Extent of Visceral Pleural Invasion Affects Prognosis of Resected Non-small Cell Lung Cancer: A meta-analysis

Recurrence of Non-Small Cell Lung Cancer With Visceral Pleural Invasion: A Seconday Analysis of a Randomized Clinical Trial

Importance

The randomized clinical trial Cancer and Leukemia Group B (CALGB) 140503 showed that for patients with clinically staged T1N0 non-small cell lung cancer (NSCLC; ≤2 cm), sublobar resections were associated with similar oncological outcomes to those after lobar resection. The association of the extent of parenchymal resection with recurrence and survival in patients with tumors pathologically upstaged to T2 based on visceral pleural invasion (VPI) is controversial.

Objective

To determine survival and recurrence rates in patients with small peripheral pT2 NSCLC (≤2 cm) that was treated by either lobar or sublobar resection in CALGB 140503.

Design, Participants, and Setting

CALGB 140503, a randomized multicenter noninferiority trial, included 697 patients with small peripheral NSCLC that was clinically staged as T1N0. Enrollment was from June 2007 through March 2017 at 83 participating institutions, and after a median follow-up of 7 years, the primary outcome of disease-free survival after sublobar resection was noninferior to that after lobar resection.

Intervention

Lobar or sublobar resection.

Main Outcomes and Measures

Survival end points were estimated by the Kaplan-Meier estimator. Hazard ratios and 95% CIs were estimated using stratified Cox proportional hazard models.

Results

Of 679 participants, 390 (57.4%) were female, and the median (range) age was 67.8 (37.8-89.7) years. Among 697 patients randomized, 566 (81.2%) had pT1 tumors (no VPI) and 113 (16.2%) had pT2 tumors (VPI). Five-year disease-free survival was 65.9% (95% CI, 61.9%-70.2%) in patients with pT1 compared with 53.3% (95% CI, 44.3%-64.1%) in patients with pT2 tumors (stratified log-rank: P = .02). Disease recurrence developed in 27.6% of patients with pT1 (locoregional only: 60 [10.8%]; distant only: 81 [14.6%]) and 41.6% of those with pT2 (locoregional only: 17 [15.0%]; distant only: 27 [23.9%]). Five-year recurrence-free survival was 73.1% (95% CI, 69.2%-77.1%) for pT1 tumors and 58.2% (95% CI, 49.2%-68.8%) for pT2 tumors (stratified log-rank: P = .01). There were no intergroup differences in disease-free or recurrence-free survival based on the extent of parenchymal resection.

Conclusions and Relevance

The results of this secondary analysis suggest that compared with patients with tumors without VPI, patients who had tumors with VPI had worse disease-free and recurrence-free survival and a higher rate of local and distant disease recurrence. These high rates of recurrence were independent of the extent of parenchymal resection, and these data support the inclusion of these patients in adjuvant therapy trials.

Trial Registration

ClinicalTrials.gov Identifier: NCT0049933.

Impact of adjuvant chemotherapy on patients with stage IB non-small cell lung cancer with visceral pleural invasion

Background

Adjuvant chemotherapy has reduced the risk of recurrence and death in stage IB non-small cell lung cancer (NSCLC) with high-risk factors; however, the impact of visceral pleural invasion (VPI) on outcomes in stage IB NSCLC treated with adjuvant chemotherapy remains controversial. The aim of this study was to explore the clinical and prognostic significance of adjuvant chemotherapy for stage IB (1-4 cm) NSCLC with VPI.

Methods

This retrospective study included 251 patients admitted between January 2008 and May 2018 from four hospitals who underwent complete resection for Tumor-Node-Metastasis (TNM) 8th edition stage IB NSCLC with VPI. The relationship between adjuvant chemotherapy and overall survival (OS) or recurrence-free survival (RFS) was analyzed using the Kaplan-Meier method and Cox proportional hazards model.

Results

Of 251 patients with stage IB NSCLC with VPI, 122 (48.6%) received adjuvant chemotherapy after surgical resection and 129 (51.4%) were placed under observation. Multivariable analysis showed that adjuvant chemotherapy was an independent predictor of RFS [adjusted hazard ratio (aHR), 0.57; 95% confidence interval (CI): 0.33-0.96; P=0.036]. A micropapillary pattern (aHR, 2.46; 95% CI: 1.33-4.55; P=0.004) and lymphovascular invasion (aHR, 2.86; 95% CI: 1.49-5.48; P=0.002) were associated with a higher risk of recurrence. Multivariable analysis also showed that adjuvant chemotherapy was an independent predictor of OS (aHR, 0.22; 95% CI: 0.09-0.58; P=0.002). In a subgroup analysis of patients with a tumor size of 1-3 cm, adjuvant chemotherapy was associated with improved RFS and OS, and this association was maintained even when patients with VPI had additional risk factors.

