Importance of Lymph Node Evaluation in ≤2-cm Pure-Solid Non-Small Cell Lung Cancer

BACKGROUND

The prevalence of lymph node (LN) metastasis in small-sized lung cancer varies depending on the tumor size and proportion of ground-glass opacity. We investigated occult LN metastasis and prognosis in patients with small-sized non-small cell lung cancer (NSCLC), mainly focusing on the pure-solid tumor.

METHODS

We retrospectively reviewed patients with ≤2-cm clinical N0 NSCLC who underwent lung resection with curative intent from 2003 to 2017. Among them we analyzed patients who also underwent adequate complete systematic LN dissection. Pathologic results and disease-free survival of the radiologically mixed ground-glass nodule (mGGN) and pure-solid nodule (PSN) groups were analyzed.

RESULTS

Of 1329 patients analyzed, 591 had mGGNs and PSNs. As tumor size increased, patients in the mGGN group showed no difference in LN metastasis: ≤1 cm, 2.27%; 1.0 to 1.5 cm, 2.19%; and 1.5 to 2.0 cm, 2.18% (P = .999). However the PSN group showed a significant difference in LN metastasis as the tumor size increased: ≤1 cm, 2.67%; 1.0 to 1.5 cm, 12.46%; and 1.5 to 2.0 cm, 21.31% (P < .001). In the multivariate analysis tumor size was a significant predictor of nodal metastasis in the PSN group but not in the mGGN group. In terms of 5-year disease-free survival, the mGGN group showed a better prognosis than the PSN group (94.4% vs 71.2%, P < .001).

CONCLUSIONS

We need to conduct a thorough LN dissection during surgery for small-sized NSCLC, especially for pure-solid tumors ≥ 1 cm.

The role of adenocarcinoma subtypes and immunohistochemistry in predicting lymph node metastasis in early invasive lung adenocarcinoma

BACKGROUND

Identifying lymph node metastasis areas during surgery for early invasive lung adenocarcinoma remains challenging. The aim of this study was to develop a nomogram mathematical model before the end of surgery for predicting lymph node metastasis in patients with early invasive lung adenocarcinoma.

METHODS

In this study, we included patients with invasive lung adenocarcinoma measuring ≤ 2 cm who underwent pulmonary resection with definite pathology at Qilu Hospital of Shandong University from January 2020 to January 2022. Preoperative biomarker results, clinical features, and computed tomography characteristics were collected. The enrolled patients were randomized into a training cohort and a validation cohort in a 7:3 ratio. The training cohort was used to construct the predictive model, while the validation cohort was used to test the model independently. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors. The prediction model and nomogram were established based on the independent risk factors. Recipient operating characteristic (ROC) curves were used to assess the discrimination ability of the model. Calibration capability was assessed using the Hosmer-Lemeshow test and calibration curves. The clinical utility of the nomogram was assessed using decision curve analysis (DCA).

RESULTS

The overall incidence of lymph node metastasis was 13.23% (61/461). Six indicators were finally determined to be independently associated with lymph node metastasis. These six indicators were: age (P < 0.001), serum amyloid (SA) (P = 0.008); carcinoma antigen 125 (CA125) (P = 0. 042); mucus composition (P = 0.003); novel aspartic proteinase of the pepsin family A (Napsin A) (P = 0.007); and cytokeratin 5/6 (CK5/6) (P = 0.042). The area under the ROC curve (AUC) was 0.843 (95% CI: 0.779-0.908) in the training cohort and 0.838 (95% CI: 0.748-0.927) in the validation cohort. the P-value of the Hosmer-Lemeshow test was 0.0613 in the training cohort and 0.8628 in the validation cohort. the bias of the training cohort corrected C-index was 0.8444 and the bias-corrected C-index for the validation cohort was 0.8375. demonstrating that the prediction model has good discriminative power and good calibration.

CONCLUSIONS

The column line graphs created showed excellent discrimination and calibration to predict lymph node status in patients with ≤ 2 cm invasive lung adenocarcinoma. In addition, the predictive model has predictive potential before the end of surgery and can inform clinical decision making.

A Shift in Paradigm: Selective Lymph Node Dissection for Minimizing Oversurgery in Early Stage Lung Cancer

Systematic lymph node dissection has been widely accepted and turned into a standard procedure for lung cancer surgery. In recent years, the concept of "minimal invasive surgery (MIS)" has greatly changed the surgical paradigm of lung cancer. Previous studies revealed that excessive dissection of lymph nodes without metastases had uncertain clinical benefit. Meanwhile, it leads to the elevated risk of postoperative complications including chylothorax and laryngeal nerve injury. In addition, dissection of nonmetastatic lymph nodes may disturb systematic immunity, resulting in the secondary effect on primary tumor or latent metastases. The past decades have witnessed the innovative strategies such as lobe-specific lymph node dissection and selective lymph node dissection. On the basis of evolution of lymph node dissection strategy, we discuss the negative effects of excessive nonmetastatic lymph node dissection and summarize the recent advances in the optimized dissection strategies, hoping to provide unique perspectives on the future directions.

Extent of Lymph Node Dissection in Patients with Small-Sized Peripheral Non-Small Cell Lung Cancer during Intentional Segmentectomy

PURPOSE

Segmentectomy and mediastinal lymph node dissection (MLND) are becoming standard procedures for small-sized (<2 cm) peripheral non-small cell lung cancer (NSCLC). Although the benefits of the less resected lung are proven, the extent of lymph node dissection remains unchanged.

METHODS

We studied 422 patients who underwent lobectomy with MLND (lobe specific or systemic) for small peripheral NSCLC with clinical N0 disease. Patients with middle lobectomy (n = 39) and a consolidation-to-tumor (C/T) ratio ≤0.50 (n = 33) were excluded. We investigated the clinical factors, lymph node metastasis distributions, and lymph node recurrence patterns of 350 patients.

RESULTS

Thirty-five (10.0%) patients had lymph node metastasis; none with C/T ratio <0.75 had lymph node metastasis and lymph node recurrence. None had solitary lymph node metastasis in the outside lobe-specific MLND. Six patients had mediastinal lymph node metastasis at the initial site of recurrence; none had mediastinal lymph node recurrence outside the lobe-specific MLND, except for two patients with S6 primary disease.

CONCLUSION

NSCLC patients with small peripheral tumors and a C/T ratio <0.75 during segmentectomy may not require MLND. The optimal MLND for patients with a C/T ratio ≥0.75, except for those with S6 primary, may be lobe-specific MLND.

Growth characteristics of early-stage (IA) lung adenocarcinoma and its value in predicting lymph node metastasis

BACKGROUND

We aim to compare the differences in growth characteristics between part-solid and solid lung adenocarcinoma, and to investigate the value of volume doubling time (VDT) or mass doubling time (MDT) in predicting lymph node (LN) metastasis and preoperative evaluation in patients of early-stage (IA) non-small cell lung cancer (NSCLC).

METHOD

We reviewed 8,653 cases of surgically resected stage IA lung adenocarcinoma between 2018 and 2022, with two follow-up visits at least 3 months apart, comparing diameter, volume, and mass growth of pSN and SN. VDT and MDT calculations for nodules with a volume change of at least 25%. Univariable or multivariable analysis was used to identify the risk factors. The area under the curve (AUC) for the receiver operating characteristic (ROC) curves was used to evaluate the diagnostic value.

RESULTS

A total of 144 patients were included 114 with solid nodules (SN) and 25 with part-solid nodules (pSN). During the follow-up period, the mean VDTt and MDTt of SN were shorter than those of pSN, 337 vs. 541 days (p = 0.005), 298 vs. 458 days (p = 0.018), respectively. Without considering the ground-glass component, the mean VDTc and MDTc of SN were shorter than the solid component of pSN, 337 vs. 498 days (p = 0.004) and 298 vs. 453 days (p = 0.003), respectively. 27 nodules were clinically and pathologically diagnosed as N1/N2. Logistic regression identified initial diameter (p < 0.001), consolidation increase (p = 0.019), volume increase (p = 0.020), mass increase (p = 0.021), VDTt (p = 0.002), and MDTt (p = 0.004) were independent factors for LN metastasis. The ROC curves showed that the AUC for VDTt was 0.860 (95% CI, 0.778-0.943; p < 0.001) and for MDTt was 0.848 (95% CI, 0.759-0.936; p < 0.001).

CONCLUSIONS

Our study showed significant differences in the growth characteristics of pSN and SN, and the application of VDT and MDT could be a valid predictor LN metastasis in patients with early-stage NSCLC.

N1 lymph node detection in lymph node harvesting in non-small cell lung cancer: Formaldehyde exposure is a drawback?

OBJECTIVE

This study aimed to evaluate the effect of lymph node dissection method on staging results, diagnosis of tumor metastasis in single or multiple N1 lymph nodes and survival rates in patients with non-small cell lung cancer (NSCLC).

