Relevance of EGFR mutation with micropapillary pattern according to the novel IASLC/ATS/ERS lung adenocarcinoma classification and correlation with prognosis in Chinese patients

Multiparametric evaluation of mediastinal lymph node metastases in clinical T0-T1c stage non-small-cell lung cancers

OBJECTIVES

This study aimed to determine the predictive factors of lymph node metastases in clinical T0-T1c stage non-small-cell lung cancers, so as to help making surgical strategy.

METHODS

From January 2016 to December 2017, patients with clinical T0-T1c stage non-small-cell lung cancers were retrospectively reviewed. We elucidated the lymph node metastatic incidence and distribution according to the primary tumour radiographic findings and maximal standard uptake values, and extracted the associated clinicopathological factors. Univariable and multivariable logistic regressions were used to identify independent predictive parameters for lymph node metastases. The performance of predictive model was evaluated using receiver operating characteristic analysis.

RESULTS

A total of 517 patients were included. Seventy-two patients had lymph node metastases. Among patients with pure ground-glass nodule and solid component size ≤10 mm, none had any lymph node metastasis. Multivariable logistic regression analysis demonstrated that age, carcinoembryonic antigen level, solid component size, consolidation-tumour ratio and tumour maximal standard uptake values were independent predictors of lymph nodal metastases. Receiver operating characteristic analyses indicated that the area under the curve of predictive model in evaluating lymph node metastases was 0.838 (95% CI 0.791-0.886).

CONCLUSIONS

Younger age, elevated carcinoembryonic antigen level, larger solid component size, higher consolidation-tumour ratio and tumour maximal standard uptake values were associated with lymph node involvement. Employing such a predictive model in the future may affect the surgical option of lymph node excision for patients in cT1 stage non-small-cell lung cancer.

Papillary Adenocarcinoma: A Rare Subtype of Lung Adenocarcinoma

Papillary adenocarcinoma (PA) of the lung is a specific form of lung cancer characterized by papillary structures in tumor cells. This type of cancer is relatively rare and has distinct pathological and radiological features that differentiate it from other types of lung adenocarcinomas. Determining the specific subtype of adenocarcinoma is a crucial factor in the choice of chemotherapy treatment. Detecting PA is fundamental, as it has both prognostic and therapeutic implications for patients with lung carcinoma. In this paper, we discuss two cases of young patients diagnosed with PA of the lung. The cases we present are particularly intriguing due to the relatively young age of the patients.

Stromal micropapillary pattern and CD44s expression predict worse outcome in lung adenocarcinomas with micropapillary pattern

OBJECTIVES

This study aims to investigate the clinicopathologic characteristics of lung adenocarcinoma with micropapillary pattern (MPP) and the expression of CD44s and CD44v6 in MPP.

METHODS

A total of 202 patients diagnosed with primary lung adenocarcinoma with MPP were included. We estimated the proportion of MPP in each tumor tissue and divided MPP into aerogenous micropapillary pattern (AMP) and stromal micropapillary pattern (SMP). The expression of CD44s and CD44v6 was estimated by immunohistochemical staining. Clinicopathologic data were collected from the patients' medical records. We also collected patients' follow-up data and used PFS (progression-free survival) as a survival indicator.

RESULTS

Lung adenocarcinoma with MPP had a high risk of pleural invasion, lymph node metastasis, in advanced TNM stage, and a high rate of EGFR mutation. The presence of SMP indicated a higher rate of pleural invasion, lymphovascular invasion, lymph node metastasis, and a worse PFS compared with pure AMP. We found high expression of CD44s in micropapillary, especially in AMP, while the absence of CD44s expression indicated shorter survival, which was an independent unfavorable factor for PFS.

CONCLUSIONS

Lung adenocarcinoma with micropapillary pattern indicated an unfavorable prognosis, which had two different pattens, AMP and SMP. SMP indicated a worse survival than AMP, and was an independent unfavorable factor for PFS. So, AMP/SMP subclassification is necessary to evaluate patient's prognosis. Furthermore, the absent expression of CD44s in micropapillary indicated shorter survival, especially in patients with EGFR mutation. Herein, CD44s may be a biological marker for micropapillary lung adenocarcinoma.

Correlation between clinicopathological characteristics of lung adenocarcinoma and the risk of venous thromboembolism

Background

Patients with primary lung adenocarcinoma are at increased risk of venous thromboembolism (VTE). However, lung adenocarcinoma characteristics differ across histological subtypes. Therefore, we performed comprehensive analyses on the clinicopathological characteristics of lung adenocarcinoma and risk of VTE.

Methods

A total of 952 surgically resected lung adenocarcinoma cases were reviewed and classified according to criteria of the International Association for the Study of Lung Cancer (IASLC)/American Thoracic Society (ATS) /European Respiratory Society (ERS). The correlation between this classification and VTE risk was retrospectively analyzed. The risks of other clinicopathological features including pleural invasion, vascular invasion and associated surgical intervention risks were also assessed.

Results

Of the 952 patients, 100 (10.4%) cases experienced VTE events during the follow‐up period. Among those with VTE, 28 (28%) were found before surgery, 47 (47%) were found within 1 month after surgery, and 91 (91%) were found in hospital. Univariate analysis revealed that ages, extent of resection and presence of micropapillary features were predictive of VTE risk. Furthermore, multivariable analysis demonstrated that the presence of micropapillary features (subdistribution hazard ratio [SHR] 1.560, 95% CI: 1.043–2.330) and age >60 (SHR: 2.270, 95% CI:1.491–3.470) were associated with increased risk of VTE. After one year, the probability of developing VTE was 13.1% and 8.3% in patients with micropapillary features and those without, respectively.

Conclusions

VTE is a common complication for lung adenocarcinoma patients who undergo surgery, especially during the perioperative process and hospitalization. Presence of micropapillary subtype and age are positively associated with VTE risk.

The nonsmokers' and smokers' pathways in lung adenocarcinoma: Histological progression and molecular bases

There could be two carcinogenetic pathways for lung adenocarcinoma (LADC): the nonsmokers' pathway and the smokers' pathway. This review article describes the two pathways with special reference to potential relationships between histological subtypes, malignant grades, and driver mutations. The lung is composed of two different tissue units, the terminal respiratory unit (TRU) and the central airway compartment (CAC). In the nonsmokers' pathway, LADCs develop from the TRU, and their histological appearances change from lepidic to micropapillary during the progression process. In the smokers' pathway, LADCs develop from either the TRU or the CAC, and their histological appearances vary among cases in the middle of the progression process, but they are likely converged to acinar/solid at the end. On a molecular genetic level, the nonsmokers' pathway is mostly driven by EGFR mutations, whereas in the smokers' pathway, approximately one-quarter of LADCs have KRAS mutations, but the other three-quarters have no known driver mutations. p53 mutations are an important factor triggering the progression of both pathways, with unique molecular alterations associated with each, such as MUC21 expression and chromosome 12p13-21 amplification in the nonsmokers' pathway, and HNF4α expression and TTF1 mutations in the smokers' pathway. However, investigation into the relationship between histological progression and genetic alterations is in its infancy. Tight cooperation between traditional histopathological examinations and recent molecular genetics can provide valuable insight to better understand the nature of LADCs.

