The IASLC Lung Cancer Staging Project: Background Data and Proposals for the Classification of Lung Cancer with Separate Tumor Nodules in the Forthcoming Eighth Edition of the TNM Classification for Lung Cancer

Pathological T3 Non-Small Cell Lung Cancer with satellite nodules: Number or size, what does matter?

BACKGROUND

Non-small Cell Lung Cancer (NSCLC) with intralobar satellite nodule are defined as T3 (T3SN). We investigated the main features of these tumors and analyzed their impact on Overall Survival (OS).

METHODS

This was a retrospective multicentric study including all pT3SN NSCLC operated on between 2005 and 2020, excluding patients with multifocal ground-glass opacities; who received induction therapies; N3 or stage IV. The diameter of largest (LgN) and smallest nodule (SmN), the total diameter (sum of diameter of all nodules, TS), and the number of SN were measured.

RESULTS

Among 102 patients, 64.7 % were male. 84.3 % of patients had one SN (84.3 %), 9.8 % two SN while 5.9 % more than 2 SN. 63 patients were pN0. LgN (p = 0.001), SN (p = 0.005) and TS (p = 0.014) were significantly related to lymph-node metastasis; the LgN and TS were related to visceral pleural invasion (p < 0.001). Five-year OS was 65.1 %; at univariable analysis more than 2 satellite nodules, LgN and TS were significantly related to worse OS; at multivariable analysis, TS (Hazard Ratio [HR] 1.116 95 % Confidence Interval [CI] 1.008-1.235, p = 0.034) was an independent prognostic factors for OS. No significant prognostic factors were found for DFS at multivariable analysis. In pN0 patients, LgN (HR 1.051, 95 % CI 1.066-1.099, p = 0.027) and non-adenocarcinoma (HR 5.315 CI 95 % 1.494-18.910, p = 0.010) influenced OS.

CONCLUSIONS

Tumor size is related to tumor's local invasiveness. TS is an independent prognostic factor for OS. Patients with more than 2 SN seem to be at higher risk for death and recurrence.

The characteristics and prognosis of different disease patterns of multiple primary lung cancers categorized according to the 8th edition lung cancer staging system

INTRODUCTION

The 8th edition lung cancer staging system was the first to describe the detailed diagnosis and staging of multiple primary lung cancers (MPLC). However, the characteristics and prognosis of MPLC categorized according to the new system have not been evaluated.

METHOD

We retrospectively analyzed data from surgically treated MPLC patients in a single center from 2011 to 2013 and explored the characteristics and outcomes of different MPLC disease patterns.

RESULTS

In total, 202 surgically treated MPLC patients were identified and classified into different groups according to disease categories and diagnostic time (multifocal ground glass/lepidic (GG/L) nodules: n = 139, second primary lung cancer (SPLC): n = 63, simultaneous MPLC (sMPLC): n = 171, and metachronous MPLC (mMPLC): n = 31). There were significant differences in clinical characteristics between SPLC and GG/L nodule patients and simultaneous and metachronous MPLC patients. The overall 1-, 3-, and 5-year lung cancer-specific survival rates of MPLC were 97.98%, 90.18%, and 82.81%, respectively. Five-year survival was better in patients with multiple GG/L nodules than in those with SPLC (87.94% vs. 71.29%, P < 0.05). Sex was an independent prognostic factor for sMPLC (5-year survival, female vs. male, 88.0% vs. 69.5%, P < 0.05), and in multiple tumors, the highest tumor stage was an independent prognostic factor for all categories of MPLC.

CONCLUSIONS

The different disease patterns of MPLC have significantly different characteristics and prognoses. Clinicians should place treatment emphasis on the tumor with the highest stage as it is the main contributor to the prognosis of all categories of MPLC patients.

Contemporary Incidence of Synchronous Multiple Primary Lung Cancers and Survival in the Era of Lung Cancer Screening

OBJECTIVE

Up to 15% of lung cancer patients have multiple suspicious nodules. While some of these nodules may represent metastatic lung cancer, others represent synchronous multiple primary lung cancer (SMPLC). The incidence of SMPLC ranges from 0.8% to 8.4% and appears to be increasing. Inconsistent identification of SMPLC can be detrimental for patients who are misdiagnosed as having intrapulmonary metastasis and not offered stage-based treatment. We sought to identify the contemporary incidence of SMPLC at a tertiary institution.

METHODS

From January 2018 to September 2019, patients who underwent lung cancer resection were retrospectively reviewed. Patients with SMPLC were identified using the modified Martini-Melamed criteria.

RESULTS

During the 21-month period, 227 patients underwent lung cancer resection. There were 47 patients (20.7%) who had 119 pathologically confirmed SMPLC. Most patients had ipsilateral tumors (n = 24, 51.1%) with at least 1 adenocarcinoma (n = 40, 85.1%). Considering histologic subtyping, 38 (80.9%) had histologically distinct tumors. Overall and cancer-specific survival at 4 years was 86% and 90%, respectively. Only patients with 3 or more SMPLC had poor 4-year overall (P = 0.002) and cancer-specific survival (P = 0.043) compared with those with 2 SMPLC. Patient demographics, histology, tumor location, and highest pathologic staging did not affect survival outcomes.

CONCLUSIONS

Using a strict inclusion criterion, the incidence of SMPLC is higher than previously reported. SMPLC patients have favorable survival outcomes, suggesting that they behave like primary lung cancer, not intrapulmonary metastasis. Awareness of SMPLC by thoracic surgeons is critical in optimizing outcomes in this patient population.

Prognostic factors and survival prediction of resected non-small cell lung cancer with ipsilateral pulmonary metastases: a study based on the Surveillance, Epidemiology, and End Results (SEER) database

BACKGROUND

Prognostic factors and survival outcomes of non-small cell lung cancer (NSCLC) with Ipsilateral pulmonary metastasis (IPM) are not well-defined. Thus, this study intended to identify the prognostic factors for these patients and construct a predictive nomogram model.

METHODS

One thousand, seven hundred thirty-two patients with IPM identified between 2000 to 2019 were from the Surveillance, Epidemiology, and End Results (SEER) database. Independent prognostic factors were identified using multivariate Cox regression analyses. Nomograms were constructed to predict the overall survival (OS), C-index, the area under the curve (AUC), and the calibration curve to determine the predictive accuracy and discrimination; the decision curve analysis was used to confirm the clinical utility.

RESULTS

Patients were randomly divided into training (n = 1213) and validation (n = 519) cohorts. In the training cohort, the multivariable analysis demonstrated that age, sex, primary tumor size, N status, number of regional lymph nodes removed, tumor grade, and chemotherapy were independent prognostic factors for IPM. We constructed a 1-year, 3-year, and 5-year OS prediction nomogram model using independent prognostic factors. The C-index of this model for OS prediction was 0.714 (95% confidence interval [CI], 0.692 to 0.773) in the training cohort and 0.695 (95% CI, 0.660 to 0.730) in the validation cohort. Based on the AUC of the receiver operating characteristic analysis, calibration plots, and decision curve analysis, we concluded that the prognosis model of IPM exhibited excellent performance. Patients with total nomogram points greater than 96 were considered high-risk.