METHODS

Patients with NSCLC who underwent anatomic resection between September 2014 and October 2019 were examined prospectively. All patients with similar clinico-demographic characteristics were randomly assigned to either the surgical group (n = 83) or the pathology group (n = 87). Lymph node dissection was performed by the surgeon in the surgical group and by the pathologists after formaldehyde exposure in the pathology group. Data were analyzed according to formaldehyde exposure, N1 positivity, and number of N1 positive lymph nodes.

RESULTS

There were no significant differences in N1 lymph node positivity between the two groups (p = 0.482). On average 9.08 lymph node sampling was performed in the surgical group and 2.39 in the pathology group (p = 0.0001). Multiple lymph node involvement was significantly higher in the surgical group (P = 0.0001) than in the pathology group.

CONCLUSION

It is easier to detect lymph node involvement without introducing formaldehyde into the sample. We recommend that N1 lymph node dissection be performed on fresh specimens to detect more lymph node involvement.

Selective Mediastinal Lymph Node Dissection Strategy for Clinical T1N0 Invasive Lung Cancer: A Prospective, Multicenter, Clinical Trial

INTRODUCTION

We aimed to prospectively evaluate our previously proposed selective mediastinal lymph node (LN) dissection strategy for peripheral clinical T1N0 invasive NSCLC.

METHODS

This is a multicenter, prospective clinical trial in China. We set six criteria for predicting negative LN stations and finally guiding selective LN dissection. Consolidation tumor ratio less than or equal to 0.5, segment location, lepidic-predominant adenocarcinoma (LPA), negative hilar nodes (stations 10-12), and negative visceral pleural invasion (VPI) were used separately or in combination as predictors of negative LN status in the whole, superior, or inferior mediastinal zone. LPA, hilar node involvement, and VPI were diagnosed intraoperatively. All patients actually underwent systematic mediastinal LN dissection. The primary end point was the accuracy of the strategy in predicting LN involvement. If LN metastasis occurred in certain mediastinal zone that was predicted to be negative, it was considered as an "inaccurate" case.

RESULTS

A total of 720 patients were enrolled. The median number of LN dissected was 15 (interquartile range: 11-20). All negative node status in certain mediastinal zone was correctly predicted by the strategy. Compared with final pathologic findings, the accuracy of frozen section to diagnose LPA, VPI, and hilar node metastasis was 94.0%, 98.9%, and 99.6%, respectively. Inaccurate intraoperative diagnosis of LPA, VPI, or hilar node metastasis did not lead to inaccurate prediction of node-negative status.

CONCLUSIONS

This is the first prospective trial validating the specific mediastinal LN metastasis pattern in cT1N0 invasive NSCLC, which provides important evidence for clinical applications of selective LN dissection strategy.

Risk profiles and a concise prediction model for lymph node metastasis in patients with lung adenocarcinoma

BACKGROUND

Lung cancer is the second most commonly diagnosed cancer and ranks the first in mortality. Pathological lymph node status(pN) of lung cancer affects the treatment strategy after surgery while systematic lymph node dissection(SLND) is always unsatisfied.

METHODS

We reviewed the clinicopathological features of 2,696 patients with LUAD and one single lesion ≤ 5 cm who underwent SLND in addition to lung resection at the Sun Yat-Sen University Cancer Center. The relationship between the pN status and all other clinicopathological features was assessed. All participants were stochastically divided into development and validation cohorts; the former was used to establish a logistic regression model based on selected factors from stepwise backward algorithm to predict pN status. C-statistics, accuracy, sensitivity, and specificity were calculated for both cohorts to test the model performance.

RESULTS

Nerve tract infiltration (NTI), visceral pleural infiltration (PI), lymphovascular infiltration (LVI), right upper lobe (RUL), low differentiated component, tumor size, micropapillary component, lepidic component, and micropapillary predominance were included in the final model. Model performance in the development and validation cohorts was as follows: 0.861 (95% CI: 0.842-0.883) and 0.840 (95% CI: 0.804-0.876) for the C-statistics and 0.803 (95% CI: 0.784-0.821) and 0.785 (95% CI: 0.755-0.814) for accuracy, and 0.754 (95% CI: 0.706-0.798) and 0.686 (95% CI: 0.607-0.757) for sensitivity and 0.814 (95% CI: 0.794-0.833) and 0.811 (95% CI: 0.778-0.841) for specificity, respectively.

CONCLUSION

Our study showed an easy and credible tool with good performance in predicting pN in patients with LUAD with a single tumor ≤ 5.0 cm without SLND and it is valuable to adjust the treatment strategy.

Pathologic node-negative lung cancer: Adequacy of lymph node yield and a tool to assess the risk of occult nodal disease

INTRODUCTION

Accurate lymph node (LN) staging is crucial for prognostication in NSCLC. Diagnosis of pN0 disease is based on the absence of positive LNs, irrespective of the number of LNs excised, and is thus susceptible to sampling error. Tumors that are assumed to be pN0 may in fact be understaged. We developed a tool to quantify the risk of occult nodal disease (OND) among patients with pN0 NSCLC in terms of the number of LNs examined.

METHODS

Patients treated surgically for stage I-III primary NSCLC between 2004 and 2014 (n = 49,356) were extracted from the Surveillance, Epidemiology, and End Results database. The probability of missing a positive node in terms of the number of LNs examined was modeled using a beta-binomial model. A mathematical tool was then used to calculate the negative predictive value (NPV) corresponding to the number of LNs examined. Ranging from 0 to 100%, higher NPV reflects greater confidence in the pN0 diagnosis and a lower probability of OND.

RESULTS

The median number of LNs examined was 7 for N0, 10 for N1/N2, and 8 for N3 disease. The probability of missing a positive node decreased as LNs examined increased. Additionally, higher T stage required more LNs to confirm an N0 diagnosis. After accounting for false-negative diagnoses, the prevalence of node-positive disease was readjusted from 16% to 22% among patients with T1 disease. According to our tool, with 10 LNs examined, the NPV was 85% (15% probability of OND) for a patient with T3 disease, compared with 95% (5% probability of OND) for a patient with T1 disease.

CONCLUSIONS

Accurate pN0 diagnosis depends on the number of LNs examined. The proposed tool offers the ability to quantify, in a patient-specific manner, the confidence in a diagnosis of node-negative disease on the basis of the number of LNs examined.

Fusion of CT images and clinical variables based on deep learning for predicting invasiveness risk of stage I lung adenocarcinoma

PURPOSE

To develop a novel multimodal data fusion model by incorporating computed tomography (CT) images and clinical variables based on deep learning for predicting the invasiveness risk of stage I lung adenocarcinoma that manifests as ground-glass nodules (GGNs), and compare the diagnostic performance of it with that of radiologists.

METHODS

A total of 1946 patients with solitary and histopathologically confirmed GGNs with maximum diameter less than 3 cm were retrospectively enrolled. The training dataset containing 1704 GGNs was augmented by resampling, scaling, random cropping, etc., to generate new training data. A multimodal data fusion model based on residual learning architecture and two multilayer perceptron with attention mechanism combining CT images with patient general data and serum tumor markers was built. The distance-based confidence scores (DCS) were calculated and compared among multimodal data models with different combinations. An observer study was conducted and the prediction performance of the fusion algorithms was compared with that of the two radiologists by an independent testing dataset with 242 GGNs.

RESULTS

Among the whole GGNs, 606 GGNs are confirmed as invasive adenocarcinoma (IA) and 1340 are non-IA. The proposed novel multimodal data fusion model combining CT images, patient general data and serum tumor markers achieved the highest accuracy (88.5%), Area under a ROC curve (AUC) (0.957), F1 (81.5%), F1_weighted (81.9%) and Matthews correlation coefficient (MCC) (73.2%) for classifying between IA and non-IA GGNs, which was even better than the senior radiologist's performance (accuracy, 86.1%). In addition, the DCSs for multimodal data suggested that CT image had a stronger influence (0.9540) quantitatively than general data (0.6726) or tumor marker (0.6971).

CONCLUSION

This study demonstrated that the feasibility of integrating different types of data including CT images and clinical variables, and the multimodal data fusion model yielded higher performance for distinguishing IA from non-IA GGNs. This article is protected by copyright. All rights reserved.

Reclassifying the International Association for the Study of Lung Cancer Residual Tumor Classification According to the Extent of Nodal Dissection for NSCLC: One Size Does Not Fit All

INTRODUCTION

The extent of nodal assessment may require risk-based adjustments in NSCLC. We reclassified the International Association for the Study of Lung Cancer Residual tumor classification according to the extent of nodal dissection and evaluated its long-term prognosis by tumor stage and histologic subtype.

METHODS

We reclassified 5117 patients who underwent resection for clinical stages I to III NSCLC and had complete or uncertain resection by International Association for the Study of Lung Cancer classification into the following 3 groups according to compliance with three components (N1, N2, and subcarinal node) of systematic nodal dissection criteria: fully compliant group (FCG), partially compliant group (PCG), and noncompliant group (NCG). Recurrence-free survival (RFS) and overall survival (OS) were compared.

