Evaluation of extratumoral lymphatic permeation in non-small cell lung cancer as a means of predicting outcome

Development and validation of a deep learning signature for predicting lymphovascular invasion and survival outcomes in clinical stage IA lung adenocarcinoma: A multicenter retrospective cohort study

PURPOSE

The presence of lymphovascular invasion (LVI) influences the management and outcomes of patients with clinical stage IA lung adenocarcinoma. The objective was the development of a deep learning (DL) signature for the prediction of LVI and stratification of prognosis.

METHODS

A total of 2077 patients from three centers were retrospectively enrolled and divided into a training set (n = 1515), an internal validation set (n = 381), and an external set (n = 181). A -three-dimensional residual neural network was used to extract the DL signature and three models, namely, the clinical, DL, and combined models, were developed. Diagnostic efficiency was assessed by ROC curves and AUC values. Kaplan-Meier curves and Cox proportional hazards regression analyses were conducted to evaluate links between various factors and disease-free survival.

RESULTS

The DL model could effectively predict LVI, shown by AUC values of 0.72 (95 %CI: 0.68-0.76) and 0.63 (0.54-0.73) in the internal and external validation sets, respectively. The incorporation of DL signature and clinical-radiological factors increased the AUC to 0.74 (0.71-0.78) and 0.77 (0.70-0.84) in comparison with the DL and clinical models (AUC of 0.71 [0.68-0.75], 0.71 [0.61-0.81]) in the internal and external validation sets, respectively. Pathologic LVI, LVI predicted by both DL and combined models were associated with unfavorable prognosis (all p < 0.05).

CONCLUSION

The effectiveness of the DL signature in the diagnosis of LVI and prognosis prediction in patients with clinical stage IA lung adenocarcinoma was demonstrated. These findings suggest the potential of the model in clinical decision-making.

Extracellular vesicle-associated microRNA signatures related to lymphovascular invasion in early-stage lung adenocarcinoma

Lymphovascular invasion (LVI) is a fundamental step toward the spread of cancer. Extracellular vesicles (EVs) promote cellular communication by shuttling cargo, such as microRNAs (miRNAs). However, whether EV-associated miRNAs serve as biomarkers for LVI remains unclear. This study aimed to identify EV-associated miRNAs related to LVI and validate the miRNA levels from patients with early-stage lung adenocarcinoma (LADC). Blood samples were collected from patients undergoing pulmonary resection for stage I LADC before surgery. The patients were classified into three groups according to the presence of LVI and postoperative recurrence. Serum-derived EVs in the derivation cohort were used for small RNA sequencing, while the selected LVI miRNA candidates were validated via real-time quantitative polymerase chain reaction using 44 patient and 16 healthy donor samples as the validation cohorts. Five miRNAs (miR-99b-3p, miR-26a-5p, miR-93-5p, miR-30d-5p, and miR-365b-3p) were assessed, and miR-30d-5p (p = 0.036) levels were significantly downregulated in the LVI-positive group. miR-30d-5p levels in healthy donors were lower than those in LADC patients. Patients with high miR-30d-5p levels had favorable survival compared to those with low miR-30d-5p levels. miR-30d-5p level in EVs may serve as a promising biomarker for detecting LVI in patients with early-stage LADC.

Intratumoral and peritumoral radiomics nomograms for the preoperative prediction of lymphovascular invasion and overall survival in non-small cell lung cancer

OBJECTIVES

To evaluate the predictive value of intratumoral and peritumoral radiomics and radiomics nomogram for preoperative lymphovascular invasion (LVI) status and overall survival (OS) in patients with non-small cell lung cancer (NSCLC).

METHODS

In total, 240 NSCLC patients from our institution were randomly divided into the training cohort (n = 145) and internal validation cohort (n = 95) with a ratio of 6:4, and 65 patients from the Cancer Imaging Archive were enrolled as the external validation cohort. We extracted 1217 CT-based radiomics features from the gross tumor volume (GTV) and gross tumor volume incorporating peritumoral 3, 6, and 9 mm regions (GPTV₃, GPTV₆, GPTV₉). A radiomics nomogram based on clinical independent predictors and radiomics score (Radscore) of the best radiomics model was constructed. The correlation between factors and OS was evaluated with the Kaplan-Meier survival analysis and Cox proportional hazards regression analysis.

RESULTS

Compared with GTV, GPTV₃, and GPTV₆ radiomics models, GPTV₉ radiomics model exhibited better prediction performance with the AUCs of 0.82, 0.75, and 0.67 in the training, internal validation, and external validation cohorts, respectively. In the clinical model, smoking and clinical stage were independent predictors. The nomogram incorporating independent predictors and GPTV₉-Radscore was clinically useful, with the AUCs of 0.89, 0.83, and 0.66 in three cohorts. Pathological LVI, GPTV₉-Radscore-predicted, and Nomoscore-predicted LVI were associated with poor OS (p < 0.05).

CONCLUSIONS

CT-based radiomics nomogram can predict LVI and OS in patients with NSCLC and may help in making personalized treatment strategies before surgery.

KEY POINTS

• Compared with GTV, GPTV₃, and GPTV₆ radiomics models, GPTV₉ radiomics model showed better prediction performance for LVI status in NSCLC. • The radiomics nomogram based on GPTV₉ radiomics features and clinical independent predictors could effectively predict LVI status and OS in NSCLC and outperformed the clinical model. • The radiomics nomogram had a wider scope of clinical application.