CONCLUSION

We constructed and internally validated a nomogram to predict 1-year, 3-year, and 5-year OS for NSCLC patients with IPM according to independent prognostic factors. This nomogram demonstrated good calibration, discrimination, clinical utility, and practical decision-making effects for the prognosis of NSCLC patients with IPM.

New trend in artificial intelligence-based assistive technology for thoracic imaging

Although there is no solid agreement for artificial intelligence (AI), it refers to a computer system with intelligence similar to that of humans. Deep learning appeared in 2006, and more than 10 years have passed since the third AI boom was triggered by improvements in computing power, algorithm development, and the use of big data. In recent years, the application and development of AI technology in the medical field have intensified internationally. There is no doubt that AI will be used in clinical practice to assist in diagnostic imaging in the future. In qualitative diagnosis, it is desirable to develop an explainable AI that at least represents the basis of the diagnostic process. However, it must be kept in mind that AI is a physician-assistant system, and the final decision should be made by the physician while understanding the limitations of AI. The aim of this article is to review the application of AI technology in diagnostic imaging from PubMed database while particularly focusing on diagnostic imaging in thorax such as lesion detection and qualitative diagnosis in order to help radiologists and clinicians to become more familiar with AI in thorax.

Association between Mortality and Lung Low Attenuation Areas in NSCLC Treated by Surgery

BACKGROUND

to test the association with overall survival (OS) of low attenuation areas (LAAs) quantified by staging computed tomography (CT) of patients who underwent radical surgery for nonsmall-cell lung cancer (NSCLC).

METHODS

patients who underwent radical surgery for NSCLC at our institution between 1 January 2017 and 30 November 2021 were retrospectively evaluated. Patients who performed staging or follow-up CTs in other institutions, who received lung radiotherapy or chemotherapy, and who underwent previous lung surgery were excluded. At staging and 12-months follow-up CT, LAAs defined as voxels <-950 Hounsfield units, were extracted by software. The percent of LAAs relative to whole-lung volume (%LAAs) and the ratio between LAAs in the lobe to resect and whole-lung LAAs (%LAAs lobe ratio) were calculated. Cox proportional hazards regression analysis was used to test the association between OS and LAAs.

RESULTS

the final sample included 75 patients (median age 70 years, IQR 63-75 years; females 29/75, 39%). It identified a significant association with OS for pathological stage III (HR, 6.50; 95%CI, 1.11-37.92; p = 0.038), staging CT %LAAs ≥ 5% (HR, 7.27; 95%CI, 1.60-32.96; p = 0.010), and staging CT %LAA lobe ratio > 10% (HR, 0.24; 95%CI 0.05-0.94; p = 0.046).

CONCLUSIONS

in patients with NSCLC who underwent radical surgery, a %LAAs ≥ 5% and a %LAA lobe ratio > 10% at staging CT are predictors, respectively, of shorter and longer OS. The LAA ratio to the whole lung at staging CT could be a critical factor to predict the overall survival of the NSCLC patients treated by surgery.

Reconsidering the T category for the T3 non-small cell lung cancer with additional tumor nodules in the same lobe: A population-based study

Background

This study aimed to evaluate the prognosis of the T3 non-small cell lung cancer (NSCLC) patients with additional tumor nodules in the same lobe (T3-Add), and externally validate the current T category of this population.

Methods

NSCLC data deposited in the Surveillance, Epidemiology, and End Results (SEER) dataset was extracted. Survivals were estimated using the Kaplan-Meier method with a log-rank test. Propensity score matching (PSM) was performed to reduce bias. The least absolute shrinkage and selection operator (LASSO)-penalized Cox model was used to determine the prognostic factors.

Results

A total of 41,370 eligible cases were included. There were 2,312, 20,632, 12,787, 3,374 and 2,265 cases in the T3-Add, T1, T2, T3 and T4 group, respectively. The Kaplan-Meier curves demonstrated that the survivals of the T3-Add patients were superior to those of the T3 patients both before and after PSM. Additionally, the OS of the T3-Add patients were worse than that of the T2 patients, but the CSS differences between these two groups were not statistically significant. In the subset analyses, the survivals of the T3-Add patients were inferior to those of the T2a patients, but were comparable to those of the T2b patients (5-year OS rate: 54.3% vs. 57.2%, P = 0.884; 5-year CSS rate: 76.2% vs. 76.8%, P = 0.370). In the T3-Add &amp; T2b matched pair, multivariable Cox analysis further confirmed that T category was not a prognostic factor for survivals.

Conclusion

T3-Add and T2b NSCLC patients had similar survivals, and we proposed that it is necessary to reconsider the T category of the patients with additional nodules in the same lobe in the forthcoming 9th edition of TNM staging manual.

A Novel Prognostic Score Based on Multiple Quantitative Parameters of Chest CT for Patients with Synchronous Multiple Primary Lung Cancer: Is Solid Component Size a Better Prognostic Indicator?

BACKGROUND

There is no simple and definitive way to predict the prognosis of synchronous multiple primary lung cancer (SMPLC). In this study, we developed a clinical prognostic score for predicting the survival of patients with SMPLC.

PATIENTS AND METHODS

This study included 206 patients with SMPLC between 2011 and 2020 at three hospitals. Kaplan-Meier analysis was used to determine the optimal cutoff values for the quantitative chest computed tomography (CT) parameters. Multivariable Cox proportional hazards regression was carried out to identify independent prognostic factors for predicting overall survival (OS) and disease-free survival (DFS). The time-dependent receiver operating characteristic curve was analyzed to evaluate the prognostic performance.

RESULTS

A CT-based prognostic score (CTPS) comprising six chest CT parameters was developed. Compared with T stage, CTPS had a higher prediction accuracy for OS and DFS. All C-indices of the model reached a satisfactory level in both the development and validation cohorts. Significant differences in the OS and DFS curves were observed when the patients were stratified into different risk groups. The high-risk group (CTPS of 5-6) had poorer survival than the low-risk group (CTPS of 0-4).

CONCLUSIONS

The developed CTPS and the corresponding risk stratification system are valid for predicting the survival of patients with SMPLC.

Challenges of the eighth edition of the American Joint Committee on Cancer staging system for pathologists focusing on early stage lung adenocarcinoma

BACKGROUND

The eighth edition of the American Joint Committee on Cancer (AJCC) staging system for lung cancer adopts new criteria for tumor size, and for determining pTis, pT1a(mi), and pT1a. The latter is based on the size of stromal invasion. It is quite challenging for lung pathologists.

METHODS

All patients who had undergone surgical resection for pulmonary adenocarcinoma (ADC) at Chung Shan Medical University Hospital between January 2014 and April 2018 were reviewed, and restaged according to the eighth AJCC staging system. The clinical characteristics and survival of patients with tumor stage 0 (pTis), I or II were analyzed.

RESULTS

In total, 376 patients were analyzed. None of the pTis, pT1a(mi), or pT1a tumors recurred during the follow-up period up to 5 years, but pT1b, pT1c, pT2a, and pT2b tumors all had a few tumor recurrences (p < 0.0001). In addition, 95.2%, 100%, and 77.5% of pTis, pT1a(mi), and pT1a tumors, respectively, had tumor sizes ≤1.0 cm by gross examination. All pTis, pT1a(mi), and pT1a tumors exhibited only lepidic, acinar, or papillary patterns histologically.