Driver and novel genes correlated with metastasis of non-small cell lung cancer: A comprehensive analysis

Although mutations of genes are crucial events in tumorigenesis and development, the association between gene mutations and lung cancer metastasis is still largely unknown. The goal of this study is to identify driver and novel genes associated with non-small cell lung cancer (NSCLC) metastasis. Candidate genes were identified using a novel comprehensive analysis, which was based on bioinformatics technology and meta-analysis. Firstly, EGFR, KRAS, ALK, TP53, BRAF and PIK3CA were identified as candidate driver genes. Further meta-analysis identified that EGFR (Pooled OR 1.33, 95% CI 1.19, 1.50; P < .001) and ALK (Pooled OR 1.52, 95% CI 1.22, 1.89; P < .001) mutations were associated with distant metastasis of NSCLC. Besides, ALK (Pooled OR 2.40, 95% CI 1.71, 3.38; P < .001) mutation was associated with lymph node metastasis of NSCLC. In addition, thirteen novel gene mutations were identified to be correlated with NSCLC metastasis, including SMARCA1, GGCX, KIF24, LRRK1, LILRA4, OR2T10, EDNRB, NR1H4, ARID4A, PRKCI, PABPC5, ACAN and TLN1. Furthermore, elevated mRNA expression level of SMARCA1 and EDNRB was associated with poor overall survival in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC), respectively. Additionally, pathway and protein-protein interactions network analyses found the two genes were correlated with epithelial-mesenchymal transition process. In conclusion, mutations of EGFR and ALK were significantly correlated with NSCLC metastasis. In addition, thirteen novel genes were identified to be associated with NSCLC metastasis, especially SMARCA1 in LUAD and EDNRB in LUSC.

A clinicopathological study of lung adenocarcinomas with pure ground-glass opacity > 3 cm on high-resolution computed tomography

OBJECTIVES

This study aimed to discuss whether a diameter of 3 cm is a threshold for diagnosing lung adenocarcinomas presenting with radiological pure ground-glass mass (PGGM, pure ground-glass opacity > 3 cm) as adenocarcinomas in situ or minimally invasive adenocarcinomas (AIS-MIAs). Another aim was to identify CT features and patient prognosis that differentiate AIS-MIAs from invasive adenocarcinomas (IACs) in patients with PGGMs.

METHODS

From June 2007 to October 2015, 69 resected PGGMs with HRCT and followed up for ≥ 5 years were included in this study and divided into AIS-MIA (n = 13) and IAC (n = 56) groups. Firth's logistic regression model was performed to determine CT characteristics that helped distinguish IACs from AIS-MIAs. The discriminatory power of the significant predictors was tested with the area under the receiver operating characteristics curve (AUC). Disease recurrence was also evaluated.

RESULTS

Univariable and multivariable analyses identified that the mean CT attenuation (odds ratio: 1.054, p = 0.0087) was the sole significant predictor for preoperatively discriminating IACs from AIS-MIAs in patients with PGGMs. The CT attenuation had an excellent differentiating accuracy (AUC: 0.981), with the optimal cut-off value at -600 HU (sensitivity: 87.5%; specificity: 100%). Additionally, no recurrence was observed in patients manifesting with PGGMs > 3 cm, and the 5-year recurrence-free survival and overall survival rates were both 100%, even in cases of IAC.

CONCLUSIONS

This study demonstrated that PGGMs > 3 cm could still be AIS-MIAs. When PGGMs are encountered in clinical practice, the CT value may be the only valuable parameter to preoperatively distinguish IACs from AIS-MIAs.

KEY POINTS

• Patients with pure ground-glass opacity > 3 cm in diameter are rare but can be diagnosed as adenocarcinomas in situ or minimally invasive adenocarcinomas. • The mean CT attenuation is the sole significant CT parameter that differentiates invasive adenocarcinoma from adenocarcinoma in situ or minimally invasive adenocarcinoma in patients with pure ground-glass opacity > 3 cm. • Lung adenocarcinoma with pure ground-glass opacity > 3 cm has an excellent prognosis, even in cases of invasive adenocarcinoma.

The prognostic utility of the histologic subtype of stage I lung adenocarcinoma may be diminished when using only the invasive component to determine tumor size for tumor node metastasis (TNM) staging

Background

Histologic subtypes were considered prognostic factors in early-stage lung adenocarcinoma in the 7^th edition of the tumor node metastasis (TNM) staging system (TNM-7). However, the T-staging system has changed and now measures only the size of the invasive component to determine tumor size. The aim of this study was to determine whether the histologic subtype is still a prognostic factor in the 8^th edition of the TNM staging system (TNM-8).

Methods

From 2010 to 2017, 788 patients who underwent curative surgery for stage I lung adenocarcinoma according to TNM-8 were analyzed retrospectively. Survival rates were compared among predominant patterns of adenocarcinoma. Prognostic factors were analyzed according to risk factors for recurrence in stage I lung adenocarcinoma.

Results

The 5-year recurrence-free survival rates among predominant histologic subtypes were statistically different, especially between the lepidic/acinar/papillary group and the micropapillary/solid group. Total tumor size was not significantly different between the two groups, but invasive component size was different (1.5 vs. 2.3 cm, P<0.001). In the multivariate analysis that adopted total tumor size as a variable, visceral pleural invasion (VPI), lymphovascular invasion (LVI), and micropapillary-predominant adenocarcinoma were significant predictors for recurrence. Conversely, adenocarcinoma subtypes were not significant risk factors for recurrence in the multivariate analysis that adopted invasive component size as a variable.

Conclusions

The importance of adenocarcinoma subtype for prognosis may be reduced when only the invasive component of a tumor is used to determine tumor size, as described in the TNM-8 staging system.

High-risk-pattern lung adenocarcinoma with epidermal growth factor receptor mutation is associated with distant metastasis risk and may benefit from adjuvant targeted therapy

OBJECTIVES

This study aimed to evaluate the value of the high-risk-pattern histology (micropapillary and solid components) for predicting distant metastasis in lung adenocarcinoma and to determine the survival benefit with adjuvant targeted therapy for resected non-small cell lung cancer with high-risk-pattern histology.

METHODS

Patients receiving surgery for non-small cell lung cancer were included in this retrospective study. Histological classification was performed according to 2015 World Health Organization classification. Tumours with micropapillary and solid components were defined as high-risk-pattern tumours. Univariable and multivariable Cox regression analyses were used for survival analysis. Adjuvant targeted therapy was alternative for patients with epidermal growth factor receptor (EGFR)-mutation and refusing adjuvant chemotherapy, and outcome was evaluated between 2 groups.

RESULTS

The 514 patients (78 in high-risk group and 436 in low-risk group) were followed up for a median of 64 months. High-risk-pattern adenocarcinoma was significantly more common in male patients (P < 0.001) and in smokers (P < 0.001). Among patients with EGFR mutation (n = 164), the high-risk pattern was significantly associated with distant metastasis (P = 0.028) including brain metastasis (P = 0.022). In the 42 patients with high-risk pattern plus EGFR mutation, survival was significantly better after treatment with adjuvant targeted therapy than with chemotherapy (5-year overall survival: 56.4 ± 2.6 vs 44.7 ± 3.7 months, P = 0.011; 5-year disease-free survival: 54.0 ± 3.3 vs 41.9 ± 4.5 months, P = 0.006).

CONCLUSIONS

High-risk pattern is associated with distant metastasis in non-small cell lung cancer after surgery. Adjuvant targeted therapy may be superior to chemotherapy for treatment of patients with high-risk pattern and EGFR mutation.