Prognostic impact of count of extratumoral lymphatic permeation in lung adenocarcinoma and its relation to immune microenvironment

Extratumoral lymphatic permeation (ly‐ext) has been reported as an independent poor prognostic factor for lung adenocarcinoma, but whether or not the number of ly‐ext foci is associated with prognosis and its relationship to the immune microenvironment is unclear. We counted the number of ly‐ext foci on pathological slides from patients with completely resected lung adenocarcinoma with ly‐ext, and divided them into two groups: a group with a high number of ly‐ext foci (ly‐ext high) and one with a low number of ly‐ext foci (ly‐ext low). Among the patients with ly‐ext, only a high number of ly‐ext foci was an independent poor prognostic factor. The 3‐year recurrence‐free survival (RFS) rate of the ly‐ext high group was significantly lower than that of the ly‐ext low group (14.7% vs. 50.0%, P < 0.01). Then, we analyzed the immune microenvironment of pT1 lung adenocarcinoma with ly‐ext (13 cases of ly‐ext high and 11 cases of ly‐ext low tumor) by immunohistochemistry using antibodies for stem cell markers (aldehyde dehydrogenase 1 A1 and CD44), tumor‐promoting mucin (MUC1), tumor‐infiltrating lymphocytes (CD4, CD8, FOXP3, and CD79a), and tumor‐associated macrophages (CD204). The number of CD8+ TILs within the primary lesion was significantly lower and the number of FOXP3+ TILs within the primary lesion was significantly higher in the ly‐ext high group (P < 0.05 and P < 0.01, respectively). Our results indicated that a high number of ly‐ext foci was an independent poor prognostic factor. Moreover, tumors with high numbers of ly‐ext foci had a more immunosuppressive microenvironment.

Improving the accuracy of prognosis for clinical stage I solid lung adenocarcinoma by radiomics models covering tumor per se and peritumoral changes on CT

OBJECTIVES

To assess methods to improve the accuracy of prognosis for clinical stage I solid lung adenocarcinoma using radiomics based on different volumes of interests (VOIs).

METHODS

This retrospective study included patients with postoperative clinical stage I solid lung adenocarcinoma from two hospitals, center 1 and center 2. Three databases were generated: dataset A (training set from center 1), dataset B (internal test set from center 1), and dataset C (external validation test from center 2). Disease-free survival (DFS) data were collected. CT radiomics models were constructed based on four VOIs: gross tumor volume (GTV), 3 mm external to the tumor border (peritumoral volume [PTV]_0~+3), 6 mm crossing tumor border (PTV_-3~+3), and 6 mm external to the tumor border (PTV_0~+6). The area under the receiver operating characteristic curve (AUC) was used to compare the model accuracies.

RESULTS

A total of 334 patients were included (204 and 130 from centers 1 and 2). The model using PTV_-3~+3 (AUC 0.81 [95% confidence interval {CI}: 0.75, 0.94], 0.81 [0.63, 0.90] for datasets B and C) outperformed the other three models, GTV (0.73 [0.58, 0.81], 0.73 [0.58, 0.83]), PTV_0~+3 (0.76 [0.52, 0.87], 0.75 [0.60, 0.83]), and PTV_0~+6 (0.72 [0.60, 0.81], 0.69 [0.59, 0.81]), in datasets B and C, all p < 0.05.

CONCLUSIONS

A radiomics model based on a VOI of 6 mm crossing tumor border more accurately predicts prognosis of clinical stage I solid lung adenocarcinoma than that based on VOIs including overall tumor or external rims of 3 mm and 6 mm.

KEY POINTS

• Radiomics is a useful approach to improve the accuracy of prognosis for stage I solid adenocarcinoma. • The radiomics model based on VOIs that includes 3 mm within and external to the tumor border (peritumoral volume [PTV]_-3~+3) outperformed models that included either only the tumor itself or those that only included the peritumoral volume.

Integrative nomogram of intratumoral, peritumoral, and lymph node radiomic features for prediction of lymph node metastasis in cT1N0M0 lung adenocarcinomas

