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

Survival benefit of adjuvant chemotherapy after resection of Stage I lung adenocarcinoma containing micropapillary components

BACKGROUND

The usefulness of postoperative adjuvant chemotherapy (ACT) for patients with stage I lung adenocarcinoma with micropapillary (MIP) components remains unclear. We analyzed whether postoperative ACT could reduce recurrence in patients with stage I lung adenocarcinoma with MIP components, thereby improving their overall survival (OS) and disease-free survival (DFS).

METHODS

Data for patients with pathologically confirmed stage I lung adenocarcinoma with MIP components from January 2012 to December 2018 were retrospectively analyzed. OS and DFS were analyzed in groups and subgroups.

RESULTS

Overall, 259 patients were enrolled. Patients who received ACT in stage IA showed significantly better survival than did those with no-adjuvant chemotherapy (NACT); (5-year OS 89.4% vs. 73.6%, p < 0.001; 5-year DFS 87.2% vs. 66.0%, p = 0.008). A difference was also observed for in-stage IB patients (5-year OS 82.0% vs. 51.8%, p = 0.001; 5-year DFS 76.0% vs. 41.11 %, p = 0.004). In subgroup analysis based on the proportion of MIP components, patients with 1%-5% MIP components had a significantly better prognosis in the ACT group than in the NACT group (5-year OS 82.4% vs. 66.0%, p = 0.005; 5-year DFS 76.5% vs. 49.1%, p = 0.032). A similar difference was observed for patients with MIP ≥5% (5-year OS 80.7% vs. 47.8%, p = 0.009; 5-year DFS 73.11% vs. 43.5%, p = 0.007).

CONCLUSION

Among patients with stage I lung adenocarcinoma with MIP components, those who received ACT showed significant survival benefits compared to those without ACT. Patients with lung adenocarcinoma with MIP components could benefit from ACT when the MIP was ≥1%.

Predicting occult lymph node metastasis in solid-predominantly invasive lung adenocarcinoma across multiple centers using radiomics-deep learning fusion model

BACKGROUND

In solid-predominantly invasive lung adenocarcinoma (SPILAC), occult lymph node metastasis (OLNM) is pivotal for determining treatment strategies. This study seeks to develop and validate a fusion model combining radiomics and deep learning to predict OLNM preoperatively in SPILAC patients across multiple centers.

METHODS

In this study, 1325 cT1a-bN0M0 SPILAC patients from six hospitals were retrospectively analyzed and divided into pathological nodal positive (pN+) and negative (pN-) groups. Three predictive models for OLNM were developed: a radiomics model employing decision trees and support vector machines; a deep learning model using ResNet-18, ResNet-34, ResNet-50, DenseNet-121, and Swin Transformer, initialized randomly or pre-trained on large-scale medical data; and a fusion model integrating both approaches using addition and concatenation techniques. The model performance was evaluated by the area under the receiver operating characteristic (ROC) curve (AUC).

RESULTS

All patients were assigned to four groups: training set (n = 470), internal validation set (n = 202), and independent test set 1 (n = 227) and 2 (n = 426). Among the 1325 patients, 478 (36%) had OLNM (pN+). The fusion model, combining radiomics with pre-trained ResNet-18 features via concatenation, outperformed others with an average AUC (aAUC) of 0.754 across validation and test sets, compared to aAUCs of 0.715 for the radiomics model and 0.676 for the deep learning model.

CONCLUSION

The radiomics-deep learning fusion model showed promising ability to generalize in predicting OLNM from CT scans, potentially aiding personalized treatment for SPILAC patients across multiple centers.

