Impact of Elastic Staining on the Staging of Peripheral Lung Cancers

Diagnosis, treatment, and prognosis of stage IB non-small cell lung cancer with visceral pleural invasion

With the increasing implementation of early lung cancer screening and the increasing emphasis on physical examinations, the early-stage lung cancer detection rate continues to rise. Visceral pleural invasion (VPI), which denotes the tumor's breach of the elastic layer or reaching the surface of the visceral pleura, stands as a pivotal factor that impacts the prognosis of patients with non-small cell lung cancer (NSCLC) and directly influences the pathological staging of early-stage cases. According to the latest 9th edition of the TNM staging system for NSCLC, even when the tumor diameter is less than 3 cm, the final T stage remains T2a if VPI is present. There is considerable controversy within the guidelines regarding treatment options for stage IB NSCLC, especially among patients exhibiting VPI. Moreover, the precise determination of VPI is important in guiding treatment selection and prognostic evaluation in individuals with NSCLC. This article aims to provide a comprehensive review of the current status and advancements in studies pertaining to stage IB NSCLC accompanied by VPI.

Using CT imaging features to predict visceral pleural invasion of non-small-cell lung cancer

AIM

To examine the diagnostic performance of different models based on computed tomography (CT) imaging features in differentiating the invasiveness of non-small-cell lung cancer (NSCLC) with multiple pleural contact types.

MATERIALS AND METHODS

A total of 1,573 patients with NSCLC (tumour size ≤3 cm) were included retrospectively. The clinical and pathological data and preoperative imaging features of these patients were investigated and their relationships with visceral pleural invasion (VPI) were compared statistically. Multivariate logistic regression was used to eliminate confounding factors and establish different predictive models.

RESULTS

By univariate analysis and multivariable adjustment, surgical history, tumour marker (TM), number of pleural tags, length of solid contact and obstructive inflammation were identified as independent risk predictors of pleural invasiveness (p=0.014, 0.003, <0.001, <0.001, and 0.017, respectively). In the training group, comparison of the diagnostic efficacy between the combined model including these five independent predictors and the image feature model involving the latter three imaging predictors were as follows: sensitivity of 88.9% versus 77% and specificity of 73.5% versus 84.1%, with AUC of 0.868 (95% CI: 0.848-0.886) versus 0.862 (95% CI: 0.842-0.880; p=0.377). In the validation group, the sensitivity and specificity of these two models were as follow: the combined model, 93.5% and 74.3%, the imaging feature model, 77.4% and 81.3%, and their areas under the curve (AUCs) were both 0.884 (95% CI: 0.842-0.919). The best cut-off value of length of solid contact was 7.5 mm (sensitivity 68.9%, specificity 75.5%).

CONCLUSIONS

The image feature model showed great potential in predicting pleural invasiveness, and had comparable diagnostic efficacy compared with the combined model containing clinical data.

Upstaged from cT1a-c to pT2a lung cancer, related to visceral pleural invasion patients, after segmentectomy: is it an indication to complete resection to lobectomy?

OBJECTIVES

Segmentectomy may be indicated for T1a-cN0 non-small-cell lung cancer. However, several patients are upstaged pT2a at final pathological examination due to visceral pleural invasion (VPI). As resection is usually not completed to lobectomy, this may raise issue of potential worse prognosis. The aim of this study is to compare prognosis of VPI upstaged cT1N0 patients operated on by segmentectomy or lobectomy.

METHODS

Data of patients from 3 centres were analysed. This was a retrospective study, of patients operated on from April 2007 to December 2019. Survival and recurrence were assessed by Kaplan-Meier method and cox regression analysis.

