Oncologic outcomes of segmentectomy compared with lobectomy for clinical stage IA lung adenocarcinoma: Propensity score–matched analysis in a multicenter study

Enhancing identification of early-stage lung adenocarcinomas through solid component analysis of three-dimensional computed tomography images

OBJECTIVES

As the role of segmentectomy expands in managing early-stage lung adenocarcinoma, precise preoperative assessments of tumor invasiveness via computed tomography become crucial. This study aimed to evaluate the effectiveness of solid component analysis of three-dimensional (3D) computed tomography images and establish segmentectomy criteria for early-stage lung adenocarcinomas.

METHODS

This retrospective study included 101 cases with adenocarcinoma diagnoses, with patients undergoing segmentectomy for clinical stage 0 or IA between 2012 and 2017. The solid component volume (3D-volume) and solid component ratio (3D-ratio) of tumors were calculated using 3D computed tomography. Additionally, based on two-dimensional (2D) computed tomography, the solid component diameter (2D-diameter) and solid component ratio (2D-ratio) were calculated. The area under the receiver-operating characteristic curve (AUC) was calculated for each method, facilitating predictions of mortality and recurrence within 5 years. The AUC of each measurement was compared with those of invasive component diameter (path-diameter) and invasive component ratio (path-ratio) obtained through pathology analysis.

RESULTS

The predictive performance of 3D-volume did not differ significantly from that of path-diameter, whereas 2D-diameter exhibited less predictive accuracy (AUC: 3D-volume, 2D-diameter, and path-diameter: 0.772, 0.624, and 0.747, respectively; 3D-volume vs. path-diameter: p = 0.697; 2D-diameter vs. path-diameter: p = 0.048). Results were similar for the solid component ratio (AUC: 3D-ratio, 2D-ratio, path-ratio: 0.707, 0.534, and 0.698, respectively; 3D-ratio vs. path-ratio: p = 0.882; 2D-ratio vs. path-ratio: p = 0.038).

CONCLUSION

Solid component analysis using 3D computed tomography offers advantages in prognostic prediction for early-stage lung adenocarcinomas.

Disparity in Treatment Receipt by Race and Treatment Guideline Revision Years for Stage 1A Non-Small Cell Lung Cancer Patients in the US

INTRODUCTION

Treatment guideline revision introduced by the National Comprehensive Cancer Network (NCCN) is referred to by about 95% of the United States (US) oncologists in treatment decision-making for stage 1A non-small cell lung cancer. It is vital to account for this factor that affects the standard treatment receipt among stage 1A patients, with about a 75% survival rate if treated on time. The first choice for medically fit patients is lobectomy; however, over the decades since the initial guidelines were published, several medical advances have introduced trends in treatment receipt along with other sociodemographic factors that could help identify survival outcomes associated with treatment receipt. Establishing the role of treatment guideline revision years is important to determine a close to true causal relationship in racial treatment disparities.

METHODS

US national cancer registry data for all US counties and historical Area Health Resource Files for the study period 1988-2015 were utilized. Logistic regression analysis was adjusted for clustering of standard errors at the state level and for time-invariant unobserved factors for the year of diagnosis and county. The time-invariant unobservable for each year of diagnosis and county specificity were accounted for by including their dummy variables in the regression model with standard errors clustered at the state level.

RESULTS

Black patients, Medicaid beneficiaries, large fringe metropolitan residents, and those diagnosed post-2007 treatment revisions years are less likely to receive lobectomy, which is the standard treatment guideline for medically fit patients.

CONCLUSION

The study concludes that there exists a difference in treatment type received among stage 1A NSCLC patients in the US by race, socioeconomic status, and treatment guideline revisions.