Comprehensive analyses unveil novel genomic and immunological characteristics of micropapillary pattern in lung adenocarcinoma

Lung adenocarcinoma (LUAD) usually contains heterogeneous histological subtypes, among which the micropapillary (MIP) subtype was associated with poor prognosis while the lepidic (LEP) subtype possessed the most favorable outcome. However, the genomic features of the MIP subtype responsible for its malignant behaviors are substantially unknown. In this study, eight FFPE samples from LUAD patients were micro-dissected to isolate MIP and LEP components, then sequenced by whole-exome sequencing. More comprehensive analyses involving our samples and public validation cohorts on the two subtypes were performed to better decipher the key biological and evolutionary mechanisms. As expected, the LEP and MIP subtypes exhibited the largest disease-free survival (DFS) differences in our patients. EGFR was found with the highest mutation frequency. Additionally, shared mutations were observed between paired LEP and MIP components from single patients, and recurrent mutations were verified in the Lung-Broad, Lung-OncoSG, and TCGA-LUAD cohorts. Distinct biological processes or pathways were involved in the evolution of the two components. Besides, analyses of copy number variation (CNV) and intratumor heterogeneity (ITH) further discovered the possible immunosurveillance escape, the discrepancy between mutation and CNV level, ITH, and the pervasive DNA damage response and WNT pathway gene alternations in the MIP component. Phylogenetic analysis of five pairs of LEP and MIP components further confirmed the presence of ancestral EGFR mutations. Through comprehensive analyses combining our samples and public cohorts, PTP4A3, NAPRT, and RECQL4 were identified to be co-amplified. Multi-omics data also demonstrated the immunosuppression prevalence in the MIP component. Our results uncovered the evolutionary pattern of the concomitant LEP and MIP components from the same patient that they were derived from the same initiation cells and the pathway-specific mutations acquired after EGFR clonal mutation could shape the subtype-specificity. We also confirmed the immunosuppression prevalence in the MIP subtype by multi-omics data analyses, which may have resulted in its unfavorable prognosis.

Genomics Analysis and Nomogram Risk Prediction of Occult Lymph Node Metastasis in Non-Predominant Micropapillary Component of Lung Adenocarcinoma Measuring ≤ 3 cm

Background

The efficacy of sublobar resection and selective lymph node dissection is gradually being accepted by thoracic surgeons for patients within early-stage non-small cell lung cancer (NSCLC). Nevertheless, there are still some NSCLC patients develop lymphatic metastasis at clinical T1 stage. Lung adenocarcinoma with a micropapillary (MP) component poses a higher risk of lymph node metastasis and recurrence even when the MP component is not predominant. Our study aimed to explore the genetic features and occult lymph node metastasis (OLNM) risk factors in patients with a non-predominant micropapillary component (NP-MPC) in a large of patient’s cohort with surgically resected lung adenocarcinoma.

Methods

Between January 2019 and December 2021, 6418 patients who underwent complete resection for primary lung adenocarcinoma at the Qilu Hospital of Shandong University. In our study, 442 patients diagnosed with lung adenocarcinoma with NP-MPC with a tumor size ≤3 cm were included. Genetic alterations were analyzed using amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). Abnormal protein expression of gene mutations was validated using immunohistochemistry. A nomogram risk model based on clinicopathological parameters was developed to predict OLNM. This model was invalidated using the calibration plot and concordance index.

Results

In our retrospective cohort, the incidence rate of the micropapillary component was 11.17%, and OLNM was observed in 20.13% of the patients in our study. ARMS-PCR suggested that EGFR exon 19 del was the most frequent alteration in NP-MCP patients compared with other gene mutations (frequency: 21.2%, P<0.001). Patients harboring exon 19 del showed significantly higher risk of OLNM (P< 0.001). A nomogram was developed based on five risk parameters, which showed good calibration and reliable discrimination ability (C-index = 0.84) for evaluating OLNM risk.

Conclusions.

Intense expression of EGFR exon 19 del characterizes lung adenocarcinoma in patients with NP-MCP and it’s a potential risk factor for OLNM. We firstly established a nomogram based on age, CYFRA21-1 level, tumor size, micropapillary and solid composition, that was effective in predicting OLNM among NP-MCP of lung adenocarcinoma measuring ≤ 3 cm.

Absence of clinical benefit of FDG PET-CT in staging T1 part-solid lung adenocarcinoma

AIM

To assess the rates of nodal and metastatic disease and change in management when staging part-solid T1 lung adenocarcinomas using integrated 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET)-computed tomography (CT) in a UK population.

MATERIALS AND METHODS

This was a retrospective review of PET-CT examinations performed to stage radiologically suspected T1 part-solid lung adenocarcinoma (n=58) from two different centres. Rates of detection of nodal and metastatic disease, change in management, and final patient outcome were recorded.