Targeted Sequencing Analysis of Predominant Histological Subtypes in Resected Stage I Invasive Lung Adenocarcinoma

Objective: Lung adenocarcinoma (LADC) is classified into five main histological subtypes with distinct clinicopathologic characteristics: lepidic-predominant adenocarcinoma (LPA), acinar-predominant adenocarcinoma (APA), papillary-predominant adenocarcinoma (PPA), micropapillary-predominant adenocarcinoma (MPA) and solid-predominant adenocarcinoma (SPA). However, the mutational profiles of predominant histological subtypes have not been well defined. In this study, we aimed to reveal the genomic landscape of 5 main histological subtypes. Patients and Methods: We performed next-generation sequencing (NGS) in a cohort of 86 stage I invasive adenocarcinoma (IAC) patients, using a customized panel including 168 cancer-associated genes. Results: Our analysis identified a total of 302 genomic alterations. Five subtypes showed different mutation profiles with LPA, APA, PPA, MPA and SPA had an average mutation rate of 1.95 (range: 0-5), 2.56 (range: 1-6), 3.5 (range: 1-7), 3.75 (range: 1-8) and 6.05 (range: 2-12), respectively (p=4.17e-06). Driver mutations occurred in 96.55% (83/86) of all patients. EGFR (73.3%), KRAS (9.3%), ALK (4.7%) and MET (4.7%) are the most commonly mutated lung cancer driver genes, TP53 is the top mutated tumor suppressor gene. SPA patients harbored more driver mutations and higher frequency of TP53 than LPA patients. Interestingly, LRP1B mutations, which has been reported to be associated with high tumor mutation burden and better response to immunotherapy, were only detected from 5 SPA patients (p=0.001). No patients from other four cohorts harbored LRP1B mutations. Conclusions: We revealed distinctive mutation landscape of the 5 major histological subtypes of LADC, evident by distinctive average mutation rate with SPA and LPA having the highest and lowest average mutation rate, respectively. SPA patients showed higher mutation rate of LRP1B and higher rates for PD-L1 positivity, indicating that SPA patients may have better response to immunotherapy.

Tumor Margin Contains Prognostic Information: Radiomic Margin Characteristics Analysis in Lung Adenocarcinoma Patients

Simple Summary

The tumor microenvironment is a dynamic area, with continuous interaction between tumor cells and their surrounding environment. We aimed to investigate the relationship between tumor radiomic margin characteristics and prognosis in patients with lung cancer. When compared to the model with clinical variables only (C-index = 0.738), the model incorporating clinical variables and radiomic margin characteristics (C-index = 0.753) demonstrated a higher C-index for predicting overall survival. In the model integrating both clinical variables and radiomic margin characteristics, convexity, Laplace of Gaussian (LoG) kurtosis 3, and roundness factor were independent predictive factors of overall survival. Our study showed that radiomic margin characteristics helped predict overall survival in patients with lung adenocarcinomas, thus implying that the tumor margin contains prognostic information.

Abstract

We aimed to investigate the relationship between tumor radiomic margin characteristics and prognosis in patients with lung cancer. We enrolled 334 patients who underwent complete resection for lung adenocarcinoma. A quantitative computed tomography analysis was performed, and 76 radiomic margin characteristics were extracted. The radiomic margin characteristics were correlated with overall survival. The selected clinical variables and radiomic margin characteristics were used to calculate a prognostic model with subsequent internal and external validation. Nearly all of the radiomic margin characteristics showed excellent reproducibility. The least absolute shrinkage and selection operator (LASSO) method was used to select eight radiomic margin characteristics. When compared to the model with clinical variables only (C-index = 0.738), the model incorporating clinical variables and radiomic margin characteristics (C-index = 0.753) demonstrated a higher C-index for predicting overall survival. In the model integrating both clinical variables and radiomic margin characteristics, convexity, a Laplace of Gaussian (LoG) kurtosis of 3, and the roundness factor were each independently predictive of overall survival. In addition, radiomic margin characteristics were also correlated with the micropapillary subtype, and the sphericity value was able to predict the presence of the micropapillary subtype. In conclusion, our study showed that radiomic margin characteristics helped predict overall survival in patients with lung adenocarcinomas, thus implying that the tumor margin contains prognostic information.

Clinical implication of minimal presence of solid or micropapillary subtype in early-stage lung adenocarcinoma

BACKGROUND

We investigated the clinical features and surgical outcomes of lung adenocarcinoma with minimal solid or micropapillary (S/MP) components, with a focus on stage IA.

METHODS

We enrolled 506 patients with lung adenocarcinoma who underwent curative resection in this study. Clinical features and surgical outcomes were compared between the groups with and without the S/MP subtype (S/MP+ and S/MP-, respectively), and between the group with an S/MP proportion of ≤5% (S/MP5) and the S/MP-.

RESULTS

The S/MP subtype was present in 247 patients (48.8%); 129 (25.5%) were grouped as the S/MP5 group. The S/MP+ and S/MP5 groups had larger tumors, higher frequency of lymph node metastasis, and more advanced stages of disease than the S/MP- group (P < 0.001, all comparisons). Pleural, lymphatic, and vascular invasions occurred more frequently in the S/MP+ and S/MP5 groups (P < 0.001, all comparisons for S/MP+ vs. S/MP-; P ≤ 0.01, all comparisons for S/MP5 vs. S/MP-). The S/MP+ and S/MP5 groups showed a shorter time to recurrence and cancer-related death than the S/MP- group(P < 0.001, both comparisons). For stage I, the presence or absence of the S/MP subtype defined prognostic subgroups better than the stage IA/IB classification. Notably, in the multivariate analysis, the minimal S/MP component was a significant predictor of recurrence, even in stage IA.

CONCLUSIONS

The presence of the minimal S/MP component was a significant predictor of poor prognosis after surgery, even in stage IA patients. Clinical trials to evaluate the advantages of adjuvant chemotherapy for this subset of patients and further investigations to understand underlying biological mechanisms of poor prognosis are needed.

KEY POINTS

Significant findings of the study: We demonstrated that only minimal presence of solid or micropapillary component was profoundly associated with aggressive clinicopathological features and poor prognosis after complete resection even in stage IA lung adenocarcinoma.

WHAT THIS STUDY ADDS

Our results suggest that minimal presence of these subtypes is a strong prognostic factor which should be taken into account in the risk assessment for adjuvant chemotherapy in lung adenocarcinoma.

New International Association for the Study of Lung Cancer (IASLC) Pathology Committee Grading System for the Prognostic Outcome of Advanced Lung Adenocarcinoma

Simple Summary

This study investigated the association between survival outcome and the new grading system among advanced stage lung adenocarcinoma (LADC) (stages IIIA, IIIB and IV) patients who were diagnosed as LADC with a pathologic report according to a new grading system by the International Association for the Study of Lung Cancer (IASLC) pathology committee. The results indicate that the poorly differentiated group had a poorer prognosis in PFS, as did patients with wild-type EGFR who were treated with chemotherapy. No survival difference could be found among EGFR mutation patients. Older age and a lower body mass index also led to worse survival. Patients with poorly differentiated adenocarcinoma likewise had worse survival, especially compared to those with moderately differentiated adenocarcinoma. Our findings highlight that the therapeutic regimen should be adjusted for wild-type EGFR patients with poorly differentiated adenocarcinoma treated with chemotherapy to provide better outcomes. No survival difference could be seen among EGFR mutation patients.

Abstract

The impact of the new International Association for the Study of Lung Cancer pathology committee grading system for advanced lung adenocarcinoma (LADC) on survival is unclear, especially in Asian populations. In this study, we reviewed the prognostic outcomes of patients with late-stage disease according to the new grading system. We reviewed 136 LADC cases who underwent a small biopsy from 2007 to 2018. Tumors were classified according to the new grading system for LADC. Baseline characteristics (age, sex, smoking status, body mass index, and driver gene mutations) were analyzed. Kaplan–Meier and Cox regression analyses were used to determine correlations with the new grading system and prognosis. Patients with poorly differentiated adenocarcinoma were significantly correlated with a poor progression-free survival (PFS) (p = 0.013) but not overall survival (OS) (p = 0.154). Subgroup analysis showed that wild-type EGFR patients with poorly differentiated adenocarcinoma treated with chemotherapy had significantly worse PFS (p = 0.011). There was no significant difference in survival among the patients with epidermal growth factor receptor mutations who were treated with tyrosine kinase inhibitors. Patients aged >70 years and those with a BMI ≤ 25 kg/m² and wild-type patients had significantly worse OS in both univariate (HR = 1.822, p = 0.006; HR = 2.250, p = 0.004; HR = 1.537, p = 0.046, respectively) and multivariate analyses (HR = 1.984, p = 0.002; HR = 2.383, p = 0.002; HR = 1.632, p = 0.028, respectively). Despite therapy, patients with poorly differentiated tumors still fared worse than those with better differentiated tumors. No differences were found among the EGFR mutations treated with TKI. Our findings highlight that the therapeutic regimen should be adjusted for EGFR Wild-type patients with poorly differentiated adenocarcinoma treated with chemotherapy to provide better outcomes.

