Sublobar resection is equivalent to lobectomy for clinical stage 1A lung cancer in solid nodules

Oncologic Outcomes of Surgery Versus SBRT for Non-Small-Cell Lung Carcinoma: A Systematic Review and Meta-analysis

BACKGROUND

The optimal treatment of stage I non-small-cell lung carcinoma is subject to debate. The aim of this study was to compare overall survival and oncologic outcomes of lobar resection (LR), sublobar resection (SR), and stereotactic body radiotherapy (SBRT).

METHODS

A systematic review and meta-analysis of oncologic outcomes of propensity matched comparative and noncomparative cohort studies was performed. Outcomes of interest were overall survival and disease-free survival. The inverse variance method and the random-effects method for meta-analysis were utilized to assess the pooled estimates.

RESULTS

A total of 100 studies with patients treated for clinical stage I non-small-cell lung carcinoma were included. Long-term overall and disease-free survival after LR was superior over SBRT in all comparisons, and for most comparisons, SR was superior to SBRT. Noncomparative studies showed superior long-term overall and disease-free survival for both LR and SR over SBRT. Although the papers were heterogeneous and of low quality, results remained essentially the same throughout a large number of stratifications and sensitivity analyses.

CONCLUSION

Results of this systematic review and meta-analysis showed that LR has superior outcomes compared to SBRT for cI non-small-cell lung carcinoma. New trials are underway evaluating long-term results of SBRT in potentially operable patients.

Survival outcomes of resection for pulmonary malignancies including non-small cell lung cancer and pulmonary metastasis after esophagectomy for esophageal carcinoma

OBJECTIVES

This study investigated survival outcomes of resection for pulmonary malignancies after esophagectomy for esophageal carcinoma, comparing non-small cell lung cancer and pulmonary metastases.

METHODS

We retrospectively reviewed consecutive patients who underwent resection for pulmonary malignancies after esophagectomy for esophageal carcinoma between 2009 and 2018. The overall survival and relapse-free survival rate were assessed using Kaplan-Meier analysis.

RESULTS

Eleven patients had non-small cell lung cancer and eight patients had pulmonary metastases from esophageal carcinoma. The 5-year overall survival rate was 92.9% in all patients with a median follow-up period of 50.4 (range: 9.1-130.2) months. While the 5-year overall survival rate was 100.0% in patients with non-small cell lung cancer, it was 85.7% in patients with pulmonary metastases from esophageal carcinoma. The 5-year relapse-free survival rate was 85.7% in patients with non-small cell lung cancer.

CONCLUSIONS

Our data suggest that resection for pulmonary malignancies after esophagectomy for esophageal carcinoma is associated with favorable survival outcomes and should be considered in selected patients.

CT Radiomics Signature of Tumor and Peritumoral Lung Parenchyma to Predict Nonsmall Cell Lung Cancer Postsurgical Recurrence Risk

RATIONALE AND OBJECTIVES

To estimate recurrence risk after surgery in nonsmall cell lung cancer (NSCLC) patients by employing tumoral and peritumoral radiomics analysis.

MATERIALS AND METHODS

One-hundred twenty-four surgically treated stage IA-IIB NSCLC patients' data from 2008 to 2013 were retrospectively collected. Patient outcome was defined as local recurrence (LR), distant metastasis (DM), and (sum of LR and DM) total recurrence (TR) at follow-up. Volumetric region of interests (ROIs) were drawn for the tumor, peritumoral lung parenchyma (2 cm around the tumor) and involved lobe on CT images. Ninety-four (morphological, first-order, textural, fractal-based) radiomics features were extracted from the ROIs and datasets were created from single or combined ROIs. Predictive models were built with radiomics signature (RS) and clinicopathological data, and the area under the curve (AUC) was used to evaluate the performance. Radiomics score was calculated with the best models' feature coefficients, low- and high-risk groups of patients defined accordingly. Kaplan-Meier curves were built, and the log-rank test was used for comparison among low- and high-risk groups. Differences in recurrence risk among the two risk groups were calculated (chi-square test).

RESULTS

Fifty-six patients developed TR (25 LR, 31 DM). The tumor-node-metastasis (TNM) stage recurrence predictability (AUC_TR 0.680; AUC_DM 0.672; AUC_LR 0.580) was substantially improved when RS was added to the predictive model (AUC_TR 0.760; AUC_DM 0.759; AUC_LR 0.750). Seventy-five percent of high-risk patients developed TR. Recurrence risk of the high-risk group was 16-fold higher than that of the low-risk group (p < 0.001).

CONCLUSION

Combination of the tumoral and peritumoral RS with TNM staging system outperformed TNM staging alone in individualized recurrence risk estimation of patients with surgically treated NSCLC.

Clinicopathological features, survival outcomes, and appropriate surgical approaches for stage I acinar and papillary predominant lung adenocarcinoma

Background

Whether prognosis differs between lung acinar predominant adenocarcinoma (ACN) and papillary predominant adenocarcinoma (PAP) patients remains controversial. Furthermore, the appropriate surgical plan for each subtype is undetermined.

Methods

Data of stage I ACN or PAP patients from 2004 to 2015 were retrospectively reviewed by SEER*Stat 8.3.5. The primary outcome was overall survival (OS) and lung cancer specific survival (LCSS).

Results

1531 patients (PAP, 484; ACN, 1047) were included. ACN patients had better OS (P = .001) and LCSS (P = .003) than PAP patients. Among stage I ACN patients, lobectomy with mediastinal lymph node dissection (Lob) (P = .001) or segmentectomy (Seg) (P = .003) provided a better OS than wedge resection (Wed). And ACN patients who received Lob had a equivalent LCSS, compared to those who received Seg (P = .895). For patients with PAP in stage I, those who received Lob tended to have a better prognosis than that received Seg (HR of OS, 0.605, 95% CI: 0.263‐1.393; HR of LCSS, 0.541, 95% CI: 0.194‐1.504) or Wed (HR of OS, 0.735, 95% CI: 0.481‐1.123; HR of LCSS, 0.688, 95% CI: 0.402‐1.180).

Conclusions

Among patients with lung adenocarcinoma in stage I, those with ACN have a better OS and LCSS than that with PAP. For patients with stage I ACN, Seg and Lob, rather than Wed, seem to be an equivalent treatment choice; however, Seg is the prior option because it could preserve more lung function than Lob. For patients with PAP, Lob tends to be a better choice than Wed and Seg, although the prognostic difference between them is nonsignificant.

Lymphadenectomy is Unnecessary for Pure Ground-Glass Opacity Pulmonary Nodules

BACKGROUND

Lobectomy plus lymph node dissection is the standard treatment of early-stage lung cancer, but the low lymph node metastasis rate with ground-glass opacity (GGO) makes surgeons not perform lymphadenectomy. This study aimed to re-evaluate the lymph node metastasis rate of GGO to help make a clinical judgment.

METHODS

We performed this retrospective study to enroll patients who received lung cancer surgery from 2011 to 2016. Patient characteristics collected included tumor size, solid part size and lymph node metastasis rate. These patients were categorized into pure GGO and part solid GGO groups to undergo analysis.

RESULTS

Lymph node metastasis rates were 0%, 3.8% and 6.9% in order of the pure GGO group, the GGO predominant group and the solid predominant group. In the lobectomy patients, the solid predominant group still showed to have the highest lymph node metastasis rate and recurrence rate (8.3% and 10.1%).

CONCLUSION

It is unnecessary to perform lymphadenectomy for patients with pure GGO in view of the 0% lymph node metastasis rate. The higher lymph node metastasis rate in the patients with the solid predominant group, 6.9%, suggested that surgeons should choose a rational lymphadenectomy method according to their GGO property and clinical judgment.

Systematic review and meta-analysis of video-assisted thoracoscopic surgery segmentectomy versus lobectomy for stage I non-small cell lung cancer

BACKGROUND

Whether video-assisted thoracoscopic surgery (VATS) segmentectomy and VATS lobectomy provide similar perioperative and oncological outcomes in stage I non-small cell lung cancer (NSCLC) is still controversial.