RESULTS

Lobectomy and segmentectomy were performed in 191 (75.4%) and in 62 (24.5%) patients, respectively. No difference in 5-year disease-free survival rate between lobectomy (70%) and segmentectomy (64.7%) was observed. There was no difference in loco-regional recurrence, nor in ipsilateral pleural recurrence. The distant recurrence rate was higher (P = 0.027) in the segmentectomy group. Five-year overall survival rate was similar for both lobectomy (73%) and segmentectomy (75.8%) groups. After propensity score matching, there was no difference in 5-year disease-free survival rate (P = 0.27) between lobectomy (85%) and segmentectomy (66.9%), and in 5-year overall survival rate (P = 0.42) between the 2 groups (lobectomy 76.3% vs segmentectomy 80.1%). Segmentectomy was not impacting neither recurrence, nor survival.

CONCLUSIONS

Detection of VPI (pT2a upstage) in patients who underwent segmentectomy for cT1a-c non-small-cell lung cancer does not seem to be an indication to extend resection to lobectomy.

Clinical Significance of Dual-Block Elastic Stain Evaluating Visceral Pleural Invasion in Peripheral Non-Small Cell Lung Cancer

Visceral pleural invasion (VPI) is a critical component in the staging of peripheral non-small cell lung carcinoma (NSCLC). We aim to investigate whether dual-block elastic stain increases visceral pleural invasion positivity compared with single-block elastic stain. We further analyze the potential predictors of visceral pleural invasion. 8419 peripheral NSCLC patients (including 6008 patients with tumor size≤3 cm in stage I) were divided into a cohort using one paraffin block (single-block group, n = 5184) and a cohort using dual paraffin blocks (dual-block group, n = 3235) for elastic stain. The VPI-positive rate demonstrated by the dual-block elastic stains group was significantly higher than that of the single-block elastic stain group (17.7% (573/3235) versus 9.1% (474/5184), respectively, P < .001). The presence of visceral pleural invasion in T1 (≤3 cm) patients detected by single- and dual-block elastic stain was 6.3% (235/3730) and 12.0% (273/2278), respectively (P < .001). 5.7% of T1 patients (stage IA) were additionally upstaged to T2a (stage IB) by dual-block elastic stain. However, the incidence of visceral pleural invasion in pT2a patients showed no significant difference between the single-block group and the dual-block group (16.8% vs. 17.1%, P = .916). Lymphovascular invasion, lymph node metastasis, dedifferentiated carcinomas, the presence of spread through airspaces (STAS) and a poorly differentiated adenocarcinomatous growth pattern could be significant predictors of visceral pleural invasion (P < .001). Our results indicate that using dual-block elastic stain identifies more visceral pleural invasion positive T1 NSCLC patients who are upstaged to T2a, and who could benefit from optimal management post-operatively. The application of dual-block elastic stain is an efficient and practical method to detect visceral pleural invasion status.

Non-small Cell Lung Cancer Surpassing the Elastic Layer Should Remain Classified as pT2a

We aimed to evaluate the prognostic value of visceral pleural invasion on the survival of node-negative non-small cell lung cancer ≤3 cm using a large cohort. The Kaplan-Meier method was used to compare overall survival (OS); competing risk analysis with Fine-Gray's test was used to compare cancer- specific survival between groups. The least absolute shrinkage and selection operator penalized Cox regression model was used to identify prognostic factors. In total, 9725 eligible cases were included in this study, and they were separated into 3 groups: tumor invasion beneath the elastic layer (PL0), 8837 cases; tumor invasion surpassing the elastic layer (PL1), 505 cases; and tumor invasion to the visceral pleural surface (PL2), 383 cases. Visceral pleural invasion was more likely to occur in poorly differentiated and larger-sized tumors. Survival curves displayed that PL0 conferred better survival rates than PL1 and PL2, and PL1 achieved outcomes equivalent to those of PL2. Tumor size and histology subset analyses further corroborated this conclusion. Least absolute shrinkage and selection operator -penalized Cox regression analysis confirmed that PL status was an independent prognostic factor for both OS and cancer- specific survival. This study supported the notion that in node-negative non-small cell lung cancer ≤3 cm, PL1 patients should remain classified as pT2a, which could improve staging accuracy.

