence intervals To assess the prognostic effect of miRNA-21 on overall survival and disease-free survival. Meta analysis was performed using RevMan 5.3 and Stata 14.0 software.

RESULTS

This study will provide a high-quality evidence-based medical evidence of the correlations between miRNA-21 expression and overall survival, disease-free survival and clinicopathological features.

CONCLUSION

The study will provide updated evidence to evaluate whether the expression of miRNA-21 is in association with poor prognosis in patients with lung cancer.

ETHICS AND DISSEMINATION

The private information from individuals will not publish. This systematic review also will not involve endangering participant rights. Ethical approval is not available. The results may be published in a peer- reviewed journal or disseminated in relevant conferences.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/X3MD6.

Impact of postoperative complications on outcomes of second surgery for second primary lung cancer

PURPOSE

The best surgical approach for second primary lung cancer remains a subject of debate. The purpose of this study was to review the postoperative complications after second surgery for second primary lung cancer and to investigate the outcomes based on these complications.

METHODS

The clinical data of 105 consecutive patients who underwent pulmonary resection for multiple primary lung cancers between January, 1996 and December, 2017, were reviewed according to the Martini-Melamed criteria.

RESULTS

After the second surgery, low body mass index (BMI) (< 18.5 kg/m²) (P = 0.004) and high Charlson comorbidity index (CCI) (P = 0.002) were independent predictors of postoperative complications. Survival analysis revealed the 5-year overall survival rates of 74.5% and 61.4% for patients without postoperative complications and those with postoperative complications (P = 0.044), respectively, but the 5-year cancer-specific survival rates of 82.5% and 80.0% (P = 0.926), respectively. During this period, there were significantly more respiratory-related deaths of patients with complications than of those without complications (P = 0.011).

CONCLUSION

Surgical intervention is feasible and potentially effective for second primary lung cancer but may not achieve positive perioperative and long-term outcomes for patients with a low BMI or a high CCI. Treatment options should be considered carefully for these patients.

Lung Cancer Staging

Lung cancer staging is a foundation of patient care, informing management decisions and prognosis. This comprehensive overview of the current 8th edition American Joint Committee on Cancer Cancer Staging Manual addresses common difficulties in staging, such as measuring the invasive component of adenocarcinomas and staging multiple lung nodules.

Comprehensive Next-Generation Sequencing Unambiguously Distinguishes Separate Primary Lung Carcinomas From Intrapulmonary Metastases: Comparison with Standard Histopathologic Approach

PURPOSE

In patients with >1 non-small cell lung carcinoma (NSCLC), the distinction between separate primary lung carcinomas (SPLCs) and intrapulmonary metastases (IPMs) is a common diagnostic dilemma with critical staging implications. Here, we compared the performance of comprehensive next-generation sequencing (NGS) with standard histopathologic approaches for distinguishing NSCLC clonal relationships in clinical practice.

EXPERIMENTAL DESIGN

We queried 4,119 NSCLCs analyzed by 341-468 gene MSK-IMPACT NGS assay for patients with >1 surgically resected tumor profiled by NGS. Tumor relatedness predicted by prospective histopathologic assessment was contrasted with comparative genomic profiling by subsequent NGS.

RESULTS

Sixty patients with NGS performed on >1 NSCLCs were identified, yielding 76 tumor pairs. NGS classified tumor pairs into 51 definite SPLCs (median, 14; up to 72 unique somatic mutations per pair), and 25 IPMs (24 definite, one high probability; median, 5; up to 16 shared somatic mutations per pair). Prospective histologic prediction was discordant with NGS in 17 cases (22%), particularly in the prediction of IPMs (44% discordant). Retrospective review highlighted several histologic challenges, including morphologic progression in some IPMs. We subsampled MSK-IMPACT data to model the performance of less comprehensive assays, and identified several clinicopathologic differences between NGS-defined tumor pairs, including increased risk of subsequent recurrence for IPMs.