METHODS

Meta-analysis of 12 studies comparing outcomes after VATS lobectomy and VATS segmentectomy for stage I NSCLC. Data were analyzed by the RevMan 5.3 software.

RESULTS

Disease-free survival (HR 1.19, 95% CI 0.89 to 1.33, P = 0.39), overall survival (HR 1.11, 95% CI 0.89 to 1.38, P = 0.36), postoperative complications (OR = 1.10, 95% CI 0.69 to 1.75, P = 0.7), intraoperative blood loss (MD = 3.87, 95% CI - 10.21 to 17.94, P = 0.59), operative time (MD = 10.89, 95% CI - 13.04 to 34.82, P = 0.37), air leak > 5 days (OR = 1.20, 95% CI 0.66 to 2.17, P = 0.55), and in-hospital mortality (OR = 1.67, 95% CI 0.39 to 7.16, P = 0.49) were comparable between the groups. Postoperative hospital stay (MD = - 0.69, 95% CI - 1.19 to - 0.19, P = 0.007) and number of dissected lymph nodes (MD = - 6.44, 95%CI - 9.49 to - 3.40, P < 0.0001) were significantly lower in VATS segmentectomy patients.

CONCLUSIONS

VATS segmentectomy and VATS lobectomy provide similar oncological and perioperative outcomes for stage I NSCLC patients. This systematic review was registered on PROSPERO and can be accessed at http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID = CRD42019133398.

Is lobe specific lymph node dissection adequate for cN0-1 non-small cell lung cancer?

Purpose

This study aims to explore whether lobe specific lymph node dissection (LND) is adequate for cN0–1 non-small cell lung cancer (NSCLC) or not.

Methods

Among 5613 cN0–1 NSCLC patients, 394 cases (7.0%) with pN2 were enrolled and the distribution of mediastinal lymph node metastasis was analyzed. The included patients were divided into the non-lobe specific lymph node metastasis (NLSLNM) group and the lobe specific lymph node metastasis (LSLNM) group. The clinicopathological characteristics were compared between two groups and multivariable analysis was performed to find independent factors predicting NLSLNM.

Results

The incidence of pN2 cases deserved serious attention. The proportion of upper zone lymph node metastases was not rare in right (55.0%) and left (35.7%) lower lobe tumors. The proportion of subcarinal zone lymph node involvement was also high in right (21.8%) and left (25.8%) upper lobe tumors. Multivariable analysis showed that elevated carcinoembryonic antigen (CEA) level (P = 0.034), right lower lobe (RLL) tumors (P = 0.022) and station 11 involvement (P = 0.030) were independent risk factors for NLSLNM.

Conclusion

Systematic LND seems to be superior to lobe specific LND in the assessment of lymph node status and high CEA level, RLL tumors and station 11 involvement are predictors for NLSLNM.

Clinical significance of PET/CT uptake for peripheral clinical N0 non-small cell lung cancer

Objective

In this cohort study, we determined the clinical value of the maximum standardized uptake value (SUVmax) of primary tumors in non‐small cell lung cancer (NSCLC).

Study Design

A retrospective review of NSCLC patients was performed from January 2011 to December 2017. Peripheral cN0 NSCLC patients with tumor size ≤2 cm were included. SUVmax was calculated as a continuous variable for semiquantitative analyses. A receiver operating characteristic curve was analyzed to assess the cutoff threshold of SUVmax on pathological (p) nodal metastasis. We further evaluated the clinical relevance of SUVmax in peripheral cN0 NSCLC patients.

Results

A total of 670 peripheral NSCLC patients with tumor size ≤2 cm were deemed cN0 by preoperative PET/CT scan. Statistical analyses suggested significant correlations of SUVmax with smoking status (P = .026), tumor volume (P = .001), pathology type (P = .008), tumor differentiation (P < .001), vessel invasion (P = .001), plural invasion (P < .001), pT stage (P < .001), nodal involvement (P < .001), and pathological tumor node metastasis stage (P < .001). A cutoff point of SUVmax of 3.8 (P < .001) could be used to predict pathological nodal metastasis. Multivariable analyses indicated that preoperative SUVmax >3.8 (odds ratio, 12.149; P < .001) was an independent predictor of nodal metastasis. Overall survival analyses further suggested that SUVmax was an independent prognostic indicator (hazard ratio, 2.050; P = .017).

Conclusion

Preoperative SUVmax is a predictor of pathological nodal metastasis and prognosis for peripheral cN0 NSCLC patients with tumor size ≤2 cm. Our results indicate that assessment of PET SUVmax could improve stratification of these patients.

Surgeons' preference sublobar resection for stage I NSCLC less than 3 cm

Background

This study aimed to compare survival between standard lobectomy and surgeons' preference sublobar resection among patients with stage I non‐small cell lung cancer (NSCLC).

Methods

Medical records of patients undergoing pulmonary resection between 2006 and 2016 were reviewed retrospectively. Differences in disease‐free survival (DFS) and DFS‐associated factors between patients receiving lobectomy and surgeons' preference sublobar resection were analyzed after 1‐1 propensity score‐matching (n = 119 per group).

Results

In total, 1064 pathological stage I NSCLC patients were identified, including 816 (76.7%) who underwent lobectomy, 111 (10.4%) who underwent sublobar resection as a compromised procedure (medically unfit), and 137 (12.9%) who underwent surgeons' preference sublobar resection. Rates of five‐year DFS for patients undergoing lobectomy, medically unfit, and surgeons' preference sublobar resection were 88.7%, 71.0%, and 93.4%, respectively (P < 0.001). Multivariable Cox regression analysis demonstrated that radiological solid‐appearance (adjusted hazard [aHR] = 2.908, P = 0.003), PL2 invasion (aHR = 1.970, P = 0.024), and angiolymphatic invasion (aHR = 2.202, P = 0.005) were significantly associated with lower DFS after adjusting for surgeons' preference sublobar resection (aH = 1.031, P = 0.939). Subgroup analysis of all 403 solid‐dominant patients demonstrated equivalent five‐year DFS between surgeons' preference sublobar resection and lobectomy (87.7% and 84.1%, respectively, P = 0.721). Propensity‐matched analysis showed no differences in five‐year DFS in stage I NSCLC patients undergoing lobectomy or surgeons' preference sublobar resection (90.5% vs. 93.4% P = 0.510), and DFS for surgeons' preference sublobar resection remained an insignificant factor (aHR = 0.894, P = 0.834).

Conclusions

Carefully selected patients who have undergone surgeons' preference sublobar resection have comparable outcomes to those receiving lobectomy for stage I NSCLC <3 cm.

Key points

Significant findings of the study Intended sublobar resection has a good outcome. What this study adds Sublobar resection is applicable for stage I NSCLC <3 cm.

Minimizing residual occult nodal metastasis in NSCLC: recent advances, current status and controversies

Introduction: Nodal involvement in lung cancer is a significant determinant of prognosis and treatment management. New evidence exists regarding the management of occult lymph node metastasis and residual disease in the fields of imaging, mediastinal staging, and operative management.Areas covered: This review summarizes the latest body of knowledge on the identification and management of occult lymph node metastasis in NSCLC. We focus on tumor-specific characteristics; imaging modalities; invasive mediastinal staging; and operative management including, technique, degree of resection, and lymph node examination.Expert opinion: Newly identified risk-factors associated with nodal metastasis including tumor histology, location, radiologic features, and metabolic activity are not included in professional societal guidelines due to the heterogeneity of their reporting and uncertainty on how to adopt them into practice. Imaging as a sole diagnostic method is limited. We recommend confirmation with invasive mediastinal staging. EBUS-FNA is the best initial method, but adoption has not been uniform. The diagnostic algorithm is less certain for re-staging of mediastinal nodes after neoadjuvant therapy. Mediastinal node sampling during lobectomy remains the gold-standard, but evidence supports the use of minimally invasive techniques. More study is warranted regarding sublobar resection. No consensus exists regarding lymph node examination, but new evidence supports reexamination of current quality metrics.