Pleural Invasion Depth of Disseminated Nodules in Patients with Stage IVa or Recurrent Thymoma: Assessment, Curative Impact, and Surgical Outcomes

BACKGROUND

Thymoma patients with pleural dissemination are difficult to manage, and their treatment strategy remains undefined. This study aimed to investigate the clinicopathologic features of these patients, focusing on the association between the depth of pleural invasion and prognosis.

METHODS

Between 2003 and 2019, the study identified 120 disseminated lesions in 20 thymoma patients. Seven patients had de novo stage IVa thymoma and 13 were recurrent cases. Extrapleural pneumonectomy was performed for 8 patients and debulking surgery for 12 patients. Invasion depth of pleural tumors was classified into two groups: when the disseminated tumors invaded the pleura beneath the elastic layer, the tumor was diagnosed as Da, and when the disseminated tumors invaded the pleura beyond the elastic layer, the tumor was diagnosed as Db.

RESULTS

Of 120 nodules, 31 (26%), found in eight patients with recurrent malignancies, were classified as Db. The pathologic status of the surgical margin (PSM) was positive in eight patients, seven of whom had Db nodules. The 5-year overall survival (OS) rate was 100% in the Da group and 75% in the Db group (P = 0.02). The 5-year progression-free survival (PFS) rate was 66.7% in the Da group and 25% in the Db group (P = 0.02). Cox univariate analysis showed that PFS was significantly influenced by the depth of invasion (P = 0.04) and PSM (P = 0.03).

CONCLUSION

Depth of pleural invasion may influence survival outcomes for thymoma patients with pleural dissemination. The patients in this study with Da-disseminated nodules had an increased probability of a longer OS and PFS and tended to achieve negative PSM compared with the patients with Db.

Modification of Pathologic T Classification for Non-small Cell Lung Cancer With Visceral Pleural Invasion: Data From 1,055 Cases of Cancers ≤ 3 cm

BACKGROUND

Visceral pleural invasion (VPI) with PL1 or PL2 increases the T classification from T1 to T2 in non-small cell lung cancers (NSCLCs) ≤ 3 cm. We proposed a modified T classification based on VPI to guide adjuvant therapy.

RESEARCH QUESTION

Is it reasonable to upstage PL1-positive cases from T1 to T2 for NSCLCs ≤ 3 cm?

STUDY DESIGN AND METHODS

In total, 1,055 patients with resected NSCLC were retrospectively included. Tumor sections were restained with hematoxylin and eosin stain and Victoria blue elastic stain for the elastic layer. Disease-free survival (DFS) and overall survival (OS) were calculated by the Kaplan-Meier method. Subgroup analysis and a Cox proportional hazards model were used to further determine the impact of VPI on survival.

RESULTS

The extent of VPI was diagnosed as PL0 in 824 patients, PL1 in 133 patients, and PL2 in 98 patients. The 5-year DFS rates of patients with PL0, PL1, and PL2 were 62.6%, 60.2%, and 28.8% (P < .01), whereas the corresponding 5-year OS rates were 78.6%, 74.4%, and 50.0% (P < .01), respectively. As predicted, the DFS and OS of patients with PL2 were much worse than those of patients with PL0 (P < .01) and PL1 (P < .01). However, both the DFS and OS of patients with PL0 and PL1 were comparable (DFS: P = .198; OS: P = .150). For node-negative cases, the DFS and OS of patients with PL0 and PL1 were also comparable (DFS: P = .468; OS: P = .388), but patients with PL2 had much worse DFS and OS than patients with PL0 (P < .01) and PL1 (P < .01). Multivariable analyses suggested that PL2, together with node positivity and poor cell differentiation, was an independent adverse prognostic factor.