Both the presence of a micropapillary component and the micropapillary predominant subtype predict poor prognosis after lung adenocarcinoma resection: a meta-analysis

Objective

It has been confirmed that the micropapillary (MP) pattern is a poor prognostic factor after resection of lung adenocarcinoma (ADC), but the proportion of the MP component as a prognostic criterion is still controversial. Hence, a meta-analysis was performed to evaluate whether the presence of an MP component has equal prognostic power as the MP predominant subtype.

Methods

Literature retrieval was performed in the MEDLINE, EMBASE, and Cochrane databases until December 23, 2019. Eligible studies were selected based on the inclusion and exclusion criteria. The included studies were divided into two subgroups, the MP component subgroup and the MP predominant subgroup, according to the proportion of the MP pattern to analyse the effect of this pattern on disease-free survival (DFS) and overall survival (OS). The hazard ratio (HR) and 95% confidence interval (CI) were extracted from each study. Review Manager 5.3 was used for statistical analyses.

Results

Finally, 10 studies, including a total of 4934 lung ADC patients, were included in this meta-analysis. Our results indicated a significantly worse pooled DFS (HR 1.62, 95% CI 1.20–2.21) and OS (HR 1.53, 95% CI 1.19–1.96) in the subgroup of MP predominant subtype patients. The pooled DFS (HR 1.80, 95% CI 1.45–2.85) and OS (HR 2.26, 95% CI 1.46–3.52) were also poor in the subgroup of patients with the presence of an MP component.

Conclusions

Both the presence of an MP component and the MP predominant subtype are related to poor DFS and OS after lung ADC resection and represent adverse prognostic factor for lung ADC patients. However, there are some limitations in this meta-analysis, and quantitative stratification based on the proportion of the MP component is needed to explore its effect on prognosis of lung ADC patients in the future.

Micropapillary pattern is associated with the development of brain metastases and the reduction of survival time in EGFR-mutation lung adenocarcinoma patients with surgery

OBJECTIVE

The role of micropapillary pattern (MIP) in EGFR-mutated NSCLC patients with brain metastases (BM) after complete surgical resection still remains unclear. Therefore, a retrospective study was conducted to evaluate the role of MIP in those patients.

METHODS

This study included 332 stage I-III patients with EGFR-mutant lung adenocarcinoma and complete resection. Patients were classified in four groups: the MIP-positive patients without BM development, the MIP-negative patients without BM development, the MIP-positive patients with BM development and the MIP-negative patients with BM development. Intracranial disease-free survival (iDFS), systemic disease-free survival (DFS) and overall survival (OS) were evaluated.

RESULTS

The median OS in the whole group was 70 months. The patients with MIP show inferior DFS (13 months vs. 22 months; P < 0.001) and OS (56 months vs. 74 months; P < 0.001). Furthermore, BM development was more likely to be found in patients with MIP (P = 0.001). In addition, the MIP-positive patients showed a significantly shorter iDFS compared with MIP-negative patients (14.5 months vs. 26 months; P < 0.001). Furthermore, the MIP-positive patients had significantly inferior iDFS in both BM as first line development groups (13 months vs. 19 months; P < 0.001) and BM as non-first line development groups (18 months vs. 33 months; P = 0.007).

CONCLUSIONS

MIP was related to the earlier recurrence and shortened survival time. In addition, MIP was an independent poor prognostic factor for the increase of BM rate and the shortened time of BM development after surgery.

High CXCR4 Expression Predicts a Poor Prognosis in Resected Lung Adenosquamous Carcinoma

Background: Primary adenosquamous carcinoma (ASC) is a rare malignant tumor in the lung and its biological behavior has not yet been thoroughly described. In this study, we aimed to explore the clinical and biological role of CXCR4 in patients with resected lung ASC. Methods: We retrospectively reviewed the clinical records of patients with histologically confirmed lung ASC who underwent surgical resection with systematic lymph node dissection. Immunohistochemical staining was performed to detect the expression of CXCR4 in tumor tissues. The correlation between CXCR4 expression and clinicopathological characteristics were evaluated. The association between CXCR4 expression and patients' prognosis was analyzed by Kaplan-Meier and Cox regression. Moreover, we performed in vitro studies including CCK8, transwell and cell apoptosis to explore the potential role of CXCR4 in lung ASC. Results: A total of 78 patients with resected lung ASC were reviewed. Seventy (89.7%) patient tumors expressed CXCR4, with high level of CXCR4 expression observed in 45 (57.7%) cases. In vitro, CXCR4 conferred no difference in proliferative capacity but increased invasive potential, enhanced chemoresistance and inhibited apoptosis of lung ASC. Clinically, high CXCR4 expression was significantly associated with solid ASC, lymph node metastasis and advanced TNM stage. Patients with high CXCR4 expression and solid ASC had decreased disease-free survival and overall survival.Conclusions: CXCR4 was commonly expressed in lung ASC tumors. High CXCR4 expression might be a novel marker in predicting a poor prognosis in resected lung ASC and might serve as a potential therapeutic target.

Association between the novel classification of lung adenocarcinoma subtypes and EGFR/KRAS mutation status: A systematic literature review and pooled-data analysis

OBJECTIVES

This study aims to determine the association of EGFR/KRAS mutation status with histological subtypes of lung adenocarcinoma (LAC) based on the IASLC/ATS/ERS classification.

METHODS

Pubmed and Cochrane databases were searched from January 2011 to June 2018 for studies that included patients with LAC who underwent surgical resection were classified according to the new IASLC/ATS/ERS classification. EGFR/KRAS status assessment was requireded. The primary outcome was determined by the odds ratio (OR) of the incidence of mutation status of certain of each histological subtype. The reference group consisted of EGFR/KRAS mutation negative patients.

RESULTS

Twenty-seven eligible studies involving 9022 patients with mutation gene detection were included for analysis. Among them, 6717 (74.5%) patients were from the Asian region and, 2305 (25.5%) patients were from Non-Asian regions. The most prevalent subtype was acinar (34.7%), followed by papillary (22.9%), lepidic (18.9%), solid (13.6%), micropapillary (6.3%), and invasive mucinous adenocarcinoma (3.5%). EGFR mutations were more common in patients with resected lepidic predominant adenocarcinoma (OR,1.76; 95%CI, 1.38-2.24;p < 0.01) and were rarely found in solid predominant adenocarcinoma (OR,0.28; 95%CI, 0.23-0.34;p < 0.01) or IMA (OR,0.10; 95%CI, 0.06-0.14;p < 0.01). Conversely, KRAS mutations were characterized by IMA (OR,7.01; 95%CI, 5.11-9.62;p < 0.01), and were less frequently identified in lepidic (OR,0.58; 95%CI, 0.45-0.75;p < 0.01) and acinar (OR,0.65; 95%CI, 0.55-0.78;p < 0.01) predominant subtypes. Further analyses were performed in Asian and Non-Asian groups and the results were consistent.

CONCLUSIONS

The current study confirms that the IASLC/ATS/ERS classification is associated with driver gene alterations in resected LAC.