Development and External Validation of a Nomogram for Predicting Survival in Patients With Stage IA Non-small Cell Lung Cancer ≤2 cm Undergoing Sublobectomy

Background: Postoperative prognosis of early stage non-small cell lung cancer (NSCLC) undergoing sublobectomy is heterogeneous. Therefore, we sought to construct a novel survival prediction model for stage IA NSCLC ≤2 cm undergoing sublobectomy.

Methods: Based on the data from the Surveillance, Epidemiology, and End Results (SEER) program, we successfully determined and incorporated independent prognostic markers to construct the nomogram. Internal validation of the constructed nomogram was conducted through 1,000 bootstrap resamples. The constructed nomogram was further subjected to external validation with an independent cohort of patients from two Chinese institutions. The performance of the survival prediction model was assessed by concordance index, calibration plots, and risk subgroup classification.

Results: A total of 3,238 patients from SEER registries (development cohort), as well as 769 patients from two Chinese institutions (validation cohort) was included. Gender, age, size, histologic type, grade, and examined lymph nodes count were identified as significant prognostic parameters. A novel nomogram was developed and externally validated. Concordance index of constructed nomogram was significantly better than that of the current TNM staging system. Calibration plots demonstrated an optimal consistency between the nomogram predicted and actual observed probability of survival. Survival curves of different risk subgroups within respective TNM stage demonstrated significant distinctions.

Conclusion: We developed and externally validated a survival prediction model for patients with stage IA NSCLC ≤2 cm undergoing sublobectomy. This novel nomogram outperforms the conventional TNM staging system and could help clinicians in postoperative surveillance and future clinical trial design.

Current Controversies in Cardiothoracic Imaging: Overdiagnosis at Lung Cancer Screening-Not So Bad After All-Counterpoint

Initially introduced into the medical literature in research publications from "Special Project #1" of the Council for Tobacco Research, the concept of overdiagnosed lung cancer (OD LC) has consistently served to misinform and confuse the medical community, contributing to interminable delays in implementation of population lung cancer screening. Estimates of overdiagnosis vary enormously (9.5% to 75%). Careful, judicious application of diagnostic algorithms and clinical practice guidelines prevents overtreatment of potentially OD LC and offers a safe and effective method to prevent tens of thousands of LC-related deaths. Speculative concern over potential OD should not further block availability of computed tomography screening to those at risk.

Surgical treatment to multiple primary lung cancer patients: a systematic review and meta-analysis

BACKGROUND

As there is no consensus on the optimal surgery strategy for multiple primary lung cancer (MPLC), we conducted this study to address this issue by comparing the prognosis of MPLC patients underwent different surgical strategies including sublobar resection and the standard resection through a systemic review and meta-analysis.

METHODS

Relevant literature was obtained from three databases including PubMed, Embase and Web of Science. Inclusion and exclusion criteria were set for the screening of articles to be selected for further conduction of systemic review and meta-analysis. The HRs of OS of the sublobar group compared with standard resection group were extracted directly or calculated indirectly from included researches.

RESULTS

Ten researches published from 2000 to 2017 were included in this study, with 468 and 445 MPLC cases for the standard resection group and sublobar resection group respectively. The result suggested that OS of MPLC patients underwent sublobar resection (segmentectomy or wedge resection for at least one lesion) was comparable with those underwent standard resection approach (lobectomy or pneumonectomy for all lesions), with HR 1.07, 95% CI 0.67-1.71, p = 0.784. Further analysis found no difference in subgroups of synchronous and metachronous (from second metachronous lesion), different population region and dominant sex type.

CONCLUSIONS

This study may reveal that sublobar resection is acceptable for patients with MPLC at an early stage, because of the equivalent prognosis to the standard resection and better pulmonary function preservation. Further research is needed to validate these findings.

Clinical study of video-assisted thoracoscopic surgery wedge resection in early-stage lung cancer by tumor mapping with indocyanine green

Aim

This study aimed to assess the clinical effectiveness of video-assisted thoracoscopic surgery (VATS) in early-stage lung cancer by indocyanine green (ICG) for tumor mapping.

Material and methods

Thirty patients with early-stage lung cancer with peripheral nodules smaller than 2 cm scheduled for computed tomography (CT)-guided microcoil placement followed by ICG tumor mapping by VATS wedge resection were enrolled. After microcoil deployment, 100 to 150 ml of diluted ICG was injected percutaneously near the nodule. The nodule initially was localized solely by using a near-infrared ray (NIR) thoracoscope to visualize ICG fluorescence. Thoracoscopic instruments were used to determine the staple line. Wedge resection was performed after confirmation of the location of the microcoil using fluoroscopy and pathology results.

Results

Thirty patients underwent VATS resection. The median tumor size was 1.3 cm by CT. The median depth from the pleural surface was 1.7 cm (range: 0.5–3.8 cm). The median CT-guided intervention time was 25 min, and VATS procedural time was 50 min. ICG fluorescence was clearly identified in 30 of 30 patients (100%). The surgical margins were all negative on final pathology in all included cases. The final diagnoses were 30 primary lung cancers; none needed additional resection.

Conclusions

CT-guided percutaneous ICG injection and intraoperative NIR localization of small nodules are safe and feasible. These offer surgeons the ease of localization through direct indocyanine green fluorescence imaging without the use of fluoroscopy and may be a complementary technique to preoperative microcoil placement for nonvisible, nonpalpable intrapulmonary nodules.

Comprehensive Study of Surgical Treated Lung Adenocarcinoma with Ground Glass Nodule Component

BACKGROUND More and more patients with lung adenocarcinoma were detected with ground glass nodule (GGN) due to the popularity of low-dose spiral computed tomography (LDCT) recently. The clinicopathological characteristics and epidermal growth factor receptor (EGFR) mutation features were unclear. MATERIAL AND METHODS This retrospective study enrolled patients with surgical resected primary lung adenocarcinomas with GGN component. The clinicopathological data included age, gender, smoking history, tumor staging, lymph node staging, surgical methods, subtypes, thyroid transcription factor-1 (TTF-1) expression, EGFR gene mutation and follow-up records were investigated. RESULTS There were 338 lung adenocarcinoma patients with GGN component eligible for our analysis: 219 patients (64.8%) harbored the EGFR mutation. In addition, the EGFR mutation rate was higher in patients with TTF-1+ than in patients with TTF-1- (72 out of 108 patients, 66.7% versus 147 out of 231 patients, 63.6%). In multivariable analysis, surgical procedure, tumor size, nodal stage, and subtype were still significant factors for relapse-free survival (RFS) while only subtype acted as the significant factor for overall survival (OS). In subgroup analyses, patients with TTF-1- had better prognosis in RFS (log-rank P=0.0142) when compared with those with TTF-1+ but not in OS (log-rank P=0.1113). Furthermore, patients with high-risk subtype had worse outcomes than those with low-risk subtype (RFS: log-rank P<0.0001; OS: log-rank P<0.0001). Patients who underwent limited resection experienced high risk of relapse (log-rank P<0.0001) while there was no statistical significance in OS (log-rank P=0.1644) between patients underwent lobectomy and those underwent limited resection. CONCLUSIONS The prognosis of lung adenocarcinomas with GGN component depends mainly on the pathological subtype and there is no significant correlation between EGFR mutation and prognosis. Lobectomy should be performed actively in patients whose preoperative puncture biopsy or intraoperative freezing indicates an invasive or worse subtype. For postoperative patients, we should consider follow-up more frequently.

Single-port video-assisted thoracoscopic surgery subsegmentectomy: The learning curve and initial outcome

BACKGROUND

We report initial surgical results and learning process of single-port video-assisted thoracoscopic surgery (VATS) subsegmentectomy in comparison with segmentectomy in our institution as the presentative of minimal invasiveness and precise resection for early stage lung cancer.