CONCLUSIONS

This study demonstrated excellent survival for lung ADC patients with pTis, pT1a(mi), and pT1a tumors when completely excised. To reduce the inconsistencies between pathologists, staging lung ADC with tumors of ≤1 cm in size grossly as pTis, pT1a(mi), or pT1a may not be necessary when the tumors exhibit only lepidic, acinar, or papillary histological patterns. A larger cohort study with sufficient follow-up data is necessary to support this proposal.

Reconsidering T component of cancer staging for T3/T4 non-small-cell lung cancer with additional nodule

Background

Non-small-cell lung cancer (NSCLC) with additional nodule(s) located in the same lobe or ipsilateral different lobe were designated as T3 and T4, respectively, which was merely defined by anatomical location of additional nodule(s), regardless of other prognostic factors.

Methods

A total of 4711 patients with T1-4, N0-2, M0 NSCLC undergoing complete resection were identified between 2009 and 2014, including 145 patients with additional nodule(s) in the same lobe (T3-Add) and 174 patients with additional tumor nodule(s) in ipsilateral different lobe (T4-Add). Overall survival (OS) was compared using multivariable Cox regression models and propensity score matching analysis (PSM).

Results

T3-Add patients [T3-Add versus T3, hazard ratio (HR), 0.695; 95% confidence interval (CI), 0.528-0.915; p = 0.009] and comparable OS with T2b patients through multivariable Cox analysis, and further validated by PSM. T4-Add patients carried a wide spectrum of prognosis, and the largest diameter of single tumor was screened out as the most effective indicator for distinguishing prognosis. T4-Add (⩽3 cm) patients had better OS than T4 patients [T4-Add (⩽3 cm) versus T4, HR, 0.629; 95% CI, 0.455-0.869; p = 0.005] and comparable OS with T3 patients. And T4-Add (>3 cm) patients had comparable OS with T4 patients.

Conclusion

NSCLC patients with additional nodule(s) in the same lobe and ipsilateral different lobe (maximum tumor diameter ⩽ 3 cm) should be further validated and considered restaging as T2b and T3 in the forthcoming 9th tumor, node, and metastasis staging system.

Application of Dynamic 18F-FDG PET/CT for Distinguishing Intrapulmonary Metastases from Synchronous Multiple Primary Lung Cancer

It has been a big challenge to distinguish synchronous multiple primary lung cancer (sMPLC) from primary lung cancer with intrapulmonary metastases (IPM). We aimed to assess the clinical application of dynamic ¹⁸F-FDG PET/CT in patients with multiple lung cancer nodules. We enrolled patients with multiple pulmonary nodules who had undergone dynamic ¹⁸F-FDG PET/CT and divided them into sMPLC and IPM groups based on comprehensive features. The SUV_max, fitted K_i value based on dynamic scanning, and corresponding maximum diameter (D_max) from the two largest tumors were determined in each patient. We determined the absolute between-tumor difference of SUV_max/D_max and K_i/D_max (ΔSUV_max/D_max; ΔK_i/D_max) and assessed the between-group differences. Further, the diagnostic accuracy was evaluated by ROC analysis and the correlation between ΔSUV_max/D_max and ΔK_i/D_max from all groups was determined. There was no significant difference for ΔSUV_max/D_max between the IPM and sMPLC groups, while the IPM group had a significantly higher ΔK_i/D_max than the sMPLC group. The AUC of ΔK_i/D_max for differentiating sMPLC from IPM was 0.80 (cut-off value of K_i = 0.0059, sensitivity 79%, specificity 75%, p < 0.001). There was a good correlation (Pearson r = 0.91, 95% CI: 0.79-0.96, p < 0.0001) between ΔSUV_max/D_max and ΔK_i/D_max in the IPM group but not in the sMPLC group (Pearson r = 0.45, p > 0.05). Dynamic ¹⁸F-FDG PET/CT could be a useful tool for distinguishing sMPLC from IPM. K_i calculation based on Patlak graphic analysis could be more sensitive than SUV_max in discriminating IPM from sMPLC in patients with multiple lung cancer nodules.

A "real" tumor-spread through air space (STAS) of lung adenocarcinoma presented intrapulmonary metastases through bronchiole air space: case report

Here, we report a rare case of lung adenocarcinoma with intrapulmonary metastases that have “spread through air spaces” (STAS) by means of the alveoli and bronchioles. The peripheral intrapulmonary metastases were exhibiting pure ground-glass nodules along the bronchioles on computed tomography. The primary pathologic diagnosis was micropapillary adenocarcinoma with prominent tumor STAS. Histopathologic examination revealed that the cancer cells in the bronchioles around the primary tumor revealed micropapillary clusters on the mucosal surface or in the air spaces and reached peripheral intrapulmonary metastatic nodules. Notably, no vascular and stromal invasion was observed. The pathologic findings suggest that cancer cells are viable in the airspace of the bronchioles and alveoli and may support the significance of STAS as a pattern of airborne metastasis.

Integrating NGS-derived mutational profiling in the diagnosis of multiple lung adenocarcinomas

MICROABSTRACT

Integration of Next Generation Sequencing (NGS) information for use in distinguishing between Multiple Primary Lung Cancer and intrapulmonary metastasis was evaluated. We used a probabilistic model, comprehensive histologic assessment and NGS to classify patients. Integrating NGS data confirmed initial diagnosis (n = 41), revised the diagnosis (n = 12), while resulted in non-informative data (n = 8). Accuracy of diagnosis can be significantly improved with integration of NGS data.

BACKGROUND

Distinguishing between multiple primary lung cancers (MPLC) and intrapulmonary metastases (IPM) is challenging. The goal of this study was to evaluate how Next Generation Sequencing (NGS) information may be integrated in the diagnostic strategy.

PATIENTS AND METHODS

Patients with multiple lung adenocarcinomas were classified using both the comprehensive histologic assessment and NGS. We computed the joint probability of each pair having independent mutations by chance (thus being classified as MPLC). These probabilities were computed using the marginal mutation rates of each mutation, and the known negative dependencies between driver genes and different gene loci. With these NGS-driven data, cases were re-classified as MPLC or IPM.

RESULTS

We analyzed 61 patients with a total of 131 tumors. The most frequent mutation was KRAS (57.3%) which occured at a rate higher than expected (p < 0.001) in lung cancer. No mutation was detected in 25/131 tumors (19.1%). Discordant molecular findings between tumor sites were found in 46 patients (75.4%); 11 patients (18.0%) had concordant molecular findings, and 4 patients (6.6%) had concordant molecular findings at 2 of the 3 sites. After integration of the NGS data, the initial diagnosis was confirmed for 41 patients (67.2%), the diagnosis was revised for 12 patients (19.7%) or was considered as non-informative for 8 patients (13.1%).

CONCLUSION

Integrating the information of NGS data may significantly improve accuracy of diagnosis and staging.

Reconsidering the American Joint Committee on Cancer Eighth Edition TNM Staging Manual Classifications for T2b and T3 NSCLC

INTRODUCTION

The American Joint Committee on Cancer (AJCC) eighth edition TNM staging manual for NSCLC, derived from the International Association for the Study of Lung Cancer (IASLC) Staging Project, designates tumors with additional nodule(s) in the same lobe as T3. This study sought to externally validate the results of the IASLC, which showed a trend in improved survival for such tumors, but excluded treatment-based adjustment, by assessing whether these tumors have worse survival than T2b NSCLC.