Stage I and II nonsmall cell lung cancer treatment options

Chest radiography, computed tomography (CT) and positron emission tomography (PET)-CT are required for staging nonsmall cell lung cancers. Stage I cancers may be up to 4 cm in maximal diameter, with stage IA tumours being up to 3 cm and stage IB up to 4 cm. A lung cancer becomes stage II if the tumour is between 4 and ≤5 cm (stage IIA), or it spreads to ipsilateral peribronchial or hilar lymph nodes (stage IIB). Stage IA tumours should be surgically resected, ideally using minimally invasive methods. Lobectomy is usually performed, although some studies have shown good outcomes for sublobar resections. If surgery is not possible, stereotactic body radiotherapy is a good alternative. This involves delivering a few high-dose radiation treatments at very high precision. For stage IB to IIB disease, combinations of surgery, chemotherapy or immunotherapy and radiotherapy are used. There is evidence that neoadjuvant treatment (immunotherapy with nivolumab and chemotherapy for stage IB and II) optimises outcomes. Adjuvant chemotherapy with a platinum-based doublet (typically cisplatin+vinorelbine) should be offered for resected stage IIB tumours and considered for resected IIA tumours. Adjuvant pembrolizumab is used for stage IB-IIIA following resection and adjuvant platinum-based chemotherapy. Osimertinib may be used for resected stage IB to IIIA cancers which have relevant mutations (epidermal growth factor receptor exon 19 deletions or exon 21 (L858R) substitution). There are no fixed guidelines for follow-up, but most centres recommend 6-monthly CT scanning for the first 2-3 years after definitive treatment, followed by annual scans.

Multidimensional biological characteristics of ground glass nodules

The detection rate of ground glass nodules (GGNs) has increased in recent years because of their malignant potential but relatively indolent biological behavior; thus, correct GGN recognition and management has become a research focus. Many scholars have explored the underlying mechanism of the indolent progression of GGNs from several perspectives, such as pathological type, genomic mutational characteristics, and immune microenvironment. GGNs have different major mutated genes at different stages of development; EGFR mutation is the most common mutation in GGNs, and p53 mutation is the most abundant mutation in the invasive stage of GGNs. Pure GGNs have fewer genomic alterations and a simpler genomic profile and exhibit a gradually evolving genomic mutation profile as the pathology progresses. Compared to advanced lung adenocarcinoma, GGN lung adenocarcinoma has a higher immune cell percentage, is under immune surveillance, and has less immune escape. However, as the pathological progression and solid component increase, negative immune regulation and immune escape increase gradually, and a suppressive immune environment is established gradually. Currently, regular computer tomography monitoring and surgery are the main treatment strategies for persistent GGNs. Stereotactic body radiotherapy and radiofrequency ablation are two local therapeutic alternatives, and systemic therapy has been progressively studied for lung cancer with GGNs. In the present review, we discuss the characterization of the multidimensional molecular evolution of GGNs that could facilitate more precise differentiation of such highly heterogeneous lesions, laying a foundation for the development of more effective individualized treatment plans.

Outcomes of Completion Lobectomy for Locoregional Recurrence after Sublobar Resection in Patients with Non-small Cell Lung Cancer

Background

This retrospective study aimed to determine the treatment patterns and the surgical and oncologic outcomes after completion lobectomy (CL) in patients with locoregionally recurrent stage I non-small cell lung cancer (NSCLC) who previously underwent sublobar resection.

Methods

Data from 36 patients who initially underwent sublobar resection for clinical, pathological stage IA NSCLC and experienced locoregional recurrence between 2008 and 2016 were analyzed.

Results

Thirty-six (3.6%) of 1,003 patients who underwent sublobar resection for NSCLC experienced locoregional recurrence. The patients' median age was 66.5 (range, 44-77) years at the initial operation, and 28 (77.8%) patients were men. Six (16.7%) patients underwent segmentectomy and 30 (83.3%) underwent wedge resection as the initial operation. The median follow-up from the initial operation was 56 (range, 9-150) months. Ten (27.8%) patients underwent CL, 22 (61.1%) underwent non-surgical treatments (chemotherapy, radiation, concurrent chemoradiation therapy), and 4 (11.1%) did not receive treatment or were lost to follow-up after recurrence. Patients who underwent CL experienced no significant complications or deaths. The median follow-up time after CL was 64.5 (range, 19-93) months. The 5-year overall survival (OS) and post-recurrence survival (PRS) were higher in the surgical group than in the non-surgical (p<0.001) and no-treatment groups (p<0.001).

Conclusion

CL is a technically demanding but safe procedure for locoregionally recurrent stage I NSCLC after sublobar resection. Patients who underwent CL had better OS and PRS than patients who underwent non-surgical treatments or no treatments; however, a larger cohort study and long-term surveillance are necessary.