Conclusions

Our study shows that adjuvant chemotherapy is appropriate for patients with stage IB (1-4 cm) NSCLC with VPI, and even those with smaller tumors (1-3 cm).

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.

Predicting pleural invasion of invasive lung adenocarcinoma in the adjacent pleura by imaging histology

The aim of the present study was to develop a non-invasive method based on histological imaging and clinical features for predicting the preoperative status of visceral pleural invasion (VPI) in patients with lung adenocarcinoma (LUAD) located near the pleura. VPI is associated with a worse prognosis of LUAD; therefore, early and accurate detection is critical for effective treatment planning. A total of 112 patients with preoperative computed tomography presentation of adjacent pleura and postoperative pathological findings confirmed as invasive LUAD were retrospectively enrolled. Clinical and histological imaging features were combined to develop a preoperative VPI prediction model and validate the model's efficacy. Finally, a nomogram for predicting LUAD was established and validated using a logistic regression algorithm. Both the clinical signature and radiomics signature (Rad signature) exhibited a perfect fit in the training cohort. The clinical signature was overfitted in the testing cohort, whereas the Rad signature showed a good fit. To combine clinical and radiomics signatures for optimal performance, a nomogram was created using the logistic regression algorithm. The results indicated that this approach had the highest predictive performance, with an area under the curve of 0.957 for the clinical signature and 0.900 for the Rad signature. In conclusion, histological imaging and clinical features can be combined in columnar maps to predict the preoperative VPI status of patients with adjacent pleural infiltrative lung carcinoma.

Diastole/Body Mass Index Ratio Can Predict Post-Thoracoscopic Surgery Metastasis in Stage I Lung Adenocarcinoma

Background: According to recent animal models for lung adenocarcinoma metastasis, cardiac function may be related to the clinical outcome. The aim of this study is to identify a predictable index for postoperative metastasis (POM) that is associated with cardiac function. Methods. Two hundred and seven consecutive patients who underwent thoracoscopic resection for stage I lung adenocarcinoma were included. Disease-free survival (DFS), overall survival (OS), and patients’ clinical and pathological characteristics were analyzed. Results. Among the 207 patients, 17 cases demonstrated metastasis, 110 cases received a preoperative echocardiogram, and six cases had POM. Mitral valve peak A velocity, which is one of the left ventricular diastolic function parameters affected by BMI (MVPABMI), was associated with a negative factor for POM (hazard ratio (HR): 2.139, p = 0.019) and a poor 5-year DFS in the above median (100% vs. 87%, p = 0.014). The predictable rate increased from 30.7% to 75% when the MVPABMI was above the median = 3.15 in the solid subtype). Conclusions. MVPABMI is a novel index for POM prediction in early-stage lung adenocarcinoma. This is a pilot study and the first attempt at research to verify that the diastole and the BMI may be associated with POM in early-stage lung adenocarcinoma.

[Research Progress of Relationship between Pleural Deformation and Visceral Pleural Invasion in Lung Cancer Manifesting as Ground-glass Opacity]

Visceral pleural invasion (VPI) is one of the negative prognostic factors of non-small cell lung cancer (NSCLC). With the popularization of computed tomography (CT) screening for lung cancer, more and more ground-glass nodule (GGN) have been found. However, it remains unclear whether the relationship between the pleural deformation of lung cancer manifesting as ground-glass opacity (GGO) and VPI affects the effect of sub-lobectomy, which is reviewed in this paper.
.

The effects of the degree of pleural invasion on survival in patients with non-small cell lung cancer undergoing surgical resection

Background

The aim of this study was to evaluate the degree and size of pleural invasion in non-small cell lung cancer patients and to compare its relationship with the survival time.

Methods

Between January 2008 and June 2019, a total of 164 patients (143 males, 21 females; median age: 64.65 years; range 39 to 92 years) who underwent surgical resection with a diagnosis of non-small cell lung cancer and who were found to have pleural invasion histopathologically were retrospectively analyzed. The control group consisted of 105 patients (95 males, 10 females; median age: 61.7 years; range, 32 to 82 years) who underwent surgical resection but who were not found to have pleural invasion histopathologically during the same time period. Survival time was compared between the groups.