Radiomics studies to predict lymph node (LN) metastasis has only focused on either primary tumor or LN alone. However, combining radiomics features from multiple sources may reflect multiple characteristic of the lesion thereby increasing the discriminative performance of the radiomic model. Therefore, the present study intends to evaluate the efficiency of integrative nomogram, created by combining clinical parameters and radiomics features extracted from gross tumor volume (GTV), peritumoral volume (PTV) and LN, for the preoperative prediction of LN metastasis in clinical cT1N0M0 adenocarcinoma. A primary cohort of 163 patients (training cohort, 113; and internal validation cohort, 50) and an external validation cohort of 53 patients with clinical stage cT1N0M0 were retrospectively included. Features were extracted from three regions of interests (ROIs): GTV; PTV (5.0 mm around the tumor) and LN on pre-operative contrast enhanced computed tomography (CT). LASSO logistic regression method was used to build radiomic signatures. Multivariable regression analysis was used to build a nomogram. The performance of the nomogram was assessed with respect to its calibration, discrimination, and clinical usefulness. The discriminative performance of nomogram was validated both internally and externally. The radiomic signatures using the features of GTV, PTV and LN showed a good ability in predicting LN metastasis with an area under the curve (AUC) of 0.74 (95% CI 0.60–0.88), 0.72 (95% CI 0.57–0.87) and 0.64 (95% CI 0.48–0.80) respectively in external validation cohort. The integration of different signature together further increases the discriminatory ability: GTV + PTV (GPTV): AUC 0.75 (95% CI 0.61–0.89) and GPTV + LN: AUC 0.76 (95% CI 0.61–0.91) in external validation cohort. An integrative nomogram of clinical parameters and radiomic features demonstrated further increase in discriminatory ability with AUC of 0.79 (95% CI 0.66–0.93) in external validation cohort. The nomogram showed good calibration. Decision curve analysis demonstrated that the radiomic nomogram was clinically useful. The integration of information from clinical parameters along with CT radiomics information from GTV, PTV and LN was feasible and increases the predictive performance of the nomogram in predicting LN status in cT1N0M0 adenocarcinoma patients suggesting merit of information integration from multiple sources in building prediction model.

Prognostic markers in resected large cell neuroendocrine carcinoma: a multicentre retrospective analysis

Background

Large cell neuroendocrine carcinomas (LCNEC) are rare pulmonary malignancies. Reported survival rates are heterogeneous and the optimal therapeutic strategy is still debated. The prognosis of LCNEC is generally inferior compared to other non-small lung cancers. In early stages, surgery is recommended but might not be sufficient alone.

Methods

We retrospectively analyzed all consecutive LCNEC patients operated at three institutions with curative intent between May 2005 and January 2017. Data retrieved from individual clinical databases were analyzed with the aim to identify prognostic parameters.

Results

A total of 251 patients with LCNEC underwent curative intent surgery during the observation period. The median age was 64 years, 156 patients (62.2%) were male and 88.4% were smokers. The pathologic AJCC stage was I in 136 patients, II in 77, III in 33, and IV in 5 patients. Median follow-up was 26 months. Lymphatic vessel invasion (P=0.031) was identified as significant prognostic factor by multivariable analysis. There was a trend towards decreased survival in patients with blood vessel invasion (P=0.067). Even in earlier tumor stages, adjuvant chemotherapy had a positive effect on survival. The overall 1-, 3- and 5-year survival rates were 79.2%, 48.6% and 38.8% respectively.

Conclusions

Lymphatic invasion (L1) is an independent prognostic factor. Surgery in LCNEC is beneficial in early tumor stages and platinum-based adjuvant chemotherapy may help in achieving better long-term outcomes resulting in most obvious survival differences in stage Ib.

Prognostic significance of blood and lymphatic vessel invasion in pathological stage IA lung adenocarcinoma in the 8th edition of the TNM classification

OBJECTIVES

The prognostic significance of blood and lymphatic vessel invasion in the 8th edition of the Tumor, Node, Metastasis (TNM) classification remains unclear. Therefore, this study aimed to evaluate the prognostic significance of blood and lymphatic vessel invasion in p-stage IA lung adenocarcinoma in the 8th edition of the TNM classification.

MATERIALS ANDMETHODS

We retrospectively examined patients with p-Stage 0-IA lung adenocarcinoma, reclassified according to the 8th edition of the TNM classification. Blood and lymphatic vessel invasion were evaluated using hematoxylin-eosin and Elastica van Gieson and hematoxylin-eosin and anti-podoplanin antibody staining, respectively. Combined blood and lymphatic vessel invasion constituted tumor vessel invasion (TVI).

RESULTS

Overall, 306 patients were evaluated. The median follow-up period was 98.0 (range: 10-216) months. The 5-year recurrence-free survival differed significantly among patients with and without TVI in p-stage IA1 (TVI-: 100%, TVI+: 88.9%, P = 0.007) and IA2 (TVI-: 94.6%, TVI+: 80.8%, P = 0.012) but not in p-stage IA3 (TVI-: 66.7%, TVI+: 75.0%, P = 0.598). The 5-year lung cancer-specific survival also differed significantly among those with and without TVI in p-stage IA1 (TVI-: 100%, TVI+: 88.9%, P < 0.001) and IA2 (TVI-: 98.2%, TVI+: 88.7%, P = 0.043) but not in p-Stage IA3 (TVI-: 66.7%, TVI+: 75.0%, P = 0.858). No recurrence and lung cancer-specific deaths occurred in p-stage IA1 patients without TVI. On multivariate analysis, the presence of TVI was independently associated with recurrence and lung cancer-specific death in patients with p-stage IA1-2 lung adenocarcinoma. TVI did not affect the prognosis of those with p-stage IA3 adenocarcinoma.

CONCLUSION

TVI is a prognostic factor in patients with p-stage IA1-2 lung adenocarcinoma. P-stage IA1 lung adenocarcinoma without TVI may therefore be classified as minimally invasive.

Combination of Peri- and Intratumoral Radiomic Features on Baseline CT Scans Predicts Response to Chemotherapy in Lung Adenocarcinoma

Purpose

To identify the role of radiomics texture features both within and outside the nodule in predicting (a) time to progression (TTP) and overall survival (OS) as well as (b) response to chemotherapy in patients with non-small cell lung cancer (NSCLC).