The value of CT shape quantification in predicting pathological classification of lung adenocarcinoma

OBJECTIVE

To evaluate whether quantification of lung GGN shape is useful in predicting pathological categorization of lung adenocarcinoma and guiding the clinic.

METHODS

98 patients with primary lung adenocarcinoma were pathologically confirmed and CT was performed preoperatively, and all lesions were pathologically ≤ 30 mm in size. On CT images, we measured the maximum area of the lesion's cross-section (MA). The longest diameter of the tumor (LD) was marked with points A and B, and the perpendicular diameter (PD) was marked with points C and D, which was the longest diameter perpendicular to AB. and D, which was the longest diameter perpendicular to AB. We took angles A and B as big angle A (BiA) and small angle A (SmA). We measured the MA, LD, and PD, and for analysis we derived the LD/PD ratio and the BiA/SmA ratio. The data were analysed using the chi-square test, t-test, ROC analysis, and binary logistic regression analysis.

RESULTS

Precursor glandular lesions (PGL) and microinvasive adenocarcinoma (MIA) were distinguished from invasive adenocarcinoma (IAC) by the BiA/SmA ratio and LD, two independent factors (p = 0.007, p = 0.018). Lung adenocarcinoma pathological categorization was indicated by the BiA/SmA ratio of 1.35 and the LD of 11.56 mm with sensitivity of 81.36% and 71.79%, respectively; specificity of 71.79% and 74.36%, respectively; and AUC of 0.8357 (95% CI: 0.7558-0.9157, p < 0.001), 0.8666 (95% CI: 0.7866-0.9465, p < 0.001), respectively. In predicting the pathological categorization of lung adenocarcinoma, the area under the ROC curve of the BiA/SmA ratio combined with LD was 0.9231 (95% CI: 0.8700-0.9762, p < 0.001), with a sensitivity of 81.36% and a specificity of 89.74%.

CONCLUSIONS

Quantification of lung GGN morphology by the BiA/SmA ratio combined with LD could be helpful in predicting pathological classification of lung adenocarcinoma.

Maximum amplitude and mean platelet volume in the blood as biomarkers to detect lung adenocarcinoma cancer featured with ground-glass nodules

Objectives

The development and progression of malignancies are closely linked to hypercoagulability. As an early type of lung adenocarcinoma, ground glass nodules (GGNs) have been detected increasingly. Blood Maximum amplitude (MA) and mean platelet volume (MPV) are related to various conditions of hypercoagulability. Therefore, the role of MA and MPV in diagnosing lung adenocarcinoma cancer featured with GGNs was investigated in this case-control study.

Methods

The analyzed data of this study is derived from GGNs patients and healthy individuals in West China (Airport) Hospital Sichuan University. The differences between GGNs patients and healthy individuals were determined by one-way ANOVA, logistic regression or chi-squared test. The accuracy of diagnostic was performed by receiver operating characteristic curve (ROC). The relative mRNA expressions were studied by RT-qPCR.

Results

470 patients diagnosed with GGNs which benign lesions (BN group) are inflammatory and malignant lesions (LC group) are adenocarcinoma in stage IA, and 235 healthy subjects (HC group) were enrolled in this study. Levels of MA and MPV were increased in LC group compared with BN and HC group ( p < 0.001, p < 0.001). When we combined MA and MPV, MA and MPV presented a sensitivity (SEN) of 0.809 and a specificity (SPE) of 0.774. And the area under the curve (AUC) increased to 0.871 (0.837–0.900) when confidence interval was 95%.

Conclusion

This study demonstrates that there have been systemic changes in coagulation disorders in the pathogenesis of GGNs. The diagnostic ability to different lung adenocarcinoma cancer featured with GGNs from benign or healthy controls can be improved by the combination of MA and MPV. Maximum amplitude and MPV may be used as biomarkers to detect lung adenocarcinoma cancer featured with GGNs.