Results

Median survival was 52 months in the group with pleural invasion, while it was 70.6 months in the group without pleural invasion. In the pleural invasion group, the patients who underwent sublobar resection had shorter survival. The degree of pleural invasion (p=0.028), advanced age (p=0.022), and lymph node involvement (p=0.011) were found to be poor prognostic factors for survival.

Conclusion

In non-small cell lung cancer patients, the increase in the degree and size of pleural invasion is negatively correlated with the survival time and this is thought to be associated with advanced disease stage.

Rethinking the Selection of Pathological T-Classification for Non-Small-Cell Lung Cancer in Varying Degrees of Visceral Pleural Invasion: A SEER-Based Study

Background

The T classification of non-small-cell lung cancer (NSCLC) was upgraded from T1 to T2 when accompanied by visceral pleural invasion (VPI). However, the association between VPI and prognostic outcomes was obscure in NSCLC patients with ≤3 cm tumor size (TS), which leaded the controversy of selection of T classification. The goal was to evaluate the effect of VPI on the prognosis of NSCLC with ≤ 3cm TS and present a modified T classification.

Methods

A total of 14,934 NSCLC patients without distant metastasis were recruited through a retrospective study in the SEER database. The effect of VPI on lung cancer specific survival (LCSS) was evaluated using survival curve and COX regression analysis in NSCLC patients with ≤3 cm TS.

Results

Although there was no difference of the LCSS of PL0 and PL1 patients with ≤2 cm TS in patients without lymph node (LN) metastasis, the LCSS was lower in PL2 patients than those in PL0 (T1a: p < 0.001; T1b: p = 0.001). Moreover, the LCSS was decreased in PL1 and PL2 patients with 2–3 cm TS compared with PL0 (T1c: PL1, p < 0.001; PL2, p = 0.009) of patients without LN metastasis. No difference of LCSS was observed in patients with LN metastasis between PL0 with PL1 and PL2.

Conclusion

In NSCLC patients without LN metastasis and TS ≤ 2 cm, tumor with PL1 should remain defined as T1, tumor with PL2 should be defined as T2. However, 2–3 cm TS patients with PL1 or PL2 should both defined as T2. Meanwhile, ≤3 cm TS patients with LN metastasis can be regarded as T1, whether NSCLC patients accompanied with PL1 or PL2.

Is lobectomy superior to sub-lobectomy in non-small cell lung cancer with pleural invasion? A population-based competing risk analysis

Background

Pleural invasion (PL) has been regarded as an unfavorable prognostic factor for non-small cell lung cancer (NSCLC). But there was no agreement on the optimal surgical extent in NSCLC patients with PL. We aimed to compare the survival outcomes of lobectomy and sub-lobectomy in these patients.

Method

2717 patients were included in the Surveillance, Epidemiology, and End Results (SEER) database and divided into the lobectomy and sub-lobectomy groups. The propensity score matching (PSM) and competing risk analysis were implemented. Then the predictive nomogram was constructed and validated.

Results

2230 Patients received lobectomy while the other 487 patients underwent sub-lobectomy. After 1:1 PSM, the cumulative incidence of cancer-specific death (CSD) was lower in the lobectomy group compared with the sub-lobectomy group (1-year: 12% vs. 15%; 3-year: 30% vs. 37%, 5-year: 34% vs. 45%, P = 0.04). According to the subgroup analysis, the patients who underwent lobectomy suffered lower CSD in the N0–1 stage, adenocarcinoma, and PL-2 cohort (p < 0.05). And there was a significant relationship between the sub-lobectomy group and CSD in the multivariate competing risks regression analysis (HR, 1.26; 95%CI, 1.02–1.56; P = 0.034). Furthermore, a competing event nomogram was constructed to assess the 1-, 3-, and 5-year chances of CSD based on the variables from the multivariate analysis. The 1-, 3-, 5-year area under the receiver operating characteristic curve (AUC) values were 0.720, 0.706, and 0.708 in the training cohort, and 0.738, 0.696, 0.680 in the validation cohorts, respectively. And calibration curves demonstrated ideal consistency between the predicted and observed probabilities of CSD.

Conclusion

Lobectomy should be considered the preferred surgery compared to sub-lobectomy for NSCLC patients with PL. The proposed nomograms presented great prediction ability for these patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09634-w.

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.