Correlation between high-resolution computed tomography lung nodule characteristics and EGFR mutation in lung adenocarcinomas

Background

The aim of this study was to investigate the correlation of EGFR mutation on the high-resolution computed tomography (HRCT) features in lung adenocarcinoma.

Patients and methods

A total of 121 patients were diagnosed with lung adenocarcinoma from January 2014 to December 2016. The correlation of indexes (gender, age, tumor diameter, and EGFR mutation) was analyzed based on the HRCT characteristics of lung adenocarcinoma.

Results

There were 73 cases of EGFR mutation and 48 cases of wild-type EGFR. One hundred and three cases had pleural indentation that was significant in patients with EGFR mutation than those with wild-type EGFR (P=0.038). Forty-two out of 121 cases exhibited the bronchus cutoff sign. Patients with EGFR mutation were likely to develop the bronchus cutoff sign (P=0.017). Sixty-one out of 121 cases exhibited the lobulation sign, which was significant in patients with EGFR mutation than those with wild-type EGFR (P<0.001). A significant correlation was found between lobulation sign and tumor diameter (P=0.024). Forty-eight out of 121 and 23 out of 121 cases showed the vessel and vacuole signs, respectively. However, patients with EGFR mutation did not exert a significant correlation on either of these signs (P=0.555 and P=0.372, respectively). A statistical significance was not observed in indexes such as age, gender, and tumor diameter on pleural indentation, bronchus cutoff sign, vessel sign, and vacuole sign (P>0.05). Age and gender did not vary significantly in the lobulation sign (P>0.05).

Conclusion

HRCT characteristics such as pleural indentation, bronchus cutoff sign, and lobulation sign in lung adenocarcinoma with EGFR mutation were significantly greater than those with wild-type EGFR; however, further study is essential in determining the predictive ability of computed tomography (CT) for EGFR mutations in lung adenocarcinoma.

Comparison of Clinicopathological Features and Prognosis between ALK Rearrangements and EGFR Mutations in Surgically Resected Early-stage Lung Adenocarcinoma

Background: A number of mutations in key oncogenes have been identified as important for the initiation and maintenance of lung adenocarcinoma (LAC). This study elucidated the prevalence and prognostic significance of mutations in the epidermal growth factor receptor gene (EGFR) and rearrangements in the anaplastic lymphoma kinase gene (ALK) in patients with surgically resected primary LAC.

Patients and Methods: We retrospectively analyzed 675 consecutive patients who underwent radical resection at a single institution. We concurrently analyzed mutations in EGFR and the Kirsten rat sarcoma viral oncogene homolog gene (KRAS) by reverse transcription (RT)-PCR, and investigated ALK rearrangements by immunohistochemistry. LAC with or without various oncogenic mutations was studied for clinicopathological features and their association with disease-free survival (DFS) and overall survival (OS).

Result: ALK rearrangements and EGFR mutations were detected in 75 and 312 patients, respectively, with coexistence in 5 cases. ALK rearrangements and mutations in EGFR and KRAS were mutually exclusive. Compared with patients with EGFR mutations, ALK rearrangements were more common in younger patients, and those with advanced tumors, lymph node metastases, and higher rates of postoperative adjuvant therapy. Histologically, EGFR mutations were more common than ALK rearrangements in patients with the acinar predominant subtype and the lepidic predominant subtype of LAC, whereas ALK rearrangements were more frequent in the solid predominant subtype with mucin production and invasive mucinous adenocarcinomas. ALK-positive patients had a significantly worse DFS than those with EGFR mutations and wild-type (WT) patients. The mean OS after surgical procedures was significantly longer in EGFR-mutated versus WT patients. No significant differences were found in patients with ALK-positive tumors compared with EGFR-mutated and WT patients.

Conclusion: Clinicopathological features of LAC with ALK rearrangements differ from those of LAC with EGFR mutations. Patients with ALK rearrangements had a significantly worse DFS than those harboring EGFR mutations. Thus, ALK rearrangements are an adverse prognostic factor in surgically-resected LAC patients, while EGFR mutations are associated with a better prognosis.

Papillary lung adenocarcinoma with psammomatous calcifications

We present the case of a 71 y/o man with chronic obstructive pulmonary disease (COPD) who presented with 3 weeks of cough, phlegm, fever, and failed outpatient antibiotic therapy for pneumonia. CT of the chest showed unilateral interstitial changes and bronchoscopic biopsies demonstrated primary lung papillary adenocarcinoma and extensive concentric psammomatous calcifications.

The relationship between EGFR mutation status and clinic-pathologic features in pulmonary adenocarcinoma

To detect the relationship of the epidermal growth factor receptor (EGFR) mutation status and the clinicopathologic features. Six hundred thirty-three patients with pathologically confirmed lung adenocarcinoma who underwent lung cancer resection surgery at the Fourth Hospital of Hebei Medical University between April 2012 and April 2015 were selected for the study. The 32 types of mutations in exons 18-21 of the EGFR gene were detected. The total EGFR mutation rate among patients with lung adenocarcinoma was 56.9%. The mutation rates were 71.2% among females and 42.8% among males (P < 0.05). Among patients with TNM stage I, II, III, and IV disease, the EGFR mutation rates were significant differences (P < 0.05). Concerning different subtypes of lung adenocarcinoma, the EGFR mutation rates were differences, and these differences were statistically significant (P < 0.05). Cox multivariate regression model analysis considering EGFR mutation status revealed that differences in TNM stage (P < 0.01), smoker status, and tumor size were statistically significant predictors. Patients with minimally invasive and lepidic adenocarcinomas were categorized as low-risk group with high EGFR mutation rate; Patients with micro-papillary and solid adenocarcinomas were categorized as high-risk with lower EGFR mutation rate, so there are different mechanisms in different types of adenocarcinomas.

Pathologic subtype-defined prognosis is dependent on both tumor stage and status of oncogenic driver mutations in lung adenocarcinoma

Previous studies have shown that the prognosis of lung adenocarcinoma is associated with pathological characterization. In this study, we investigated whether pathology-based prognosis was further influenced by both tumor stage and oncogenic driver mutations. To this end, we recruited a cohort of 465 lung adenocarcinoma patients in China. These patients were classified into 6 pathology-defined subtypes i.e., lepidic-predominant adenocarcinoma (LPA), acinar-predominant adenocarcinoma (APA), papillary-predominant adenocarcinoma (PPA), micropapillary-predominant adenocarcinoma (MPA), solid-predominant adenocarcinoma (SPA), and invasive mucinous adenocarcinoma (IMA). Oncogenic mutations in EGFR, KRAS, ALK, RET, and BRAF genes were determined using fluorescent real-time RT-PCR. The associations of pathogenic subtype or oncogenic mutation with clinical characteristics were analyzed using Fisher’s exact tests. The interactive effects on overall survival (OS) by pathologic subtype, oncogenic mutations, and tumor stage were also determined. We have found that pathogenic subtype of lung adenocarcinoma correlated with smoking habit and tumor cell differentiation. These pathology-defined subtypes can be regrouped into 3 pathology-based prognostic groups: PPG1 (LPA), PPG2 (IMA+APA+PPA), and PPG3 (MPA+SPA) with a favorable, intermediate, and poor OS, respectively. We further demonstrated that this pathology-determined OS can be affected by both tumor stage and status of oncogenic mutations in EGFR, KRAS, ALK, RET, and BRAF genes. Interestingly, the presence of genetic mutations related to ALK, RET and BRAF had an opposite effect on OS between PPG2 (worsen) and PPG3 (improved) patients, reversing the prognostic favorability for patients within these two groups. In conclusion, prognosis of lung adenocarcinoma was defined interactively by pathologic subtype, tumor stage and oncogenic mutation.