INTERPRETATION

In NSCLCs ≤ 3 cm, tumors with PL1 should remain defined as T1, not T2. Overtreatment by adjuvant chemotherapy in node-negative NSCLCs ≤ 3 cm might be avoided in PL1 cases.

Clinical significance of visceral pleural and lymphovascular invasion in surgically resected adenosquamous lung cancer

OBJECTIVES

The aim of this study was to assess the relationship between visceral pleural invasion (VPI), lymphovascular invasion (LVI) and other clinicopathological characteristics and their prognostic impact on surgically resected adenosquamous carcinoma (ASC).

METHODS

We retrospectively reviewed 256 patients with radically resected ASC between January 2010 and December 2015. Patients were divided into 2 groups: those with VPI and those with LVI. The effects of VPI and LVI on disease-free survival and overall survival were evaluated, further stratified by tumour size and lymph node status.

RESULTS

Finally, 213 patients with ASC were enrolled in our study. VPI was correlated with tumour location (P < 0.001), pT stage (P < 0.001) and pN stage (P = 0.012). LVI was related to age (P = 0.005) and pN stage (P = 0.003). Both VPI and LVI were adverse prognostic factors for disease-free survival (P = 0.008, P = 0.028) and overall survival (P = 0.005, P = 0.009) using the Kaplan-Meier method. In multivariable analysis only, VPI was an independent risk factor for disease-free survival [hazard ratio (HR) 0.61, 95% confidence interval (CI) 0.42-0.87; false discovery rate, adjusted P = 0.020] and overall survival (HR 0.60, 95% CI 0.42-0.86; false discovery rate, adjusted P = 0.017). When the prognostic value of VPI was stratified by tumour size and lymph node status, we observed that only patients with VPI in tumours ≤4 cm and patients with N0 status had a worse prognosis than those without visceral invasion (P < 0.05).

CONCLUSIONS

VPI and LVI were poor prognostic factors in patients with ASC, but only VPI was an independent factor for survival, especially in patients with tumours ≤4 cm and pN0 status.

Nucleolin and nucleophosmin expression patterns in pulmonary adenocarcinoma invading the pleura and in pleural malignant mesothelioma

BACKGROUND

Visceral pleural invasion (VPI) in adenocarcinoma of the lung is considered a poor prognostic factor. The purpose of this study was to analyze nucleolin and nucleophosmin expression in pulmonary adenocarcinoma (PA) with VPI and in pleural malignant mesothelioma.

METHODS

The study was conducted on the basis of 19 pathologically-confirmed cases of adenocarcinoma of the lung and 29 cases of epithelioid malignant mesothelioma. The nucleolin and nucleophosmin expression was assessed immunohistochemically and analyzed with image analysis software.

RESULTS

Nucleolin expression was lower while nucleophosmin was higher in pleural invasion of pulmonary adenocarcinoma than in the central part of the tumor. Differences in subpopulations of cells with different expression of proteins studied were also found. Malignant mesothelioma showed lower nucleolin expression than adenocarcinoma of the lung but no differences in nucleophosmin expression were found.

CONCLUSIONS

The results of our study suggested that lower nucleolin and higher nucleophosmin expression may be related to higher invasiveness of adenocarcinoma of the lung. Differences in nucleolin expression between pulmonary adenocarcinoma and malignant mesothelioma indicate another aspect of biology of these pleura-invading cancers that requires further study.

KEY POINTS

SIGNIFICANT FINDINGS OF THE STUDY: Differences in nucleolin and nucleophosmin expression in pleura invading pulmonary adenocarcinoma indicate the involvement of these proteins in its locoregional spread while differences in nucleolin expression between pulmonary adenocarcinoma and malignant mesothelioma suggest another aspect of biology of these cancers.

WHAT THIS STUDY ADDS

This is the first study on nucleolin and nucleophosmin expression in pleural malignant mesothelioma and pleura-invading pulmonary adenocarcinoma. Our findings may assist in understanding the mechanisms of locoregional spread of adenocarcinoma and differences between these two pleura-invading cancers.

