Dual-Block Elastic Stain Significantly Increasing Visceral Pleural Invasion(VPI) Positivity and Analysis of Potential Predictors of VPI in Peripheral Non-Small Cell Lung Cancer

Background: Visceral pleural invasion (VPI) is a critical component in the staging of peripheral non–small cell lung carcinoma (NSCLC). Single tumor tissue block for elastic stain is conducive to identifying pleural invasion in routine pathologic examination. We aim to investigate whether dual-block elastic stain increase VPI positivity compared with single-block elastic stain, further analyze the potential predictors of VPI status.Methods: Resected 8419 consecutive peripheral NSCLC cases including tumor size≤3cm 6008 patients were retrospectively reviewed. Total cases were divided into a cohort using one tumor tissue paraffin block (single-block group, n=5184) and a cohort using dual tumor tissue paraffin blocks (dual-block group, n=3235) for elastic stain. Each case was performed with Victoria-blue van Gieson staining to assess VPI status. The clinicopathologic features of patients were collected from the electronic medical record system.Results: The overall incidence of VPI was 12.4% (1047/8419) in peripheral NSCLC patients. The VPI positivity detected by dual-block elastic stain was significantly higher than that by single-block elastic stain (17.7% (573/3235) v.s. 9.1% (474/5184), P＜0.001). The presence of VPI in T1 ≤3cm patients detected by single and dual block elastic stain was 6.3% (235/3730) and 12.0% (273/2278), respectively (P＜0.001). Therefore, 5.7% T1 patients (stage IA) are additionally upstaged to T2a (stage IB) by dual block elastic stain. But the incidence of VPI in pT2a patients had no significant difference between single-block group and dual-block group (16.8% vs 17.1%, P=0.916). The lymphovascular invasion, lymph node metastasis, poor differentiated carcinomas and the presence of STAS status could be well significant predictors of VPI (P＜0.001). Area under the ROC curve of adenocarcinoma morphology was 0.263 for lepidic pattern, 0.544 for acinar and papillary pattern, and 0.720 for micropapillary and solid pattern in predicting invasion of pleura.Conclusion: Our results indicated that using dual-block elastic stain identify more VPI positive T1 NSCLC patients who are upstaged to T2a and could benefit from optimal management after post-operation. The application of dual-block elastic stain is an efficient and practical method to detect VPI, especially for patients with high-risk prognostic factors.

Ultra-High-Resolution CT Features of Pulmonary Nodules Correlate with Visceral Pleural Invasion in Early Stage Lung Adenocarcinoma

Backgroundvisceral pleural invasion (VPI) is an important prognostic factor in early stage lung adenocarcinoma, which can affect the TNM Classification of Tumors.PurposeTo investigate whether ultra-high-resolution computed tomography (U-HRCT) features can predict VPI of early stage pulmonary nodules contacting the interlobar pleura.Material and MethodsA total of 126 patients with lung adenocarcinoma (age, 24-77 years) confirmed by surgical pathology were retrospectively enrolled. All patients underwent U-HRCT scan and were divided into two groups according to pulmonary nodular type: pure (pGGN) and mixed (mGGN). Clinical features were recorded, and U-HRCT features were manually measured using PHILIPS EBW V4.5.5. Univariate and multivariate logistic regression were used to determine factors that can significantly predict VPI. ResultsU-HRCT and three-dimensional orthogonal post-processing method could better display the relationship between GGNs and interlobar fissures. Among all patients, fifteen patients (12%) had VPI. None of the patients with pGGN had VPI. In the mGGN group, the solid ratio (odds ratio [OR]=1.275, 95% CI 1.1-1.478; P=0.001) and solid diameter (OR=1.139, 95% CI 1.06-2.346; P=0.046) were independent risk factors for VPI in early stage lung adenocarcinoma. For VPI diagnosis, the area under the curve, sensitivity, and specificity of the solid ratio and solid diameter were 0.803, 80%, and 75% and 0.807, 80%, and 80.36%, respectively.ConclusionU-HRCT can display GGNs and interlobar fissures in detail. VPI was not detected in patients with pGGN. In patients with mGGNs, a solid diameter >6mm and solid ratio >38% can be independent predictors of VPI, which may be helpful in surgical decision-making.

Nomogram for Predicting the Relationship between the Extent of Visceral Pleural Invasion and Survival in Non-Small-Cell Lung Cancer

Objective. Although visceral pleural invasion (VPI) has already been incorporated into the TNM staging system, few studies have been conducted to evaluate the prognostic value of the extent of VPI for the survival of non-small-cell lung cancer (NSCLC) patients. Thus, we utilized the Surveillance, Epidemiology, and End Results (SEER) database to assess the correlation between the extent of VPI and survival in NSCLC. Methods. We identified and incorporated the extent of VPI to build a prognostic nomogram in this study. Patients in the SEER database diagnosed with NSCLC (n = 87,045) from 2010 to 2015 were further analyzed and randomly assigned into either the training group (n = 60,933) or validation group (n = 26,112). Clinical variables were calculated by means of multivariate Cox regressions and incorporated into the predictive model. Subsequently, the accuracy and discrimination of nomogram were further assessed through the concordance index (C-index), calibration curves, and Kaplan–Meier curves. Results. Multivariate analysis demonstrated that the extent of visceral pleural invasion was an independent and unfavorable prognostic factor. The C-indexes of the training and validation groups were 0.772 (95% CI: 0.770–0.774) and 0.769 (95% CI: 0.765–0.773), respectively, which revealed that the nomogram had sufficient credibility and stable predictive accuracy. The calibration curve displayed consistency between the actual and predictive values in both training and validation groups. Conclusion. The prognostic nomogram with the extent of VPI could offer an accurate risk evaluation for patients with NSCLC. Independent external validation of this research should be conducted in the future.