Prognostic Impact of EGFR Amplification and Visceral Pleural Invasion in Early Stage Pulmonary Squamous Cell Carcinomas Patients after Surgical Resection of Primary Tumor

Over the last few decades, an increasing amount of information has been accumulated on biomarkers in non-small cell lung cancer (NSCLC). Despite these advances, most biomarkers have been identified in the adenocarcinoma histological subtype (AC). However, the application of molecular-targeted therapies in the prognosis and treatment of SCC in the clinical setting is very limited, becoming one of the main focus areas in research. Here, we prospectively analyzed the frequency of numerical/structural abnormalities of chromosomes 5, 7, 8, 9, 13 and 22 with FISH in 48 pulmonary SCC patients. From a total of 12 probes, only abnormalities of the 7p12 and 22q12 chromosomal regions were identified as unique genetic variables associated with the prognosis of the disease. The study for these two chromosomal regions was extended to 108 patients with SCC. Overall, chromosome losses were observed more frequently than chromosome gains, i.e., 61% versus 19% of all the chromosome abnormalities detected. The highest levels of genetic amplification were detected for the 5p15.2, 7p12, 8q24 and 22q11 chromosome bands, of which several genes are potentially involved in the pathogenesis of SCC, among others, include the EGFR gene at chromosome 7p12. Patients who displayed EGFR amplification (n = 13; 12%) were mostly older than 65 years (p = 0.07) and exclusively patients in early T-primary tumor stage (pT1−pT2; p = 0.03) with a significantly shortened overall survival (OS) (p ≤ 0.001). Regarding prognosis, the clinical, biological, and histopathologic characteristics of the disease that displayed a significant adverse influence on OS in the univariate analysis included patients older than 65 years (p = 0.02), the presence of lymph node involvement (p = 0.005), metastasis (p = 0.01) and, visceral pleural invasion (VPI) at diagnosis (p = 0.04). EGFR amplification also conferred an adverse impact on patient OS in the whole series (p = 0.02) and especially in patients in early stages (pT1−pT2; p = 0.01). A multivariate analysis of the prognostic factors for OS showed that the most informative combination of independent variables to predict an adverse outcome was the presence of VPI and/or EGFR amplification (p < 0.001). Based on these two variables, a scoring system was built to stratify patients into low- (no adverse features: score 0; n = 69), intermediate- (one adverse feature: score 1; n = 29) and high-risk (two adverse features: score 2; n = 5) groups, with significantly different (p = 0.001) OS rates at 50 months, which were as following: 32%, 28% and 0%, respectively. In the present study, we show that the presence of a high level of 7p12 (EGFR) amplification, exclusively detected in early stage SCC (pT1−pT2), is an independent adverse prognostic factor for OS. The identification of the EGFR gene copy number using FISH techniques may provide a more accurate diagnosis of high-risk populations after the complete resection of the primary tumor. When combined with VPI, three groups of pulmonary SCC were clearly identified that show the extent of the disease. This is of such importance that further prospective studies are necessary in larger series of SCC patients to be classified at the time of diagnosis. This could be achieved with the combined assessment of 7p12 amplification and VPI in primary tumor samples.

Updated Prognostic Factors in Localized NSCLC

Lung cancer is the most common cause of cancer mortality worldwide, and non-small cell lung cancer (NSCLC) represents 80% of lung cancer subtypes. Patients with localized non-small cell lung cancer may be considered for upfront surgical treatment. However, the overall 5-year survival rate is 59%. To improve survival, adjuvant chemotherapy (ACT) was largely explored and showed an overall benefit of survival at 5 years < 7%. The evaluation of recurrence risk and subsequent need for ACT is only based on tumor stage (TNM classification); however, more than 25% of patients with stage IA/B tumors will relapse. Recently, adjuvant targeted therapy has been approved for EGFR-mutated resected NSCLC and trials are evaluating other targeted therapies and immunotherapies in adjuvant settings. Costs, treatment duration, emergence of resistant clones and side effects stress the need for a better selection of patients. The identification and validation of prognostic and theranostic markers to better stratify patients who could benefit from adjuvant therapies are needed. In this review, we report current validated clinical, pathological and molecular prognosis biomarkers that influence outcome in resected NSCLC, and we also describe molecular biomarkers under evaluation that could be available in daily practice to drive ACT in resected NSCLC.

The clinical prognostic factors of patients with stage IB lung adenocarcinoma

Background

Lung adenocarcinoma (ADC) at stage IB has its own prognostic characteristics. This study aimed to investigate the clinical factors that may affect the prognosis of patients with stage IB ADC.