Transcriptomic landscape based on annotated clinical features reveals PLPP2 involvement in lipid raft-mediated proliferation signature of early-stage lung adenocarcinoma

BACKGROUND

Image-based screening improves the detection of early-stage lung adenocarcinoma (LUAD)but also highlights the issue of high false-positive diagnoses, which puts patients at a risk of unnecessary over-treatment. Therefore, more precise discrimination criteria are required to ensure that patients with early-stage LUAD receive appropriate treatments.

METHODS

We integrated 158 early-stage LUAD cases from 2 independent cohorts, including 30 matched resected specimens with complete radiological and pathological information, and 128 retrospective pathological pair-samples with partial follow-up data. This integration allowed us to conduct a correlation analysis between clinical phenotype and transcriptome landscape. Immunohistochemistry was performed using tissue microarrays to examine the expression of phospholipid phosphatase 2 (PLPP2) and lipid-raft markers. Lipidomics analysis was used to determine the changes of lipid components in PLPP2-overexpressed cells. To assess the effects of PLPP2 on the malignant phenotypes of LUAD cells, we conducted mice tumor-bearing experiments and in vitro cellular experiments by knocking down PLPP2 and inhibiting lipid raft synthesis with MβCD, respectively.

RESULTS

Bioinformatics analysis indicated that the co-occurrence of lipid raft formation and rapid cell proliferation might exhibit synergistic effects in driving oncogenesis from lung preneoplasia to adenocarcinoma. The enhanced activation of the cell cycle promoted the transition from non-invasive to invasive status in early-stage LUAD, which was related to an increase in lipid rafts within LUAD cells. PLPP2 participated in lipid raft formation by altering the component contents of lipid rafts, such as esters, sphingomyelin, and sphingosine. Furthermore, elevated PLPP2 levels were identified as an independent prognostic risk factor for LUAD patients. Further results from in vivo and in vitro experiments confirmed that PLPP2 could induce excessive cell proliferation by enhancing lipid raft formation in LUAD cells.

CONCLUSIONS

Our study has revealed the characteristics of gene expression profiles in early-stage LUAD patients with the different radiological and pathological subtypes, as well as deciphered transcriptomic evolution trajectory from preneoplasia to invasive LUAD. Furthermore, it suggests that PLPP2-mediated lipid raft synthesis may be a significant biological event in the initiation of early-stage LUAD, offering a potential target for more precise diagnosis and therapy in clinical settings.

[Robot-assisted Lung Surgery: Techniques, Evidence and Data on Anatomical Resections]

Thanks to improved visualisation and instruments with an endowrist function, robot-assisted thoracic surgery has led to technical progress in thoracic surgery. This makes it easier to carry out complex thoracic surgical interventions, e.g. with an intrathoracic suture. As a result, this technology is increasingly being adopted and implemented in therapeutic use. Worldwide, the number of thoracotomies for lung cancer has decreased, while the number of minimally invasive surgical thoracic resections has increased. The aim of this work is to give an up-to-date overview of robotic operations on bronchial carcinoma.

Clinical and Oncological Outcomes after Uniportal Anatomical Segmentectomy for Stage IA Non-Small Cell Lung Cancer

Background and Objectives: The existing literature comparing sublobar and lobar resection in the treatment of stage IA lung cancer highlights the trend and overall need for further evaluation of minimally invasive, parenchymal-sparing techniques. The role of uniportal minimally invasive segmentectomy in the oncological therapy of early-stage non-small cell lung cancer (NSCLC) remains controversial. The aim of this study was to evaluate the clinical and midterm oncological outcomes of patients who underwent uniportal video-assisted anatomical segmentectomy for pathological stage IA lung cancer. Materials and Methods: We retrospectively analyzed all patients with pathological stage IA lung cancer (8th edition UICC) who underwent uniportal minimally invasive anatomical segmentectomy at our institution from January 2015 to December 2018. Results: 85 patients, 54 of whom were men, were included. The median length of hospital stay was 3 days (1.-3. IQR 3-5), whereas 30-day morbidity was 15.3% (13 patients), and the in-hospital mortality rate was 1.2% (1 patient). The 3-year overall survival rate was 87.9% for the total population. It was 90.5% in the IA1 group, 93.3% in the IA2 group, and 70.1% in the IA3 group, respectively. Conclusions: There were satisfactory short-term clinical outcomes with low 30-day morbidity and mortality and promising midterm oncological survival results following uniportal minimally invasive anatomical segmentectomy for pathological stage IA non-small cell lung cancer.