METHODS

Overall survival of patients with T2b-T3, N0-3, M0 NSCLC (satisfying a single T descriptor of tumors >4 cm but ≤5 cm in greatest dimension ["T2b"], tumors >5 cm but ≤7 cm in greatest dimension ["T3-Size"], or tumors with additional nodule(s) in the same lobe ["T3-Add"]), according to the AJCC eighth edition, in the National Cancer Database (2010-2015), was evaluated using multivariable Cox proportional hazards modeling and propensity score matching.

RESULTS

31,563 patients with T2b-T3, N0-3, M0 NSCLC met the study inclusion criteria. In multivariable-adjusted analysis, T3-Add tumors had improved overall survival compared with T3-Size tumors (Hazard Ratio = 0.86, 95% Confidence Interval: 0.82-0.89, p < 0.001) and similar survival compared with T2b tumors (Hazard Ratio = 1.04, 95% Confidence Interval: 0.97-1.12, p = 0.28). A propensity score-matched analysis of 2260 T3-Add and 2,260 T2b patients, well-balanced on 16 common prognostic covariates, including treatment type (surgery, chemotherapy, or radiation), revealed similar 5-year survival (53.4% versus 52.3%, p = 0.30).

CONCLUSIONS

In this national analysis, T3-Add tumors had better survival than other T3 tumors and similar survival to T2b tumors. These findings may be taken into consideration for the AJCC ninth edition staging classifications.

Therapeutic method for early-stage second primary non-small lung cancer: analysis of a population-based database

BACKGROUND

Early-stage non-small lung cancer patients may survive long enough to develop second primary lung cancers. However, few studies have accurately described the therapeutic method, evaluation or prognostic factors for long-term survival in this complex clinical scenario.

METHODS

Patients who had first and second primary non-small lung cancer in the Surveillance, Epidemiology, and End Results database between 2004 and 2015 were evaluated. Patients were included when their tumors were pathologically diagnosed as non-small lung cancer and in the early-stage (less than 3 cm and with no lymph node metastasis). Therapeutic methods were categorized as lobectomy, sublobectomy or no surgery. The influence of different therapeutic methods on the overall survival rate was compared.

RESULTS

For the first primary tumor, patients who underwent lobectomy achieved superior survival benefits compared with patients who underwent sublobectomy. For the second primary tumor, long-term survival was similar in patients who underwent lobectomy and those who underwent sublobectomy treatment. The multivariate analysis indicated that age, disease-free time interval, sex, and first and second types of surgery were independent prognostic factors for long-term survival. Our results showed that the 5-year overall survival rate was 91.9% when the disease-free interval exceeded 24 months.

CONCLUSION

Lobectomy for the first primary tumor followed by sublobectomy for the second primary tumor may be a beneficial therapeutic method for patients. If the disease-free interval exceeds 24 months, the second primary tumor will have no influence on the natural course for patients diagnosed with a first primary non-small lung cancer.

[Expert Consensus for Thermal Ablation of Pulmonary Subsolid Nodules (2021 Edition)]

局部热消融技术在肺部结节治疗领域正处在起步与发展阶段，为了肺结节热消融治疗的临床实践和规范发展，由“中国医师协会肿瘤消融治疗技术专家组”“中国医师协会介入医师分会肿瘤消融专业委员会”“中国抗癌协会肿瘤消融治疗专业委员会”“中国临床肿瘤学会消融专家委员会”组织多学科国内有关专家，讨论制定了“热消融治疗肺部亚实性结节专家共识（2021年版）”。主要内容包括：①肺部亚实性结节的临床评估；②热消融治疗肺部亚实性结节技术操作规程、适应证、禁忌证、疗效评价和相关并发症；③存在的问题和未来发展方向。

Future Perspectives on the TNM Staging for Lung Cancer

Since its conception by Pierre Denoix in the mid-20th century, the tumor, node, and metastasis (TNM) classification has undergone seven revisions. The North American database managed by Clifton Mountain was used to inform the 2nd to the 6th editions, and an international database collected by the International Association for the Study of Lung Cancer, promoted by Peter Goldstraw, was used to inform the 7th and the 8th editions. In these two latest editions, it was evident that the impact of tumor size was much greater than it was suggested in previous editions; that the amount of nodal disease had prognostic relevance; and that the number and location of the distant metastases had prognostic implications. However, the TNM classification is not the only prognostic factor. Data are being collected now to inform the 9th edition of the TNM classification, scheduled for publication in 2024. Patient-, environment-, and tumor-related factors, including biomarkers (genetic biomarkers, copy number alterations, and protein alterations) are being collected to combine them in prognostic groups to enhance the prognosis provided by the mere anatomic extent of the tumor, and to offer a more personalized prognosis to an individual patient. International collaboration is essential to build a large and detailed database to achieve these objectives.

Presentation of EGFR mutations in 162 family probands with multiple primary lung cancer

Background

The number of multiple primary lung cancer (MPLC) patients has rapidly increased in recent years. However, information regarding the etiology of MPLC and responsiveness to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) is rare. The present study aims to describe the mutation signatures of EGFR in MPLC.

Methods

Polymerase chain reaction (PCR) and Sanger sequencing were used to screen EGFR mutations in 162 family probands comprising 366 tumor lesions and 162 paired noncancerous adjacent tissues (NATs). Sequencing data from 3,243 sporadic lung adenocarcinoma (LUAD) samples were analyzed as a control.

Results

Candidate germline mutations were observed in exons 19 (3, 1.85%), 20 (8, 4.94%) and 21 (5, 3.10%), with a total frequency of 9.88% in NATs (16/162). There were 63 probands harboring somatic mutations (63/162, 38.89%), 9 patients harbored the consistency mutations among lesions, and 8 patients carried 2 or more mutations. The overall rate of EGFR somatic mutations was lower in the MPLC probands, but those of exon 19 p.747-752del, 20 p.V769indelsVASV and 20 p.D770indelsDSVD were significantly higher in MPLC probands than in patients with sporadic LUAD.

Conclusions

There exists unique EGFR mutation signatures in a large cohort of MPLC probands, which might provide objective evidence of the etiology and effectiveness of clinical TKI treatment of high-risk MPLC patients.

Distinct tumor bacterial microbiome in lung adenocarcinomas manifested as radiological subsolid nodules

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Subsolid nodules have higher microbiome diversity compared with solid nodules

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Microbiome composition of Subsolid nodules is distinct from that of solid nodules

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Microbial signatures show robust performance to predict lung adenocarcinoma or subsolid nodules

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Some lung microbial species are associated with clinical characteristics

Objectives

Increasing evidence indicates that microbiota dysbiosis in the human body may play vital roles in carcinogenesis. However, the relationship between microbiome and lung cancer remains unclear. In this study, we aimed to characterize the microbiome in early stage of lung adenocarcinoma (LUAD), which presented as subsolid nodules (SSN) or solid nodules (SN).

Materials and Methods

We performed 16S rRNA sequencing of 35 pairs (10 SSN and 25 SN) of LUAD tumor tissues and paired adjacent normal tissues. Machine learning was used to identify microbial signatures and construct predictive models.