RESULTS

Of the 5117 patients, 2806 (55%), 1959 (38%), and 359 (7%) were FCG, PCG, and NCG, respectively. PCG and NCG were more likely to be of lower clinical stage and adenocarcinoma with lepidic component than FCG. The 5-year RFS and OS were significantly better in NCG than in FCG or PCG (RFS, 86% versus 70% or 74%, p < 0.001; OS, 90% versus 80% or 83%, p < 0.001). In particular, NCG had better RFS and OS than FCG or PCG in clinical stage I and in lepidic-type adenocarcinoma.

CONCLUSIONS

In early stage NSCLC with low-risk histologic subtype, a less rigorous nodal assessment was not associated with a worse prognosis. Although surgeons should continue to aim for complete resection and thorough nodal assessment, a uniform approach to the extent and invasiveness of nodal assessment may need to be reconsidered.

Detection and treatment of lung adenocarcinoma at pre-/minimally invasive stage: is it lead-time bias?

OBJECTIVES

This study investigates whether lead-time bias contributes to the excellent survival of AIS and MIA.

METHODS

We enrolled patients with resected adenocarcinoma from 2008 to 2012. Age, sex, smoke history, surgical approach, radiological features, invasive stage and postoperative follow-up data were documented. 1:1 PSM was performed to balance the influence of sex and smoking status on survival. After matching, the average age of the two groups was compared to calculate the lead time of diagnosis. The gain in life years for adenocarcinoma diagnosed at pre-/minimally invasive stage was estimated by subtracting the "lead time" and "median survival year of IAC" from "the life expectancy of AIS/MIA patients" referring to the Centre for Health and Information.

RESULTS

There were 124 AIS/MIA patients and 1148 IAC patients. The frequency of female and never-smoking patients in AIS/MIA group was much higher than that in IAC group. PSM analysis identified 124 patient pairs. No cancer-related death and recurrence were observed among AIS/MIA patients 5 years after surgery. For IAC patients, the 5-year disease-specific survival rate was 73.5% and the median survival is 13.5 years. The average age of AIS/MIA group and IAC group are 53.6 years and 58.2 years, respectively. The lead time between diagnosis of AIS/MIA and IAC is 4.6 years. Referring to the Centre for Health and Information, the life expectancy of patients with AIS/MIA diagnosed at 53.6 years old is 28.9 years. With adjustment for the lead time, the gain in life years for adenocarcinoma diagnosed at pre-/minimally invasive stage is 10.8 years.

CONCLUSIONS

With adjustment for the lead time between diagnosis of AIS/MIA and IAC, resecting lung adenocarcinoma at pre-/minimally invasive stage can improve life expectancy. The excellent survival of AIS/MIA is not lead-time bias.

Pre-surgical assessment of mediastinal lymph node metastases in patients having ≥ 30 mm non-small-cell lung cancers

INTRODUCTION

Computed tomography (CT) and fluorodeoxyglucose-positron-emission-tomography (FDG-PET) measurements of mediastinal lymph nodes (MLNs) of patients with non-small-cell-lung-cancers (NSCLCs) ≤ 30 mm in maximum diameter are recommended for pre-surgical prediction of MLN metastases.

METHODS

We reviewed all patients at Mount Sinai Health System enrolled in the Initiative for Early Lung Cancer Research on Treatment (IELCART), prospective cohort between 2016 and 2020, who had pre-surgical FDG-PET and underwent surgery with MLN resection and/or pre-operative endobronchial ultrasound (EBUS) for a first primary NSCLC ≤ 30 mm in maximum diameter on pre-surgical CT.

RESULTS

Among 470 patients, none with part-solid (n = 63) or nonsolid (n = 23) NSCLCs had MLN metastases. Solid NSCLCs were identified in 384 patients, none in typical carcinoid (n = 48) or NSCLC ≤ 10 mm in maximum diameter (n = 47, including 8 typical carcinoids) had MLN metastases. Among the remaining 297 patients with solid NSCLCs 10.1-30.0 mm, 7 (2.4%) had MLN metastases. Area-under-the-curve (AUC) for predicting MLN metastases in solid NSCLCs 10.1-30.0 mm, using the CT maximum short-axis MLN diameter was 0.62 (95% CI:0.44-0.81, p = 0.18) and using the highest SUVmax of any MLN, AUC was 0.58 (95% CI:0.39-0.78,p = 0.41). Neither AUCs were significantly different from chance alone. Optimal cutoff for prediction of MLN metastases was ≥ 18.9 mm for CT maximum short-axis diameter [sensitivity 14.3% (95%CI:0.0%-57.9%); specificity 100.0% (95%CI:98.9%-100.0%)] and for highest SUVmax was ≥ 11.7 [sensitivity 14.3% (95%CI:0.0%-57.9%) and specificity 99.7% (95%CI:98.3%-100.0%)].

CONCLUSIONS

CT and SUVmax had low sensitivity but high specificity for predicting MLN metastases in solid NSCLCs 10.1-30.0 mm. Clinical Stage IA NSCLCs ≤ 30 mm should be based on CT maximum tumor diameter and MLN maximum short-axis diameter ≤ 20 mm.

Mandatory Nodal Evaluation During Resection of Clinical T1a Non-Small-Cell Lung Cancers

BACKGROUND

Recommendations for intraoperative lymph node evaluation are uniform regardless of whether a primary tumor is clinical T1a or T2a according to TNM 8^th edition for Stage I Non-Small-Cell lung cancers (NSCLC). We quantified nodal disease risk in patients with T1a disease (≤1cm).

METHODS

The National Cancer Database was queried for clinical T1aN0M0 primary NSCLCs ≤1cm undergoing lobectomy with mediastinal nodal evaluation from 2004-2014. Nodal disease risk was analyzed as a function of demographics and tumor characteristics.

RESULTS

Among 2,157 cases, 6.7% had occult nodal disease: 5.1% occult N1 and 1.6% N2. Adenocarcinoma (7.5%), large cell carcinoma (25%), and poor differentiation (11.8%) or undifferentiated/anaplastic (25.0%) had high rates of combined pN1 and N2 disease (p<0.001). In univariable analysis, odds of pathologic N1, N2, or N1/N2 nodal disease with respect to N0 was greatest for large cell carcinoma (ref. adenocarcinoma Odds Ratio (OR): 4.31, 3.62, 4.12 respectively; all p<0.05), and anaplastic grade (OR: 10.71, 13.09, 11.55). Bronchoalveolar adenocarcinomas had the lowest odds (OR 0.41, 0.11, 0.32) and squamous cell carcinoma had lower odds for N2 (OR 0.29, all p<0.05). In multivariable analysisonly bronchoalveolar adenocarcinomas had lower odds of pathologic N2 and N1/N2 disease with respect to N0. Worsening grade remained significant for pathologic N1 and N1/N2 disease (both p<0.05).

CONCLUSIONS

A significant rate (6.7%) of occult nodal disease is present in primary NSCLCs ≤1cm. Risk increases with certain histology and worsening grade. We recommend mandatory systematic hilar and mediastinal nodal evaluation for T1a NSCLC tumors for accurate staging and adjuvant therapy.

Appropriate Extent of Lymphadenectomy in Segmentectomy: A Multicenter Study

BACKGROUND

The significance of lymphadenectomy is yet to be fully examined in segmentectomy. We compared the oncological outcomes of mediastinal lymph node dissection (LND) and hilar LND for lung cancer treated with segmentectomy via a multicenter database using propensity score-matched analysis.

METHODS

We reviewed 357 clinical stage IA radiologically solid-dominant lung cancer patients who underwent segmentectomy with lymphadenectomy. The extent of LND was classified into systematic/lobe-specific mediastinal LND and hilar LND only groups. Postoperative results after segmentectomy with mediastinal LND (n = 179) and hilar LND (n = 178) were analyzed for all patients and their propensity score-matched pairs.

RESULTS

Cancer-specific survival (CSS) and recurrence-free interval (RFI) rates for the mediastinal LND group were determined to be not significantly different compared with the hilar LND group in all non-adjusted cohorts. In the propensity score-matched cohort (129 pairs), mediastinal LND harvested more lymph nodes compared with hilar LND, and both groups had significantly different pathological stages (P = 0.015). Adjuvant chemotherapy was performed in 10 (7.8%) patients in the mediastinal LND group and 4 (3.1%) in the hilar LND group. The mediastinal LND group tended to have better prognosis than the hilar LND group (5-year CSS rates, 97.4% vs 93.2%; 5-year RFI rates, 93.5% vs 88.5%).

CONCLUSIONS

Mediastinal LND was found to provide more appropriate pathological staging compared with hilar LND in patients with segmentectomy by harvesting more lymph nodes. In addition, mediastinal LND might lead to better oncological outcome than hilar LND in segmentectomy.