RESULTS

PET-CT changed the stage in one patient from N0 to N1. It did not change final management in any patient.

CONCLUSIONS

In this UK population, PET-CT had minimal additional diagnostic benefit in staging patients with T1 part-solid lung adenocarcinoma. Especially given its cost, the inclusion of PET-CT for this indication in guidelines should be reviewed.

A Comprehensive Nomogram Combining CT Imaging with Clinical Features for Prediction of Lymph Node Metastasis in Stage I-IIIB Non-small Cell Lung Cancer

OBJECTIVE

The status of lymph node metastasis (LNM) is highly correlated with the recurrence and survival outcomes of patients with lung cancer. Thus, a tool that predicts LNM could benefit patient treatment and prognosis. The present study established a new radiomic model by combining computed tomography (CT) radiomic features and clinical parameters to predict the LNM status in patients with non-small cell lung cancer (NSCLC).

METHODS

Demographic parameters and clinical laboratory values were analyzed in 217 patients with stage I-IIIB NSCLC; 107 of the patients received CT scanning and radiomic characteristics were used for LNM assessment (76 in the training cohort and 31 in the validation cohort). The minimum redundancy maximum relevance (mRMR) and the least absolute shrinkage and selection operator (LASSO) regression model were used to select the most predictive features on the basis of the 76 patients in the training set. The value of the area under the receiver operator characteristic (ROC) curve (AUC) was adopted to determine the correlation between LN status and the radiomics signature in training cohorts and then validated in the 31 patients of validation set. The radiomics nomogram was analyzed using univariate and multivariate logistic regression. Decision curve analysis (DCA) was performed to evaluate the clinical utility of this model.

RESULTS

This was a retrospective study. Five radiomic characteristics were significantly correlated with LNM in the two cohorts (P < 0.05). The radiomic nomogram that incorporated the above radiomic characteristics, the RDW, and the CT-based LN status had satisfactory discrimination and calibration in the training (AUC, 0.79; 95% CI 0.69-0.89) and validation cohorts (AUC, 0.70; 95% CI 0.50-0.89).The DCA showed that the developed nomogram had promising clinical utility.

CONCLUSIONS

The developed nomogram, combined with preoperative radiomics evidence, the RDW, and the CT-based LN status, has the potential to preoperatively predict LNM with high accuracy and can facilitate the prediction of LN status for NSCLC patients.

Clinicopathological and computed tomographic features associated with occult lymph node metastasis in patients with peripheral solid non-small cell lung cancer

OBJECTIVES

To investigate the value of combining clinicopathological characteristics with computed tomographic (CT) features of tumours for predicting occult lymph node metastasis (OLNM) in peripheral solid non-small cell lung cancer (PS-NSCLC).

METHODS

The study included 478 NSCLC clinically N0 (cN0) patients who underwent lobectomy and systemic lymph node dissection from January 2014 to August 2019. Patients were classified into OLNM and negative lymph node metastasis (NLNM) groups. The CT features of non-metastatic and metastatic lymph nodes with a largest short-diameter > 5 mm were compared in the OLNM group. Thereafter, the clinicopathological characteristics and CT morphological features of tumours were compared between both groups. Multivariable logistic regression analysis and receiver-operating characteristic curve were developed.

RESULTS

CT images detected 103 metastatic and 705 non-metastatic lymph nodes, and no significant differences in CT features of lymph nodes were found in all 161 OLNM patients (P > 0.05). For both groups, sex, carcinoembryonic antigen and pathological type differed significantly (all P < 0.05), while tumour size, necrosis, calcification, vascular convergence, pleural involvement, and the shortest interval of tumour-pleura differed significantly on CT images (all P < 0.05). Multivariable logistic regression analysis showed that carcinoembryonic antigen > 5.00 ng/ml, adenocarcinoma, absence of vascular convergence, and pleural involvement of Type II (one linear or cord-like pleural tag or tumour abut to the pleura with a broad base observed on both lung and mediastinal window images) were independent predicting factors of OLNM.