CONCLUSIONS

Comprehensive NGS allows unambiguous delineation of clonal relationship among NSCLCs. In comparison, standard histopathologic approach is adequate in most cases, but has notable limitations in the recognition of IPMs. Our results support the adoption of broad panel NGS to supplement histology for robust discrimination of NSCLC clonal relationships in clinical practice.

Prognostic Classification of Multiple Primary Lung Cancers Based on a Ground-Glass Opacity Component

BACKGROUND

We evaluated the prognostic impact of the presence of a ground-glass opacity (GGO) component on thin-section computed tomography for the refined clinical T classification of multiple primary lung cancers.

METHODS

We reviewed 272 surgically resected, clinically node-negative multiple lung cancers. Dominant tumors were classified into 2 groups based on the presence of a GGO component; that is, a GGO tumor (consolidation tumor ratio, 0 to <1.0) or pure-solid (PS) tumor (consolidation tumor ratio, 1.0). Furthermore, multifocal GGOs (MFGGOs) were defined as lesions showing a GGO component for all tumors. Their prognoses were evaluated using Cox proportional hazard model.

RESULTS

There were 153 MFGGOs (56%) with a significantly better 5-year overall survival than non-MFGGOs (97.2% vs 68.5%, P < .001). A multivariable analysis revealed that MFGGO and absence of nodal involvement were independently significant prognosticators of better survival (P = .007 and P = .012, respectively). Furthermore, among the patients of non-MFGGO groups, multivariate analysis showed that a PS + PS pattern and presence of nodal involvement were independently significant prognosticators of poorer survival (P = .008 and P = .001, respectively). We divided the tumors into 3 groups based on the results and focusing on the presence of a GGO; that is, MFGGO (n = 153), PS + additional GGO (n = 81), and PS + PS (n = 38). The 5-year overall survival was clearly split among them: MFGGO, 97.2%; PS + additional GGO, 82.1%; and PS + PS, 41.3% (P < .001).

CONCLUSIONS

Our results suggest that presence of a GGO component has the ability to distinguish the survival even for multiple lung cancers. Further investigations including multicenter trials are certainly warranted to address the revision of T variable of multiple lung cancers considering a presence of GGO component.

A Novel Computer-Aided Diagnosis Scheme on Small Annotated Set: G2C-CAD

Purpose

Computer-aided diagnosis (CAD) can aid in improving diagnostic level; however, the main problem currently faced by CAD is that it cannot obtain sufficient labeled samples. To solve this problem, in this study, we adopt a generative adversarial network (GAN) approach and design a semisupervised learning algorithm, named G2C-CAD.

Methods

From the National Cancer Institute (NCI) Lung Image Database Consortium (LIDC) dataset, we extracted four types of pulmonary nodule sign images closely related to lung cancer: noncentral calcification, lobulation, spiculation, and nonsolid/ground-glass opacity (GGO) texture, obtaining a total of 3,196 samples. In addition, we randomly selected 2,000 non-lesion image blocks as negative samples. We split the data 90% for training and 10% for testing. We designed a DCGAN generative adversarial framework and trained it on the small sample set. We also trained our designed CNN-based fuzzy Co-forest on the labeled small sample set and obtained a preliminary classifier. Then, coupled with the simulated unlabeled samples generated by the trained DCGAN, we conducted iterative semisupervised learning, which continually improved the classification performance of the fuzzy Co-forest until the termination condition was reached. Finally, we tested the fuzzy Co-forest and compared its performance with that of a C4.5 random decision forest and the G2C-CAD system without the fuzzy scheme, using ROC and confusion matrix for evaluation.

Results

Four different types of lung cancer-related signs were used in the classification experiment: noncentral calcification, lobulation, spiculation, and nonsolid/ground-glass opacity (GGO) texture, along with negative image samples. For these five classes, the G2C-CAD system obtained AUCs of 0.946, 0.912, 0.908, 0.887, and 0.939, respectively. The average accuracy of G2C-CAD exceeded that of the C4.5 random decision tree by 14%. G2C-CAD also obtained promising test results on the LISS signs dataset; its AUCs for GGO, lobulation, spiculation, pleural indentation, and negative image samples were 0.972, 0.964, 0.941, 0.967, and 0.953, respectively.