Materials and Methods

Data in a total of 125 patients who had been treated with pemetrexed-based platinum doublet chemotherapy at Cleveland Clinic were retrospectively analyzed. The patients were divided randomly into two sets with the constraint that there were an equal number of responders and nonresponders in the training set. The training set comprised 53 patients with NSCLC, and the validation set comprised 72 patients. A machine learning classifier trained with radiomic texture features extracted from intra- and peritumoral regions of non-contrast-enhanced CT images was used to predict response to chemotherapy. The radiomic risk-score signature was generated by using least absolute shrinkage and selection operator with the Cox regression model; association of the radiomic signature with TTP and OS was also evaluated.

Results

A combination of radiomic features in conjunction with a quadratic discriminant analysis classifier yielded a mean maximum area under the receiver operating characteristic curve (AUC) of 0.82 ± 0.09 (standard deviation) in the training set and a corresponding AUC of 0.77 in the independent testing set. The radiomics signature was also significantly associated with TTP (hazard ratio [HR], 2.8; 95% confidence interval [CI]: 1.95, 4.00; P < .0001) and OS (HR, 2.35; 95% CI: 1.41, 3.94; P = .0011). Additionally, decision curve analysis demonstrated that in terms of clinical usefulness, the radiomics signature had a higher overall net benefit in prediction of high-risk patients to receive treatment than the clinicopathologic measurements.

Conclusion

This study suggests that radiomic texture features extracted from within and around the nodule on baseline CT scans are (a) predictive of response to chemotherapy and (b) associated with TTP and OS for patients with NSCLC.© RSNA, 2019Supplemental material is available for this article.

Peritumoral radiomics features predict distant metastasis in locally advanced NSCLC

Purpose

Radiomics provides quantitative tissue heterogeneity profiling and is an exciting approach to developing imaging biomarkers in the context of precision medicine. Normal-appearing parenchymal tissues surrounding primary tumors can harbor microscopic disease that leads to increased risk of distant metastasis (DM). This study assesses whether computed-tomography (CT) imaging features of such peritumoral tissues can predict DM in locally advanced non-small cell lung cancer (NSCLC).

Material and methods

200 NSCLC patients of histological adenocarcinoma were included in this study. The investigated lung tissues were tumor rim, defined to be 3mm of tumor and parenchymal tissue on either side of the tumor border and the exterior region extended from 3 to 9mm outside of the tumor. Fifteen stable radiomic features were extracted and evaluated from each of these regions on pre-treatment CT images. For comparison, features from expert-delineated tumor contours were similarly prepared. The patient cohort was separated into training and validation datasets for prognostic power evaluation. Both univariable and multivariable analyses were performed for each region using concordance index (CI).

Results

Univariable analysis reveals that six out of fifteen tumor rim features were significantly prognostic of DM (p-value < 0.05), as were ten features from the visible tumor, and only one of the exterior features was. Multivariablely, a rim radiomic signature achieved the highest prognostic performance in the independent validation sub-cohort (CI = 0.64, p-value = 2.4×10⁻⁵) significantly over a multivariable clinical model (CI = 0.53), a visible tumor radiomics model (CI = 0.59), or an exterior tissue model (CI = 0.55). Furthermore, patient stratification by the combined rim signature and clinical predictor led to a significant improvement on the clinical predictor alone and also outperformed stratification using the combined tumor signature and clinical predictor.

Conclusions

We identified peritumoral rim radiomic features significantly associated with DM. This study demonstrated that peritumoral imaging characteristics may provide additional valuable information over the visible tumor features for patient risk stratification due to cancer metastasis.

Management of Brain Metastasis in Patients With Pulmonary Neuroendocrine Carcinomas

Background:

The patterns of intracranial failure in patients with brain metastasis from pulmonary neuroendocrine carcinoma (PNEC) remain unknown.

Methods:

From 1998 to 2013, 29 patients with the diagnosis of PNEC were treated for brain metastasis: 16 patients (55%) underwent whole-brain radiation therapy (WBRT), 5 (17%) patients underwent WBRT with a stereotactic radiosurgery (SRS) boost, and 8 (28%) patients underwent primary SRS alone.

Results:

The median age at treatment was 61 years (range: 44-84 years) and the median follow-up was 9.6 months (0-157.4 months). Of the patients treated with SRS alone, 1 patient had radiographic local progression of disease and 1 patient had a distant intracranial failure. Of the patients treated with WBRT with or without an SRS boost, 9 patients developed intracranial progression, including 1 local failure. No differences in rates of intracranial progression or local failure between the 2 groups ( P = .94 and P = .44, respectively) were observed. The actuarial rates of distant intracranial failure at 12 months were 32.9% (95% confidence interval [95% CI] 8.9%-56.8%) and 25% (95% CI 0.0%-67.4%) in patients undergoing primary WBRT or SRS, respectively ( P = .31). The median overall survival was 15.8 months in patients treated with WBRT and 20.4 months in patients treated with primary SRS ( P = .78).

Conclusion:

Patients with brain metastasis from PNECs can be effectively treated with either WBRT or SRS alone, with a pattern of failure more consistent with non-small cell lung cancer than small cell lung cancer. In this series, there was not a statistically significant increased risk of distant intracranial failure when patients were treated with primary SRS.