Use of Autofluorescence to Intraoperatively Diagnose Visceral Pleural Invasion From Frozen Sections in Patients With Lung Adenocarcinoma 2 cm or Less

OBJECTIVES

We prospectively investigate the accuracy of frozen sections for diagnosing visceral pleural invasion (VPI) by autofluorescence and evaluated its usefulness in sublobar resection.

METHODS

We included patients with lung adenocarcinoma 2 cm or less to evaluate the diagnostic performance of autofluorescence for VPI in frozen sections via a fluorescence microscope. Furthermore, the impact of VPI on patients treated with sublobar resection was assessed in another cohort.

RESULTS

A total of 112 patients were enrolled. The accuracy, sensitivity, and specificity of autofluorescence for VPI diagnosis was 95.5%, 86.8%, and 100%, respectively. Sublobar resection was an independent risk factor for recurrence in patients with lung adenocarcinomas 2 cm or less with VPI positivity (hazard ratio, 3.30; P = .023), whereas it was not in those with VPI negativity.

CONCLUSIONS

Using autofluorescence in frozen sections appears to be an accurate method for diagnosing VPI, which is helpful for surgical decision making.

Pleural contact decreases survival in clinical T1N0M0 lung cancer patients undergoing SBRT

BACKGROUND

Clinical staging, as used for patients treated with stereotactic body radiotherapy (SBRT) for early-stage lung cancer, inadequately accounts for pleural invasion, which is a pathologic criteria. Considering the current situation, we analyzed effects of relationships between tumors and the pleura on treatment outcomes of SBRT for early-stage lung cancer.

MATERIALS AND METHODS

Among consecutive patients treated with SBRT between 2006 and 2017, we retrospectively identified non-small cell lung cancer patients with primary tumor diameters ≤4 cm and N0M0. The relationships between tumors and the pleura were investigated. The effects of these findings on treatment outcomes were analyzed.

RESULTS

We identified 386 patients which met the inclusion criteria. Among these patients, 323 patients were with tumors of 0.1-3.0 cm (T1-size), and 63 patients were with tumors of 3.1-4.0 cm (T2a-size). Among patients with T1-size tumors, 120, 134, and 23 had findings of pleural contact, pleural indentation, and pleural thickening, respectively. When we divided T1-size patients into 2 groups based on pleural contact (contact- or contact+), the 3-year cause-specific mortality and overall survival in patients with T1-size & contact+ were significantly worse than those in patients with T1-size & contact- (17.6% (95% confidence interval (CI), 10.7-25.9%) vs. 6.6% (95% CI, 3.5-11.1%), p < 0.01), and 58.2% (95% CI, 47.6-67.5%) vs. 77.6% (95% CI, 70.5-83.2%), p < 0.01). Local recurrence, regional recurrence, pleural cavity recurrence, and distant metastasis were associated with worse cause-specific mortality and overall survival. On multivariate analysis, pleural contact was associated with cause-specific mortality (hazard ratio (HR), 1.96; 95% CI, 1.09-3.52; p = 0.03) and overall survival (HR, 1.59; 95% CI, 1.08-2.34; p = 0.02).

CONCLUSION

Pleural contact in clinical T1N0M0 lung cancer patients was associated with significantly worse survivals.

Effect of visceral pleural invasion on the prognosis of patients with lymph node negative non-small cell lung cancer

Background

Visceral pleural invasion (VPI) is an adverse prognostic factor in non‐small cell lung cancer (NSCLC); however, its effect in relation to tumor size remains under debate. To better understand the prognostic impact and potential consequences for staging, we examined correlations between VPI and clinicopathologic characteristics in patients with NSCLC, particularly those with lymph node negative NSCLC.