High risk lung nodule: A multidisciplinary approach to diagnosis and management

Pulmonary nodules are often discovered incidentally during CT scans performed for other reasons. While the vast majority of nodules are benign, a small percentage may represent early-stage lung cancer with the potential for curative treatments. With the growing use of CT for both clinical purposes and lung cancer screening, the number of pulmonary nodules detected is expected to increase substantially. Despite well-established guidelines, many nodules do not receive proper evaluation due to a variety of factors, including inadequate coordination of care and financial and social barriers. To address this quality gap, novel approaches such as multidisciplinary nodule clinics and multidisciplinary boards may be necessary. As pulmonary nodules may indicate early-stage lung cancer, it is crucial to adopt a risk-stratified approach to identify potential lung cancers at an early stage, while minimizing the risk of harm and expense associated with over investigation of low-risk nodules. This article, authored by multiple specialists involved in nodule management, delves into the diagnostic approach to lung nodules. It covers the process of determining whether a patient requires tissue sampling or continued surveillance. Additionally, the article provides an in-depth examination of the various biopsy and therapeutic options available for malignant lung nodules. The article also emphasizes the significance of early detection in reducing lung cancer mortality, especially among high-risk populations. Furthermore, it addresses the creation of a comprehensive lung nodule program, which involves smoking cessation, lung cancer screening, and systematic evaluation and follow-up of both incidental and screen-detected nodules.

Treatment Decisions for Resectable Non-Small-Cell Lung Cancer: Balancing Less With More?

For patients with non-small-cell lung cancer (NSCLC), the outcomes for patients with resectable disease are historically poor compared with other solid organ malignancies. In recent years, there have been significant advances in multidisciplinary care, which have resulted in improved outcomes. Innovations in surgical oncology include the use of limited resection and minimally invasive techniques. Recent data in radiation oncology have suggested refinements in pre- and postoperative radiation therapy, resulting in optimization of techniques in the curative setting. Finally, the success of immune checkpoint inhibitors and targeted therapies in the advanced setting has paved the way for inclusion in the adjuvant and neoadjuvant settings, resulting in recent regulatory approvals for four regimens (CheckMate-816, IMpower010, PEARLS, ADAURA). In this review, we will provide an overview of the seminal studies informing advancements in optimal surgical resection, radiation treatment, and systemic therapy for resectable NSCLC. We will summarize the key data on survival outcomes, biomarker analyses, and future directions for perioperative studies.

Prevalence and anatomical characteristics of subsuperior segment in lung lower lobe

OBJECTIVE

The subsuperior segment is an atypical pulmonary segment of the lung lower lobe. With the increased application of segmentectomy, it has received increased attention from thoracic surgeons. Studies of the subsuperior segment are scarce and mostly on the basis of small-sample autopsy studies, whose described characteristics are inconsistent with intraoperative observations. Our objective was to accurately define the subsuperior segment and elucidate its prevalence and anatomical characteristics in detail.

METHODS

A total of 2194 chest computed tomography images were obtained using separate random sampling on the basis of the amount of data available to each of the 6 thoracic surgery institutions in different provinces covering various regions of China. All of the images were reconstructed in 3 dimensions. Subsuperior segments were screened according to their new definition and statistically analyzed for their prevalence and anatomical characteristics.

RESULTS

The prevalence of subsuperior segments was 32.04%, with 413 on the right (18.79%); the value was higher than that on the left (347; 15.81%). The average volume of the subsuperior segment was 52.81 ± 21.96 cm3. Only 1 bronchus was detected in the unilateral subsuperior segment, with an average diameter of 2.53 ± 0.61 mm. Only 1 pulmonary artery was observed in most of the subsuperior segments (89.34%), but 81 cases (10.66%) had 2 in our study. One intersegmental vein of the subsuperior segment was the most common situation on both sides.

CONCLUSIONS

Using a multicenter large-sample study, we calculated a 32.04% prevalence and systematically detailed the anatomical characteristics of the subsuperior segment in the lung lower lobe, corrected previous reports, and supplemented pulmonary anatomical studies.