Lymphangiogenic Markers and Their Impact on Nodal Metastasis and Survival in Non-Small Cell Lung Cancer--A Structured Review with Meta-Analysis

Background

In non-small cell lung cancer (NSCLC), nodal metastasis is an adverse prognostic factor. Several mediating factors have been implied in the development of nodal metastases and investigated for predictive and prognostic properties in NSCLC. However, study results differ. In this structured review and meta-analysis we explore the published literature on commonly recognized pathways for molecular regulation of lymphatic metastasis in NSCLC.

Methods

A structured PubMed search was conducted for papers reporting on the expression of known markers of lymhangiogenesis in NSCLC patients. Papers of sufficient quality, presenting survival and/or correlation data were included.

Results

High levels of vascular endothelial growth factor C (VEGF-C, HR 1.57 95% CI 1.34–1.84) and high lymphatic vascular density (LVD, HR 1.84 95% CI 1.18–2.87) were significant prognostic markers of poor survival and high expression of VEGF-C, vascular endothelial growth factor receptor 3 (VEGFR3) and LVD was associated with lymph node metastasis in NSCLC.

Conclusion

Lymphangiogenic markers are prognosticators of survival and correlate with lymph node metastasis in NSCLC. Their exact role and clinical implications should be further elucidated.

Prognostic impact of vascular invasion and standardization of its evaluation in stage I non-small cell lung cancer

Background

Patients with pathologic stage (p-Stage) IA non-small cell lung cancer (NSCLC) have a good survival rate because of possible curative resection. However, up to 10% of these patients relapse postoperatively. To identify unfavorable prognostic factors, we retrospectively analyzed the clinicopathological features of p-Stage IA disease, focusing on vascular invasion.

Methods

Of 467 patients with p-Stage I NSCLC, 335 were diagnosed with p-Stage IA or IB disease based on a lesion size ≤3 cm and the presence of pleural invasion (PL). Univariate and multivariate analyses of recurrence-free survival (RFS) were performed with age, sex, PL, and vascular invasion (blood vessel invasion [v] and lymphatic vessel invasion [ly]) as variables. To examine vascular invasion, hematoxylin-eosin (HE), Elastica van Gieson staining, and immunostaining with anti-podoplanin antibody were performed. The presence or absence of v and ly was recorded; the number of involved vessels was counted. Survival rates were obtained using the Kaplan–Meier method and log-rank test. Multivariate analyses were performed using the Cox proportional hazards model.

Results

RFS differed significantly between patients with no or one involved blood vessel (0 v or 1 v) and those with ≥2 involved vessels (≥2 v). Similarly, RFS differed significantly between patients with no lymphatic vessel involvement (0 ly) and those with one involved lymphatic vessel (1 ly). Thus, BVI(+) and BVI(−) were defined as ≥2 v and 0 v + 1 v, and LVI(+) and LVI(−) as ≥1 ly and 0 ly, respectively. BVI and LVI together represented tumor vessel invasion (TVI). On multivariate analyses, PL and TVI were independently associated with recurrence. Additionally, patients with p-Stage IA TVI(+) disease had a comparable recurrence rate to those with p-Stage IB disease.

Conclusions

Similar to PL, TVI is an important factor increasing the likelihood of recurrence. As HE staining alone is insufficient for evaluating vascular invasion, specific staining is necessary. Moreover, patients with p-Stage IA TVI(+) disease had a recurrence rate comparable to those with p-Stage IB disease; therefore, further studies should aim to elucidate whether patients with p-Stage IA TVI(+) disease should be administered postoperative chemotherapy similar to that received by p-Stage IB patients.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5213064891369688

Impact of extratumoral lymphatic permeation on postoperative survival of non-small-cell lung cancer patients

Introduction:

Lymphatic permeation has been reported as a prognostic factor for patients with resected non–small-cell lung cancer (NSCLC). Lymphatic canals are located in both intratumoral and extratumoral areas. Since 2001, we have prospectively evaluated lymphatic permeation based on its location. The purpose of this study was to determine the survival impact of extratumoral lymphatic permeation in patients with resected NSCLC by analyzing the long-term follow-up data.

Methods:

We reviewed 1069 consecutive patients with NSCLC who underwent complete resection between 2001 and 2006. Lymphatic permeation was classified as follows: ly0, absence of lymphatic permeation; ly1, intratumoral; and ly2, extratumoral.

Results:

There were 845 patients (79%) with ly0, 134 (12%) with ly1, and 90 (9%) with ly2. Ly2 was more frequently observed in patients with advanced disease and intrapulmonary metastases than ly0–1. The 5-year overall survival (OS) rates of the ly0, ly1, and ly2 groups were 75%, 63%, and 34%, respectively. The OS rate was significantly worse in the ly2 group compared with OS rate in the ly0 (p < 0.01) and ly1 groups (p < 0.01). In multivariate analyses, ly2 proved to be an independent poor prognostic factor (hazard ratio, 1.73; p < 0.01). OS and recurrence-free survival of patients with T1 and T2 tumors with ly2 were not statistically different from that of the patients with T3 tumor (OS, p = 0.43 and p = 0.77; recurrence-free survival, p = 0.94 and p = 0.94, respectively).