Micropapillary histological subtype in lung adenocarcinoma of 2 cm or less: impact on recurrence and clinical predictors

OBJECTIVE

This study examined the clinical and radiological characteristics of adenocarcinoma having the micropapillary histological subtype.

METHODS

We included 233 patients who were operated from 2001 to 2012 for lung adenocarcinoma of 2 cm or less. The pathology was reviewed according to the 2015 WHO classification. We defined adenocarcinoma with a micropapillary component as adenocarcinoma in which the area of the micropapillary histological subtype exceeded 5% of the tumor. The difference in cumulative incidence of recurrence (CIR) in the presence of death as a competing risk between two groups was assessed using the methods of Gray.

RESULTS

Twenty-one cases (9.0%) had a micropapillary component. The micropapillary component was associated with a higher frequency of lymphatic invasion (28.6 vs. 7.5% in adenocarcinoma without a micropapillary component; P = 0.008) and vascular invasion (38.1 vs. 15.1%, P = 0.014) and lymph node metastasis (31.3 vs. 5.2%, P = 0.003). The median follow-up period was 6.5 years. CIR at 5 years was 23.8% [95% confidence interval (CI), 8.3-43.7%] for adenocarcinoma with a micropapillary component, and 11.4% (95% CI, 7.4-16.2%) for adenocarcinoma without a micropapillary component (P = 0.033). Adenocarcinoma with a micropapillary component was more frequent in solid nodules (17.8%, 16/90) on high-resolution computed tomography (HRCT) than in either ground-glass nodules (1.5%, 1/67) or part-solid nodules (5.3%, 4/76) (P = 0.001). The HRCT finding was the only preoperative factor that was associated with a micropapillary component in the multivariate analysis.

CONCLUSIONS

The micropapillary component in adenocarcinoma should be regarded as indicative of a high-grade malignancy and was associated with the HRCT finding.

Imaging Phenotyping Using Radiomics to Predict Micropapillary Pattern within Lung Adenocarcinoma

INTRODUCTION

Lung adenocarcinomas (ADCs) with a micropapillary pattern have been reported to have a poor prognosis. However, few studies have reported on the imaging-based identification of a micropapillary component, and all of them have been subjective studies dealing with qualitative computed tomography variables. We aimed to explore imaging phenotyping using a radiomics approach for predicting a micropapillary pattern within lung ADC.

METHODS

We enrolled 339 patients who underwent complete resection for lung ADC. Histologic subtypes and grades of the ADC were classified. The amount of micropapillary component was determined. Clinical features and conventional imaging variables such as tumor disappearance rate and maximum standardized uptake value on positron emission tomography were assessed. Quantitative computed tomography analysis was performed on the basis of histogram, size and shape, Gray level co-occurrence matrix-based features, and intensity variance and size zone variance-based features.

RESULTS

Higher tumor stage (OR = 3.270, 95% confidence interval [CI]: 1.483-7.212), intermediate grade (OR = 2.977, 95% CI: 1.066-8.316), lower value of the minimum of the whole pixel value (OR = 0.725, 95% CI: 0.527-0.98800), and lower value of the variance of the positive pixel value (OR = 0.961, 95% CI: 0.927-0.997) were identified as being predictive of a micropapillary component within lung ADC. On the other hand, maximum standardized uptake value and tumor disappearance rate were not significantly different in groups with a micropapillary pattern constituting at least 5% or less than 5% of the entire tumor.

CONCLUSION

A radiomics approach can be used to interrogate an entire tumor in a noninvasive manner. Combining imaging parameters with clinical features can provide added diagnostic value to identify the presence of a micropapillary component and thus, can influence proper treatment planning.

A Histopathological Feature of EGFR-Mutated Lung Adenocarcinomas with Highly Malignant Potential - An Implication of Micropapillary Element

The purpose of this study was to define histological features determining the malignant potential of EGFR-mutated lung adenocarcinoma (LADC). Surgically resected tumors (EGFR-mutated LADCs with (21) and without (79) lymph node metastasis and EGFR wild-type LADCs with (26) and without (108) lymph node metastasis) and biopsy samples from inoperably advanced tumors (EGFR-mutated LADCs (78) and EGFR wild-type LADCs (99)) were examined. In surgically resected tumors, the EGFR-mutated LADCs with lymph node metastasis had the micropapillary element in a significantly greater proportion than others (Mann-Whitney tests P ≤0.026). The proportion of micropapillary element was higher in the EGFR-mutated LADC at the advanced stage (stage II, III, or IV) than in the tumor at the early stage (stage I) (Mann-Whitney test, P<0.0001). In the biopsy samples from inoperably advanced LADCs (177), EGFR-mutated tumors also had micropapillary element at a higher frequency than EGFR-wild type tumors (53/78 (68%), versus 30/99 (30%), Pearson x2 test, P<0.0001). In stage I EGFR-mutated LADCs (84), the tumors with the micropapillary element (34) exhibited a significantly higher recurrence rate than tumors without micropapillary element (50) (5-year Recurrence-free survival 64.4% versus 93.3%, log-rank test P = 0.028). The micropapillary element may be an exclusive determinant of malignant potential in EGFR-mutated LADC. It is suggested that EGFR-mutated LADC may develop through a distinct histogenesis, in which the micropapillary element is important for promoting progression.

Identification of lymph node metastasis-related microRNAs in lung adenocarcinoma and analysis of the underlying mechanisms using a bioinformatics approach

This study aimed to screen lymphatic metastasis-related microRNAs (miRNAs) in lung adenocarcinoma and explore their underlying mechanisms using bioinformatics. The miRNA expression in primary lung adenocarcinoma, matched adjacent non-tumorigenic and lymph node metastasis tissues of patients were profiled via microarray. The screened metastasis-related miRNAs were then validated using quantitative real-time PCR in a second cohort of lung adenocarcinoma patients with lymphatic metastasis. Significance was determined using a paired t-test. Target genes of the metastasis-related miRNAs were predicted using TargetScan, and transcription factors (TFs) were predicted based on the TRANSFAC and ENCODE databases. Furthermore, the related long non-coding RNAs (lncRNAs) were screened with starBase v2.0. The miRNA-TF-mRNA and lncRNA-miRNA-mRNA networks were constructed to determine the key interactions associated with lung adenocarcinoma metastasis. According to the miRNA microarray results, there were 10 miRNAs that were differentially expressed in metastatic tissues compared with primary tumor and adjacent non-tumorigenic tissues. Among them were increased levels of miR-146a-5p, miR-342-3p, and miR-150-5p, which were validated in the second cohort. Based on the miRNA-TF-mRNA network, vascular endothelial growth factor A and transcription factors (TFs) including TP53, SMAD4, and EP300 were recognized as critical targets of the three miRNAs. Interactions involving SNHG16-miR-146a-5p-SMAD4 and RP6-24A23.7-miR-342-3p/miR-150-5p-EP300 were highlighted according to the lncRNA-miRNA-mRNA network. miR-146a-5p, miR-342-3p, and miR-150-5p are lymphatic metastasis-related miRNAs in lung adenocarcinoma. Bioinformatics analyses demonstrated that SNHG16 might inhibit the interaction between miR-146a-5p and SMAD4, while RP6-24A23.7 might weaken miR-342-3p-EP300 and miR-150-5p-EP300 interactions in metastasis.

Clinicopathological characteristics and prognosis of non-lepidic invasive adenocarcinoma presenting as ground glass opacity nodule

BACKGROUND

Ground glass opacity (GGO) generally associated with the lepidic component of lung adenocarcinoma. However, in some cases, GGO nodules have been associated with invasive adenocarcinomas, where a lepidic component is minimal or absent. The purpose of this study is to evaluate the clinicopathological characteristics and prognosis of non-lepidic invasive adenocarcinoma presenting as GGO nodules.