Conclusion

The experimental results show that G2C-CAD is an appropriate method for addressing the problem of insufficient labeled samples in the medical image analysis field. Moreover, our system can be used to establish a training sample library for CAD classification diagnosis, which is important for future medical image analysis.

Definitive Radiation for Stage I Lung Cancer in a Screened Population: Results From the I-ELCAP

PURPOSE

The International Early Lung Cancer Action Program is a cohort study to assess the cure rate of participants undergoing annual low-dose computed tomography screening for lung cancer. This study compares the characteristics and outcomes of patients who received a diagnosis of clinical stage I non-small cell lung carcinoma (NSCLC) treated with definitive radiation therapy and surgical resection.

METHODS AND MATERIALS

Patient information was drawn from the International Early Lung Cancer Action Program database from 1992 to 2017. All instances in which treatment was performed for histologically proven stage I NSCLC using definitive radiation therapy and surgery were identified. The home institution determined radiation plans. Patient characteristics and Kaplan-Meier lung cancer-specific (LCS) long-term survival rates were compared for both types of treatment. Follow-up time was calculated from time of diagnosis until death from lung cancer, loss to follow-up, or December 31, 2017, whichever came earlier.

RESULTS

Among 82,628 baseline and 109,250 annual repeat screenings, 853 patients received a diagnosis of clinical stage I NSCLC, of whom 31 (3.6%) were treated by definitive radiation therapy and 702 (82.3%) by surgical resection alone. Radiation therapy prescription information was obtainable for 24 of the 31 patients: The median dose was 54.5 Gy, the median number of fractions was 5, and 17 patients were treated using stereotactic body radiation therapy. LCS survival rates were not significantly different for radiation therapy compared with surgery: 90.0% (95% confidence interval, 84.9%-100.0%) versus 94.8% (95% confidence interval, 93.0%-96.6%) (P = .09). Median follow-up time was 9.7 years for all, but it was shorter for those treated by radiation therapy than for those who underwent surgery (4.3 vs 10.0 years, P < .0001).

CONCLUSIONS

The majority of patients identified by computed tomography screening were treated with surgical resection. Despite being older and having more comorbidities, LCS long-term survival rates of patients treated with definitive radiation therapy were not significantly different compared with survival rates of patients treated with surgery alone. Radiation therapy appears to be a viable alternative to surgery for screen-diagnosed patients with lung cancer.

The Diagnostic Value of Quantitative CT Analysis of Ground-Glass Volume Percentage in Differentiating Epidermal Growth Factor Receptor Mutation and Subtypes in Lung Adenocarcinoma

Objective

To retrospectively investigate computed tomographic (CT) quantitative analysis of ground-glass opacity (GGO) volume percentage and morphologic features of resected lung adenocarcinomas according to epidermal growth factor receptor (EGFR) mutation status and subtypes.

Methods

Amplification refractory mutation system was used to detect mutations in the EGFR gene. Distribution of demographics and GGO volume percentage were performed according to EGFR mutation status and subtypes.

Results

EGFR mutations were significantly more frequent in women (55.2% vs. 37.0%, p=0.001) and in never-smokers (59.5% vs. 38.4%, p < 0.001) than those without EGFR mutation. GGO volume percentage was significantly higher in tumors with EGFR mutation than in tumors without EGFR mutation (52.8±25.7% vs. 29.0±20.7%, p < 0.001). The GGO volume percentages in tumors with exon 21 mutation and EGFR mutation showed a significant difference compared with those without EGFR mutation (p < 0.001, area under the curve=0.871, sensitivity=94.6%, specificity=73.8%, and p < 0.001, area under the curve=0.783, sensitivity=69.9%, specificity=75.4%, resp.), with cut-off values of 37.7% and 34.3% in receiver operating characteristic curve analysis.