Conclusions:

The adverse prognostic impact of lymphatic permeation was remarkably different whether it is detected in intratumoral or extratumoral lymphatic canals. We recommend that lymphatic permeation in resected NSCLC should be evaluated by considering its location.

Identification of biological properties of intralymphatic tumor related to the development of lymph node metastasis in lung adenocarcinoma

Background

Intralymphatic tumors in the extratumoral area are considered to represent the preceding phase of lymph node metastasis. The aim of this study was to clarify the biological properties of intralymphatic tumors susceptible to the development of lymph node metastasis, with special reference to the expression of cancer initiating/stem cell (CIC/CSC) related markers in cancer cells and the number of infiltrating stromal cells.

Material and Methods

Primary lung adenocarcinomas with lymphatic permeation in the extratumoral area were retrospectively examined (n = 107). We examined the expression levels of CIC/CSC related markers including ALDH1, OCT4, NANOG, SOX2 and Caveolin-1 in the intralymphatic cancer cells to evaluate their relationship to lymph node metastasis. Moreover, the number of infiltrating stromal cells expressing CD34, α-smooth muscle actin, and CD204 were also evaluated.

Results

Among the intralymphatic tissues, low ALDH1 expression in cancer cells, high SOX2 expression in cancer cells, and a high number of CD204(+) macrophages were independent predictive factors for lymph node metastasis (P = 0.004, P = 0.008, and P = 0.028, respectively). Among these factors, only low ALDH1 expression in cancer cells was significantly correlated with the farther spreading of lymph node metastasis (mediastinal lymph node, pathological N2) (P = 0.046) and the metastatic lymph node ratio (metastatic/resected) (P = 0.028). On the other hand, in the primary tumors, ALDH1 expression in the cancer cells was not associated with lymph node metastasis. Intralymphatic cancer cells expressing low ALDH1 levels exhibited lower E-cadherin expression levels than cancer cells with high levels of ALDH1 expression (P = 0.015).

Conclusions

Intralymphatic cancer cells expressing low levels of ALDH1 and infiltrating macrophages expressing CD204 have a critical impact on lymph node metastasis. Our study also highlighted the significance of evaluating the biological properties of intralymphatic tumors for tumor metastasis.

Prognostic impact of vascular and lymphovascular invasion in early lung cancer

Background

The prognostic significance of vascular and lymphatic invasion in non-small-cell lung cancer is under continuous debate. We analyzed the effect of tumor aggressiveness (lymphatic and/or vessel invasion) on survival and relapse in stage I and II non-small-cell lung cancer.

Methods

We retrospectively analyzed prospectively collected data of 457 patients with stage I and II non-small-cell lung cancer from 1998 to 2008. Specimens were analyzed for intratumoral vascular invasion and lymphovascular space invasion. Overall survival and disease-free survival were estimated using the Kaplan-Meier method, and differences were determined by the logrank test. Cox regression analysis was performed to identify independent risk factors.

Results

The incidence of intratumoral vascular invasion was 23.4%, and this correlated significantly with grade of differentiation, visceral pleural involvement, lymphovascular space invasion, and N status. The incidence of lymphovascular space invasion was 5.5%, and this correlated significantly with grade of differentiation, lymph nodes involved, and intratumoral vascular invasion. On multivariate analyses, intratumoral vascular invasion proved to be an significant independent risk factor for overall survival but not for disease-free survival. Lymphovascular space invasion was associated significantly with early tumor recurrence but not with overall survival.

Conclusions

Vascular and lymphatic invasion can serve as independent prognostic factors in completely resected non-small-cell lung cancer. Intratumoral vascular invasion and lymphovascular space invasion in early stage non-small-cell lung cancer are important factors in overall survival and early tumor recurrence. Further large scale studies with more recent patient cohorts and refined histological techniques are warranted.

Clinical significance and role of lymphatic vessel invasion as a major prognostic implication in non-small cell lung cancer: a meta-analysis

Background

Lymphatic vessel invasion (LVI) exerts an important process in the progression and local spread of cancer cells. However, LVI as a prognostic factor for survival in non-small cell lung cancer (NSCLC) remains controversial.

Methodology/Principal Findings

A meta-analysis of published studies from PubMed and EMBASE electronic databases was performed to quantity the effects of LVI on both relapse-free survival and overall survival for patients with NSCLC. Hazard ratios (HRs) with 95% confidence intervals (95% CIs) were used to assess the strength of these effects. This meta-analysis included 18,442 NSCLC patients from 53 eligible studies. LVI appeared in 32.1% (median; range, 2.8% to 70.9%) of tumor samples. In all, patients with LVI were 2.48 times more likely to relapse by univariate analysis (95% CI: 1.92–3.22) and 1.73 times by multivariate analysis (95% CI: 1.24–2.41) compared with those without LVI. For the analyses of LVI and overall survival, the pooled HR estimate was 1.97 (95% CI: 1.75–2.21) by univariate analysis and 1.59 (95% CI: 1.41–1.79) by multivariate analysis. Multivariate analysis showed a risk was 91% higher for recurrence (HR  = 1.91, 95% CI: 1.14–2.91) and 70% higher for mortality (HR = 1.70, 95% CI: 1.38–2.10) in LVI-positive I stage patients compared with LVI-negative I stage patients. Subgroup analyses showed similar significant adjusted risks for recurrence and death in adenocarcinomas, and a significant adjusted risk for death in studies that utilized elastic staining with or without immunohistochemistry in defining LVI.