Results

SSN has higher microbiome richness and diversity compared with SN (richness p = 0.017, Shannon index p = 0.17), and the microbiome composition of SSN is distinct from that of SN (Bray-Curtis p = 0.013, unweighted unifrac p = 0.001). Phylum Chloroflexi (p = 0.009), Gemmatimonadetes (p = 0.018) and genus including Cloacibacterium (p = 0.003), Subdoligranulum (p = 0.002), and Mycobacterium (p = 0.034) were significantly increased in SSN. Tumor and normal tissues had similar richness and diversity, as well as overall microbiome composition. Probiotics with anti-cancer potential, like Lactobacillus, showed elevated levels in normal tissues (p = 0.018). A random forest model with 20 genera-based biomarkers achieved high accuracy for LUAD prediction (area under curve, AUC = 0.879). Meanwhile, a five genera-based signature can accurately discriminate SSN between SN (AUC = 0.950). Cross-validation of these two models also showed high predictive performance (LUAD AUC = 0.813, SSN AUC = 0.933).

Conclusions

This study demonstrates, for the first time, the tumor bacterial microbiome composition of LUAD manifested as SSN is distinct from that presented as SN, which adds new knowledge to SSN in the perspective of microbiome. Furthermore, microbiome signatures showed good performance to predict LUAD or SSN.

Pleural recurrence after transthoracic needle lung biopsy in stage I lung cancer: a systematic review and individual patient-level meta-analysis

INTRODUCTION

Conflicting results exist regarding whether preoperative transthoracic biopsy increases the risk of pleural recurrence in early lung cancer. We conducted a systematic, patient-level meta-analysis to evaluate the risk of pleural recurrence in stage I lung cancer after percutaneous transthoracic lung biopsy.

METHODS

A systematic search of OVID-MEDLINE, Embase and the Cochrane Database of Systematic Reviews was performed through October 2018. Eligible studies were original articles on the risk of pleural recurrence in stage I lung cancer after transthoracic biopsy. We contacted the corresponding authors of eligible studies to obtain individual patient-level data. We used the Fine-Gray model for time to recurrence and lung cancer-specific survival and a Cox proportional hazards model for overall survival.

RESULTS

We analysed 2394 individual patient data from 6 out of 10 eligible studies. Compared with other diagnostic procedures, transthoracic biopsy was associated with a higher risk for ipsilateral pleural recurrence, which manifested solely (subdistribution HR (sHR), 2.58; 95% CI 1.15 to 5.78) and concomitantly with other metastases (sHR 1.99; 95% CI 1.14 to 3.48). In the analysis of secondary outcomes considering a significant interaction between diagnostic procedures and age groups, reductions of time to recurrence (sHR, 2.01; 95% CI 1.11 to 3.64), lung cancer-specific survival (sHR 2.53; 95% CI 1.06 to 6.05) and overall survival (HR 2.08; 95% CI 1.12 to 3.87) were observed in patients younger than 55 years, whereas such associations were not observed in other age groups.

DISCUSSION

Preoperative transthoracic lung biopsy was associated with increased pleural recurrence in stage I lung cancer and reduced survival in patients younger than 55 years.

Characteristics and prognosis of synchronous multiple primary lung cancer after surgical treatment: A systematic review and meta-analysis of current evidence

Background

This study aims to quantitatively summary the characteristics of synchronous multiple primary lung cancer (sMPLC), postoperative mortality, long‐term prognosis, and prognostic effects of potential clinical parameters in patients with sMPLC after surgery.

Methods

PubMed and Embase databases were systematically searched to identify studies that explored the prognosis of patients with sMPLC after surgery.

Results

Fifty‐two studies with 3486 participants were included, and clinical characteristics were quantitatively summarized. The pooled proportion of sMPLC in lung cancer was 2.0% (95%CI, 1.6%–2.5%) with an increasing trend over time, and postoperative mortality was 1.4% (95%CI, 0.5%–2.7%) with a decreasing trend over time. The 5‐year survival rate was 44.9% (95%CI, 37.4%–52.6%) and all long‐term survival rates showed increasing trends over time. Poor long‐term prognosis was observed in both limited resection (HR = 1.357, 95%CI, 1.047–1.759, p = 0.0210) and pneumonectomy (HR = 2.643, 95%CI, 1.539–4.541, p = 0.0004) by comparison of anatomical resection. Other clinical parameters of age, gender, smoking status, FEV1, and lymph node metastasis significantly impacted the long‐term prognosis (all p < 0.05).

Conclusions

The proportion of sMPLC in lung cancer and 5‐year survival rate are increasing, while postoperative mortality is decreasing trend over time. Lobectomy should be preferred, while pneumonectomy should be avoided for sMPLC. Age, gender, FEV1, smoking, tumor size, surgical methods, and lymph node status are prognostic factors for sMPLC. Considering the heterogeneity and publication bias, these findings should be treated with caution.

Lung Cancer Staging

Anatomic staging is a critical step in evaluation of patients with lung cancer. Accurate identification of stage based on features of primary tumor (T), regional nodes (N), and metastatic disease (M) is fundamental to determining appropriate care. In this article, the TNM components of the anatomic staging system and a framework for description of lung cancer with multiple pulmonary sites of involvement are discussed. TNM combinations are grouped according to prognosis, with patient-level, tumor-level, and environment-level factors also influencing survival outcomes. Although the staging system does not include molecular and immunologic information, anatomic staging remains the common language for communicating extent of disease.

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.

Synchronous Pulmonary Adenocarcinomas

OBJECTIVES

To determine concordance/discordance between morphology and molecular testing (MT) among synchronous pulmonary carcinomas using targeted next generation sequencing (NGS), with and without comprehensive molecular review (CMR), vs analyses of multiple singe genes (non-NGS).

METHODS

Results of morphologic and MT assessment were classified as concordant, discordant, or indeterminate. For discordant cases, comprehensive histologic assessment (CHA) was performed.

RESULTS

Forty-seven cases with 108 synchronous tumors were identified and underwent MT (NGS, n = 23 and non-NGS, n = 24). Histology and MT were concordant, discordant, and indeterminate in 53% (25/47), 21% (10/47), and 26% (12/47) of cases, respectively. CHA of the 10 discordant cases revised results of three cases.

CONCLUSIONS

There is discordance between histology and MT in a subset of cases and MT provides an objective surrogate for staging synchronous tumors. A limited gene panel is sufficient for objectively assessing a relationship if the driver mutations are distinct. Relatedness of mutations require CMR with a larger NGS panel (eg, 50 genes).

Comprehensive genomic profiling aids in understanding the lesion origins of a patient with six synchronous invasive lung adenocarcinomas: a case study

BACKGROUND

Synchronous multiple primary lung cancers (sMPLC) are rare forms of lung cancer, and their diagnosis remains as a significant challenge. Distinguishing sMPLC from advanced disease is important as their prognoses and therapeutic management vary dramatically.