CONCLUSIONS

CT findings of lymph nodes can provide limited value and integrating clinicopathological characteristics with the CT morphological features of tumours is helpful in predicting OLNM in patients with PS-NSCLC.

What Should Thoracic Surgeons Consider during Surgery for Ground-Glass Nodules?: Lymph Node Dissection

Thoracic surgeons need to be aware of several important points regarding intraoperative lymph node dissection during surgery for non-small cell lung cancer with ground-glass opacities. The first point relates to the need for lymph node dissection during sublobar resection. Since even patients undergoing sublobar resection may benefit from lymph node dissection, it should be selectively performed according to adequate indications, which require further study. Second, there seems to be no difference in postoperative morbidity between systematic sampling and systematic dissection, but the survival benefit from systematic dissection remains unclear. The results of randomized controlled trials on this topic are conflicting, and their evidence is jeopardized by a high risk of bias in terms of the study design. Therefore, further randomized controlled trials with a sound design should investigate this issue. Third, more favorable survival outcomes tend to be positively associated with the number of examined lymph nodes. Minimum requirements for the number of examined lymph nodes in non-small cell lung cancer should be defined in the future. Finally, lobe-specific lymph node dissection does not have a negative prognostic impact. It should not be routinely performed, but it can be recommended in selected patients with smaller, less invasive tumors. Results from an ongoing randomized controlled trial on this topic should be awaited.

Assessing Differences in Lymph Node Metastasis Based Upon Sex in Early Non-Small Cell Lung Cancer

BACKGROUNDS

Whether sex has any impact on the risk of lymph node (LN) metastasis (LNM) in patients with early-stage non-small cell lung cancer (NSCLC) remains controversial. Therefore, we aimed to objectively compared the risk of LNM between female and male patients with early-stage NSCLC so as to figure out whether sex-different extent of surgery may be justified for treating these patients.

METHODS

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 June 2014 to April 2019. Both multivariate logistic regression analysis and propensity score-matched(PSM) analysis were applied to compare the risk of LNM between female and male patients.

RESULTS

We finally included a total of 660 patients for analysis. In the analysis of unmatched cohorts, there was no significant different rate of LNM (12.4% Vs 13.9%, P=0.556), hilar/intrapulmonary LNM (8.4% Vs 10.7%, P=0.318) and mediastinal LNM(7.9% Vs 7.5%, P=0.851) between female and male patients. In the multivariate analysis, sex was not found to be an independent predictor of LN in these patients. Moreover, in the analysis of well-matched cohorts generated by PSM analysis, there was still no significant different rate of LNM (13.8% Vs 13.4%, P=0.892), hilar/intrapulmonary LNM (9.1% Vs 11.2%, P=0.442) and mediastinal LNM (9.1% Vs 6.5%, P=0.289) between female and male patients.

CONCLUSIONS

Sex was not an independent predictor of LNM in early-stage NSCLC and there is no sufficient evidence justifying for sex-different extent of surgical resection for these patients.

Clinical impact and utility of positron emission tomography on occult lymph node metastasis and survival: radical surgery for stage I lung cancer

OBJECTIVE

The surgical result of early-staged lung cancer is not satisfactory due to unexpected postoperative lymph node metastasis and recurrence. This study aimed to investigate which preoperative factors-including the standard uptake value max (SUV_max) of positron emission tomography-could predict occult lymph node metastasis and survival.

METHODS

We retrospectively analyzed data from 598 patients with clinical stage I lung cancer who underwent surgery, and examined their preoperative clinical characteristics.

RESULTS

A total of 1586 patients had surgery for primary lung cancer between 2006 and 2019; 598 patients with clinical stage I lung cancer were the study inclusion; occult lymph node metastasis was detected in 102 (17.1%). Univariable and multivariable analyses showed that SUV_max ≥ 3 (P < 0.001), clinical invasive tumor size ≥ 2 cm (P = 0.009), and carcinoembryonic antigen > 5 (P = 0.03) were associated with significant risk factors rated (%) for occult lymph node metastasis, as follows: high-risk group (three factors), moderate-risk group (two factors) and low-risk group (one factor or none) corresponding to 32.2 (28/87), 22.8 (41/180) and 7.3 (19/262), respectively (P < 0.001). The 5-year overall survival rates (%) of patients without lymph node metastasis holding SUV_max 6 or over were as poor as those of patients with lymph node metastasis (72.0% vs 64.1%; P = 0.56).