Conclusions/Significance

The present study indicates that LVI appears to be an independent poor prognosticator in surgically managed NSCLC. NSCLC patients with LVI would require a more aggressive treatment strategy after surgery. However, large, well-designed prospective studies with clinically relevant modeling and standard methodology to assess LVI are required to address some of these important issues.

Prognostic impact of intratumoural microvascular invasion and microlymphatic permeation on node-negative non-small-cell lung cancer: which indicator is the stronger prognostic factor?

OBJECTIVES

Microvascular invasion and microlymphatic permeation are indicators of microscopic tumour invasion into small vessels and have been considered to be powerful prognostic indicators for non-small-cell lung cancer (NSCLC). Several studies have suggested that these should be included in the TNM classification, but, there have been conflicting results regarding the prognostic impact of microvascular invasion and microlymphatic permeation. The aim of the current study was to clarify the prognostic impact of microvascular invasion and microlymphatic permeation on resected node-negative NSCLC by comparative analyses.

METHODS

We reviewed the data of 1039 consecutive patients with pathological size-based stage T1a-3N0M0 NSCLC who underwent lobectomy or greater resection between 1993 and 2005. The median follow-up period was 108 months. Microvascular invasion and microlymphatic permeation were identified by the Victoria blue-van Gieson staining. The overall survival was then analysed.

RESULTS

Microvascular invasion and microlymphatic permeation were observed in 358 (34.5%) and 205 (19.7%) of patients, respectively. Both microvascular invasion and microlymphatic permeation were more prevalent in non-adenocarcinoma and larger-sized tumours. The 5-year overall survival rate of the microvascular invasion-positive group and microlymphatic permeation-positive group were 69.2 and 84.6%, respectively, and the difference was statistically significant (P = 0.002). On multivariate analyses, microvascular invasion, but not microlymphatic permeation, was an independent prognostic factor (microvascular invasion, hazard ratio [HR] 1.648, P = 0.001; microlymphatic permeation, HR 1.138, P = 0.588). The 5-year overall survival rate of either the microvascular invasion- or microlymphatic permeation-positive T1a-b group was significantly lower than that of the corresponding double-negative (dn) T1a-b group (dnT1a-b, 93.7%; microvascular invasion-positive T1a-b, 85.2%, P < 0.001; microlymphatic permeation-positive T1a-b, 85.4%, P = 0.014), and overlapped to that of the dnT2a group (84.8%). However, in the T2a-b group, only microvascular invasion-positive T2a-b patients showed significantly lower overall survival than dnT2a-b patients, and their overall survival overlapped that of dnT3 patients (dn T2a-b, 83.5%; microvascular invasion-positive T2a-b, 60.6%, P < 0.001; dnT3, 53.8%; P = 0.316). The 5-year overall survival of microlymphatic permeation-positive T2a-b patients (86.2%) did not statistically differ from that of dnT2a-b patients (P = 0.856).

CONCLUSIONS

Microvascular invasion and microlymphatic permeation have different impact on survival, and microvascular invasion rather than microlymphatic permeation is a strong prognostic factor in resected node-negative NSCLC. Microvascular invasion and microlymphatic permeation should be examined separately by elastic staining.

Morphophenotypic characteristics of intralymphatic cancer and stromal cells susceptible to lymphogenic metastasis

The intravessel microenvironment has significant effects on cancer metastasis. The aim of the present study was to determine how the morphologic and immunophenotypic features of cancer cells and infiltrating stromal cells within the permeated lymphatic vessels are associated with lymphogenic metastasis. A total of 137 primary lung adenocarcinoma patients with extratumoral lymphatic permeations were examined. Morphologically, the floating cancer nests within the permeated lymphatic vessels were divided into two types: Type A, consisting of a single large cancer nest; and Type B, consisting of multiple small cancer nests. We compared the clinicopathologic characteristics and the immunophenotypes of the cancer cells and infiltrating stromal cells between the Type A and Type B nests. Eleven of 54 Type A patients (20%) had intrapulmonary metastases, compared with 36 of 83 Type B patients (43%; P = 0.006). Immunohistochemically, Type B cancer cells expressed significantly higher levels of CD44 than Type A cancer cells (mean scoresAUTHOR: Scores - what is this score? Is it the number of cells expressing CD44 or the concentration of CD44 or some other type of scoring system? 43.0 vs 20.5, respectively) and E-cadherin (60.5 vs 31.5, respectively), but lower levels of Geminin (11.9% vs 20.3%, respectively) and cleaved caspase 3 (2.4% vs 7.8%AUTHOR: 11.9% vs 20.3%, respectively) and cleaved caspase 3 (2.4% vs 7.8%, - what do the percentages here refer to? The number of cells expressing geminin and caspase 3? The levels of these factors? Please clarify., respectively). Moreover, a significantly larger number of CD204-positive macrophages were present within the cancer-permeated lymphatic vessels in Type B patients than in Type A patients (mean number 9.5 vs 4.6, respectively). The present study reveals that intralymphatic cancer cell and stromal cell phenotypes are susceptible to lymphogenic metastasis, suggesting that lymphogenic metastasis may be affected by the intralymphatic microenvironment they create.