Conclusion

GGO volume percentage in adenocarcinomas with EGFR mutation was significantly higher than that in tumors without EGFR mutation, and adenocarcinomas with exon 21 mutation showed significantly higher GGO volume percentage than in tumors with exon 19 mutation and those without EGFR mutation. Our results indicate that GGO volume percentage cut-off values of more than 37.7% and 34.3% were predictors of positive exon 21 mutation and EGFR mutation, respectively.

Multiple primary lung cancer: a rising challenge

With the use of high-resolution chest imaging system and lung cancer screening program, patients with multiple primary lung cancers (MPLCs) are becoming a growing population in clinical practice worldwide. The diagnostic criteria for MPLCs has been established and modified by three major lung cancer research institutes. However, due to the fact that the differential diagnosis between MPLCs and a recurrence, metastatic, or satellite lesion arising from the original lesion remains ambiguous and confusing, there is still insufficient evidence to support a uniform guideline. Newly developed molecular and genomic methods have the potential to better define the relationship among multiple lesions and bring the possibility of targeted therapy. Surgical resection remains the first choice for the treatment of MPLCs and detailed strategy should be carefully planned taking characteristics of the tumor and status of patients into consideration. For those who are intolerant to surgery, a new technology called stereotactic body radiation therapy (SBRT) is now an optional therapeutic strategy. Furthermore, multiple GGOs are unique MPLCs that need special attentions in the clinical practice.

Electromagnetic navigation bronchoscopic dye marking for localization of small subsolid nodules: Retrospective observational study

Thoracoscopic resection of small subsolid nodules is challenging and requires preoperative localization. We investigated the efficacy, safety, and factors affecting accuracy in localizing pulmonary nodules with electromagnetic navigation bronchoscopy (ENB)-guided dye marking.Patients with small subsolid nodule(s) who underwent thoracoscopic resection after ENB-guided dye marking were retrospectively reviewed. Dye marking was performed at the nearest pleura and the localized nodule(s) was resected thoracoscopically. Efficacy was evaluated by success rates of dye marking and resection of nodules. Navigation accuracy was represented by target distance, which was the closest distance between target and the tip of locatable guide. Factors affecting target distance were evaluated by linear regression analyses.Twenty-nine ENB-guided dye markings were done for 24 nodules in 20 patients. The success rate of the dye marking and nodule localization were 93.1% (27/29) and 95.8% (23/24), respectively. Twenty-three nodules were completely resected thoracoscopically without conversion. There were no ENB-related complications: pneumothorax or bronchopulmonary hemorrhage. Nine targets were in the upper, 14 in the middle, and 6 in the lower zone. Even though navigation time was longer in the upper zone, target distance showed no significant inter-zone difference. Approach angle was the only significant predictor for target distance (0-45°, estimate = -1.24, P = .01; 45-90°, estimate = -1.26, P = .006; reference = ≥90°).Localization with ENB-guided dye marking is effective and safe for thoracoscopic resection of small subsolid nodules. For better performance, a pathway with smaller approach angle (<90°) should be selected to increase the navigation accuracy.

Survival with Parenchymal and Pleural Invasion of Non-Small Cell Lung Cancers Less than 30 mm

OBJECTIVE

To determine long-term survival of visceral pleural invasion (VPI) and parenchymal invasion (PAI) (angiolymphatic and/or vascular) on survival of NSCLCs less than 30 mm in maximum diameter.

METHODS

Kaplan-Meier survivals for NSCLCs, with and without VPI and/or PAI, were determined for a prospective cohort of screening participants stratified by pathologic tumor size (≤10 mm, 11-20 mm, and 21-30 mm) and nodule consistency. Log-rank test statistics were calculated.