CASE PRESENTATION

The patient was a 56-year-old Chinese male who exhibited six synchronous invasive adenocarcinomas at diagnosis [T2(6)N0M0], and who achieved durable clinical benefit under adjuvant chemotherapy for 41 months following wedge resection and lobectomy. Whole-exome sequencing revealed that two lesions (L4 and L6) in the left upper lobe of the patient's lung shared 28 nonsynonymous mutations; thus, suggesting that the lesions may have arisen from a common ancestor at the early stages of tumorigenesis, and spread into distinct histologic subtypes. Moreover, while L5 was in the same lobe as L4 and L6, it represented a distinct lineage as it did not share any mutations with other lesions. Notably, the BRAF V600E oncogenic mutation was exclusive to L5. In addition, the KRAS G12C mutation was identified in three lesions (L1-L3) located in the right lung, which may have resulted from convergent evolution.

CONCLUSION

We report a patient with six synchronous invasive adenocarcinomas who demonstrated durable clinical benefits under adjuvant chemotherapy following surgical treatment. While cancer staging is one of the many challenges associated with sMPLC, the data generated through next-generation sequencing can provide information on lesion origins, and thus, advance the era of precision medicine.

Imaging Features Suggestive of Multiple Primary Lung Adenocarcinomas

BACKGROUND

The tumor-node-metastasis classification system has proposed that lung cancers presenting as multifocal ground-glass nodules (multi-GGN) on computed tomography scan should be staged as multiple primaries instead of intrapulmonary metastases. However, the problem still exists for those synchronous multiple lung adenocarcinomas (SMLA) involving solid lesions. This study aimed to explore the distinct features of SMLA to better define the diagnosis and staging of this disease.

METHODS

Between 2008 and 2016, consecutive patients with complete resection of SMLA were prospectively enrolled in the study. The patients were divided into three groups based on CT images as follows: multi-GGN, one solid nodule plus one or more GGNs (solid-GGN), and multiple solid lesions with or without GGN (multi-solid). Clinicopathologic features and survival outcomes were compared between these groups. Multivariate Cox proportional hazards analyses using bootstrap internal validation were performed to identify independent predictors for recurrence-free survival (RFS) and overall survival (OS).

RESULTS

Of the 695 patients who met the inclusion criteria, 486 (69.9%) presented with multi-GGN tumor, 124 (17.9%) with solid-GGN tumor, and 85 (12.2%) with multi-solid tumor. The three groups had distinguished clinicopathologic features of gender, smoking history, nodal metastases, tumor size, subtype, and location (all P < 0.001). Multivariate analyses demonstrated that multi-solid tumor was an independent predictor for both decreased RFS [hazard ratio (HR) 2.941; 95% confidence interval (CI) 1.07-8.08; P = 0.036] and poor OS (HR 6.13; 95% CI 1.15-32.63; P = 0.034), but neither RFS (P = 0.384) nor OS (P = 0.811) differed between solid-GGN and multi-GGN tumors.

CONCLUSIONS

Both multi-GGN and solid-GGN tumors should be staged as multiple primaries, whereas multi-solid tumor was indicated to be advanced disease.

Molecular profiling of key driver genes improves staging accuracy in multifocal non-small cell lung cancer

OBJECTIVE

Multifocal non-small cell lung cancer has historically been separated into synchronous primary lung cancers or intrapulmonary metastases with the use of histopathology. We hypothesize that using targeted next-generation sequencing of key driver mutations in multifocal non-small cell lung cancer will improve our ability to differentiate intrapulmonary metastases from synchronous primary lung cancers.

METHODS

We identified patients who underwent surgery for non-small cell lung cancer between 2013 and 2018 with multifocal tumors. Archived specimens were reviewed with a 4-gene next-generation sequencing panel identifying mutations of EGFR, KRAS, BRAF, and NRAS. Synchronous primary lung cancers were classified as lesions with different histopathologic subtypes or driver mutations. Tests of hypotheses were performed with the Fisher exact test. Calculations were performed in Stata (v13.0; StataCorp LLC, College Station, Tex).

RESULTS

A total of 18 patients had non-small cell lung cancer tumor specimens (n = 41) available from 2 or more sites. The pathologic diagnosis was predominantly adenocarcinoma (39/41 specimens). We detected a driver mutation in 68.3% (28/41) of all tumors. The most common mutations observed were in KRAS (n = 17/41) and EGFR (n = 7/41). Eleven patients had synchronous primary lung cancers, and 4 patients had intrapulmonary metastases based on combined histopathologic and molecular profiling results. Three lacked driver mutations in either lesion. Eight synchronous primary lung cancers (8/18, 44%) were downstaged when compared with their original diagnosis (P = .08). Of these, 4 patients received adjuvant chemotherapy unnecessarily in hindsight.

CONCLUSIONS

Molecular non-small cell lung cancer profiling using a 4-gene next-generation sequencing panel allows for better distinction between synchronous primary lung cancers and intrapulmonary metastases than histopathology alone. Routine use of next-generation sequencing for multifocal lesions prevents unnecessary adjuvant treatment for patients with histologically similar synchronous primary lung cancers.

Relationship between tumor size and metastatic site in patients with stage IV non-small cell lung cancer: A large SEER-based study

Objective

To analyze the relationship between tumor size and metastatic site in stage IV NSCLC patients.

Methods

A total of 40,196 stage IV NSCLC patients from 2010 to 2015 were screened by SEER database. Chi-square test was used to compare the characteristics of clinical variables. At the same time, multivariate Logistic regression analysis was used to evaluate the relationship between tumor size and organ metastasis.

Results

Regardless of tumor size, the proportion of bone metastasis and lung metastasis was higher and similar in patients with squamous cell carcinoma, while in patients with adenocarcinoma, bone metastasis accounted for the highest proportion. We found that whether the metastatic site was bone, brain, liver or lung, the proportion of patients with a tumor size of 3–7 cm was the highest. Multivariate regression analysis demonstrated that patients with a tumor size of 3–7 cm and a tumor size ≥7 cm were more likely to develop brain metastasis and lung metastasis compared with patients with a tumor size ≤3 cm (all P < 0.001), which meant the larger the tumor, the greater the risk of brain or lung metastasis. At the same time, the results indicated that patients with a tumor size of 3–7 cm had a tendency to develop liver metastasis (P = 0.004), while the statistical significance was not found for patients with a tumor size ≥7 cm (P = 0.524). The results also revealed that patients with a tumor size of 3–7cm had no significant difference to develop bone metastasis (P = 0.116), while the statistical significance was found for patients with a tumor size ≥7 cm (P < 0.001).

Conclusions

There was statistical significance between tumor size and metastatic site in patients with stage IV NSCLC. For brain or lung metastasis, the larger the tumor, the higher the risk of brain or lung metastasis. For liver metastasis, patients with a tumor size of 3–7 cm were more prone to develop liver metastasis. For bone metastasis, patients with a tumor size ≥7 cm were more likely to have bone metastasis.

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.

Whole genome sequencing revealed microbiome in lung adenocarcinomas presented as ground-glass nodules

Background

Emerging evidence has suggested that dysbiosis of the microbiota may play vital roles in tumorigenesis. However, the interplay between the microbiome and lung cancer remains undetermined. In this study, we characterize the microbiome in the early stage of lung cancer, which presented as ground-glass nodules (GGNs).

Methods

We sequenced the whole genomes from 10 GGN lesions and 5 adjacent normal lung tissue samples. After being filtered with human genome sequences, the sequence reads were mapped to prokaryotic genomes refSeq and non-redundant protein database for taxa and gene functions profiling, respectively.