Methods

We retrospectively analyzed 813 cases of radically resected NSCLC treated in our institution between December 2005 and December 2011. Patients were divided into two groups according to VPI status to compare their clinicopathologic characteristics. Survival analysis was performed in 521 cases with pN0 NSCLC.

Results

VPI was diagnosed in 379 (46.6%) cases. It was more common in women, patients with non‐squamous cell carcinoma, elevated preoperative serum carcinoembryonic antigen levels, moderately or poorly differentiated tumors, and larger‐sized tumors. The incidence of mediastinal lymph node metastasis, particularly multi‐station metastasis, was higher in patients with VPI. Patients with pN0 NSCLC, 2–3 cm tumors, and VPI had a significantly poorer prognosis (VPI vs. non‐VPI: five‐year overall survival 78.3% vs. 84.5%, P = 0.039; five‐year disease‐free survival 69.2% vs. 80.0%, P = 0.046, respectively); however, no significant effect was observed for tumors ≤2, 3–5, and 5–7 cm. P‐N0 patients with VPI had a significantly higher incidence of postoperative local recurrence and distant metastasis than those without VPI (P = 0.01), especially ipsilateral pleural recurrence.

Conclusion

VPI was an adverse prognostic factor in radically resected pN0 NSCLC, especially for tumors 2–3 cm in size.

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

Visceral pleural invasion remains a size-independent prognostic factor in stage I non-small cell lung cancer

BACKGROUND

The prognostic effect of visceral pleural invasion remains controversial when a tumor is less than 3 cm in stage I non-small cell lung cancer patients. We conducted this meta-analysis to evaluate the prognostic impact of visceral pleural invasion in these early patients.

METHODS

We searched PubMed, EMBASE, Cochrane Library, and China National Knowledge Infrastructure and included published studies on the prognostic significance of visceral pleural invasion in stage I non-small cell lung cancer. Meta-analysis was performed and heterogeneity and publication bias were also evaluated.

RESULTS

Twenty-two studies were included in the meta-analysis. In all stage I patients, visceral pleural invasion was associated with death (hazard ratio1.427; p = 0.000) and recurrence (hazard ratio1.600; p = 0.000). In subgroup analyses, visceral pleural invasions were consistently associated with death in each tumor size subgroup and recurrence in tumor less than 3 cm subgroup. Publication bias was not found.

CONCLUSIONS

Visceral pleural invasion is a size-independent poor prognostic factor in stage I non-small cell lung cancer patients. We suggest adjuvant treatment should be considered in stage I patients with visceral pleural invasion.

Judging pathological assessment in cancer specimens

The pathologist plays a critical role in the multidisciplinary team in charge of treating cancer patients, as many of the therapeutic decisions rely on the information conveyed through the pathology reports. The task of the pathologist includes not only an accurate assessment of pathological T and N categories, but also the evaluation of other indicators of prognosis including quality of surgery, margins of resection, as well as additional histopathological and molecular markers that influence prognosis and could predict response to therapy.

Visceral pleural invasion is not a significant prognostic factor in patients with a part-solid lung cancer

BACKGROUND

Visceral pleural invasion (VPI) has been considered to be a prognostic factor. If a tumor shows VPI, it increases the T descriptor and upstages a tumor from stage IA to stage IB pathologically, even for those less than 30 mm in diameter. However, there is still some controversy regarding the prognostic significance of VPI in patients with radiologically early lung cancer with ground glass opacity.

METHODS

Between 2004 and 2012, 466 patients with surgically resected pathologic N0 non-small cell lung cancer less than 30 mm in diameter who showed a "part-solid" or "pure-solid" appearance on thin-section computed tomography scan were retrospectively reviewed. A Cox proportional hazard model was used to evaluate prognostic factors. Survival was calculated by the Kaplan-Meier method.