CONCLUSIONS

We might consider wedge resection or segmentectomy, omitting lymphadenectomy, for the low-risk group; adjuvant therapy is indicated for patients without lymph node metastasis having SUV_max 6 or over.

F-18 fluorodeoxyglucose uptake in lymph nodes and sonographic features on endobronchial ultrasonography predict lymph node metastasis in lung cancer patients

Background

Sonographic findings of lymph nodes on endobronchial ultrasonography (EBUS) images have been reported to be useful to predict lymph node metastasis (LNM) in lung cancer patients. F-18 fluorodeoxyglucose (FDG) uptake in lymph nodes was also found to be useful. In this study, we aimed to clarify whether a combination of sonographic features and maximum standardized uptake values of lymph nodes (LN-SUVmax) is useful for predicting LNM in lung cancer patients.

Methods

From January 2014 to December 2019, a total of 147 lymph nodes from 104 patients with lung cancer, who underwent preoperative EBUS and FDG-positron emission tomography (PET)/computed tomography (CT) followed by surgery were retrospectively assesses. The characteristics of the patients, LN-SUVmax, and sonographic findings of lymph nodes were reviewed. Predictive factors associated with LNM were identified using the logistic regression model.

Results

The average size of the lymph nodes was 8.55 (range, 3–22) mm and the average LN-SUVmax was 5.36 (range, 1.79–31.19). The prevalence of nodal metastasis was 26/147 (17.4%), including 22 in mediastinal lymph nodes and 4 in hilar lymph nodes. Multivariate analysis demonstrated four independent predictive factors for LNM; size, round or oval shape, absence of a central hilar structure, and LN-SUVmax. The optimal cutoff value for lymph node size and LN-SUVmax were 10 mm and 6.00, respectively. By combinating of the two modalities, we obtained the results with sensitivity of 76.9%, specificity of 95.1% and accuracy of 93.2%.

Conclusions

A combination of sonographic findings and LN-SUVmax showed a higher diagnostic rate of LNM than either modality alone in lung cancer patients.

Metastatic Patterns of Mediastinal Lymph Nodes in Small-Size Non-small Cell Lung Cancer (T1b)

Background: Lymph node metastasis (LNM) status is critical to the treatment. Fewer studies has focused on LNM in patients with small-size non-small cell lung cancer (NSCLC). This study aims to investigate clinicopathological characteristics associated with skip N2 (SN2) and non-skip N2 (NSN2) metastasis, and their metastatic patterns in NSCLC with tumor size of 1–2 cm.

Methods: We reviewed the records of NSCLC patients with tumor size of 1–2 cm who underwent lobectomy with systematic lymph node dissection (LND) between January 2013 and June 2019. Clinical, radiographical, and pathological characteristics were compared among N1, SN2, and NSN2 groups. Metastatic patterns of mediastinal lymph node were analyzed based on final pathology.

Results: A total of 63 NSCLC patients with tumor size of 1–2 cm were staged as pN2, including 25 (39.7%) SN2 and 38 (60.3%) NSN2. The incidence rates of SN2 and NSN2 were 2.8% (25/884) and 4.3% (38/884), respectively. For all clinicopathological characteristics, no significant difference was observed among the groups of N1, SN2, and NSN2. For the tumor located in each lobe, specific nodal drainage stations were identified: 2R/4R for right upper lobe; 2R/4R and subcarinal node (#7) for right middle lobe and right lower lobe; 4L and subaortic node (#5) for left upper lobe; #7 for left lower lobe. However, there were still a few patients (10.9%, 5/46) had the involvement of lower zone for tumors of upper lobe and the involvement of upper zone for lower lobe.

Conclusions: SN2 occurs frequently in patients with small-size NSCLC. Whether lobe-specific selective LND is suitable for all small-size patients deserves more studies to confirm. Surgeons should be more careful when performing selective LND for tumors located in the lower and upper lobes.