Patterns of Postoperative Changes in Lung Volume and Perfusion Assessed by Dual-Energy CT: Comparison of Lobectomy and Limited Resection

BACKGROUND. Pulmonary function tests (PFTs) and perfusion scintigraphy have limited utility for evaluating postoperative changes in regional pulmonary function after lung cancer resection surgery. OBJECTIVE. The purpose of this study is to compare postoperative changes in lung volume and perfusion, as assessed by dual-energy CT (DECT), between patients undergoing surgical resection of lung cancer by lobectomy versus limited resection as well as to assess associations between such changes and the lobar location of the resected tumor. METHODS. This study entailed a retrospective post hoc analysis of a prospective study that enrolled patients awaiting lung cancer resection surgery between March 2019 and February 2020. Eighty-one patients (38 men and 43 women; mean age, 60.5 ± 8.9 [SD] years), 43 of whom underwent lobectomy and 38 of whom underwent limited resection, were included. Patients underwent thoracic DECT and PFT evaluation preoperatively and at 6 months postoperatively. Pulmonary lobes were segmented. Lobar lung volume and lung perfusion ratios (both relative to whole-lung values) were computed. Perfusion measures reflected DECT-derived iodine content. Patients completed 6-month postoperative quality-of-life (QOL) questionnaires. RESULTS. Patients undergoing lobectomy, compared with those undergoing limited resection, had greater increases in the lung volume ratio of the ipsilateral nonresected lobe(s) (mean, 42.3% ± 24.2% [SD] vs 22.9% ± 13.2%, p < .001) and the contralateral lung (mean, 14.6% ± 14.0% vs 6.4% ± 6.9%, p = .002) as well as greater increases in the lung perfusion ratio of the ipsilateral nonresected lobe(s) (mean, 39.9% ± 20.7% [SD] vs 22.8% ± 17.8%, p < .001) and the contralateral lung (mean, 20.9% ± 9.4% vs 4.3% ± 5.6%, p < .001). In patients with right lower lobe tumors, the largest postoperative increases in the lung volume ratio were in the right middle lobe in those undergoing lobectomy (mean, 44.1% ± 21.0%) and limited resection (mean, 24.6% ± 14.5%), whereas the largest postoperative increase in the lung perfusion ratio was in the left lower lobe in those undergoing lobectomy (mean, 53.9% ± 8.6%) and in the right middle lobe in those undergoing limited resection (mean, 32.5% ± 24.1%). Otherwise, the largest increases in lung volume and perfusion ratios occurred in the ipsilateral nonresected lobes (vs the contra-lateral lobes), regardless of the operative approach used and the lobar location. Changes in the lung volume and perfusion ratios in the ipsilateral lobe(s) and the contralateral lung showed weak correlations with certain quality-of-life scores (e.g., for role functioning: ρ = 0.234-0.279 [volume] and -0.233 to -0.284 [perfusion]). CONCLUSION. DECT depicts patterns of lung volume and perfusion changes after lung cancer surgery, depending on the surgical approach (lobectomy vs limited resection) used and the lobar location of the tumor. CLINICAL IMPACT. DECT-derived metrics can help understand variable physiologic impacts of lung cancer resection surgeries.

Clinical application of VATS combined with 3D-CTBA in anatomical basal segmentectomy

Objective

This study aimed to summarize the clinical application experience of video-assisted thoracic surgery (VATS) combined with three-dimensional computed tomography-bronchography and angiography (3D-CTBA) in anatomical basal segmentectomy.

Methods

Clinical data of 42 patients who underwent bilateral lower sub-basal segmentectomy by VATS combined with 3D-CTBA in our hospital from January 2020 to June 2022 were retrospectively analyzed; the patients included 20 males and 22 females, with a median age of 48 (30-65) years. Combined with the preoperative enhanced CT and 3D-CTBA techniques to identify the altered bronchi, arteries, and veins during the operation, the anatomical resection of each basal segment of both lower lungs was completed through the fissure approach or inferior pulmonary vein approach.