Adjuvant treatment can improve prognosis in patients with non-small cell lung cancer ≤3 cm after sublobectomy: a propensity score analysis

Background

Numerous retrospective studies have reported that sublobectomy has a poorer prognosis than lobectomy in patients with early-stage lung cancer. The purpose of this study was to determine whether adjuvant treatment could improve the prognosis of patients with non-small cell lung cancer (NSCLC) ≤3 cm after sublobectomy.

Methods

We collected data from 17,763 patients with T1N0M0 NSCLC after surgery from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015. Kaplan-Meier curves were generated to compare the overall survival (OS) rates and the lung cancer-specific survival (LCSS) rates. Cox proportional hazards regressions were performed to discover the independent risk factors for both the OS and LCSS rates.

Results

Lobectomy was performed in 12,428 cases and sublobectomy was performed in 5,335 cases. In the sublobectomy group, among the 394 patients treated with adjuvant therapy, larger tumor diameter, a lower number of lymph node dissections, and more wedge resections were observed in the patients treated with adjuvant therapy. In the subsequent survival analysis, the OS and LCSS rates of adjuvant therapy patients showed a significant survival advantage over those treated with sublobectomy alone (P<0.05). The survival analysis was performed again after propensity match scoring, generating similar results (P<0.05). There was still a significant difference in OS between adjuvant therapy and lobectomy alone (P<0.05).

Conclusions

Chemoradiotherapy can improve the OS of patients with NSCLC ≤3 cm after sublobectomy and reduce death caused by tumors. Therefore, when patients cannot tolerate lobectomy or are given inappropriate sublobectomy, adjuvant therapy can improve the prognosis of patients.

Excellent Prognosis of Patients With Invasive Lung Adenocarcinomas During Surgery Misdiagnosed as Atypical Adenomatous Hyperplasia, Adenocarcinoma In Situ, or Minimally Invasive Adenocarcinoma by Frozen Section

BACKGROUND

Our previous study revealed that intraoperative frozen section (FS) analysis could differentiate invasive lung adenocarcinoma (LUAD) accurately from preinvasive lesions. However, few articles have analyzed the clinical impact of FS errors such as underestimation of invasive adenocarcinomas (IACs), and whether complementary therapy is needed remains controversial.

RESEARCH QUESTION

What is the prognosis of patients undergoing limited resection for invasive LUAD misdiagnosed as atypical adenomatous hyperplasia (AAH), adenocarcinoma in situ (AIS), or minimally invasive adenocarcinoma (MIA) by intraoperative FS analysis?

STUDY DESIGN AND METHODS

From 2012 through 2018, data on 3031 patients undergoing sublobar resection of AAH, AIS, or MIA diagnosed by FS analysis were collected. The concordance rate between FS analysis and final pathologic results was evaluated. To assess the clinical significance of a discrepancy between FS and final pathologic results, patients with final pathologic results of IAC were identified for prognostic evaluation.

RESULTS

When AAH, AIS, and MIA were classified together as a group, the overall concordance rate between FS and final pathologic results was 93.7%, and 192 patients (6.3%) received an upgraded diagnosis from the final pathologic results. Misdiagnosed IACs consisted of 94 patients (48.9%) with lepidic-predominant adenocarcinoma, 77 patients (40.1%) with acinar predominant adenocarcinoma, 19 patients (9.9%) with papillary predominant adenocarcinoma, one patient with solid predominant adenocarcinoma, and one patient with invasive mucinous adenocarcinoma. Among these patients, no positive N1 or N2 lymph node findings were observed. Moreover, the 5-year recurrence-free survival was still 100%, although the final pathologic results turned out to be IAC.

INTERPRETATION

Patients undergoing limited resection of invasive LUAD misdiagnosed as AAH, AIS, or MIA by FS analysis showed excellent prognoses. Sublobar resection guided by FS diagnosis would be adequate for these underestimated cases of invasive LUAD.

Impact of histological components on selecting limited lymphadenectomy for lung adenocarcinoma ≤ 2 cm

OBJECTIVES

There is still some dispute regarding the performance of limited mediastinal lymphadenectomy (LML) even for lung adenocarcinoma ≤ 2 cm. We aimed to recognize the potential candidates who can benefit from LML based on the percentage of histological components (PHC).

METHODS

We analyzed 1160 surgical patients with invasive lung adenocarcinoma ≤ 2 cm from seven institutions between January 2012 and December 2015. All histological subtypes were listed in 5% increments by pathological slices. To test the accuracy of frozen section in judging PHC, frozen section slides from 140 cases were reviewed by three pathologists.

RESULTS

There were 882 patients with systematic mediastinal lymphadenectomy (SML) and 278 with LML. Multivariable analysis indicated that, the total percentage of micropapillary and solid components (PHC_MIP+S) > 5 % was the independent predictor of N2 metastasis (P < 0.001). Overall, recurrence-free survival (RFS) and overall survival (OS) favored SML compared with LML, but the subgroup analysis revealed LML and SML had similar prognosis in the group of PHC_MIP+S ≤ 5 %. Moreover, multivariable Cox analysis showed LML (vs. SML) was independently associated with worse prognosis for patients with PHC_MIP+S > 5 % (RFS, HR = 2.143, P < 0.001; OS, HR=1.963, P < 0.001), but not for those with PHC_MIP+S ≤ 5 % (RFS, P = 0.398; OS, P = 0.298). The sensitivity and specificity of frozen section to intraoperatively identify PHC_MIP+S ≤ 5 % were 97.6 % and 84.2 %, respectively.

CONCLUSIONS

PHC_MIP+S showed the predictive value for N2 metastasis and procedure-specific outcome (LML vs. SML). It may serve as a feasible indicator for identifying proper candidates of LML by using intraoperative frozen section.

Tumor volume is more reliable to predict nodal metastasis in non-small cell lung cancer of 3.0 cm or less in the greatest tumor diameter

Background

In this study, we sought to evaluate the correlation between TV, GTD, and lymph node metastases in NSCLC patients with tumors of GTD ≤ 3.0 cm.

Methods

We retrospectively analyzed the characteristics of clinicopathologic variables for lymph node involvement in 285 NSCLC patients with tumors of GTD ≤ 3.0 cm who accepted curative surgical resection. The TVs were semi-automatically measured by a software, and optimal cutoff points were obtained using the X-tile software. The relationship between GTD and TV were described using non-linear regression. The correlation between GTD, TV, and N stages was analyzed using the Pearson correlation coefficient. The one-way ANOVA was used to compare the GTD and TV of different lymph node stage groups.

Results

The relationship between GTD and TV accorded with the exponential growth model: y = 0.113e^1.455x (y = TV, x = GTD). TV for patients with node metastases (4.78 cm³) was significantly greater than those without metastases (3.57 cm³) (P < 0.001). However, there were no obvious GTD differences in cases with or without lymph node metastases (P = 0.054). We divided all cases into three TV groups using the two cutoff values (0.9 cm³ and 3.9 cm³), and there was an obvious difference in the lymphatic involvement rate between the groups (P < 0.001). The tendency to metastasize was greater with higher TV especially when the TV was > 0.9–14.2 cm³ (P = 0.010).

Conclusions

For NSCLC tumors with GTD ≤ 3.0 cm, TV is a more sensitive marker than GTD in predicting the positive lymph node metastases. The likelihood for metastasis increases with an increasing TV especially when GTD is > 2.0–3.0 cm.

Pre-surgical assessment of mediastinal lymph node metastases in Stage IA non-small-cell lung cancers

OBJECTIVE

Evaluation of sensitivity and specificity of CT and fluorodeoxyglucose-positron emission tomography for pre-surgical staging of mediastinal lymph node metastases (N2/N3) of non-small-cell-lung-cancers ≤30 mm.

METHODS

We reviewed a total of 263 patients from a prospective cohort study, who underwent resection including mediastinal lymph nodes, for first primary non-small-cell-lung-cancer ≤30 mm in maximum diameter on pre-surgical CT. Cutoff criteria for short-axis diameter on CT of the largest N2/N3 node of 10, 15, and 20 mm and positron emission uptake of 2.5, 3.0, and 4.0 were evaluated using Area-Under-the-Curve (AUC) assessment. Accuracy criterion was used to determine the optimal cutoffs.

RESULTS

Of 263 patients, 9 had nonsolid, 42 part-solid, and 212 solid non-small-cell-lung-cancers. Post-surgically, none of the 51 patients with nonsolid or part-solid cancers had mediastinal lymph node metastases. Among the 212 patients with solid cancers, 23 had N2 node metastases. For the 212 patients with solid cancers, the AUC for CT lymph node measurements was 0.67 (95% CI: 0.57-0.77), significantly higher (p = 0.001) than chance alone, while the AUC for SUVmax measurements, 0.56 (95% CI: 0.48-0.65), was not (p = 0.13). Optimal CT cutoff was >20 mm had low sensitivity of 30.4% (95% CI: 11.6%-49.2%) but high specificity of 99.5% (95% CI: 98.4%-100.0%).