Results

Mycobacterium, Corynebacterium, and Negativicoccus were the core microbiota found in all GGNs and the normal tissue samples. The microbiota composition did not show significant difference between GGNs and normal tissues except the adenocarcinoma (AD) (P=0.047). A significant β diversity in microbiome gene functions was found among different patients. Two individual gene functions, the Secondary Metabolism (1.32 fold with P=0.01) and the Serine Threonine protein kinase (4.23 fold, P<0.001), were significantly increased in GGNs over normal tissue samples.

Conclusions

This study helps shed light on the implication of the microbiome in early stage lung cancer, which encourages the further study and development of innovative strategies for early prevention and treatment of lung cancer.

Interleukin 6-triggered ataxia-telangiectasia mutated kinase activation facilitates epithelial-to-mesenchymal transition in lung cancer by upregulating vimentin expression

Matrix metalloproteinases (MMPs) and the epithelial-mesenchymal transition (EMT) contribute to metastasis. As shown in our previous studies, interleukin-6 (IL-6) induces ATM phosphorylation to increase MMP expression and metastasis in lung cancer. However, the exact roles of ATM activation in the IL-6-induced epithelial-mesenchymal transition and lung cancer metastasis are currently unclear. Here, ATM phosphorylation exerts its pro-metastatic effect via vimentin-mediated epithelial-mesenchymal transition, which was supported by the evidence described below. Firstly, IL-6 treatment increases vimentin expression via the ATM-NF-κB pathway. Second, ATM inactivation not only abolishes IL-6-induced increases in vimentin expression but also inhibits IL-6-induced nest formation in a xenograft lung metastasis model. Moreover, close positive correlations were observed between ATM phosphorylation and vimentin upregulation, IL-6 levels and metastasis in lung cancer specimens. Hence, ATM modulates vimentin expression to facilitate IL-6-induced epithelial-mesenchymal transition and metastasis in lung cancer, indicating that ATM and vimentin might be potential therapeutic targets for inflammation-associated lung cancer metastasis.

Clinical characteristics and prognosis of nonsurgically treated patients with pneumonic-type adenocarcinoma

Pneumonic-type adenocarcinoma (P-ADC) is a subtype of lung adenocarcinoma with high mortality, which often requires lobectomy surgery. Nonsurgically treated P-ADC patients usually have more advanced or complex conditions, which remain poorly understood and pose a major challenge in clinical management. We aimed to describe the clinical profiles and prognosis of non-surgically treated P-ADC patients. We enrolled 71 patients with pathologically proven P-ADC from a university hospital in China. Clinical and laboratory data were retrieved from medical record. Their median age was 62 years, including 45% men and 35% smokers. Clinical manifestations were dominated by cough, sputum, and dyspnea. Main chest imaging features included nodules, shadow, consolidation, and air bronchogram. Nearly half or more of patients showed higher levels of inflammation and cancer biomarkers including cytokeratin-19-fragment (CYFRA 21-1) and carcinoembryonic antigen (CEA). Majority of patients were classified at the stage IIIB or IV. Palliative care was the most popular treatment option but provided a shorter overall survival compared to tyrosine kinase inhibitor therapy, standard chemotherapy, and sequential therapy while there were no significant differences in the survival among the latter 3 options. Higher serum CEA was associated with longer survival and better prognosis while higher serum CYFRA 21-1 could predict a poor prognosis. Detailed understanding the clinical characteristics and prognostic factors in nonsurgically treated P-ADC may allow the identification of patients with particular risk factors and initiation of early and specific treatment in order to optimize outcomes.

Expression of p53 in ground-glass nodule of lung cancer and non-lung cancer patients

The present study investigated the expression of p53 in ground-glass nodule (GGN) of lung cancer and non-lung cancer patients, and explored the correlation with prognosis. A total of 120 GGN patients admitted to the Department of Respiratory Medicine in the Second Affiliated Hospital of Zhejiang University School of Medicine during the period from March 2010 to March 2014 were selected. These patients included 60 lung cancer patients and 60 non-tumor patients. Biopsy or surgical specimens were collected. Fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) were used to detect p53 gene and protein expression in the two groups of GGN tissues. All patients were followed up for 3 years and the relationship between p53 protein expression and the overall survival (OS) of the two groups of patients was analyzed. In GGN cells of non-cancer patients, p53 absence was observed in 6 cases and the absence rate was 10.0%. In GGN cells of cancer patients, the absence rate was significantly higher than that of non-cancer GGN group (p<0.05). The positive rate of p53-positive cases in non-tumor patients GGN group was lower than that of in GGN tissues of lung cancer patients (p<0.05). There were no deaths in the GGN non-cancer group (n=60) within 3 years, while 43 deaths occurred in GGN lung cancer group. The median survival time and the 3-year survival rate of patients with p53 positive was lower than that of p53-negative patients (p<0.05). p53 was overexpressed in GGN of lung cancer patients, and p53 overexpression is significantly correlated with poor prognosis of lung cancer patients. p53 plays an important role in transformation from GGN to lung cancer. Detection of p53 expression in GGN tissue may provide guidance for the diagnosis and prognosis of lung cancer.

Revisions to the TNM Staging of Lung Cancer: Rationale, Significance, and Clinical Application

Lung cancer remains the leading cause of cancer-related mortality worldwide. To formulate effective treatment strategies and optimize patient outcomes, accurate staging is essential. Lung cancer staging has traditionally relied on a TNM staging system, for which the International Association for the Study of Lung Cancer (IASLC) has recently proposed changes. The revised classification for this eighth edition of the TNM staging system (TNM-8) is based on detailed analysis of a new large international database of lung cancer cases assembled by the IASLC for the purposes of this project. Fundamental changes incorporated into TNM-8 include (a) modifications to the T classification on the basis of 1-cm increments in tumor size; (b) grouping of lung cancers that result in partial or complete lung atelectasis or pneumonitis; (c) grouping of tumors with involvement of a main bronchus irrespective of distance from the carina; (d) reassignment of diaphragmatic invasion in terms of T classification; (e) elimination of mediastinal pleural invasion from the T classification; and (f) subdivision of the M classification into different descriptors on the basis of the number and site of extrathoracic metastases. In response to these revisions, established stage groups have been modified, and others have been created. In addition, recommendations for classifying patterns of disease that result in multiple sites of pulmonary involvement, including multiple primary lung cancers, lung cancers with separate tumor nodules, multiple ground-glass/lepidic lesions, and consolidation, as well as recommendations for lesion measurement, are addressed. Understanding the key revisions introduced in TNM-8 allows radiologists to accurately stage patients with lung cancer and optimize therapy. ^©RSNA, 2018.

Lung cancer staging: a concise update

Diagnosis and clinical staging of lung cancer are fundamental to planning therapy. The techniques for clinical staging, i.e anatomic and metabolic imaging, endoscopies and minimally invasive surgical procedures, should be performed sequentially and with an increasing degree of invasiveness. Intraoperative staging, assessing the magnitude of the primary tumour, the involved structures, and the loco-regional lymphatic spread by means of systematic nodal dissection, is essential in order to achieve a complete resection. In resected tumours, pathological staging, with the systematic study of the resected specimens, is the strongest prognostic indicator and is essential to make further decisions on therapy. In the present decade, the guidelines on lung cancer staging of the American College of Chest Physicians and the European Society of Thoracic Surgeons are based on the best available evidence and are widely followed. Recent advances in the classification of the adenocarcinoma of the lung, with the definition of adenocarcinoma in situ, minimally invasive adenocarcinoma and lepidic predominant adenocarcinoma, and the publication of the eighth edition of the tumour, node and metastasis classification of lung cancer, have to be integrated into the staging process. The present review complements the latest guidelines on lung cancer staging by providing an update of all these issues.