Results

All operations were successfully completed without conversion to thoracotomy or lobectomy. The median operation time was 125 (90-176) min, the median intraoperative blood loss was 15 (10-50) mL, the median postoperative thoracic drainage time was 3 (2-17) days, and the median postoperative hospital stay was 5 (3-20) days. The median number of resected lymph nodes was 6 (5-8). There was no in-hospital death. Postoperative pulmonary infection occurred in 1 case, lower extremity deep vein thrombosis (DVT) in 3 cases, pulmonary embolism in 1 case, and persistent air leakage in the chest in 5 cases, all of which were improved by conservative treatment. Two cases of pleural effusion after discharge were improved after ultrasound guided drainage. Postoperative pathology showed 31 cases of minimally invasive adenocarcinoma, 6 cases of adenocarcinoma in situ (AIS), 3 cases of severe atypical adenomatous hyperplasia (AAH), and 2 cases of other benign nodules. All cases were lymph node-negative.

Conclusion

VATS combined with 3D-CTBA is safe and feasible in anatomical basal segmentectomy; consequently, this approach should be promoted and applied in clinical work.

National trends in the quality of segmentectomy for lung cancer

OBJECTIVE

Segmentectomy has become an accepted procedure for the treatment of non-small cell lung cancer. Adequate lymph node sampling, sufficient margins, and proper tumor size selection are factors vital for achieving outcomes comparable to lobectomy. Previous studies have demonstrated poor adherence to lymph node sampling guidelines. However, national trends in the quality of segmentectomy and implications on survival are unknown.

METHODS

The National Cancer Database was used to identify patients with clinical stage I to IIA non-small cell lung cancer surgically treated between 2004 and 2018. Facility-level trends in extent of resection and segmentectomy odds of adherence to (1) 2014 Commission on Cancer guidelines of sampling 10 or more lymph nodes, (2) negative (R0) resection margins, and (3) tumor size 2 cm or less were determined. Propensity score matching was based on segmentectomy adherence to (4) a composite of all measures, and survival was evaluated with Cox models and Kaplan-Meier survival estimates.

RESULTS

The study included 249,391 patients with 4.4% (n = 11,006) treated with segmentectomy. The proportion of segmentectomies performed annually increased from 3.3% in 2004 to 6.1% in 2018 (P < .001). Overall, 12.6% (n = 1385) of patients who underwent segmentectomy between 2004 and 2018 were adherent to all measures, and adherence was more likely at academic programs (odds ratio, 1.56; 95% confidence interval, 1.14-2.15) than nonacademic programs (P < .001, reference). Adherence to all measures was associated with improved survival (hazard ratio, 0.67; 95% confidence interval, 0.56-0.79).

CONCLUSIONS

As segmentectomy is increasingly established as a valid oncological option for the treatment of non-small cell lung cancer, it is important that quality remains high. This study demonstrates that continued improvement is needed.

Oncologic outcomes of segmentectomy for stage IA radiological solid-predominant lung cancer >2 cm in maximum tumour size

OBJECTIVES

We aimed to compare the outcomes of segmentectomy with those of lobectomy in clinical-stage IA radiological solid-predominant non-small-cell lung cancer (NSCLC) >2 cm in maximum tumour size.

METHODS

A retrospective review was performed for radiological solid-predominant NSCLC >2-3 cm in maximum tumour size with a ground-glass opacity component on thin-section computed tomography. Multivariable or propensity score-matched analyses were performed to control for confounders for survival. Overall survival (OS) was analysed using a Kaplan-Meier estimation.

RESULTS

Of the 215 eligible cases, segmentectomy and lobectomy were performed in 46 and 169 patients. Multivariable analysis revealed that standardized uptake value (hazard ratio: 1.148, 95% confidence interval: 1.032-1.276, P = 0.011) was an independently significant prognosticators of OS, while the operative mode was not associated (hazard ratio: 0.635, 95% confidence interval: 0.132-3.049, P = 0.570). The 5 y-OS was excellent and did not differ significantly between segmentectomy and lobectomy (95.5% vs 90.2%; P = 0.697), which was also shown in the propensity score analysis (96.8% vs 94.0%; P = 0.406), with a median follow-up time of 5.2 years. Locoregional recurrence was found in 2 (4.3%) segmentectomy and 13 (7.7%) lobectomy (P = 0.443). In the subgroup analysis stratified by solid component size, the 5 y-OS was similar between segmentectomy and lobectomy in the c-T1b and c-T1c groups, respectively [c-T1b (n = 163): 94.1% vs 91.8%; P = 0.887 and c-T1c (n = 52): 100% vs 84.9%; P = 0.197].