RESULTS

The frequency of PAI versus VPI was significantly lower in patients with subsolid nodules than in those with solid nodules (4.9% versus 27.7% [p < 0.0001]), and correspondingly, Kaplan-Meier lung cancer survival was significantly higher among patients with subsolid nodules (99.1% versus 91.3% [p = 0.0009]). Multivariable Cox regression found that only tumor diameter (adjusted hazard ratio [HR] =1.07, 95% confidence interval [CI]: 1.01-1.14, p = 0.02) and PAI (adjusted HR = 3.15, 95% CI: 1.25-7.90, p = 0.01) remained significant, whereas VPI was not significant (p = 0.15). When clinical and computed tomography findings were included with the pathologic findings, Cox regression showed that the risk of dying of lung cancer increased 10-fold (HR = 10.06, 95% CI: 1.35-75.30) for NSCLCs in patients with solid nodules and more than twofold (by a factor of 2.27) in patients with moderate to severe emphysema (HR = 2.27, 95% CI: 1.01-5.11), as well as with increasing tumor diameter (HR = 1.06, 95% CI: 1.01-1.13), whereas PAI was no longer significant (p = 0.19).

CONCLUSIONS

Nodule consistency on computed tomography was a more significant prognostic indicator than either PAI or VPI. We propose that patients with NSCLC with VPI and a maximum tumor diameter of 30 mm or less not be upstaged to T2 without further large, multicenter studies of NSCLCs, stratified by the new T status and that classification be considered separately for patients with subsolid or solid nodules.

Looking for Lepidic Component inside Invasive Adenocarcinomas Appearing as CT Solid Solitary Pulmonary Nodules (SPNs): CT Morpho-Densitometric Features and 18-FDG PET Findings

Objective

To investigate CT morphologic and densitometric features and 18-FDG PET findings of surgically excised lung adenocarcinomas "mixed subtype" with predominant lepidic component, appearing as solid solitary pulmonary nodules (SPNs) on CT scan.

Materials and Methods

Approval for this study was given from each local institutional review board according to its retrospective nature. Nodules pathologically classified as lung adenocarcinoma mixed subtype with bronchioloalveolar otherwise lepidic predominant component, in three different Italian institutions (Napoli; Varese; Parma), were retrospectively selected.

Results

22 patients were identified. The number of SPNs with smooth margins was significantly lower with respect to the number of SPNs with spiculated margins (p: 0.033), radiating spiculations (p: 0.019), and notch sign (p: 0.011). Mean contrast enhancement (CE) was 53.34 HU (min 5.5 HU, max 112 HU); considering 15 HU as cut-off value, CE was positive in 20/22 cases. No significant correlation was found between size and CE. Mean SUVmax was 2.21, ranging from 0.2 up to 7.5 units; considering 2.5 units as cut-off, SUVmax was positive in 7/22 cases. The number of SPNs with positive CE was significantly higher than the number of SPNs with positive SUVmax (p: 0.0005).

Conclusion

CT generally helps in identifying solid SPN suspicious for malignancy but 18-FDG PET may result in false-negative evaluation; when 18-FDG PET findings of a solid SPN are negative even though CT morphology and CE suggest malignancy, radiologist should consider that lepidic component may be present inside the invasive tumor, despite the absence of ground glass.

CT screening for lung cancer: comparison of three baseline screening protocols

PURPOSE

Clinical management decisions arising from the baseline round for lung cancer screening are the most challenging, as findings have accumulated over a lifetime and may be of no clinical concern. To minimize unnecessary harms and costs of workup prior to the first, annual repeat screening, workup should be limited to participants with the highest suspicion of lung cancer while still aiming to identify small, early lung cancers.

METHODS

We compared recommendations for immediate, delayed (by 3 or 6 months) workup to assess growth at a malignant rate, and the resulting overall and potential biopsies of three baseline screening protocols: I-ELCAP, the two scenarios of ACR-LungRADS, and the European Consortium. For each protocol, the efficiency ratio (ER) of each recommendation was calculated by dividing the number of participants recommended for that workup by the number of resulting lung cancer diagnoses. The ER for potential biopsies was calculated, assuming that biopsies were performed on all participants recommended for immediate workup as well as those diagnosed with lung cancer after delayed workup.