METHODS

All patients undergoing single-port VATS sublobar anatomic resection between January 2014 and December 2018 for clinical diagnosis of lung cancer were included. The learning curve was analyzed using the cumulative summation (CUSUM) method. Comparisons were done between those who underwent single-port VATS subsegmentectomy and segmentectomy.

RESULTS

A total of 364 patients underwent single-port VATS segmentectomy and 91 patients underwent single-port VATS subsegmentectomy were included. Lung adenocarcinoma was the most common (61.1%) diagnosis. The operative time and blood loss in the subsegmentectomy group were less than the segmentectomy group. The incidence of intraoperative complication was also lower in the subsegmentectomy group. The surgical proficiency was reached at 28 cases in single-port VATS subsegmentectomy. For primary lung cancer, the tumor size in subsegmentectomy group was smaller than segmentectomy group (1.1 cm versus 1.4 cm, p = 0.026). The resection margin was smaller in subsegmentectomy group, and both groups reached adequate margin without significant difference (94.7% versus 95.5%, p = 0.737). During the follow-up period, 2 (3.5%) patients in subsegmentectomy group and 9 (4.1%) patients in segmentectomy group developed distant metastasis.

CONCLUSION

Single-port VATS subsegmentectomy is safe and feasible for small-sized lung lesion, providing the benefit of minimal invasiveness, preservation of pulmonary function, and clearance of lymphatic drainage at the intersegmental plane. The surgical proficiency could be achieved based on the experiences in single-port VATS segmentectomy.

Whole-Lesion Computed Tomography-Based Entropy Parameters for the Differentiation of Minimally Invasive and Invasive Adenocarcinomas Appearing as Pulmonary Subsolid Nodules

OBJECTIVE

The aim of this study was to investigate the differentiation of computed tomography (CT)-based entropy parameters between minimally invasive adenocarcinoma (MIA) and invasive adenocarcinoma (IAC) lesions appearing as pulmonary subsolid nodules (SSNs).

METHODS

This study was approved by the institutional review board in our hospital. From July 2015 to November 2018, 186 consecutive patients with solitary peripheral pulmonary SSNs that were pathologically confirmed as pulmonary adenocarcinomas (74 MIA and 112 IAC lesions) were included and subdivided into the training data set and the validation data set. Chest CT scans without contrast enhancement were performed in all patients preoperatively. The subjective CT features of the SSNs were reviewed and compared between the MIA and IAC groups. Each SSN was semisegmented with our in-house software, and entropy-related parameters were quantitatively extracted using another in-house software developed in the MATLAB platform. Logistic regression analysis and receiver operating characteristic analysis were performed to evaluate the diagnostic performances. Three diagnostic models including subjective model, entropy model, and combined model were built and analyzed using area under the curve (AUC) analysis.

RESULTS

There were 119 nonsolid nodules and 67 part-solid nodules. Significant differences were found in the subjective CT features among nodule type, lesion size, lobulated shape, and irregular margin between the MIA and IAC groups. Multivariate analysis revealed that part-solid type and lobulated shape were significant independent factors for IAC (P < 0.0001 and P < 0.0001, respectively). Three entropy parameters including Entropy-0.8, Entropy-2.0-32, and Entropy-2.0-64 were identified as independent risk factors for the differentiation of MIA and IAC lesions. The median entropy model value of the MIA group was 0.266 (range, 0.174-0.590), which was significantly lower than the IAC group with value 0.815 (range, 0.623-0.901) (P < 0.0001). Multivariate analysis revealed that the combined model had an excellent diagnostic performance with sensitivity of 88.2%, specificity of 73.0%, and accuracy of 82.1%. The AUC value of the combined model was significantly higher (AUC, 0.869) than that of the subjective model (AUC, 0.809) or the entropy model alone (AUC, 0.836) (P < 0.0001).

CONCLUSIONS

The CT-based entropy parameters could help assess the aggressiveness of pulmonary adenocarcinoma via quantitative analysis of intratumoral heterogeneity. The MIA can be differentiated from IAC accurately by using entropy-related parameters in peripheral pulmonary SSNs.

Less is more in solid-dominant lung cancer? Sublobar resection versus lobectomy for solid-dominant stage IA non-small-cell lung cancer: A meta-analysis study

Although lobectomy is well established as the standard surgical procedure for stage IA non-small-cell lung cancer (NSCLC), sublobar resection is increasingly preferred, particularly in intentional segmentectomy for radiologically less-invasive small NSCLC. However, the indication for sublobar resection of radiologically pure solid or solid-dominant NSCLC remains controversial, owing to its invasive pathological characteristics. Therefore, the present meta-analysis was conducted to compare the efficacy of sublobar resection with lobectomy for treating solid-dominant stage IA NSCLC. An electronic search was conducted using four online databases from their dates of inception to April 2017. The hazard ratio (HR) was used as a summary statistic for censored outcomes and the odds ratio (OR) was used as the summary statistic for dichotomous variables. A total of nine studies met the selection criteria, including a total of 2,265 patients (1,728 patients underwent lobectomy, 425 segmentectomy and 112 wedge resection). From the available data, patients treated with a sublobar resection had a higher risk of local recurrence compared with patients treated with lobectomy [OR=1.89; 95% confidence interval (CI), 1.02–3.50; P=0.04]. However, no obvious difference in local recurrence was found in a subgroup analysis of segmentectomy compared with lobectomy (OR=1.19; 95% CI, 0.68–2.10; P=0.61). Sublobar resection was not associated with a significantly negative impact on distant recurrence (OR=1.09; 95% CI, 0.55–2.16; P=0.796). Patients in the sublobar resection group had no significant differences in recurrence-free survival (RFS; HR=1.43; 95% CI, 0.76–2.69; P=0.27) and overall survival (OS; HR=0.96; 95% CI, 0.75–1.23; P=0.77) compared with those in the lobectomy group. In the subgroup analysis of anatomic segmentectomy compared with lobectomy, there was no significant difference in RFS, with mild inter-study heterogeneity. The current meta-analysis suggested that segmentectomy had a comparable oncologic efficacy to lobectomy for solid-dominant stage IA NSCLC. Therefore, segmentectomy may be a feasible alternative in selected cases of solid-dominant stage IA NSCLC. However, these findings should be confirmed by prospective randomized controlled trials in the future.

Impact of complex segmentectomies by video-assisted thoracic surgery on peri-operative outcomes

Background

Pulmonary segmentectomies are generally classified into simple (tri-segmentectomy or lingulectomy as well as apical or basilar segmentectomy) and complex (individual or bi-segmentectomy of the upper, middle and lower lobes). Complex segmentectomies are technically feasible by video-assisted thoracic surgery (VATS) but remain challenging, and reports on post-operative outcomes are scarce. This study analyzes the differences between simple and complex VATS segmentectomy in terms of peri- and post-operative outcomes.

Methods

We retrospectively reviewed records of all patients who underwent anatomical pulmonary segmentectomy by VATS from 2014 to 2018 in two university hospitals.

Results

A total of 232 patients (114 men; median age 67 years; range, 29-87 years) underwent VATS segmentectomy for primary lung cancer (n=177), metastases (n=26) and benign lesions (n=29). The overall 30-day mortality and morbidity rates were 0.8% and 29.7%, respectively. The re-operation rate was 4.7%. Complex segmentectomy was realized in 111 patients including 86 (77.5%) upper lobe segmentectomies and 44 (39.6%) bi-segmentectomies. There was no statistical difference between complex and simple segmentectomy in terms of operative time (145 vs. 143 min, respectively; P=0.79) and chest tube duration [median: 1 (range, 0-33) vs. 2 (range, 1-19) days, respectively; P=0.95]. Post-operative overall complication rates were similar for both groups (30% vs. 30%, respectively; P=0.99) and were not correlated with the type of segmentectomy. However, complex segmentectomy patients had a shorter length of hospitalization compared to simple segmentectomy patients [median: 5 (range, 1-36) vs. 7 (range, 2-31) days; P=0.026]. Interestingly, complex segmentectomies were realized most frequently 2 years after implementation of VATS segmentectomy (23% vs. 77%; P=0.01).