METHODS

We reviewed computed tomography (CT) images from 168 patients diagnosed with non-lepidic invasive adenocarcinoma classified as stage T1N0M0 (≤3 cm) who underwent curative anatomical resection. Tumors were classified according to radiologic features: 31 were GGO predominant (Group A) and 137 were solid predominant (Group B). The clinicopathological findings and recurrence free survival were used as outcome measures.

RESULTS

The mean percentages of micropapillary and solid component in tumor was higher in Group B than Group A (P<0.001) Pleural invasion and lymphatic invasion were more frequently seen in Group B. The presence of tumors with a micropapillary component was higher in Group B (P=0.040). The 3-year recurrence-free survival was lower in Group B than Group A (80.4% vs. 100%, P=0.019). Risk factors for recurrence such as presence of a micropapillary component and lymphatic invasion were more frequently seen in Group B.

CONCLUSIONS

Non-lepidic invasive adenocarcinoma presenting as GGO has fewer risk factors and better prognosis when compared with those presenting as solid tumors. Therefore, the presence of GGO on chest CT is a good prognostic indicator for lung cancer irrespective of histomorphologic classification.

Micropapillary: A component more likely to harbour heterogeneous EGFR mutations in lung adenocarcinomas

The micropapillary (MP) subtype has recently been established to be a distinct marker of poor prognosis in lung adenocarcinomas (LACs). According to the 2015 WHO classification system, LAC constituents are required to be precisely reported. T790M mutation and an insertion in exon 20 (E20ins) are associated with EGFR-TKI resistance. A total of 211 LAC patients were involved in this study, and EGFR mutations were determined using an amplification refractory mutation system (ARMS). Sex, smoking history, lymph node status, and clinical stage differed significantly between the EGFR wild type and mutant groups (p < 0.05). The EGFR mutation occurred more frequently in female, non-smokers, ACs with papillary (85.7%) or MP components (91.4%) (p < 0.001). Twenty ACs with naïve T790M or E20ins were microdissected. The AC constituents metastasizing to lymph nodes exhibited a phenotype and EGFR status that was consistent with the primary loci constituents. Glomerulus-like solid components exhibited the same EGFR status as the surrounding T790M-mutated MP components. The MP and glomerulus-like portions in AC tumours exhibited a congenial EGFR status, but the acinar cells with papillary cells were heterogeneous. The naïve T790M mutants, although minor in the MP component, dramatically increased after EGFR-TKI therapy and indicate that the MP components feature intrinsic heterogeneity.

Clinicopathologic Factors Associated With Occult Lymph Node Metastasis in Patients With Clinically Diagnosed N0 Lung Adenocarcinoma

BACKGROUND

In some patients, clinical N0 (cN0) lung adenocarcinoma diagnosed by preoperative computed tomography scanning and positron emission tomography scanning was staged as pathologic N1 (pN1) or N2 (pN2) postoperatively. The aim of this study was to determine the preoperative and postoperative clinicopathologic factors related to nodal upstaging after a surgical operation.

METHODS

We conducted a retrospective chart review of 350 patients treated for cN0 lung adenocarcinoma by curative resection. We analyzed clinicopathologic findings, comparing pN0 patients with the nodal upstaging group.

RESULTS

Of 350 patients treated for cN0 tumors, 305 (87.1%) were confirmed postoperatively as having pN0 tumors, and 45 (12.9%) were confirmed as having pN1 or pN2 tumors. The mean maximum standardized uptake value (SUVmax) was higher in the nodal upstaging group than in the pN0 group (6.9 versus 3.8, p = 0.004); the upstaging group also included more cases in which SUVmax was greater than 5 (70.5% versus 24.8%, p < 0.001). Pleural invasion, lymphatic invasion, and vascular invasion were all more frequently seen in the nodal upstaging group than in the pN0 group (all p < 0.001). The presence of tumors with a micropapillary component was higher in the nodal upstaging group (p < 0.001). Multivariate logistic regression analysis identified SUVmax greater than 5, lymphatic invasion, vascular invasion, and a micropapillary component as significant risk factors for nodal upstaging.

CONCLUSIONS

In lung adenocarcinoma diagnosed as clinical N0 by chest computed tomography and positron emission tomography scanning, the possibility of occult lymph node metastasis increases with SUVmax greater than 5 and when lymphatic invasion, vascular invasion, and a micropapillary component are present.

Clinicopathologic correlates of postoperative N1 or N2 nodal upstaging in non-small cell lung cancer

BACKGROUND

Clinical and pathologic determinations of lymph node staging are critical in the treatment of lung cancer. However, up- or downstaging of nodal status frequently is necessitated by postsurgical findings. This study was conducted to evaluate clinicopathologic features that impact nodal upstaging in patients staged primarily via positron emission tomography/computed tomography (PET/CT) and chest CT prior to surgery.

METHODS

Between years 2011 and 2014, 634 patients underwent surgical treatment for non-small cell lung cancer (NSCLC) at our institution. Excluding 37 patients (given induction chemotherapy), 103 patients pathologically staged as N1 or N2 NSCLC. Nodal upstaging patients were classified into group A and non-upstaging patients into group B. We compared clinical characteristics and pathological results of group A with group B.

RESULTS

Ultimately, 59 patients (57.3%) were assigned to group A and 44 patients (42.7%) to group B. Patients in group A (vs. group B) were significantly younger (61.6 vs. 68.4 years; P<0.001) and more often were female (47.5% vs. 15.9%; P=0.001), with shorter smoking histories (12.2 vs. 28.8 pack years; P<0.001) and lower maximum standardized uptake values (SUVmax) (7.3 vs. 10.4; P=0.001). Most upstaged (group A) tumors (50/59, 84.7%) were adenocarcinomas, displaying micropapillary (MPC; n=36) and lepidic (n=35) component positivity with significantly greater frequency (both, P<0.001); and the frequency of epidermal growth factor receptor (EGFR) mutation (n=36) was significantly greater in this subset (P=0.001). Multivariate analysis (logistic regression) indicated a significant correlation between MPC positivity and nodal upstaging (P=0.013).

CONCLUSIONS

In patients upstaged postoperatively to N1 or N2 stage of NSCLC, occult lymph node metastasis and MPC positivity were significantly related.

Differing histopathology and prognosis in pulmonary adenocarcinoma at central and peripheral locations

BACKGROUND

Pulmonary adenocarcinoma is largely peripheral in location but often does occur centrally. In the course of this study, clinicopathologic features of pulmonary adenocarcinoma, including the prognosis of early-stage disease, were assessed and compared by tumor location.

METHODS

A retrospective chart review was conducted, examining 308 patients treated for pulmonary adenocarcinoma by curative resection. Clinicopathologic findings were analyzed, comparing central and peripheral primary locations. Recurrence-free survival (RFS) rates were determined for tumor subsets (central vs. peripheral).

RESULTS

At all disease stages (N=308), 41 patients (13.3%) with central adenocarcinoma were documented. In central (vs. peripheral) adenocarcinoma, mean tumor size was larger (3.1 vs. 2.3 cm, P=0.014), nodal metastasis was more frequent (P=0.012), and the likelihood of advanced disease (stages II and III) was greater (P=0.007). Microscopically, central adenocarcinoma displayed more acinar (53.3% vs. 38.9%; P=0.006) and less lepidic (20.9% vs. 37.5%; P=0.001) growth. At stage I disease [N=329; central, 25 (10.5%)], group similarities were sustained. As with disease overall, central adenocarcinoma contained more acinar (51.8% vs. 37.1%; P=0.025) and fewer lepidic (26.2% vs. 44.1%; P=0.006) areas. Three-year RFS rates for central and peripheral adenocarcinoma at all disease stages were 63.2% and 82.5% (P=0.024), respectively, compared with 70.4% and 91.0% (P=0.023), respectively at stage I. Lepidic growth was identified as a statistically significant risk factor for early recurrence by multivariate analysis.