Methods

The data of ADC cases were selected from the Surveillance, Epidemiology, and End Results (SEER) database (2010–2016) and patients in Zhongshan Hospital, Fudan University (Department of Thoracic Surgery, 2015–2016). Kaplan-Meier method was used to obtain the overall survival (OS). Factors that significantly related to the prognosis were evaluated by univariate and multivariate analysis (UVA, MVA) using the Cox model. A nomogram was developed and validated to predict the 3-year OSs of those patients.

Results

7,605 patients with stage IB ADC were included ultimately and were divided into two groups, a training cohort (n=5,324) and a test cohort (n=2,281). Besides, there was a validation cohort (n=272) for the verification of the nomogram model. Those with significantly older age, male, the white race, lower grades of tumor differentiation, larger tumor size (31–40 mm) without pleural layer (PL) invasion as well as receiving sublobectomy suffered from poorer survival (P<0.001), which were identified as independent factors for stage IB ADC (P<0.001), and according to which, a nomogram model was created.

Conclusions

Age, sex, race, histological grade, surgery to the primary site, and tumor size combined with PL invasion were independent risk factors for stage IB ADC, based on which a nomogram was constructed to predict the prognosis.

Prognostic relevance of pleural invasion for resected NSCLC patients undergoing adjuvant treatments: A propensity score-matched analysis of SEER database

BACKGROUND

Adjuvant chemotherapy demonstrated a clear benefit in resected non-small cell lung cancer (NSCLC) with nodal disease (stages II-III), and a minimal benefit in tumors >4 cm (stage II, TNM 8th edition). Pleural invasion (PL), classified as visceral pleural invasion (VPI, which includes PL1 and PL2, and parietal pleural invasion (PL3), is an established negative prognostic factor. However, whether PL should influence the decisional algorithm of postoperative chemotherapy is controversial.

METHODS

A survival analysis of NSCLC patients who underwent radical surgery between 2010 and 2015 included in the SEER database was performed. Tumor stage and size, number of examined and positive nodes, histology, PL, and treatment data were extracted. Propensity score matching was performed. The benefit of chemotherapy was analyzed in two subgroups: standard of care (SOC), including patients with positive nodes or tumors ≥ 4 cm; non-SOC, including patients with tumors < 4 cm and negative nodes.

RESULTS

Records of 30,858 patients were extracted. 11,708 patients were included in the propensity score-matched analysis. In the SOC subgroup, including 8089 patients, all pleural invasion degrees were associated with progressively increased risk for death and shorter overall survival (OS), independently from chemotherapy administration. However, chemotherapy significantly improved the median OS regardless of the extent of PL. In the non-SOC subgroup, including 3619 patients, only PL3 was associated with increased mortality. The administration of chemotherapy did not improve survival outcomes.

CONCLUSION

Chemotherapy should be strongly recommended in patients in the SOC-subgroup with pleural invasion. VPI is not associated with unfavorable prognosis in the non-SOC subgroup.

Visceral Pleural Invasion in Pulmonary Adenocarcinoma: Differences in CT Patterns between Solid and Subsolid Cancers

PURPOSE

To analyze the incidence and CT patterns of visceral pleural invasion (VPI) in adenocarcinomas on the basis of their CT presentation as solid or subsolid nodules.

MATERIALS AND METHODS

A total of 286 adenocarcinomas in direct contact with a pleural surface, resected at an institution between 2005 and 2016, were included in this retrospective, institutional review board-approved study. CT size and longest contact length with a pleural surface were measured and their ratios computed. Pleural deviation, pleural thickening, spiculations, different pleural tag types, pleural effusion, and the CT appearance of transgression into an adjacent lobe or infiltration of surrounding tissue were evaluated. Fisher exact tests and simple and multiple logistic regression models were used.

RESULTS

Of the 286 nodules, 179 of 286 (62.6%) were solid and 107 of 286 (37.4%) were subsolid. VPI was present in 49 of 286 (17.1%) nodules and was significantly more frequent in solid (44 of 179; 24.6%) than in subsolid nodules (five of 107; 4.7%; P < .001). In solid nodules, multiple regression analysis showed an association of higher contact length-to-size ratio (adjusted odds ratio [OR], 1.02; P = .007) and the presence of multiple pleural tag types (adjusted OR, 5.88; P = .002) with VPI. In subsolid nodules, longer pleural contact length of the solid nodular component (adjusted OR, 1.27; P = .017) and the CT appearance of transgression or infiltration (adjusted OR, 10.75; P = .037) were associated with VPI.