Conclusions

In comparison with simple segmentectomy, complex segmentectomy by VATS seems to present similar post-operative complication rates. Learning curve and progressive increase in acceptance by surgeons seem to be key elements for successful implementation of complex segmentectomies and could explain the shorter length of stay we observed.

Prevalence of Occult Peribronchial N1 Nodal Metastasis in Peripheral Clinical N0 Small (≤2 cm) Non-Small Cell Lung Cancer

BACKGROUND

There has been growing interest in limited resection and nonsurgical treatment for small lung cancers. We examined the pattern and rate of occult N1 nodal metastasis in patients with peripheral, small (≤2 cm), clinically node-negative non-small cell lung cancer (NSCLC).

METHODS

Patients with peripheral small (≤2 cm) NSCLC with no evidence of locally advanced or metastatic disease (clinical T1a-b N0 M0, American Joint Committee on Cancer 8th Edition Cancer Staging Manual), who were deemed eligible for lobectomy or sublobar resection, were identified from preregistration eligibility screening logs for the Alliance/Cancer and Leukemia Group B 140503 trial at our institution. Pathologic outcomes were examined in all patients undergoing anatomic resection with mediastinal and hilar lymphadenectomy.

RESULTS

Included were 58 patients treated between November 2014 and January 2017 who met the inclusion criteria: 51 underwent lobectomy, and 7 underwent segmentectomy. Mean tumor diameter on computed tomography was 1.5 cm, and mean positron emission tomography maximal standardized uptake value was 3.9. The mean consolidation-to-tumor ratio was 0.77. Occult nodal metastases in N1 stations were found in 8 of 58 patients (14%), and most of these nodes were found in interlobar or peribronchial stations (11 or 12). An additional 2 patients (3%) had occult positive N2 nodes. Overall, the false-negative rate for clinical staging was 16%.

CONCLUSIONS

Occult nodal disease was frequently identified in peripheral N1 stations (11-13) in patients with small (≤2 cm) clinical N0 NSCLC. Hilar lymphadenectomy is essential for accurate staging in the management of patients with small clinical N0 NSCLC.

Image-guided Preoperative Localization of Pulmonary Nodules for Video-assisted and Robotically Assisted Surgery

Video-assisted thoracic surgery (VATS) and robotically assisted surgery are used increasingly for minimally invasive diagnostic and therapeutic resection of pulmonary nodules. Unsuccessful localization of small, impalpable, or deep pulmonary nodules can necessitate conversion from VATS to open thoracotomy. Preoperative localization techniques performed by radiologists have improved the success rates of VATS resection for small and subsolid nodules. Any center at which VATS diagnostic resection of indeterminate pulmonary nodules is performed should be supported by radiologists who offer preoperative nodule localization. Many techniques have been described, including image-guided injection of radioisotopes and radiopaque liquids and placement of metallic wires, coils, and fiducial markers. These markers enable the surgeon to visualize the position of an impalpable nodule intraoperatively. This article provides details on how to perform each percutaneous localization technique, and a group of national experts with established nodule localization programs describe their preferred approaches. Special reference is made to equipment required, optimization of marker placement, prevention of technique-specific complications, and postprocedural treatment. This comprehensive unbiased review provides valuable information for those who are considering implementation or optimization of a nodule localization program according to workflow patterns, surgeon preference, and institutional resources in a particular center. ^©RSNA, 2019.

Impact of Different Types of Lymphadenectomy Combined With Different Extents of Tumor Resection on Survival Outcomes of Stage I Non-small-cell Lung Cancer: A Large-Cohort Real-World Study

Background: To investigate the prognostic impact of different types of lymphadenectomy with different extents of tumor resection on the outcomes of stage I non-small-cell lung cancer (NSCLC).

Methods: Patients were classified into lobectomy and sublobectomy groups, and then each group was subdivided according to the types of lymphadenectomy. The end points of the study were overall survival (OS) and disease-free survival (DFS). Propensity score matched (PSM) comparative analysis and univariate and multivariate Cox regression analyses were performed.

Result: A total of 1,336 patients were included in the current study. Lobectomy was associated with better OS and DFS. In the lobectomy group, lobectomy with bilateral mediastinal lymphadenectomy (BML) was associated with better OS than lobectomy with systematic nodal dissection (SND) or lobe-specific systematic node dissection (L-SND). Lobectomy with SND or L-SND was associated with better OS than lobectomy with systematic nodal sampling (SNS) or selected lymph node biopsy (SLNB). Additionally, lobectomy with BML or SND was associated with better DFS than lobectomy with L-SND or SNS or SLNB. After PSM, compared with lobectomy with SNS or SLNB, lobectomy with SND resulted in more favorable OS and DFS. There was no survival difference between different types of lymphadenectomy for patients who underwent sublobectomy. A multivariable analysis revealed independent associations of lobectomy with BML or SND with better OS and DFS compared with those of lobectomy with SNS or SLNB.

Conclusion: This study reveals an association of lobectomy with more systematic and complete lymph node dissection, such as BML or SND, with better prognosis in stage I NSCLC patients.

[Diagnosis and Treatment of Pulmonary Ground-glass Nodules]

Recent widespread use of high resolution computed tomography (HRCT) for the screening of lung cancer have led to an increase in the detection rate of very faint and smaller lesions known as ground-glass nodule (GGN). However, it had been proved that GGN was well associated with lung cancer in previous studies. Therefore, the classification, imaging characteristics, pathological type, follow-up, suggested managements and other clinical concerns of GGN were reviewed in this paper.
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Attenuation and Morphologic Characteristics Distinguishing a Ground-Glass Nodule Measuring 5-10 mm in Diameter as Invasive Lung Adenocarcinoma on Thin-Slice CT

OBJECTIVE. The purpose of this study is to comprehensively investigate the role of multiple features seen on thin-section CT (TSCT) in the differential diagnosis of ground-glass nodules (GGNs) measuring 5-10 mm in diameter as invasive adenocarcinoma (IAC). MATERIALS AND METHODS. The TSCT features of 313 surgically diagnosed GGNs from 288 patients were retrospectively reviewed. A logistic regression model was applied, and the AUC values for the model and the size and attenuation of the lesions were compared using ROC curve analysis. RESULTS. A total of 247 lung adenocarcinomas in situ (AISs) and minimally invasive adenocarcinomas (MIAs) (hereafter referred to as the AIS-MIA group) and 66 invasive adenocarcinomas (IACs) were identified. Compared with the AIS-MIA group, the IAC groups were significantly larger in size and had higher attenuation values, a higher frequency of mixed GGNs (all p < 0.001), bubblelike appearance, spiculation, pleural indentation, different locations, and a lower frequency of clear tumor-lung interface (all p < 0.05). The logistic model included size and attenuation (both p < 0.001; odds ratio [OR], 1.872 and 1.009, respectively) as well as tumor-lung interface (p = 0.001; OR, 0.242), bubblelike appearance (p < 0.05; OR, 2.205), and type of nodule. The AUC value for the logistic model was 0.847 (sensitivity, 80.3%; specificity, 81.0%) and was significantly higher than that for size or attenuation (both p < 0.01). CONCLUSION. Radiologic features could help in the differential diagnosis of a GGN that was 5-10 mm in diameter as IAC versus AIS or MIA. GGNs larger than 8.12 mm and with attenuation greater than -449.52 HU were more likely to be IAC.

Three-Dimensionally Printed Template for Percutaneous Localization of Multiple Lung Nodules

BACKGROUND

When multiple target lung nodules exist, the computed tomography (CT)-guided percutaneous localization procedure becomes complicated. In this study, a three-dimensional (3D)-printed template was designed that could guide hook wire localization of multiple lung nodules. The pilot study aimed for preliminary validation of the feasibility of template-guided localization for multiple lesions.

METHODS

Patients with multiple lung nodules (<2 cm) and who were scheduled for surgical resection were recruited for participation in this study. After securing their preadmission CT images, the study investigators reconstructed a 3D thorax model from which they designed a digital model as a navigational template. A physical template was then printed for guiding the percutaneous localization of lung nodules. The localization accuracy was evaluated on the basis of the deviation between the localizer and the nodule.