RESULTS

Two hundred thirty-seven patients (55%) showed part-solid and 209 (45%) showed pure-solid nodules on thin-section computed tomography scan. VPI was found in 24 (10%) part-solid nodules and 79 (38%) pure-solid nodules. On the basis of a multivariate analysis, VPI was not a significant prognostic factor in patients with part-solid nodules (p=0.5902). In this group, the 5-year survival rates in patients with and without VPI were 85.6% and 94.9%, respectively (p=0.3798). By contrast, VPI, vessel invasion, maximum tumor diameter, and carcinoembryonic antigen level were significant prognostic factors in patients with pure-solid nodules (p=0.0211, 0.0188, 0.0372, and 0.0492, respectively). Moreover, the 5-year survival in patients with VPI (70.1%) was significantly worse than that in patients without VPI (81.3%) among patients with pure-solid nodules (p=0.0051).

CONCLUSIONS

VPI may not contribute to the prognosis of patients with part-solid nodules. Thus, upgrading of the TNM stage on the basis of VPI should be carefully considered in these patients.

Re-evaluation of the prognostic value of visceral pleura invasion in Stage IB non-small cell lung cancer using the prospective multicenter ACOSOG Z0030 trial data set

PURPOSE

This study seeks to clarify the modern prognostic significance of visceral pleura invasion (VPI) in Stage IB (T2aN0M0) non-small cell lung cancer (NSCLC) within the context of the 7th edition TNM classification using the data set from a recent prospective multicenter trial.

PATIENTS AND METHODS

1111 early-stage NSCLC patients participating in the ACOSOG Z0030 trial (1990-2004) underwent curative pulmonary resection. After excluding T2b tumours (>5 cm and ≤ 7 cm) and non-size-based T2 factors other than VPI, 289 patients were categorized as Stage IB NSCLC - T2aN0M0 - according to the AJCC 7th edition classification. The patients were divided into three groups according to size and VPI: tumours ≤ 3 cm with VPI (Group I, "VPI-alone", n=83), tumours>3 cm and ≤ 5 cm without VPI (Group II, "Size-alone", n=156), and tumours>3 cm and ≤ 5 cm with VPI (Group III, "VPI+Size", n=50). Multivariate Cox regression analysis was used to assess the association of VPI and size with survival, adjusting for age, gender, histology and type of resection.

RESULTS

VPI in Stage IB was identified in 133 patients (46.0%). Survival analysis in these patients identified an optimal cutpoint for survival based on size of 3.1cm. Group III (VPI+Size) had a 5-year survival rate of 55.0% significantly shorter when compared to Group I (VPI-alone=68.3%, p=0.009), and Group II (Size-alone=67.2%, p=0.021). No difference was found between Groups I and II. Multivariable analysis showed that VPI associated with size was an independent negative prognostic factor of long-term survival, along with older age and limited resection.

CONCLUSIONS

Stage IB patients with VPI and tumours>3 cm and ≤ 5 cm have significantly worse prognosis than those with 'T2a' tumours on the basis of VPI or tumour size alone. This finding would suggest upstaging these patients from the current IB status to Stage IIA.

Dilemmas in Lung Cancer Staging

The TNM staging system is the most important prognostic factor for lung cancer. The most encountered difficulties in pathologic staging of lung cancer include assessment of pleural invasion, synchronous tumor nodules, and lymph node sampling.

Are elastic stain and specialty sign out necessary to evaluate pleural invasion in lung cancers?