CONCLUSION

Based on these results, clinical Stage IA for non-small-cell-lung-cancers with nonsolid, part-solid, or solid consistency should be based on pre-surgical CT maximum tumor diameter and lymph node short-axis measurements on CT ≤20 mm. Further prospective evaluation of these clinical Stage IA staging criteria is needed.

Age-different extent of resection for clinical IA non-small cell lung cancer: analysis of nodal metastasis

Whether age has any impact on the risk of lymph node (LN) metastasis in patients with early-stage non-small cell lung cancer (NSCLC) remains controversial. Therefore, we aimed to objectively compare the risk of LN metastasis between elderly and young patients so as to justify for age-different extent of surgical resection for treating these patients. We retrospectively collected clinical data of patients undergoing lobectomy or segmentectomy with systematic hilar and mediastinal LN dissection for clinical stage IA peripheral NSCLC from January 2015 to December 2018. Both multivariate logistic regression analysis and propensity score-matched (PSM) analysis were applied to compare the risk of LN metastasis between elderly (>65 years old) and young (≤65 years old) patients. We finally included a total of 590 patients for analysis (142 elderly patients and 448 young patients). In the analysis of unmatched cohorts, young patients tended to have higher rates of hilar/intrapulmonary LN (13.4% VS 9.2%) and mediastinal LN metastasis (10.5% VS 6.3%) than elderly patients. In the multivariate analysis, age was found to be an independent predictor of both hilar/intrapulmonary (Odds ratio(OR) = 2.065, 95%confidence interval(CI): 1.049–4.064, P = 0.036) and mediastinal (OR = 2.400, 95%CI: 1.083–5.316, P = 0.031) LN metastasis. Moreover, in the analysis of well-matched cohorts generated by PSM analysis, young patients had significantly higher rates of hilar/intrapulmonary (18.8% VS 9.4%, P = 0.039) and mediastinal LN metastasis (17.1% VS 6.0%, P = 0.008) than elderly patients. Therefore, age remains to be an independent predictor of LN metastasis in early-stage NSCLC and age-different extent of surgical resection may be justified for these patients.

Management of Ground-Glass Opacities in the Lung Cancer Spectrum

BACKGROUND

Along with the popularity of low-dose computed tomography lung cancer screening, an increasing number of lung ground-glass opacity (GGO) lesions are detected. This review focuses on lung adenocarcinoma manifesting as GGO.

METHODS

We performed a literature search of the PubMed/MEDLINE database to identify articles reporting GGO. The following terms were used: GGO, ground-glass opacity, GGN, ground-glass nodule, part-solid nodule, and subsolid nodule.

RESULTS

GGO is a nonspecific radiologic finding showing a hazy opacity without blocking underlying pulmonary vessels or bronchial structures. The pathology of GGO can be benign, preinvasive, or invasive adenocarcinoma. Although radiographic features may indicate malignancy, a short period of follow-up is the optimal method to distinguish between benign and malignant GGO lesions. Pathologically, not only lepidic, but also nonlepidic growth patterns can present as GGO. Lung adenocarcinoma with a GGO component is associated with excellent survival compared with solid lesions. Moreover, there are distinct prognostic factors in patients with lung adenocarcinoma manifesting as GGO or solid lesions. For selected GGO-featured lung adenocarcinoma, sublobar resection with selective or no mediastinal lymph node dissection may be sufficient. Intraoperative frozen section is an effective method to guide resection strategy. A less intensive postoperative surveillance strategy may be more appropriate given the excellent survival. Management of multiple GGO lesions requires comprehensive considerations of GGO characteristics and patient conditions.

CONCLUSIONS

Lung adenocarcinoma manifesting as GGO defines a special clinical subtype with excellent prognosis. The management of GGO-featured lung adenocarcinoma should be distinct from that of solid lesions.

Segment Location and Ground Glass Opacity Ratio Reliably Predict Node-Negative Status in Lung Cancer

BACKGROUND

Although selective mediastinal lymph node dissection based on lobe-specific nodal metastasis has been proposed for non-small cell lung cancer, controversy remains over its validity. We hypothesized that different segments within the same lobe might have different patterns of lymph node metastasis.

METHODS

Data on 2749 invasive non-small cell lung cancer patients who underwent pulmonary resection with systematic lymph node dissection from April 2008 to December 2015 were retrospectively analyzed. The segment location and consolidation tumor ratio were identified using preoperative computed tomography scans.

RESULTS

None of the 151 tumors with consolidation tumor ratio ≤ 0.5 had lymph node involvement. None of the 333 tumors located in apical segments had inferior mediastinal lymph node metastasis. When the analysis was limited to patients without hilar nodes involvement, only 7 out of 740 (0.9%) peripheral upper lobe tumors had inferior mediastinal lymph node metastasis. Interestingly, all these 7 tumors showed visceral pleural invasion. If hilar nodes were negative, superior mediastinal lymph node metastasis was not present for lower lobe ground glass opacity lesions. Among patients with left lower lobe tumors, if hilar nodes were negative, station 4L lymph node metastasis was not found in superior-segment or basal-segment tumors, and station 5/6 lymph node involvement was always absent in basal-segment tumors.

CONCLUSIONS

Segment location, ground glass opacity proportion, and absence of hilar lymph nodes involvement are reliable predictors of node-negative status in specific mediastinal regions. Based on these findings, we propose a new selective mediastinal lymph node dissection strategy for non-small cell lung cancer.

Results of low-dose computed tomography as a regular health examination among Chinese hospital employees

OBJECTIVE

Lung cancer is traditionally more prevalent in the elderly patients, men, and smokers. However, as low-dose computed tomography (LDCT) is increasingly popular, we hypothesized the disease spectrum might change.

METHODS

LDCT was performed as a part of regular health examinations in 8392 of 15,686 employees from 6 hospitals in different regions of China in 2012 to 2018. Clinicopathologic characteristics, including age, sex, smoking status, radiologic features, tumor histology, and pathologic stage, were retrospectively analyzed.

RESULTS

LDCT incidentally detected lung cancer (pathologically confirmed) in a total of 179 (2.1%) hospital employees. The lung cancer detection rate was significantly greater in female than male (2.5% vs 1.3%, P = .001) patients. There was also a greater detection rate among nonsmokers than smokers, although statistical significance was not reached (2.2% vs 1.4%, P = .092). The lung cancer detection rate was 1.0% in the "age ≤40 years" group, 2.6% in the "40 < age ≤55 years" group, and 2.9% in the "age >55 years" group (P < .001). Among the hospital employees with lung cancer, 171 (95.5%) presented as ground-glass opacity, 177 (98.9%) were lung adenocarcinoma, 170 (95.0%) were early stage 0/IA, and 177 (98.9%) received curative surgical resection as the initial treatment. After a median follow-up of 38 months, no disease recurrence or death was observed among these patients.

CONCLUSIONS

LDCT detected lung cancer in a significant proportion of young, female, and nonsmoking employees. The vast majority of these lung cancers were early stage, with extremely good prognosis.

Factors associated with nodal metastasis in 2-centimeter or less non-small cell lung cancer

OBJECTIVE

Lymph node involvement is an important determinant of treatment and prognosis in non-small cell lung cancer (NSCLC) and must be determined via surgical lymph node (LN) evaluation. However, lymphadenectomy is associated with multiple significant morbidities. Recent studies have suggested LN evaluation can be foregone in some or all patients with NSCLC ≤2.0 cm. Our objective was to identify whether these patients may be safely spared the morbidity of lymphadenectomy.

METHODS

We undertook a retrospective study of patients treated for NSCLC ≤2.0 cm at a single institution from 2005 to 2017. We examined patient, demographic, and tumor variables for associations with LN metastases via univariable and multivariable analyses.

RESULTS

In total, 555 patients met our inclusion criteria. Our primary independent variables included tumor size, histology, and histologic subtype. Although tumors ≤1 cm were less likely to have LN metastases than 1.1- to 2-cm tumors (6.8% vs 13.3%), there was no statistically significant difference. Histologic type was not associated with LN status. In an adenocarcinoma subgroup analysis, micropapillary predominant tumors were more likely to have LN metastases. All invasive mucinous adenocarcinomas and minimally invasive adenocarcinomas were N0.

CONCLUSIONS

LN evaluation may be unnecessary in patients with minimally invasive adenocarcinoma or invasive mucinous adenocarcinomas ≤2.0 cm. However, this information is rarely available pre- or intraoperatively. Thus, we recommend LN evaluation always be performed when possible, even for subcentimeter NSCLC, unless the histology is absolutely certain. To our knowledge, this is the largest dataset published to study patients with NSCLC ≤2.0 cm.

Lymph node metastasis in Chinese patients with clinical T1 non-small cell lung cancer: A multicenter real-world observational study

Background

Approximately 8.3–15.9% of patients with clinical stage I non‐small cell lung cancer are subsequently shown to have lymph node metastasis. However, the clinical characteristics of patients with lymph node metastasis in China are not fully understood.