Extratumoral vascular invasion is a significant prognostic indicator and a predicting factor of distant metastasis in non-small cell lung cancer

INTRODUCTION

Vascular invasion is thought to be a fundamental step in hematogenous metastasis. The aim of this study was to assess whether the qualitative evaluation of vascular invasion according to its location (intratumoral or extratumoral) could provide an appropriate means of predicting the prognostic outcome and potential patterns of recurrence in non-small cell lung cancer.

METHODS

We reviewed the cases of 1000 consecutive patients in whom complete resection of non-small cell lung cancer had been performed. Sections stained by the Victoria blue van Gieson method were examined for the presence of vascular invasion and the evaluation of its location (v0: absence, n = 540; v1: intratumoral, n = 428; v2: extratumoral, n = 32). Survival was estimated using the Kaplan-Meier method. To determine independent prognostic factors, univariate and multivariate analyses were conducted.

RESULTS

The study cohort included 605 men and 395 women, with a mean age of 66 years (range, 20-90 years). The 5-year overall survival rate of the vascular invasion-negative group and the vascular invasion-positive group was 82.5% and 55.1%, respectively (p < 0.001), and the 5-year overall survival rates of the v1 group and v2 groups were 55.9% and 44.0%, respectively (p = 0.010). Multivariate analysis showed that location of the vascular invasion (v0-1 versus v2) (p = 0.049), age (p = 0.030), tumor size (p = 0.004), lymph node metastasis (p < 0.001), and pleural invasion (p < 0.001) were significant prognostic factors. The proportion of patients who developed distant metastasis was significantly higher in the v2 group than in the v1 group (p = 0.026).

CONCLUSION

Evaluation of vascular invasion location was a statistically significant predictor of prognosis and potential recurrence patterns.

Detection of lymphangiogenesis in non-small cell lung cancer and its prognostic value

BACKGROUND

Our aim was to detect lymphatic endothelial marker podoplanin, lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) and vascular endothelial growth factor receptor-3 (VEGFR)-3 and study the prognostic relevance of lymphangiogenesis in non-small cell lung cancer (NSCLC).

MATERIALS

82 paraffin-embedded tissues and 40 fresh frozen tissues from patients with NSCLC were studied. Tumor samples were immunostained for the lymphatic endothelial markers. Lymphangiogenesis was assessed by immunohistochemical double stains for Podoplanin and Ki-67. The prognostic relevance of lymphangiogenesis-related clinicopathological parameters in NSCLC was evaluated.

RESULTS

We found that the number of podoplanin positive vessels was correlated positively with the number of LYVE-1 positive vessels. Most of VEGFR-3 positive, few of LYVE-1 positive and none of podoplanin positive vessels were blood vessels. Peritumoral lymphatic vessel density (ptLVD), pathologic stage, lymph node status, lymphatic vessel invasion (LVI), vascular endothelial growth factor-C (VEGF-C) expression and Ki-67 index of the endothelium cells of the micro lymphatic vessels (Ki67%) were associated significantly with a higher risk of tumor progress. ptLVD, pathologic stage, lymph-node metastasis and Ki67% were independent prognostic parameters for overall survival.

CONCLUSION

Podoplanin positive ptLVD might play important roles in the lymphangiogenesis and progression of NSCLC. Patients with high podoplanin+ ptLVD have a poor prognosis.

Intrapulmonary metastasis in resected pathologic stage IIIB non–small cell lung cancer: Possible contribution of aerogenous metastasis to the favorable outcome

OBJECTIVE

Non-small cell lung cancer with pulmonary metastasis in the primary lobe (PM+) is classified as pathologic stage IIIB. Although stage IIIB PM+ indicates a poor prognosis, this stage includes various subgroups with heterogeneous clinical outcomes. The objective of this study was to extract a subgroup of patients with stage IIIB PM+ non-small cell lung cancer with a better prognosis and assess their biological characteristics and metastatic mechanisms.

METHODS

We reviewed 122 cases of surgically resected stage IIIB PM+ non-small cell lung cancer and extracted a subgroup with a favorable outcome by univariate analysis of clinicopathologic factors. The 15 cases without lymph node metastasis and vessel invasion (PM+/N-/VI-) were extracted as the most favorable group. We assessed the clinicopathologic features of the PM+/N-/VI- group in comparison with the other patients with stage IIIB PM+ disease.

RESULTS

The disease-specific survival of the PM+/N-/VI- group was significantly better than that of the other stage IIIB PM+ group. Microscopic characteristics of the metastatic lesions suggesting that the cancer cells had invaded via the aerogenous route were seen in 86.7% of the PM+/N-/VI- group, as opposed to only 9.4% of the other PM+ cases. Furthermore, in all 4 patients in the PM+/N-/VI- group who had a recurrence, the relapse involved intrapulmonary metastasis, rather than distant organ metastasis.

CONCLUSIONS

Stage IIIB PM+ cases via the airway route were enriched in the PM+/N-/VI- group and had an extremely good survival. This group should be recognized as having local disease, and if relapse occurs in the remnant lobe, it may be possible to achieve a cure by local therapy.