RESULTS

From April 2018 to November 2018, the study enrolled 16 patients with 34 lung nodules. All nodules were successfully localized under template guidance, with a median procedural time of 10.0minutes (interquartile range [IQR], 8.5-12.6 minutes) and a median radiation exposure of 235 mGy • cm (IQR, 195-254 mGy • cm). The median deviation from the hook wires and nodule centers was 9.0 mm (IQR, 6.2-11.8 mm). Except for 2 cases of pneumothorax without need for further intervention, no complications occurred.

CONCLUSIONS

Navigational templates built using 3D printing may serve as an effective approach for facilitating localization of multiple lung nodules.

Value of folate receptor-positive circulating tumour cells in the clinical management of indeterminate lung nodules: A non-invasive biomarker for predicting malignancy and tumour invasiveness

Background

Non-invasive lung adenocarcinoma could benefit from limited resection, nonetheless, there is a lack of method to determine preoperative tumour invasiveness. We aimed to investigate whether folate receptor-positive circulating tumour cells (FR⁺-CTCs) in combination with maximum tumour diameter (MTD) determines, before surgery, the invasiveness of small-sized, indeterminate solitary pulmonary nodules (SPNs).

Methods

A total of 382 patients with suspicious lung adenocarcinoma on computed tomography who were expected to undergo lung resection were enrolled in this study at three participating institutes and randomly assigned into training and validation cohorts. Before surgery, 3 mL peripheral blood was collected from all participants. FR⁺-CTCs were analyzed using immunomagnetic leukocyte depletion and quantitated by ligand-targeted PCR method. After surgery, the resected tissues were diagnosed by pathologists according to IASLC/ATS/ERS classification.

Findings

FR⁺-CTC levels in the peripheral blood can differentiate benign from malignant nodules with a sensitivity of 78·6%–82·7% and a specificity of 68·8%–78·4%. Both FR⁺-CTC and MTD are independent predictive indices of invasive tumours for lung adenocarcinoma ≤2 cm based on multivariate analyses. Further, FR⁺-CTC count in combination with MTD can differentiate non-invasive cancers from invasive cancers with a sensitivity of 63·6%–81·8% and a specificity of 71·4%–89·7%.

Interpretation

Detection of FR⁺-CTC is a reliable method to differentiate malignancy of indeterminate SPNs. Combining of FR⁺-CTC count and MTD could possibly enhance preoperative determination of the invasiveness of lung nodules and guide surgeons to select limited lung resection and avoid overtreatment for patients with non-invasive lesions.

Fund

None.

Concepts and techniques: how to determine and identify the appropriate target segment in anatomical pulmonary segmentectomy?

Anatomical segmentectomy is gathering increasing interest among thoracic surgeons because of increased detection of pulmonary nodules with ground-glass opacity (GGO) as well as an increase in the number of compromised patients. Accurate determination of intersegmental planes is a challenge in anatomical segmentectomy, and multiple methods have been proposed including developing inflation/deflation lines and injecting indocyanine green either intravenously or intrabronchially. Considering resection margins, adding a localization technique to conventional methods, or conducting virtual-assisted lung mapping (bronchoscopic multi-spot dye marking) may be an optional approach for optimal anatomical segmentectomy to identify intersegmental planes and obtain adequate resection margins. To determine optimal resection lines in anatomical segmentectomy, surgeons must also consider oncological validity such as venous and lymph drainage, resection margins, and lung anatomy to avoid complications such as venous congestion, infarction, and air leakage. Although anatomical segmentectomy is an attractive approach to resect small early-stage lung cancer and some metastatic lung tumors, caution is needed to optimally perform this technically demanding surgery.

Stereotactic body radiation therapy in early-stage NSCLC: historical review, contemporary evidence and future implications

Clinical use of stereotactic body radiation therapy (SBRT) has increased dramatically over the last 2 decades and is the current standard-of-care in cases of inoperable early stage non-small-cell lung cancer. While surgical resection remains the standard-of-care for operable patients, several ongoing clinical trials are investigating the role of SBRT in these operative candidates as well. Taking into consideration the expanding role and utility of SBRT, this paper will: review the historical basis of SBRT; examine landmark trials establishing the framework for the current body of evidence; discuss areas of active and future research; and identify epidemiological trends that are likely to further increase the use of SBRT.

The clinical value of a new method of functional lymph node dissection in video-assisted thoracic surgery right non-small cell lung cancer radical resection

Background

To evaluate the safety, thoroughness and feasibility of "tunnel-type en bloc mediastinal lymph node dissection" in video-assisted thoracic surgery (VATS) for right non-small cell lung cancer (NSCLC) radical resection, which functionally dissected the lymph nodes of station 2R/4R/7.

Methods

A retrospective study was performed in the clinical data of 196 patients with VATS right NSCLC radical resection. According to the different methods of lymph node dissection of station 2R, 4R and 7, they were divided into the tunnel-type group (n=102) and the routine group (n=94). The clinical data of two group were compared.

Results

The analyses of the baselines of the two groups are comparable. For lymph nodes dissection of station 2R/4R/7, operation time, the total number, positive number and metastasis incidence shown no significant difference between two groups (P>0.05). However, the amount of bleeding, postoperative thoracic drainage volume, extubation time, hospitalization days, the incidence of postoperative pulmonary infection and chronic cough were significantly lower in the tunnel-type group (P<0.05). There was no significant difference in 3-year recurrence and metastasis and in 3-year survival between tunnel-type group and routine group.

Conclusions

The tunnel-type group has more advantages, such as less surgical trauma, shorter hospitalization time, faster postoperative rehabilitation, even less postoperative chronic cough compared with the routine group. Therefore, we believe that the tunnel-type en bloc mediastinal lymph node dissection is a safe, thorough and feasible surgical method, which is worthy of being popularized and applied in the VATS right NSCLC radical resection.

18F-fluorodeoxyglucose positron emission tomography/computed tomography in the evaluation of clinically node-negative non-small cell lung cancer

One in four non-small cell lung cancer (NSCLC) patients are diagnosed at an early-stage. Following the results of the National Lung Screening Trial that demonstrated a survival benefit for low-dose computed tomography screening in high-risk patients, the incidence of early-stage NSCLC is expected to increase. Use of 18F-fluorodeoxyglucose positron emission tomography/computed tomography during initial diagnosis of these early-stage lesions has been increasing. Traditionally, positron emission tomography/computed tomography scans have been utilized for mediastinal nodal staging and to rule out distant metastases in suspected early-stage NSCLC. In clinically node-negative NSCLC, the use of sublobar resection and selective lymph node dissection has been increasing as a therapeutic option. The higher rate of locoregional recurrences after limited resection and the significant incidence of occult lymph node metastases underscores the need to further stratify clinically node-negative NSCLC in order to select patients for limited resection versus lobectomy with complete mediastinal lymph node dissection. In this report, we review the published data, and discuss the significance and potential role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography evaluation for clinically node-negative NSCLC. Consequently, the literature review demonstrates that maximum standardized uptake value is a predictive factor for occult nodal metastasis with an accuracy of 55-77%. In addition, maximum standardized uptake value is a predictor for worse overall, as well as disease-free, survival.

Nanoparticle-based CT visualization of pulmonary vasculature for minimally-invasive thoracic surgery planning

Purpose

To evaluate CF800, a novel lipid-based liposomal nanoparticle that co-encapsulates indocyanine green (ICG) and iohexol, for CT imaging of pulmonary vasculature in minimally-invasive thoracic surgery planning.

Methods

CF800 was intravenously administered to 7 healthy rabbits. In vivo CT imaging was performed 15 min post-injection, with a subset of animals imaged at 24h, 48h, and 72h post injection. Signal-to-background ratios (SBR) were calculated at the inferior vena cava and compared across time-points. A similar protocol was applied to 2 healthy pigs to evaluate the feasibility and efficacy in a large animal model. To evaluate the feasibility of clinical application, a survey was completed by 7 surgical trainees to assess pre- and post-injection CT images of rabbits and pigs. Responses on the discernibility of pulmonary vasculature sub-branches and comfort level to use the images for pre-operative planning were collected and analyzed.