Methods

This is a multicenter retrospective analysis of pathological T1 non‐small cell lung cancer patients who underwent surgical resection from 2 January 2014 to 27 December 2017. Clinical and pathological information was collected with the assistance of the Large‐scale Data Analysis Center of Cancer Precision Medicine‐LinkDoc database. The clinical and pathological factors associated with lymph node metastasis were analyzed by univariate and multivariate logistic regression.

Results

A total of 10 885 participants (51.6% women; 15.3% squamous cell carcinoma) were included in the analysis. The median age was 60.0 years (range 12.9–86.6 years). A total of 1159 patients (10.6%) had metastases in mediastinal nodes (N2), and 640 patients (5.9%) had metastasis in pulmonary lymph nodes (N1). Most patients had T1b lung cancer (4766, 43.8%). Of the patients, 3260 (29.9%) were current or former smokers. The univariate and multivariate analyses showed that younger age, squamous cell carcinoma, poor differentiation, larger tumor size, carcinoembryonic antigen level ≥5 ng/mL, and vascular invasion (+) were significantly associated with higher percentages of lymph node metastases (P < 0.001 for all).

Conclusion

This real‐world study showed the significant association of lymph node metastasis with age, tumor size, histology and differentiation, carcinoembryonic antigen levels, and status of vascular invasion. Female patients with T1a adenocarcinoma in the right upper lobe barely had lymph node metastasis.

Appropriate lymphadenectomy significantly reduced recurrence after segmentectomy for patients with non-small cell lung cancer

Background

Segmentectomy has been widely used for small-sized non-small cell lung cancer (NSCLC). The objective of this study is to determine the impact of number of harvested lymph nodes (LNs) on survival for patients undergoing segmentectomy.

Methods

The clinicopathologic data of patients undergoing segmentectomy for NSCLC from July 2011 to December 2014 were retrospectively analyzed. Survival analysis was performed by Kaplan-Meier method and Cox regression analysis.

Results

A total of 259 patients with NSCLC were eligible for analysis. Patients with harvested LN ≥6 had higher frequency of nodal metastasis in pathologic examination (9.4% vs. 1.5%, P=0.005). The 3-year recurrence-free survival (RFS) of patients with harvested LN ≥6 (90.2%) was significantly higher than that of patients with harvested LN <6 (73.7%, log-rank P=0.038). Multivariable Cox analysis identified harvested LN ≥6 as an independent predictor for improved RFS [hazard ratio (HR) =0.35; 95% confidence interval (CI): 0.14-0.90; P=0.029]. There was no significant difference in RFS between patients with harvested LN station ≥3 and <3 (log-rank P=0.34).

Conclusions

The number of harvest LN ≥6 was independently associated with improved RFS for NSCLC patients undergoing segmentectomy, supporting the National Comprehensive Cancer Network (NCCN) guidelines of appropriate LN sampling.

Tumor histology predicts mediastinal nodal status and may be used to guide limited lymphadenectomy in patients with clinical stage I non-small cell lung cancer

OBJECTIVE

Methods to minimize surgical trauma from mediastinal lymphadenectomy in patients with early-stage lung cancer are still immature. This study aimed to identify predictors of negative pathologic N2, which may be used to select patients for limited mediastinal lymphadenectomy.

METHODS

Clinicopathologic features of 1430 patients with resected clinical stage I non-small cell lung cancer and complete mediastinal lymphadenectomy were retrospectively analyzed for variables associated with negative N2 nodal metastasis (2008-2015). Overall and recurrence-free survival in patients after complete or limited mediastinal lymphadenectomy were assessed via Kaplan-Meier survival analysis and log-rank testing. The accuracy of frozen section diagnosis for predicting final pathology was retrospectively assessed in 126 randomly selected patients after the surgery.

RESULTS

Multivariable analysis revealed that tumor size ≤2 cm, negative pN1, lymphovascular invasion, and lepidic adenocarcinoma were associated with negative mediastinal nodal metastasis. Notably, none of the patients with histology of adenocarcinoma in situ, minimally invasive adenocarcinoma, or lepidic pattern-predominant adenocarcinoma on final pathology had pN2 disease, and the 5-year overall and recurrence free-survival of these patients (99.3% and 99.3%, respectively) was not different from those after limited mediastinal lymphadenectomy (98.7% and 100%, P = .582 and .511, respectively). If these subtypes were classified together as the low-risk group, the concordance rate between frozen section and final pathology diagnosis was 88.9% in the retrospective test cohort.

CONCLUSIONS

Tumor histology may predict negative mediastinal metastasis in patients with early-stage lung cancer. Future prospective studies are merited to validate the feasibility of using frozen section to select patients for limited mediastinal lymphadenectomy.

Comprehensive investigation of clinicopathologic features, oncogenic driver mutations and immunohistochemical markers in peripheral lung squamous cell carcinoma

Background

Although the majority of lung squamous cell carcinomas (SQCC) arise in central airways, the prevalence of peripheral (p) SQCC is increasing. This study aimed to have a comprehensive investigation of clinicopathologic features, status of common driver mutations and immunophenotypes of p-SQCC compared to central (c) SQCC.

Methods

A total of 261 p-SQCC were compared to 444 c-SQCC for clinicopathologic characteristics. Comprehensive mutational analysis of EGFR, KRAS, HER2, BRAF, PIK3CA, DDR2, AKT1, ALK, ROS1, RET and FGFRs were performed. TTF1, CK7, Napsin A and PE10 protein expression were analyzed through immunohistochemistry (IHC). TTF1, CK7, CK8, SPA and TP63 gene expression levels were measured by quantitative real-time PCR.

Results

Compared to c-SQCC, p-SQCC were associated with female (14.2% vs. 4.5%, P<0.001), never-smokers (22.6% vs. 13.3%, P=0.001), older age at diagnosis (64.9 vs. 59.5 years, P<0.001) and lower pathologic stage (P<0.001). The frequency of EGFR mutations was significantly higher in p-SQCC than c-SQCC (6.2% vs. 2.2%, P=0.040). Positive protein expression of TTF1 (P=0.010) and CK7 (P=0.001) was significantly more prevalent in p-SQCC. p-SQCC had significantly higher gene expression of SPA (P=0.003), whereas c-SQCC showed higher gene expression of TP63 (P=0.028).

Conclusions

Lung p-SQCC had distinctive clinicopathologic characteristics and molecular features compared to c-SQCC, but showed some similarity with adenocarcinoma (ADC).

Risk factors of lymph node metastasis in patients with non-small cell lung cancer ≤ 2 cm in size: A monocentric population-based analysis

Aim

This study was designed to determine the risk factors of lymph node metastasis in non‐small cell lung cancer (NSCLC) patients with tumors ≤ 2 cm, using the Shanghai Chest Hospital Lung Cancer Database.

Methods

Five hundred and eighteen patients with NSCLC ≤ 2 cm were included in this study, and were classified into lymph node‐positive and lymph node‐negative groups. Univariate and multivariate logistic regression analyses were performed to select the independent risk factors for lymph node metastasis in NSCLC patients.

Results

No evidence of metastasis was found in tumors ≤ 1 cm, all positive results were in tumors sized 1–2 cm. Imaging characteristics, including solid and part‐solid nodules, were strongly associated with lymph node metastasis (odds ratio [OR] 24.959, 95% confidence interval [CI] 5.999–103.835, P < 0.001; OR 12.559, 95% CI 3.564–44.259, P < 0.001) and subgroup logistic analysis (OR 21.384, 95% CI 5.058–90.407, P < 0.001; OR 11.632, 95% CI 3.290–41.126, P < 0.001). Greater lymph node metastasis was observed in non‐adeno non‐squamous carcinoma. The presence of pleural invasion and carcinoembryonic antigen levels indicated lymph node dissection. Similar results were revealed in subgroup analysis in tumors ≤ 2 to > 1 cm.

Conclusion

Size had a great impact on lymph node metastasis, especially tumors of 1–2 cm. Preoperative imaging, non‐adeno non‐squamous carcinoma, pleural invasion, and carcinoembryonic antigen all indicated lymph node dissection. There was no discrepancy between N1 and N2 positive lymph nodes.

Impact of maximum standardized uptake value of non-small cell lung cancer on detecting lymph node involvement in potential stereotactic body radiotherapy candidates

BACKGROUND

The retrospective study investigated the association between the maximum standardized uptake value (SUV_max) of primary tumor and lymph node involvement in potential stereotactic body radiotherapy (SBRT) candidates.

METHODS

A total of 185 patients with clinical stage I NSCLC were enrolled in the current study. All patients underwent lobectomy with systematic lymph node dissection following preoperative FDG-PET/CT scanning. The association between clinicopathological variables and lymph node involvement was analyzed by univariate and multivariate analysis. Spearman's correlation test was used to evaluate the correlation between them. Receiver operating characteristic (ROC) analysis was performed to calculate the area under the curve.