CONCLUSION

During preoperative evaluation of adenocarcinomas for the likelihood of VPI, whether a tumor manifests as a solid or a subsolid nodule is important to consider because the incidence of VPI is significantly higher in solid than in subsolid nodules. In addition, this study showed that the CT patterns associated with VPI differ between solid and subsolid nodules.© RSNA, 2019Supplemental material is available for this article.See also the commentary by Elicker in this issue.

Clinical Significance of Pleural Attachment and Indentation of Subsolid Nodule Lung Cancer

Purpose

Lung cancers presenting as subsolid nodule commonly have peripheral location, making the cancer-pleura relationship noteworthy. We aimed to evaluate the effect of pleural attachment and/or indentation on visceral pleural invasion (VPI) and recurrence-free survival.

Materials and Methods

Patients who underwent curative resection of lung cancer as subsolid nodules from April 2007 to January 2016 were retrospectively evaluated. They were divided into four groups according to their relationship with the pleura. Clinical, radiographical, and pathological findings were analyzed.

Results

Among 404 patients with malignant subsolid nodule, 120 (29.7%) had neither pleural attachment nor indentation, 26 (6.4%) had attachment only, 117 (29.0%) had indentation only, and 141 (34.9%) had both. VPI was observed in nodules of 36 patients (8.9%), but absent in nonsolid nodules and in those without pleural attachment and/or indentation. Compared to subsolid nodules with concurrent pleural attachment and indentation, those with attachment only (odds ratio, 0.12; 95% confidence interval [CI], 0.02 to 0.98) and indentation only (odds ratio, 0.10; 95% CI, 0.03 to 0.31) revealed lower odds of VPI. On subgroup analysis, the size of the solid portion was associated with VPI among those with pleural attachment and indentation (p=0.021). Such high-risk features for VPI were associated with earlier lung cancer recurrence (adjusted hazard ratio, 3.31; 95% CI, 1.58 to 6.91).

Conclusion

Concurrent pleural attachment and indentation are risk factors for VPI, and the odds increase with larger solid portion in subsolid nodules. Considering the risk of recurrence, early surgical resection could be encouraged in these patients.

Impact of visceral pleural invasion on the association of extent of lymphadenectomy and survival in stage I non-small cell lung cancer

Visceral pleural invasion (VPI) has been identified as an adverse prognostic factor for non‐small cell lung cancer (NSCLC). Accurate nodal staging for NSCLC correlates with improved survival, but it is unclear whether tumors with VPI require a more extensive lymph nodes (LNs) dissection to optimize survival. We aimed to evaluate the impact of VPI status on the optimal extent of LNs dissection in stage I NSCLC, using the Surveillance, Epidemiology, and End Results (SEER) database. We identified 9297 surgically treated T1‐2aN0M0 NSCLC patients with at least one examined LNs. Propensity score matching was conducted to balance the baseline clinicopathologic characteristics between the VPI group and non‐VPI group. Log‐rank tests along with Cox proportional hazards regression methods were performed to evaluate the impact of extent of LNs dissection on survival. VPI was correlated with a significant worse survival, but there was no significant difference in survival rate between PL1 and PL2. Patients who underwent sublobectomy had slightly decreased survival than those who underwent lobectomy. Pathologic LNs examination was significantly correlated with survival. Examination of 7‐8 LNs and 14‐16 LNs conferred the lowest hazard ratio for T1‐sized/non‐VPI tumors (stage IA) and T1‐sized/VPI tumors (stage IB), respectively. The optimal extent of LNs dissection varied by VPI status, with T1‐sized/VPI tumors (stage IB) requiring a more extensive LNs dissection than T1‐sized/non‐VPI tumors (stage IA). These results might provide guidelines for surgical procedure in early stage NSCLC.

Dilemmas in Lung Cancer Staging

The advent of the 8th edition of the lung cancer staging system reflects a further meticulous evidence-based advance in the stratification of the survival of patients with lung cancer. Although addressing many limitations of earlier staging systems, several limitations in staging remain. This article reviews from a radiological perspective the limitations of the current staging system, highlighting the process of TNM restructuring, the residual issues with regards to the assignment of T, N, M descriptors, and their associated stage groupings and how these dilemmas impact guidance of multidisciplinary teams taking care of patients with lung cancer.