Preoperative Prediction of Lymph Node Metastasis in Patients With Early-T-Stage Non-small Cell Lung Cancer by Machine Learning Algorithms

Background: Lymph node metastasis (LNM) is difficult to precisely predict before surgery in patients with early-T-stage non-small cell lung cancer (NSCLC). This study aimed to develop machine learning (ML)-based predictive models for LNM.

Methods: Clinical characteristics and imaging features were retrospectively collected from 1,102 NSCLC ≤ 2 cm patients. A total of 23 variables were included to develop predictive models for LNM by multiple ML algorithms. The models were evaluated by the receiver operating characteristic (ROC) curve for predictive performance and decision curve analysis (DCA) for clinical values. A feature selection approach was used to identify optimal predictive factors.

Results: The areas under the ROC curve (AUCs) of the 8 models ranged from 0.784 to 0.899. Some ML-based models performed better than models using conventional statistical methods in both ROC curves and decision curves. The random forest classifier (RFC) model with 9 variables introduced was identified as the best predictive model. The feature selection indicated the top five predictors were tumor size, imaging density, carcinoembryonic antigen (CEA), maximal standardized uptake value (SUV_max), and age.

Conclusions: By incorporating clinical characteristics and radiographical features, it is feasible to develop ML-based models for the preoperative prediction of LNM in early-T-stage NSCLC, and the RFC model performed best.

[Correlation between Lymph Node Ratio and Clinicopathological Features and Prognosis of IIIa-N2 Non-small Cell Lung Cancer]

BACKGROUND

IIIa-N2 non-small cell lung cancer was significant different in survival, although N stage of lung cancer based on anatomic location of metastasis lymph node. Lymph node ratio considered of prognostic factor might be the evaluation index for IIIa-N2 non-small cell lung cancer prognosis. Therefore, the aim of the study was to evaluate the correlation between lymph node ratio and clinicopathological features and prognosis of IIIa-N2 non-small cell lung cancer prognosis.

METHODS

A total of 288 cases of pathological IIIa-N2 non-small cell lung cancer were enrolled who received radical resection at the Department of Thoracic Surgery II, Peking University Cancer Hospital from January 2006 to December 2016. The univariate analysis between clinicopathological variables and lymph node ratio used Pearson's chi-squared test. Cox regression was conducted to identify the independent prognosis factors for IIIa-N2 non-small cell lung cancer.

RESULTS

There were 139 cases in the lower lymph node ratio group, another 149 cases in the higher lymph node ratio group. Adenocarcinoma (χ²=5.924, P=0.015), highest mediastinal lymph node metastasis (χ²=46.136, P<0.001), multiple-number N2 metastasis (χ²=59.347, P<0.001), multiple-station N2 metastasis (χ²=77.387, P<0.001) and skip N2 lymph node metastasis (χ²=61.524, P<0.001) significantly impacted lymph node ratio. The total number of lymph node dissection was not correlated with the lymph node ratio (χ²=0.537, P=0.464). Cox regression analysis confirmed that adenocarcinoma (P=0.008), multiple-number N2 metastasis (P=0.025) and lymph node ratio (P=0.001) were the independent prognosis factors of disease free survival. The 5-year disease free survival was 18.1% in the higher lymph node ratio group, and 44.1% in the lower. Lymph node ratio was the independent prognosis factor of overall survival (P<0.001). The 5-year overall survival was 36.7% in the higher lymph node ratio group, and 64.1% in the lower.

CONCLUSIONS

Lymph node ratio was correlative with the pathology, highest mediastinal lymph node metastasis, multiple-number N2 metastasis, multiple-station N2 metastasis and skip N2 lymph node metastasis. Lymph node ratio was the independent prognosis factor for IIIa-N2 non-small cell lung cancer.

Novel approach for predicting occult lymph node metastasis in peripheral clinical stage I lung adenocarcinoma

Background

Occult nodal metastasis results in a poor prognosis for lung cancer patients. The aim of this study was to develop an efficient approach for predicting occult nodal metastasis in peripheral clinical stage I lung adenocarcinoma.

Methods

Data for 237 peripheral clinical stage I lung adenocarcinoma patients who underwent complete resection were retrospectively reviewed. Univariate and multivariate analyses were performed to investigate predictors of occult nodal metastasis. Kaplan-Meier analysis was performed for survival.