RESULTS

Among these patients, 22.1% had occult lymph node involvement, 15.1% were N1 and 7.0% were N2. Greater tumor size (P=0.007), elevated CEA (P=0.006), central location (P=0.002), higher SUV_max (P<0.001), solid nodule type (P=0.002), visceral pleural invasion (P=0.001) and presence of micropapillary and solid patterns (P=0.002) were significantly associated with lymph node involvement. In multivariate analysis, lymph node involvement was associated with central location (OR 5.784, 95% CI: 1.584-21.114, P=0.008), SUV_max (increase of 1 unite, OR 1.147, 95% CI: 1.035-1.272, P=0.009) and visceral pleural invasion (OR 3.044, 95% CI: 1.369-6.769, P=0.006). ROC area under the curve of SUV_max for lymph node involvement was 0.770 (95% CI: 0.698-0.841), the sensitivity and specificity were 85.4% and 63.2%, respectively. Spearman's correlation test showed that SUV_max of tumor mostly depended on tumor size and nodule type.

CONCLUSIONS

SUV_max of primary tumor was a predictor of lymph node involvement for potential SBRT candidates. Centrally located tumor and visceral pleural invasion were related to higher rate of nodal metastasis. Lobectomy and systemic lymph node dissection should be performed in these patients, instead of SBRT.

Association of lymph node involvement with the prognosis of pathological T1 invasive non-small cell lung cancer

BACKGROUND

Lymph node involvement could help to predict the prognosis of pathological T1 (pT1, diameters of ≤3 cm) non-small cell lung cancer (NSCLC). This study assessed the clinicopathological factors and associated lymph node involvement in invasive lung adenocarcinoma (IAC) and squamous cell lung cancer (SCC) and the overall and disease-free survival associated with these factors.

METHODS

Three hundred and twenty-five patients with pathological T1 NSCLC (253 IAC and 72 SCC) were retrospectively analyzed from a pool of 1094 primary lung cancer patients. The data were assessed using multiple logistic regression, Kaplan-Meier curves and multivariable analyses.

RESULTS

Among patients with a ≤30-mm tumor lesion (N = 325), N1 and N2 lymph node involvement was found in 28 (8.6%) and 34 (10.4%) patients, respectively. Lymph node metastasis occurred in 13.0% (33/253) of pT1 IAC patients and 40.3% (29/72) of SCC patients. Carcinoembryonic antigen (CEA) levels, SCC by histology, and tumor lesions larger than 1.0 cm were associated with lymph node involvement (P < 0.0001, <0.0001, and 0.048, respectively). In IAC patients, negative lymph nodes were associated with better overall survival compared with lymph node-positive ones (P = 0.021). No significant difference was observed in SCC patients regardless of lymph node status (P = 0.40). Multivariable Cox analysis revealed that lymph node involvement was an independent prognostic predictor of overall IAC patient survival (P = 0.041), but not of SCC patient survival (P = 0.470). Chemotherapy was administered to 72.2% (52/72) of SCC patients, a significantly higher rate when compared with that of IAC patients (42.3%, 107/253).

CONCLUSIONS

Lymph node metastasis was inversely associated with the overall survival of IAP patients, but not with the survival of SCC patients. Patients with pT1 SCC exhibited a significantly higher rate of lymph node involvement when compared with IAC patients. Thus, a systematic lymph node dissection should be performed in pT1 IAC patients, especially in patients with IAC larger than 1.0 cm, for additional treatment selections to improve survival.

Predicting the recurrence risk factors and clinical outcomes of peripheral pulmonary adenocarcinoma ≤3 cm with wedge resection

PURPOSE

This study was designed to investigate the risk factors of recurrence and survival of clinical stage I lung adenocarcinoma underwent wedge resection by the use of Shanghai Chest Hospital Lung Cancer Database.

PATIENTS AND METHODS

A total of 746 patients with clinical stage I adenocarcinoma underwent wedge resection from 2010 to 2015 in our database were included in this study. Univariable and multivariable Cox proportional hazards regression were performed successively to select significant risk factors and then nomograms as well as the concordance indexes for RFS, OS and LCSS were developed, respectively. Kaplan-Meier survival curves were performed if necessary, with the identification of log-rank test.

RESULTS

The 5-year RFS, OS and LCSS of clinical stage I adenocarcinoma underwent wedge resection were 86.1, 83.6 and 85.2%, respectively. There were three independent risk factors related with RFS (sex, pathology, pleural invasion), two related with OS (sex, volume ratio) and two with LCSS (sex, volume ratio) with the analysis of Cox regression and were selected to develop nomograms. The C-indexes of RFS, OS and LCSS were 0.767 (95% CI 0.667-0.867), 0.782 (95% CI 0.660-0.904) and 0.794 (95% CI 0.669-0.919), respectively. Lymphadenectomy did not show differences statistically but had tendencies of better RFS, OS and LCSS among the subgroup of invasive adenocarcinoma.

CONCLUSION

Sex, pathology and pleural invasion could be recommended as criteria for clinical stage I adenocarcinoma undergoing wedge resection. And the larger the wedge volume and/or the smaller the tumor volume was, the better OS and LCSS were. If the volume ratio reached 10:1 or more, the survival rate was approximately 90% for both OS and LCSS. Whether lymphadenectomy was necessary for WR, especially in invasive adenocarcinoma, needed further research.

Recognition of "aggressive" behavior in "indolent" ground glass opacity and mixed density lesions

BACKGROUND

Radiologically characteristic ground-glass opacity (GGO) represents a special cohort of pulmonary adenocarcinomas that has been unanimously defined as biologically inert. Lymph node metastasis, however, occurs occasionally in these biologically "indolent" cancers. The incidence and underlying risk factors of nodal metastasis remain unknown.

METHODS

All surgically removed GGO lesions between January 2008 and December 2014 were retrospectively reviewed from a single treatment institution. Pathologically-confirmed adenocarcinomas with systemic lymph node dissection or sampling were enrolled into the present study. All the lesions were classified into three groups according to the proportion of solid densities: group I, pure GGO; group II, 1% to 50%; and group III, 50% to 79%. Risk factor analysis of lymph node involvement was performed by multivariate logistic regression.

RESULTS

Of the 867 patients eligible for this study, 553 (63.7%) presented as pure GGOs (Group I) and 314 (36.2%) were mixed GGOs, of which 160 (18.5%) were in group II and 154 (17.8%) in group III. Lymph node metastasis was confirmed in 25 patients, among these 25 cases, 11 (11/160) were group II and 14 (14/154) were group III; two of the 25 patients died from lung cancer metastases at their postoperative 23(rd) and 36(th) month, respectively. Statistical analysis revealed three predictors for lymph nodal metastasis: tumor size, preoperative serum carcinoembryonic antigen level and proportion of the mix density.

CONCLUSIONS

A larger size, mixed GGOs with a higher proportion of solid component, and elevated serum CEA level were associated with a higher preference for nodal metastasis.

[Issues Relevant to Surgical Intervention in 'Tiny' Non-small Cell Lung Cancer Detected by 'Lung Screening'--Orientation, Lung Resection and Lymph Node Resection]

随着胸部计算机断层扫描（computed tomography, CT）的广泛应用，以及肺癌高危人群筛查的逐渐开展，越来越多的“小肺癌”被发现及诊断。“小肺癌”具有的术中定位困难、侵袭性弱、近期和远期预后较好的特点为肺癌的外科治疗提出了新的挑战，本文着重从肺癌的筛查、小结节定位、肺叶切除与亚肺叶切除以及淋巴结清扫范围等方面对“小肺癌”带来的挑战进行探讨。

Factors predicting occult lymph node metastasis in completely resected lung adenocarcinoma of 3 cm or smaller

OBJECTIVES

The aim of the study is to demonstrate the relationship between clinicopathological variables and occult lymph node metastasis in resected lung adenocarcinoma.

METHODS

The clinicopathological characteristics of 471 patients with clinical N2-negative status undergoing resection for lung adenocarcinoma of 3 cm or smaller at Taipei Veterans General Hospital between 2004 and 2012 were retrospectively reviewed. The association between clinicopathological variables and lymph node metastasis was analysed by univariate and multivariate logistic regression.

RESULTS

Among the 471 patients, there were 386 (82.0%) patients with pathological N0 status, 35 (7.4%) with pathological N1 status and 50 (10.6%) with pathological N2 status. Greater tumour size (P = 0.002), presence of a micropapillary pattern (P < 0.001), presence of a solid pattern (P < 0.001) and predominant pattern group (micropapillary/solid predominant) (P = 0.001) were significantly associated with higher percentage of occult N2 lymph node metastasis. In multivariate analysis, greater tumour size (P = 0.008), presence of micropapillary pattern (P < 0.001) and presence of solid pattern (P = 0.001) were significant predictors of occult N2 lymph node metastasis in tumours of 3 cm or smaller. When histological pattern was entered as the predominant pattern in multivariate analysis, micropapillary/solid predominant pattern (P = 0.005) was also a significant predictor of occult N2 lymph node metastasis.