CONCLUSIONS

Central pulmonary adenocarcinoma is generally detected at an advanced stage. In early (stage I) disease, the prognosis is comparatively worse for central adenocarcinoma, owing to significant micromorphologic differences in central and peripheral tumors.

The importance of the lepidic component as a prognostic factor in stage I pulmonary adenocarcinoma

Background

Stage I pulmonary adenocarcinoma (PA) can offer an unfavorable prognosis. The aim of this study was to classify the prognosis of stage I PA on the basis of the lepidic component and to confirm whether the lepidic component can be used as a criterion for predicting the prognosis of stage I PA.

Methods

We conducted a retrospective study of patients who underwent curative surgery for stage I and IIA PA. Stage I disease was divided into three groups on the basis of the lepidic component: group 1, ≤10 %; group 2, >10 to 50 %; and group 3, >50 %. We compared recurrence-free survival (RFS) rates among groups 1, 2, and 3, and stage IIA disease. We also evaluated risk factors for disease recurrence with multivariate analysis.

Results

A total of 224 patients were included in our study; most patients (n = 201) had stage I disease. Three-year RFS rates in group 1 (n = 73), group 2 (n = 75), and group 3 (n = 53) were 74.1, 90.4, and 90.0 %, respectively. There was a significant difference in RFS between group 1 and group 2 (p = 0.009). The 3-year RFS rate in stage IIA disease was 61.4 %. There were no significant differences in RFS between group 1 and stage IIA disease (p = 0.163). In multivariate analysis, group 1 had the highest risk of recurrence (HR 5.806, p = 0.006) in stage I PA.

Conclusions

Stage I PA with a lepidic component ≤10 % was associated with an unfavorable prognosis that was similar to the prognosis of stage IIA disease. The prognosis for stage I PA should not be based on general criteria, but instead, the lepidic component should be evaluated and considered when determining disease prognosis.

Clinical impacts of a micropapillary pattern in lung adenocarcinoma: a review

Lung adenocarcinoma with a micropapillary pattern (MPPAC) has recently drawn increased attention among researchers. Micropapillary-predominant adenocarcinoma (MPA), which is defined by micropapillary pattern (MPP), is the primary histological pattern observed semiquantitatively in 5% increments on resection specimens, and MPA was formally determined to be a new histological subtype according to the new multidisciplinary classification in 2011. According to published studies, MPPAC is most common in males and nonsmokers and is associated with lymphatic invasion, pleural invasion, and lymph node metastases. MPPAC often presents as part-solid and lobulated nodules in computed tomography scans. MPP tends to have a higher maximum standardized uptake value as determined by fluorodeoxyglucose positron emission tomography combined with computed tomography, indicating a high risk of recurrence. Molecular markers, including vimentin, napsin A, phosphorylated c-Met, cytoplasmic maspin, Notch-1, MUC1, and tumoral CD10, may have higher expression in MPPAC than other subtypes; conversely, markers such as MUC4 and surfactant apoprotein A have lower expression in MPPAC. MPPAC with EGFR mutations can benefit from treatment with EGFR tyrosine kinase inhibitors. Furthermore, a complete lobectomy may be more suitable than limited resection for MPPAC because of the low sensitivity of intraoperative frozen sections and the high risk of lymph node metastasis. MPA benefits more from adjuvant chemotherapy than do other histological subtypes, whereas MPA does not benefit from adjuvant radiotherapy. Of note, MPP is associated with poor prognosis in early-stage lung adenocarcinoma, but the prognostic value of MPP is controversial in advanced-stage lung adenocarcinoma.

[Advances of Pulmonary Adenocarcinoma with Micropapillary Pattern]

伴微乳头结构(micropapillary pattern, MPP)肺腺癌是一种临床少见的具有高度侵袭性的恶性肿瘤，近年来因其高死亡率被人们所重视。2011年关于肺腺癌的病理新分类将其作为一种独立的病理类型，此后针对该类肺癌个体化治疗的相关研究逐渐展开。近期的相关研究发现，伴MPP肺腺癌在转移机制、临床病理学、影像学、治疗及预后方面具有显著异质性。本文对伴MPP肺腺癌转移机制及相关临床研究进展进行探讨。

Classification of different patterns of pulmonary adenocarcinomas

The epidemic increase of adenocarcinoma histology accounting for more than 50% of primary lung malignancies and the advent of effective molecular targeted-therapies against specific gene alterations characterizing this tumor type have led to the reconsideration of the pathologic classification of lung cancer. The new 2015 WHO classification provided the basis for a multidisciplinary approach emphasizing the close correlation among clinical, radiologic and molecular characteristics and histopathologic pattern of lung adenocarcinoma. The terms 'bronchioloalveolar carcinoma' and 'mixed adenocarcinoma' have been eliminated, introducing the concepts of 'adenocarcinoma in situ', 'minimally invasive adenocarcinoma' and the use of descriptive predominant patterns in invasive adenocarcinomas (lepidic, acinar, papillary, solid and micropapillary patterns). 'Invasive mucinous adenocarcinoma' is the new definition for mucinous bronchioloalveolar carcinoma, and some variants of invasive adenocarcinoma have been included, namely colloid, enteric and fetal-type adenocarcinomas. A concise update of the immunomorphologic, radiological and molecular characteristics of the different histologic patterns of lung adenocarcinoma is reported here.

Prognostic value of the new IASLC/ATS/ERS classification of clinical stage IA lung adenocarcinoma

OBJECTIVES

We analyzed and validated the prognostic utility of the new International Association for the Study of Lung Cancer (IASLC)/American Thoracic Society (ATS)/European Respiratory Society (ERS) for clinical stage IA lung adenocarcinoma (ADC) classification of adenocarcinoma (ADC).

METHODS

We retrospectively reviewed 347 patients with clinical stage IA nonmucinous ADC, who had undergone complete resection. The histological subtype was classified according to the predominant subtype, as proposed by the new IASLC/ATS/ERS ADC classification.

RESULTS

The histopathological subtypes, defined according to the new IASLC/ATS/ERS ADC classification, were ADC in situ (AIS) in 56 patients (16.1%), minimally invasive ADC (MIA) in 15 (4.3%), lepidic-predominant ADC in 109 (31.4%), papillary-predominant ADC in 70 (20.2%), acinar-predominant ADC in 61 (17.6%), solid-predominant ADC in 30 (8.6%), and micropapillary-predominant ADC in 6 (1.7%). The 5-year disease-free survival (DFS) rate was 100% for both AIS and MIA. All cases of recurrence involved invasive ADC. The 5-year DFS for lepidic-predominant ADC was 99.0%; acinar-predominant ADC, 82.4%; papillary-predominant ADC, 80.8%; solid-predominant ADC, 73.6%; and micropapillary-predominant ADC, 33.3%. The predominant subtype of ADC was significantly correlated with DFS (P<0.0001). Multivariate analysis indicated that the pathological stage was an independent predictor of DFS (P=0.031). Other independent predictors of increased risk of recurrence were the presence of vascular or lymphatic invasion (HR=4.96, P=0.001), and a pathological stage more advanced than IB (HR=2.87, P=0.010). The coincidence between the clinical stage and pathological stage was 79.8%. The stage migration was found in 53.3% of solid-predominat ADC and in 83.3% of micropapillary-predominant ADC.

CONCLUSION

The new IASLC/ATS/ERS ADC classification has prognostic value in predicting the recurrence and survival of patients with clinical stage IA ADC. The frequency of stage migration was found in more than half of solid and micropapillary predominant ADCs.