Results

Occult nodal metastasis was detected in 26/237 (11.0%) patients. Nodule type, tumor SUVmax, whole tumor size, solid tumor size, and preoperative serum carcinoembryonic antigen (CEA) were identified as preoperative predictors of occult nodal metastasis (all P<0.05). Solid tumor size (P<0.001) and preoperative serum CEA (P=0.004) were identified as independent predictors on multivariate analysis. A prediction model was established using the independent predictors. The occult nodal metastasis rate was 2.4% with solid tumor size ≤2.3 cm (low-risk group), 17.0% with solid tumor size >2.3 cm and CEA ≤5 ng/mL (moderate-risk group), and 56.0% with solid tumor size >2.3 cm and CEA >5 ng/mL (high-risk group). The occult nodal metastasis rate was significantly higher in papillary-predominant (11.0%) and solid-predominant subtypes (28.6%; P=0.001). Patients having a micropapillary component had a significantly higher occult nodal metastasis rate (24.2%) compared with no micropapillary component (P=0.007). Histological subtype with micropapillary component and all preoperative predictors were significant prognostic factors affecting disease-free survival (DFS) (all P<0.05).

Conclusions

A novel approach to predict occult nodal metastasis was developed for peripheral clinical stage I lung adenocarcinoma. It would be helpful for selecting candidates for stereotactic ablative radiotherapy (SABR) or wedge resection and mediastinoscopy or endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA). Complete nodal dissection should be performed for moderate to high-risk patients or patients with poor histologic subtypes.

Precision Medicine in Non-Small Cell Lung Cancer: Current Standards in Pathology and Biomarker Interpretation

Non-small cell lung cancer (NSCLC) has become a prominent example of precision medicine among solid tumor malignancies. Clinical management of NSCLC now depends on surgical, chemotherapeutic, and radiation treatment regimens based on pathologic findings and clinical staging as well as targeted therapies based on molecular profiling. As molecular testing becomes increasingly important, preserving tissue for this purpose while rendering an accurate histologic diagnosis becomes a key consideration, particularly in advanced-stage NSCLC, in which small biopsy samples or aspirates are often the only specimen available. Next-generation sequencing panels are a powerful method of providing information relevant for both standard-of-care and investigational treatment options. However, taking advantage of the abundance of information gleaned from these panels requires careful annotation, prioritization, and reporting of molecular findings and their clinical significance. Although molecular profiling has traditionally relied on direct sampling of neoplastic tissue, blood-based diagnostics now offer the potential to provide some clinically useful information noninvasively.

Comparison of perioperative and oncological outcomes between video-assisted segmentectomy and lobectomy for patients with clinical stage IA non-small cell lung cancer: a propensity score matching study

Background

Segmentectomy for lung cancer remains controversial because of the complexity of the procedure and concern about an increased recurrence rate. It is important to compare perioperative and oncological outcomes between segmentectomy and lobectomy.

Methods

From January 2007 to December 2016, 41 segmentectomies by video-assisted thoracic surgery (VATS) and 122 VATS lobectomies for 163 patients with clinical stage IA non-small cell lung cancer (NSCLC) were performed. Clinicopathological factors, including recurrence rate and survival rate, were compared. In order to reduce biases of outcomes, clinicopathological factors were used for propensity score matching (PSM). Then, 41 VATS segmentectomies and 41 lobectomies were selected and further analyzed.

Results

No significant differences were seen between the two groups in age, pulmonary function, comorbidity, operative time, blood loss, chest tube duration days, postoperative stay days, complications, histological type, and multiple primary rate. Smoking index resected number of nodes, tumor size, lymph node metastasis rate, and pathological stage were higher in the lobectomy group than in the segmentectomy group (P<0.05). In the lobectomy group, 16 patients (13.1%) had recurrence, and 2 patients (1.6%) died because of cancer progression. There were no significant differences in the recurrence rate and prognosis between the two groups. In addition, Cox regression analysis suggested that sex, lymph node metastasis, and pathology stage were associated with recurrence (P<0.05), but no factor was an independent prognostic factor. After PSM, the two groups had similar clinicopathological factors, and the type of operation still had no relationship with the recurrence rate or the death rate.