CONCLUSIONS

The presence of micropapillary or solid pattern, as well as micropapillary/solid predominant pattern, is significantly associated with occult N2 lymph node metastasis in lung adenocarcinoma. Radical mediastinal lymph node dissection may help to identify occult lymph node metastasis in these patients.

Prognosis and status of lymph node involvement in patients with adenocarcinoma in situ and minimally invasive adenocarcinoma-a systematic literature review and pooled-data analysis

BACKGROUND

Adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) have been brought up that substitute for bronchioloalveolar carcinoma (BAC), according to the new classification of lung adenocarcinoma. There has been increasing opinions that argues for the adjustment of lymph node disposition in patients with such early stage tumors. Therefore, we sought to overview the prognosis and status of lymph node involvement in AIS/MIA patients.

METHODS

PubMed, Springer and Ovid databases were searched for relevant studies. Data was extracted and results summarized to demonstrate the disposition of lymph nodes in AIS/MIA.

RESULTS

Twenty-three studies consisting of 6,137 lung adenocarcinoma were included. AIS/MIA accounted for 821 of the total 6,137. All included patients received curative surgery. After a review of the summarized data we found that only one patient (with MIA) had N1 node metastasis, N2 disease was not found in any of the included patients. In concordance with this, studies that reported 5-year disease free survival (5-year DFS) have almost 100% rate.

CONCLUSIONS

Our findings indicated that patients with AIS/MIA have good survival prognosis after surgical resection, and that recurrence and lymph node metastasis in these patients is rare. Therefore, we strongly encouraged further studies to determine the role of different lymph node disposition strategies.

Precise Diagnosis of Intraoperative Frozen Section Is an Effective Method to Guide Resection Strategy for Peripheral Small-Sized Lung Adenocarcinoma

PURPOSE

This study investigated the accuracy of intraoperative frozen section (FS) diagnosis for predicting the final pathology (FP) of peripheral small-sized lung adenocarcinoma and evaluated its usefulness in sublobar resection.

PATIENTS AND METHODS

The records of 803 patients with clinical stage I peripheral lung adenocarcinoma who underwent sublobar resection for FS diagnosis to guide surgical strategy were reviewed. The surgical extension was mainly based on FS. The FS were stratified into atypical adenomatous hyperplasia, adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and invasive adenocarcinoma. The diagnostic accuracy of FS, the reasons for the discrepancy between FS and FP, and the clinical influence of the FS errors were evaluated. To assess the survival of patients with different subtypes after surgery, 301 patients were identified for prognosis evaluation.

RESULTS

The total concordance rate between FS and FP was 84.4%. When atypical adenomatous hyperplasia, AIS, and MIA were classified together as a low-risk group, the concordance rate was 95.9%. Most discrepant cases were the underestimation of AIS and MIA. The diagnostic accuracy of FS for tumors ≤ 1 cm and larger than 1 cm in diameter was 79.6% and 90.8%, respectively (P < .01). The FS errors had significant clinical impact on 0.9% of the 803 patients due to insufficient resection. The 5-year recurrence-free survival rate (100%) was significantly better for the patients with AIS/MIA than for patients with invasive adenocarcinoma (74.1%, P < .01).

CONCLUSION

Frozen pathology has a high concordance rate with FP. Precise diagnosis by intraoperative FS is an effective method to guide resection strategy for peripheral small-sized lung adenocarcinoma.

Radiologic Predictors for Clinical Stage IA Lung Adenocarcinoma with Ground Glass Components: A Multi-Center Study of Long-Term Outcomes

Objective

This study was to define preoperative predictors from radiologic findings for the pathologic risk groups based on long-term surgical outcomes, in the aim to help guide individualized patient management.

Methods

We retrospectively reviewed 321 consecutive patients with clinical stage IA lung adenocarcinoma with ground glass component on computed tomography (CT) scanning. Pathologic diagnosis for resection specimens was based on the 2011 IASLC/ATS/ERS classification of lung adenocarcinoma. Patients were classified into different pathologic risk grading groups based on their lymph node status, local regional recurrence and overall survival. Radiologic characteristics of the pulmonary nodules were re-evaluated by reconstructed three-dimension CT (3D-CT). Univariate and multivariate analysis identifies independent radiologic predictors from tumor diameter, total volume (TV), average CT value (AVG), and solid-to-tumor (S/T) ratio. Receiver operating characteristic curves (ROC) studies were carried out to determine the cutoff value(s) for the predictor(s). Univariate cox regression model was used to determine the clinical significance of the above findings.

Results

A total of 321 patients with clinical stage IA lung adenocarcinoma with ground glass components were included in our study. Patients were classified into two pathologic low- and high- risk groups based on their distinguished surgical outcomes. A total of 134 patients fell into the low-risk group. Univariate and multivariate analyses identified AVG (HR: 32.210, 95% CI: 3.020–79.689, P<0.001) and S/T ratio (HR: 12.212, 95% CI: 5.441–27.408, P<0.001) as independent predictors for pathologic risk grading. ROC curves studies suggested the optimal cut-off values for AVG and S/T ratio were-198 (area under the curve [AUC] 0.921), 2.9 (AUC 0.996) and 54% (AUC 0.907), respectively. The tumor diameter and TV were excluded for the low AUCs (0.778 and 0.767). Both the cutoff values of AVG and S/T ratio were correlated with pathologic risk classification (p<0.001). Univariate Cox regression model identified clinical risk classification (RR: 3.011, 95%CI: 0.796–7.882, P = 0.095) as a good predictor for recurrence-free survival (RFS) in patients with clinical stage IA lung adenocarcinoma. Statistical significance of 5-year OS and RFS was noted among clinical low-, moderate- and high-risk groups (log-rank, p = 0.024 and 0.010).

Conclusions

The AVG and the S/T ratio by reconstructed 3D-CT are important preoperative radiologic predictors for pathologic risk grading. The two cutoff values of AVG and S/T ratio are recommended in decision-making for patients with clinical stage IA lung adenocarcinoma with ground glass components.

Predictive risk factors for lymph node metastasis in patients with small size non-small cell lung cancer

BACKGROUND

Accurate clinical staging of non-small cell lung cancer (NSCLC) is essential for developing an optimal treatment strategy. This study aimed to determine the predictive risk factors for lymph node metastasis, including both N1 and N2 metastases, in clinical T1aN0 NSCLC patients.

METHODS

We retrospectively evaluated clinical T1aN0M0 NSCLC patients who showed no radiologic evidence of lymph node metastasis, and who had undergone surgical pulmonary resection with systematic mediastinal node dissection or sampling at the First Affiliated Hospital of Zhejiang University between January 2011 and June 2013. Univariate and multivariate logistic regression analyses were performed to identify predictive factors for node metastasis.

RESULTS

Pathologically positive lymph nodes were found in 16.2% (51/315) of the patients. Positive N1 nodes were found in 12.4% (39/315) of the patients, and positive N2 nodes were identified in 13.0% (41/315) of the patients. Some 9.2% (29/315) of the patients had both positive N1 and N2 nodes, and 3.8% (12/315) of the patients had nodal skip metastasis. Variables of preoperative radiographic tumor size, non-upper lobe located tumors, high carcinoembryonic antigen (CEA) levels and micropapillary predominant adenocarcinoma (AC) were identified as predictors for positive N1 or N2 node multivariate analysis.

CONCLUSIONS

Pathologically positive lymph nodes were common in small size NSCLC patients with clinical negative lymph nodes. Therefore, preoperative staging should be performed more thoroughly to increase accuracy, especially for patients who have the larger size, non-upper lobe located, high CEA level or micropapillary predominant ACs.

Early lung cancer with lepidic pattern: adenocarcinoma in situ, minimally invasive adenocarcinoma, and lepidic predominant adenocarcinoma

PURPOSE OF REVIEW

This review gives a comprehensive overview on recent developments in the classification of neoplastic lung lesions with lepidic growth patterns, comprising the adenocarcinoma (ADC) precursor lesions atypical adenomatous hyperplasia (AAH), adenocarcinoma in situ (AIS), and minimally invasive adenocarcinoma (MIA) as well as lepidic predominant adenocarcinoma (LPA).

RECENT FINDINGS

The concept of a continuum between the precursor lesions AAH and AIS to MIA and frankly invasive ADC is backed by a wealth of recent data showing a gradual decrease in overall survival from 100% for AAH, AIS, and MIA to moderately lower rates for LPA. Further, it has been shown that the morphologic categorization of these tumors can be done with reasonable reliability and that nonmucinous lepidic tumors show distinct molecular alterations with high rates of epidermal growth factor receptor mutations. Importantly, lepidic tumor growth is also mirrored by specific characteristics in computed tomography images, arguing for a combined assessment of histomorphology and imaging data for an optimized classification of lepidic neoplasms.

SUMMARY

The validity and clinical importance of the novel concept of ADC precursor lesions and LPA have been confirmed by clinical, radiological, morphological, and molecular data. Thereby, it has evolved into a valuable tool to aid in clinical decision-making.