Dilemmas in Lung Cancer Staging

The advent of the 8th edition of the lung cancer staging system reflects a further meticulous evidence-based advance in the stratification of the survival of patients with lung cancer. Although addressing many limitations of earlier staging systems, several limitations in staging remain. This article reviews from a radiological perspective the limitations of the current staging system, highlighting the process of TNM restructuring, the residual issues with regards to the assignment of T, N, M descriptors, and their associated stage groupings and how these dilemmas impact guidance of multidisciplinary teams taking care of patients with lung cancer.

Prognostic significance of subclassification of stage IIB lung cancer: a retrospective study of 226 patients

We investigated the prognostic significance of subclassification of stage IIB lung cancer according to the eighth tumor-node-metastasis (TNM) classification. To this purpose, the prognostic outcomes of 226 stage IIB lung cancer patients who underwent surgery without adjuvant therapies between 2001 and 2010 were evaluated retrospectively based on the eighth TNM classification. Of the 226 patients, 23, 30, 118 and 55 had pT1b, pT1c, pT2a, and pT2b stage cancers, respectively. Their 5-year survival rates were 67%, 33%, 21%, and 27%, respectively. There was no significant difference in the 5-year survival between T1b and T1c, between T1c and T2a, and between T2a and T2b (p = 0.128, 0.105, and 0.403, respectively). There were significant differences in the 5-year survival between T1b and T2a, between T1b and T2b, and between T1c and T2b (p = 0.005, 0.002, and 0.042, respectively). The 5-year survival of patients with pleural invasion and vessel invasion was significantly worse than that of their counterparts (p = 0.009 and <0.001, respectively). Subclassification of stage IIB lung cancer is of prominent prognostic significance. It is recommended that the current stage be subclassified, in order to more accurately predict the prognosis of patients.

Management pathways for solitary pulmonary nodules

Pulmonary nodules are often detected during the clinical course of several diseases or through routine screening. Various guidelines have proposed management algorithms for suspicious solitary nodules in lung cancer. Generally, solitary pulmonary nodules are managed according to nodule appearance and risk of lung cancer using low-dose, thin section computed tomography (CT). Liquid biopsy is promising for diagnosis, therapeutic-monitoring and follow-up in lung cancer; however, diagnosis and management pathways based on genetic examination alone have not been established. Management of solitary pulmonary nodules should be carried out by a multidisciplinary team and tissue biopsy is necessary for the diagnosis of lung cancer. Genetic analysis via liquid biopsy is warranted in addition to more established techniques in pulmonary nodule management.

Validation of the 8th TNM classification for small-cell lung cancer in a retrospective material from Sweden

BACKGROUND

The purpose of this study was to evaluate on a Swedish cohort of small cell lung cancer (SCLC) patients whether the 8th TNM staging system can provide additional prognostic information in comparison with the previous 6th and 7th TNM versions and the older 2-stage LD vs ED system.

METHODS

We reviewed the medical records of patients (pts) with SCLC diagnosed between January 2008 and February 2016 in the Stockholm and Gotland region. Each patient file was revised and reclassified from the VASGL system to the 6^th, 7^th and 8^th TNM system respectively. We assessed overall survival (OS) according to the T, N, M-descriptor and compared LD/ED with the 6^th, -7^th, -8^th editions of TNM. Four separate multivariate models adjusted for basic patient characteristics were performed.

RESULTS

In total, 706 pts were eligible for the study. Median OS was 7.7 months. Differences in survival between less advanced stages (IA-IIB) were difficult to assess since there were few patients (n = 32). The majority of patients (78%) migrated to new stage categories in the 8th TNM edition; IIIC, IVA and IVB. In the 8th TNM edition subjects with M1a disease had a similar prognosis to patients with multiple metastatic diseases, M1c. Conversely, subjects with a single metastasis had a similar prognosis to M0-disease. On multivariate analysis, stage was an independent prognostic factor independently of the classification system used.

CONCLUSION

In this cohort, the 8th TNM classification system seems to provide more accurate prognostic information in patients with SCLC when compared to the previous TNM versions. There were few cases with Stages I and II and therefore no robust conclusions can be drawn in this category. The reason single metastatic lesions (M1b) had a better prognosis when compared to M1c could be due to a more aggressive treatment approach in these patients.

The 8th TNM edition for lung cancer: a critical analysis

The 8^th edition of the tumor, node and metastasis (TNM) classification provides several new categories and for the first time, some prospective data are included. The T (tumor) descriptor is further subdivided with 1 cm increments for T1 and T2 disease. For metastatic disease (M descriptor) the new M1b category comprises patients with only one metastasis in one distant organ, whereas M1c implies multiple distant metastases in one or several organs. There are no changes regarding the nodal map and N component but new categories are suggested for further analysis, subdividing the N1 and N2 descriptors into involvement of single or multiple lymph node stations. The residual tumor (R) classification, related to completeness of resection, was revised in the 7^th edition specifically for lung cancer resection and has been maintained in its revised form in the 8th edition. For the first time, a thorough analysis has been made of patients with multiple lung lesions distinguishing four distinct categories. Although prospective data were used for this edition, their overall number is low and more good-quality prospective data collection coming from all continents is certainly required. Main challenge for subsequent editions is the combination of specific anatomical factors with detailed immunohistochemical data and information from biomarkers and mutational changes inside the primary tumor as well as those occurring in lymph node and distant metastases. In this way not only prognosis of our patients with lung cancer will be better determined, but more specific diagnostic and therapeutic algorithms may be applied.

Eighth Edition Staging of Thoracic Malignancies: Implications for the Reporting Pathologist

Context The Staging and Prognostic Factors Committee of the International Association for the Study of Lung Cancer, in conjunction with the International Mesothelioma Interest Group, the International Thymic Malignancy Interest Group, and the Worldwide Esophageal Cancer Collaboration, developed proposals for the 8th edition of their respective tumor, node, metastasis (TNM) staging classification systems. Objective To review these changes and discuss issues for the reporting pathologist. Data Sources Proposals were based on international databases of lung (N = 94 708), with an external validation using the US National Cancer Database; mesothelioma (N = 3519); thymic epithelial tumors (10 808); and epithelial cancers of the esophagus and esophagogastric junction (N = 22 654). Conclusions These proposals have been mostly accepted by the Union for International Cancer Control and the American Joint Committee on Cancer and incorporated into their respective staging manuals (2017). The Union for International Cancer Control recommended implementation beginning in January 2017; however, the American Joint Committee on Cancer has deferred deployment of the eighth TNM until January 1, 2018, to ensure appropriate infrastructure for data collection. This manuscript summarizes the updated staging of thoracic malignancies, specifically highlighting changes from the 7th edition that are relevant to pathologic staging. Histopathologists should become familiar with, and start to incorporate, the 8th edition staging in their daily reporting of thoracic cancers henceforth.