Conclusions

Perioperative and oncological outcomes of VATS segmentectomy are similar to those of VATS lobectomy for patients with clinical stage IA NSCLC. VATS segmentectomy can be considered one of the surgical procedures appropriate for patients with clinical stage IA NSCLC.

Micropapillary and/or Solid Histologic Subtype Based on Pre-Treatment Biopsy Predicts Local Recurrence After Thermal Ablation of Lung Adenocarcinoma

BACKGROUND

To investigate whether histologic subtyping from biopsies can predict local recurrence after thermal ablation for lung adenocarcinoma.

METHODS

Patients treated with CT-guided thermal ablation for lung adenocarcinoma that had pre-ablation needle biopsy with analysis of histologic components were identified. Age, gender, smoking status, treatment indication (primary stage 1 tumor versus salvage), histologic subtype, ground-glass radiographic appearance, tumor size, ablation modality, and ablation margin were evaluated in relation to time to local recurrence (TTLR). Cumulative incidence of recurrence (CIR) was calculated using competing risks analysis and compared across groups using Fine and Grey method with clustering. Multivariate analysis was conducted with stepwise regression.

RESULTS

There were 53 patients with 57 tumors diagnosed as adenocarcinoma on pre-ablation biopsy and with histologic subtype analysis. Of these, 19% (11) had micropapillary components, 14% (8) had solid components, and 26% (15) had micropapillary and/or solid components. In the univariate analysis, solid (subdistribution hazard ratio [SHR] = 4.04, p = 0.0051, 95% confidence interval [CI] = 1.52-10.7), micropapillary (SHR = 3.36, p = 0.01, CI = 1.33-8.47), and micropapillary and/or solid components (SHR = 5.85, p = 0.00038, CI = 2.21-15.5) were significantly correlated with shorter TTLR. On multivariate analysis, the presence of micropapillary and/or solid component (SHR = 11.4, p = 0.00021, CI: 3.14-41.3) was the only independent predictor of TTLR. The 1-, 2-, and 3-year CIR in patients with micropapillary and/or solid components was 33, 49, and 66% compared to 5, 14, and 18% in patients with no micropapillary or solid components on biopsy specimens.

CONCLUSION

Micropapillary and/or solid histologic components identified in pre-ablation biopsy are associated with shorter TTLR after thermal ablation of lung adenocarcinoma.

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.

Inaccuracy of lung adenocarcinoma subtyping using preoperative biopsy specimens

BACKGROUND

The prognostic significance of the new classification of lung adenocarcinoma proposed in the 2015 World Health Organization guideline has been validated. This study aimed to compare the preoperative classification of the adenocarcinoma subtype based on computed tomography-guided 18-gauge core needle biopsy (CTNB) or radial probe endobronchial ultrasound (R-EBUS) specimens, with the postoperative classification based on the resected specimens.

METHODS

We retrospectively analyzed a consecutive series of 128 patients (60 CTNB and 68 R-EBUS) who underwent surgery for preoperatively confirmed lung adenocarcinoma between 2010 and 2014. Comprehensive histological subtyping was performed according to the 2015 World Health Organization classification system. Diagnostic concordance of subtypes between small biopsy and resection specimens was assessed.

RESULTS

Concordant subtyping of adenocarcinomas between the predominant pattern on resections and biopsy sections was observed in 58.6% of cases (75 of 128; 95% confidence interval [CI], 49.9%-66.8%). Preoperative subtyping was accurate in only 30% of samples (3 of 10) with a predominance of solid patterns. None of the 5 micropapillary predominant cases was detected by CTNB or R-EBUS. For the concordance of the presence or absence of micropapillary/solid component, the sensitivity was as low as 16.5% (95% CI, 9.1%-26.5%). The detection rate by CTNB/R-EBUS increased with the increase in the percentage of micropapillary/solid component; however, even in the ≥40% micropapillary/solid group, only 24% of cases were detected by CTNB/R-EBUS.

CONCLUSIONS

The accuracy of the estimation of adenocarcinoma histological subtype based on preoperative biopsy sections was unsatisfactory.