Results

CF800 injection improved visualization of pulmonary vessels in both rabbit and pig models. The SBR of rabbit pulmonary vasculature was significantly higher after CF800 injection (range 3.7–4.4) compared to pre-injection (range 3.3–3.8, n = 7; p<0.05). SBR remained significantly different up to 24 hours after injection (range 3.7–4.3, n = 4; p<0.05). Trainees’ evaluation found the post-injection CT images had significantly higher discernibility at the second vessel branch generation in both rabbit and pig models. Trainees identified smaller vasculature branch generations in the post-injection images compared to the pre-treatment images in both rabbit (mean 6.7±1.8 vs 5.4±2.1; p<0.05) and pig (mean 6.7±1.8 vs 5.4±2.1; p<0.05). Trainees were significantly more comfortable using post-injection images for surgical planning compared to the pre-injection images (rabbit: 8.1±1.1 vs. 4.7±2.1; pig: 7.6±2.1 vs. 4.9±2.2; p<0.05).

Conclusion

CF800 provides SBR and contrast enhancement of pulmonary vasculature which may assist in pre-surgical CT planning of minimally invasive thoracic surgery.

Is segmentectomy the future?

The role of anatomic segmentectomy as an acceptable, lung parenchymal sparing alternative to pulmonary lobectomy for the small peripheral stage I lung cancer is under great scrutiny today. This is not a new consideration, particularly for the patient with impaired cardiopulmonary reserve where preservation of lung function may be a critical issue in deciding on surgical resection for local/regional control of their cancer. In this review, we discuss the oncologic issues along with past and present evidence supporting "anatomic" lung preservational surgery in the management of lung cancer.

Do the surgical results in the National Lung Screening Trial reflect modern thoracic surgical practice?

INTRODUCTION

Surgical data from the National Lung Screening Trial (NLST) has yet to be closely examined. We sought to analyze surgical procedures and complications from the NLST to determine their relevance to modern surgical practice.

METHODS

The NLST database was queried for patients who underwent surgical resection for confirmed lung cancer, specifically evaluating postoperative complications. Numerical variables were compared using the Mann-Whitney U test. Categorical variables were compared using the χ² test. Logistic regression uni- and multivariable analysis of independent risk factors of postoperative complications was performed.

RESULTS

At operation, 80% of patients (n = 821) had lobectomy, 4.1% (n = 42) had pneumonectomy, and 16.1% (n = 166) had sublobar resection, among whom 69% (n = 114) had wedge resection. Only 29.6% (n = 305) of the cohort had a thoracoscopic resection. Although the overall rate of surgical patients with any complication was 31% (n = 318), only 15.5% of patients (n = 160) had major complications, most commonly prolonged air leaks (n = 67, 6.5%). Respiratory failure (n = 28, 2.7%), prolonged ventilation (n = 9, 0.9%), myocardial infarction or cardiac arrest (n = 7, 0.7%), and stroke (n = 2, 0.2%) were rare events. Overall 30-day mortality in patients undergoing resection was 1.7% (n = 18). On multivariable analysis, greater smoking pack history (odds ratio [OR], 1.01; 95% confidence interval [CI], 1.001-1.01) and pulmonary comorbidities (OR, 1.34; 95% CI, 0.98-1.82) were significant or approached significance for an association with complications/death, whereas sublobar resection (OR, 0.59; 95% CI, 0.38-0.94) and video-assisted thoracoscopic surgery approach (OR, 0.76; 95% CI, 0.56-1.04) were significant or approached significance for an association with decreased rates of complications/death.

CONCLUSIONS

Operative mortality and postoperative morbidity were very low in patients undergoing resection for screen-detected lung cancer. Increased use of sublobar resection and minimally invasive surgical approaches may be associated with fewer complications.

Persistence of racial disparities in early-stage lung cancer treatment

OBJECTIVE

Although the incidence of lung cancer has decreased over the past decades, disparities in survival and treatment modalities have been observed for black and white patients with early-stage non-small cell lung cancer, despite the fact that surgical resection has been established as the standard of care. Possible contributors to these disparities are stage at diagnosis, comorbidities, socioeconomic factors, and patient preference. This study examines racial disparities in treatment, adjusting for clinicodemographic factors.

METHODS

The Surveillance, Epidemiology, and End Results-Medicare dataset was queried to identify patients diagnosed with primary stage I non-small cell lung cancer between 1992 and 2009. Multivariable logistic regressions were performed to assess the association between race and treatment modalities within 1 year of diagnosis, adjusted for clinical and demographic factors. Adjusted Cox proportional hazards models were performed to evaluate disparities in survival, accounting for mode of treatment.

RESULTS

We identified 22,724 patients; 21,230 (93.4%) white and 1494 (6.6%) black. Black patients were less likely to receive treatment (odds ratio [OR]_adj, 0.62; 95% confidence interval [CI], 0.53-0.73) and less likely to receive surgery only when treated (OR_adj, 0.70, 95% CI, 0.61-0.79). Although univariate survival for black patients was worse, when accounting for treatment mode, there was no difference in survival (hazard ratio_adj, 0.97; 95% CI, 0.90-1.04 for all patients, hazard ratio_adj, 0.98; 95% CI: 0.90-1.06 for treated patients).

CONCLUSIONS

Treatment disparities persist, even when adjusting for clinical and demographic factors. However, when black patients receive similar treatment, survival is comparable with white patients.

Surgical Outcomes of Radiographically Noninvasive Lung Adenocarcinoma according to Surgical Strategy: Wedge Resection, Segmentectomy, and Lobectomy

Background

The aim of this study was to evaluate the outcomes of surgical resection in patients with radiographically noninvasive lung adenocarcinoma according to the surgical strategy.

Methods

A retrospective study was conducted of 128 patients who underwent pulmonary resection for ground-glass opacity (GGO)–dominant nodules measuring ≤2 cm with a consolidation/tumor ratio ≤0.25 based on computed tomography between 2008 and 2015. The 5-year disease-free survival (DFS) rate and 5-year overall survival (OS) rate were analyzed.

Results

Among the 128 patients, wedge resection, segmentectomy, and lobectomy were performed in 40 (31.2%), 22 (17.2%), and 66 patients (51.6%), respectively. No significant differences were found among the groups in the mean size of tumors (p=0.119), the rate of pure-GGO nodules (p=0.814), the consolidation/tumor ratio (p=0.695), or the rate of invasive adenocarcinoma (p=0.378). Centrally located tumors were more common in the lobectomy group (21.2%) than in the wedge resection (0%) or segmentectomy (0%) groups (p=0.001). There were no significant differences in the 5-year DFS rate (100%, 100%, 92.7%, respectively; p=0.76) or 5-year OS rate (100%, 100%, 100%; p=0.223) among the wedge resection, segmentectomy, and lobectomy groups.

Conclusion

For radiographically noninvasive lung adenocarcinoma measuring ≤2 cm with a consolidation/tumor ratio ≤0.25, wedge resection and segmentectomy could be comparable surgical options to lobectomy.