The seventh edition of American Joint Committee on Cancer (AJCC) staging system assigns lung cancers with visceral pleural invasion in the tumor size of 3 cm or less than 3 cm as T2 and without pleural invasion as T1. However, it may be difficult to distinguish with certainty between PL0 (no pleural invasion) and PL1 (extends through the elastic layer) on routine hematoxylin and eosin (H&E) stain. In this study, 25 cases of peripherally located lung adenocarcinoma were retrieved from the surgical pathology archives at the Asan Medical Center from May through June 2009. One representative H&E-stained slide was selected from each case and circulated to 31 pathology trainees and board-certified pathologists at Asan Medical Center who evaluated presence or absence of pleural invasion on H&E-stained slides. Elastic stain was used to determine the final status of pleural invasion for each case. The concordance rate of all pathologists with elastic stain results was, overall, 60.5%. The concordance rate of 2 lung specialists was 64%, better than the remaining faculty (54.7%). Fellows' and residents' evaluations were slightly more concordant than those of faculty responses (faculty overall, 56.4%; fellows, 62%; residents, 63.6%), but this difference was not statistically significant (P = .228). Our results confirm that pleural invasion status is difficult to discern with certainty on H&E-stained sections alone. Therefore, we recommend the routine use of elastic stain in evaluation of pleural invasion in all peripherally located lung cancers. Furthermore, our study indicates that subspecialty sign out may be preferable in evaluation of pleural invasion status.

Advances in the diagnosis of pleural disease in lung cancer

Pleural disease in lung cancer can be benign or malignant with the latter carrying a grave prognosis. In this review, we describe and discuss the advances in pleural imaging, procedures, and biomarkers for the diagnosis of pleural diseases in lung cancer. Ultrasound and computed tomography are increasingly applied in the planning of pleural procedures to enhance diagnostic accuracy and safety whilst pleuroscopy gives excellent yield in excess of 93% in the evaluation of cytology negative pleural effusions. Invasion beyond the elastic layer of the visceral pleura upstages lung cancer, and may indicate a need for adjuvant chemotherapy. Biomarkers isolated from pleural fluid or tissue may aid in diagnosis and guide treatment in the future. Magnetic resonance imaging, positron emission tomography, narrow band imaging of the pleura and autofluorescence thoracoscopy are technologies that require further evaluation to better define their respective roles in the diagnostic algorithms of pleural diseases in lung cancer.

An update on lung cancer staging

The staging committee of the International Association for the Study of Lung Cancer has recently published, in collaboration with the International Union Against Cancer and the American Joint Committee on Cancer, the recommendations for the upcoming 7th edition of the tumor, node, metastasis classification and staging manual. This article reviews the changes in criteria for the tumor, node, metastasis components and discusses the issues that will be faced by pathologists when examining lung cancer specimens, including recommendations for tumor measurement, differentiation of multiple primary tumors versus metastases, and visceral pleural invasion.

Prognostic impact of intratumoral vessel invasion in completely resected pathologic stage I non-small cell lung cancer

OBJECTIVE

Intratumoral vessel invasion of non-small cell lung cancer is a readily available tumor-related factor that provides direct evidence of microscopic tumor invasion. We assessed the prognostic influence of intratumoral vessel invasion and its ability to provide a differential prediction of prognosis for completely resected pathologic stage I non-small cell lung cancer.

METHODS

We analyzed 258 patients with non-small cell lung cancer who underwent complete resection between January of 1996 and December of 2005 and were diagnosed with pathologic stage I disease. In addition to the conventional staging factors, intratumoral vessel invasion in the primary lesion was histologically evaluated by both hematoxylin-eosin and elastic staining. We examined the significance of intratumoral vessel invasion in prognosis and compared the outcomes between patients with and without this factor with stage IA and IB disease, respectively.

RESULTS

Intratumoral vessel invasion was found in 124 patients (48%). Five-year survival of patients with or without intratumoral vessel invasion was 74% and 93%, respectively. On multivariate analysis, intratumoral vessel invasion and pleural invasion were shown to be independent prognostic factors. Subgroup analyses suggested that patients with pathologic-stage IA with intratumoral vessel invasion and patients with pathologic-stage IB with both intratumoral vessel and pleural invasion had significantly worse prognosis than patients with the same pathologic stage without these factors.

CONCLUSION

The current study indicated that intratumoral vessel invasion and pleural invasion are independent prognostic factors. Intratumoral vessel invasion status can complement the size-dependent TNM staging system in pathologic stage I non-small cell lung cancer.