RESULTS

For I-ELCAP, ACR-LungRADS Scenario 1, ACR-LungRADS Scenario 2, and the European consortium, the overall ER was 13.9, 18.3, 18.3, and 31.9, respectively, and for potential biopsies, it was 2.2, 8.1, 3.2, and 4.4, respectively. ER for immediate workup was 2.9, 8.6, 3.9, and 5.6, respectively, and for delayed workup was 36.1, 160.3, 57.8, and 111.9, respectively.

CONCLUSIONS

I-ELCAP recommendations had the lowest ER values for overall, immediate, and delayed workup, and for potential biopsies.

KEY POINTS

• Small differences in protocol thresholds can lead to many unnecessary diagnostic workups. • I-ELCAP recommendations were the most efficient for immediate and overall workup, and potential biopsies. • Definition of a "positive result" and recommendations for further workup in the baseline round needs to be continually reevaluated and updated.

3D Deep Learning from CT Scans Predicts Tumor Invasiveness of Subcentimeter Pulmonary Adenocarcinomas

: Identification of early-stage pulmonary adenocarcinomas before surgery, especially in cases of subcentimeter cancers, would be clinically important and could provide guidance to clinical decision making. In this study, we developed a deep learning system based on 3D convolutional neural networks and multitask learning, which automatically predicts tumor invasiveness, together with 3D nodule segmentation masks. The system processes a 3D nodule-centered patch of preprocessed CT and learns a deep representation of a given nodule without the need for any additional information. A dataset of 651 nodules with manually segmented voxel-wise masks and pathological labels of atypical adenomatous hyperplasia (AAH), adenocarcinomas in situ (AIS), minimally invasive adenocarcinoma (MIA), and invasive pulmonary adenocarcinoma (IA) was used in this study. We trained and validated our deep learning system on 523 nodules and tested its performance on 128 nodules. An observer study with 2 groups of radiologists, 2 senior and 2 junior, was also investigated. We merged AAH and AIS into one single category AAH-AIS, comprising a 3-category classification in our study. The proposed deep learning system achieved better classification performance than the radiologists; in terms of 3-class weighted average F1 score, the model achieved 63.3% while the radiologists achieved 55.6%, 56.6%, 54.3%, and 51.0%, respectively. These results suggest that deep learning methods improve the yield of discriminative results and hold promise in the CADx application domain, which could help doctors work efficiently and facilitate the application of precision medicine. SIGNIFICANCE: Machine learning tools are beginning to be implemented for clinical applications. This study represents an important milestone for this emerging technology, which could improve therapy selection for patients with lung cancer.

Preoperative Watchful-Waiting Time and Surgical Outcome of Patients with Non-small Cell Lung Cancer Found by Chest Low-Dose CT Screening

BACKGROUNDS

Chest low-dose CT screening (LDCTS) has been finding unprecedented numbers of peripheral non-small cell lung cancers (NSCLC) at an early stage and increased the number of patients with surgical indication. It is important to explore the influence of preoperative watchful-waiting time (WWT) on surgical outcomes. Objective is to clarify relationship between WWT and surgical outcomes of LDCTS-finding NSCLC from the view point of treatment delay.

METHODS

Total 283 cases of NSCLC, found by LDCTS and consecutively resected, were surveyed for preoperative WWT and surgical outcomes. Validity of the present guideline for management of pulmonary nodules detected by LDCTS was verified whether WWT before surgery was suitable for eradication of NSCLC.

RESULTS

The median value of WWT was 4.0 months in total, and the distribution of WWT exhibited long-tail-type pattern. That was 5.0 months in the group of pure ground-glass nodule (pGGN), 4.0 months in the group of part-solid nodule (PSN), and 1.7 months in the group of solid nodule (SON). During long-term postoperative observation time (median 79 months), 10-year progression-free survival rates were 100% in pGGN, 96% in PSN, and 72% in SON (P < .0001). They decreased significantly depending on enlargement of size: 91% or higher in size of 2 cm or smaller, and 71% or lower in size of larger than 2 cm (P < .0001).

CONCLUSIONS

Limited to LDCTS-finding nodules, surgical outcome will depend mainly on some malignant potential of NSCLC per se, rather than on duration of WWT or treatment delay.