Prognostic Analysis of Limited Resection Versus Lobectomy in Stage IA Small Cell Lung Cancer Patients Based on the Surveillance, Epidemiology, and End Results Registry Database

Objective: The prognostic analysis of limited resection vs. lobectomy in stage IA small cell lung cancer (SCLC) remains scarce. Methods: Using the Surveillance, Epidemiology, and End Results registry (SEER) database, we identified patients who were diagnosed with pathological stage IA (T1a/bN0M0) SCLC from 2004 to 2013. The overall survival (OS) and lung cancer-specific survival (LCSS) rates of patients with different treatment schemes were compared in stratification analyses. Univariable and multivariable analyses were also performed to identify the significant predictors of OS and LCSS. Results: In total, we extracted 491 pathological stage IA SCLC patients, 106 (21.6%) of whom received lobectomy, 70 (14.3%) received sublobar resection and 315 (64.1%) received non-surgical treatment, respectively. There were significant differences among the groups based on different treatment schemes in OS (log-rank p < 0.0001) and LCSS (log-rank p < 0.0001). Furthermore, in subgroup analyses, we did not identify any differences between sublober resection group and lobectomy group in OS (log-rank p = 0.14) or LCSS (log-rank p = 0.4565). Patients with four or more lymph node dissection had better prognosis. Multivariable analyses revealed age, laterality, tumor location, and N number were still significant predictors of OS, whereas age, tumor location, and N number were significant predictors of LCSS. Conclusion: Surgery is an important component of multidisciplinary treatment for stage IA SCLC patients and sublober resection is not inferior to lobectomy for the specific patients.

Radiologic Criteria in Predicting Pathologic Less Invasive Lung Cancer According to TNM 8th Edition

PURPOSE

The Japan Clinical Oncology Group Study 0201 has proposed radiologic criteria on thin-slice computed tomography to diagnose pathologic less invasive lung adenocarcinoma that could be a candidate for sublobar resection based on the previous tumor, node, metastasis classification system (TNM). The aim of this study was to propose the new radiologic criteria for predicting pathologic less invasive cancer according to the 8th edition TNM.

PATIENTS AND METHODS

We analyzed 744 patients who had peripheral clinical Tis-T1cN0M0 non-small-cell lung cancer of 3 cm or less and underwent complete resection by lobectomy from 2003 to 2011. We defined lung cancer with no nodal involvement and no vessel invasion pathologically as a pathologic less invasive cancer and investigated the radiologic criteria on the basis of the solid component size and by the consolidation-to-tumor (C/T) ratio (calculated with the maximum solid component diameter divided by the maximum tumor diameter) by using preoperative thin-slice computed tomography to predict them with a specificity of 97% or more, and evaluated overall survival.

RESULTS

Patients with clinical Tis/T1mi/T1a disease had no pathologic invasive cancer except for one patient (specificity, 99%). From the investigation with the C/T ratio, only the criterion of C/T ratio 0.5 or less met the standard (specificity, 100%). The final specificity after combining these criteria was 99.6%, and they showed excellent prognosis (5-year overall survival rate, 96.2%).

CONCLUSION

Lung cancer with clinical Tis/T1mi/T1a or a C/T ratio of 0.5 or less can be completely cured by sublobar resection with sufficient margin because of its less invasive nature pathologically.

Lobectomy vs. segmentectomy. A propensity score matched comparison of outcomes

BACKGROUND

Segmentectomy has emerged as a lung parenchymal sparring alternative to the gold standard lobectomy in non-small cell lung cancer (NSCLC) patients. We hypothesized that there is parity between functional, local recurrence and survival outcomes.

PATIENTS AND METHODS

Parenchymal sparring procedures including anatomical segmentectomies were propensity score matched 1:1 with lobectomies (n = 64). The primary outcomes included survival, functional and oncological outcomes. The oncological outcomes were: post-operative histology, clear margins and local recurrence rates. Kaplan Meier survival curves were used to compare the survival. Oncological and functional variables were assessed by Fischer exact test and t-test.

RESULTS

The pre-operative performance status, ASA grade, lung function, risk factors, surgical approach and tumour histology were similar between the groups. The tumour size was significantly higher for lobectomies (32.4 ± 17 vs. 24.6 ± 12 mm, p = 0.01). The tumour staging in the segmentectomy group was similar to the lobectomy group (Ia; 50 vs. 34%; Ib: 29 vs. 37%; IIa 11 vs. 9.3%; IIb 5 vs. 14%; IIIa 5 vs. 4.6%, p = 0.83). The loco-regional recurrence was lower in the segmentectomy group (1.5 vs. 3.1%, p = 0.69). The up-staging and down-staging post-surgery was similar in both groups, while neo-adjuvant therapy was used in 5 lobectomy and 3 segmentectomy cases. The survival was similar at 1 year between the groups (88 vs. 92%, p = 0.65). Between 4 and 5 years, the survival reduced in the parenchymal sparing group to 39% vs. 68% in the lobectomy group (p = 0.04).

CONCLUSION

Surgical selection bias could be an important confounder in the selection of patients undergoing segmentectomy. Similar up and down staging were demonstrated in the two groups. This is one of the first studies to investigate the results of segmentectomy versus lobectomy in stage II/IIIa NSCLC tumours. No significant differences were found in functional outcomes, but the survival decreased after 4 years in the segmentectomy group, which could be explained by lower survival in the stage II/IIIa tumours treated with segmentectomy.

Expressions of KAI1 and E-cadherin in nonsmall cell lung cancer and their correlation with vasculogenic mimicry

BACKGROUND

Metastasis and recurrence are the most common reasons for treatment failure of nonsmall cell lung cancer (NSCLC). Vasculogenic mimicry (VM, new blood supply formation in malignant tumors), E-Cadherin (a calcium-dependent transmembrane glycoprotein that mediates intercellular adhesion), KAI1 (a suppressor gene of tumor metastasis) are all valuable factors for metastasis and prognosis in diverse common human cancers. However, the correlation of VM, E-Cadherin, and KAI1 in NSCLC is still unclear. In this study, we analyzed the correlations among these factors as well as their respective correlations with clinicopathological parameters and survival in NSCLC.

METHODS

The level of VM, E-Cadherin, and KAI1 in 163 tissue samples of NSCLC was examined by immunhistochemistry. Clinical data were also collected.

RESULTS

Levels of VM was significantly higher, and levels of KAI1 and E-Cadherin significantly lower in NSCLC tissues than in normal lung tissues. Levels of VM were positively associated with lymph node metastasis (LNM), size, grade, and tumor node metastasis (TNM) stages, and negatively associated with patients' overall survival (OS). Levels of KAI1 and E-Cadherin were negatively correlated with LNM, size, grade, and TNM stage, and positively associated with patients' OS. In multivariate analysis, high levels of VM, E-Cadherin, and KAI1, as well as TNM stages were independently correlated with lower OS in patients with NSCLC.

CONCLUSION

VM and the expression of E-Cadherin and KAI1 may represent promising metastatic and prognostic biomarkers, as well as potential therapeutic targets for NSCLC.

Preoperative Watchful-Waiting Time and Surgical Outcome of Patients with Non-small Cell Lung Cancer Found by Chest Low-Dose CT Screening

BACKGROUNDS

Chest low-dose CT screening (LDCTS) has been finding unprecedented numbers of peripheral non-small cell lung cancers (NSCLC) at an early stage and increased the number of patients with surgical indication. It is important to explore the influence of preoperative watchful-waiting time (WWT) on surgical outcomes. Objective is to clarify relationship between WWT and surgical outcomes of LDCTS-finding NSCLC from the view point of treatment delay.

METHODS

Total 283 cases of NSCLC, found by LDCTS and consecutively resected, were surveyed for preoperative WWT and surgical outcomes. Validity of the present guideline for management of pulmonary nodules detected by LDCTS was verified whether WWT before surgery was suitable for eradication of NSCLC.

RESULTS

The median value of WWT was 4.0 months in total, and the distribution of WWT exhibited long-tail-type pattern. That was 5.0 months in the group of pure ground-glass nodule (pGGN), 4.0 months in the group of part-solid nodule (PSN), and 1.7 months in the group of solid nodule (SON). During long-term postoperative observation time (median 79 months), 10-year progression-free survival rates were 100% in pGGN, 96% in PSN, and 72% in SON (P < .0001). They decreased significantly depending on enlargement of size: 91% or higher in size of 2 cm or smaller, and 71% or lower in size of larger than 2 cm (P < .0001).

CONCLUSIONS

Limited to LDCTS-finding nodules, surgical outcome will depend mainly on some malignant potential of NSCLC per se, rather than on duration of WWT or treatment delay.