CONCLUSIONS

Segmentectomy showed similar oncological results compared to lobectomy in solid-predominant NSCLC with a ground-glass opacity component >2-3 cm in maximum tumour size. More prospective randomized trials are needed to adequately expand the indication of anatomic segmentectomy for early-stage NSCLC.

Selection of the surgical approach for patients with cStage IA lung squamous cell carcinoma: A population-based propensity score matching analysis

Background

This study aimed to conduct a comparative analysis of the survival rates after segmentectomy, wedge resection, or lobectomy in patients with cStage IA lung squamous cell carcinoma (SCC).

Methods

We enrolled 4,316 patients who had cStage IA lung SCC from the Surveillance, Epidemiology, and End Results (SEER) database. The Cox proportional hazards model was conducted to recognize the potential risk factors for overall survival (OS) and lung cancer-specific survival (LCSS). To eliminate potential biases of included patients, the propensity score matching (PSM) method was used. OS and LCSS rates were compared among three groups stratified according to tumor size.

Results

Kaplan–Meier analyses revealed no statistical differences in the rates of OS and LCSS between wedge resection (WR) and segmentectomy (SG) groups for patients who had cStage IA cancers. In patients with tumors ≤ 1 cm, LCSS favored lobectomy (Lob) compared to segmentectomy (SG), but a similar survival rate was obtained for wedge resection (WR) and lobectomy (Lob). For patients with tumors sized 1.1 to 2 cm, lobectomy had improved OS and LCSS rates compared to the segmentectomy or wedge resection groups, with the exception of a similar OS rate for lobectomy and segmentectomy. For tumors sized 2.1 to 3 cm, lobectomy had a higher rate of OS or LCSS than wedge resection or segmentectomy, except that lobectomy conferred a similar LCSS rate compared to segmentectomy. Multivariable analyses showed that patients aged ≥75 and tumor sizes of &gt;2 to ≤3 cm were potential risk factors for OS and LCSS, while lobectomy and first malignant primary indicator were considered protective factors. The Cox proportional analysis also confirmed that male patients aged ≥65 to &lt;75 were independent prognostic factors that are indicative of a worse OS rate.

Conclusions

The tumor size can influence the surgical procedure recommended for individuals with cStage IA lung SCC. For patients with tumors ≤1 cm, lobectomy is the recommended approach, and wedge resection or segmentectomy might be an alternative for those who cannot tolerate lobectomy if adequate surgical margin is achievable and enough nodes are sampled. For tumors &gt;1 to ≤3 cm, lobectomy showed better survival outcomes than sublobar resection. Our findings require further validation by randomized controlled trial (RCT) or other evidence.

Radiomics based on enhanced CT for differentiating between pulmonary tuberculosis and pulmonary adenocarcinoma presenting as solid nodules or masses

PURPOSE

To investigate the incremental value of enhanced CT-based radiomics in discriminating between pulmonary tuberculosis (PTB) and pulmonary adenocarcinoma (PAC) presenting as solid nodules or masses and to develop an optimal radiomics model.

METHODS

A total of 128 lesions (from 123 patients) from three hospitals were retrospectively analyzed and were randomly divided into training and test datasets at a ratio of 7:3. Independent predictors in subjective image features were used to develop the subjective image model (SIM). The plain CT-based and enhanced CT-based radiomics features were screened by the correlation coefficient method, univariate analysis, and the least absolute shrinkage and selection operator, then used to build the plain CT radiomics model (PRM) and enhanced CT radiomics model (ERM), respectively. Finally, the combined model (CM) combining PRM and ERM was established. In addition, the performance of three radiologists and one respiratory physician was evaluated. The areas under the receiver operating characteristic curve (AUCs) were used to assess the performance of each model.

RESULTS

The differential diagnostic capability of the ERM (training: AUC = 0.933; test: AUC = 0.881) was better than that of the PRM (training: AUC = 0.861; test: AUC = 0.756) and the SIM (training: AUC = 0.760; test: AUC = 0.611). The CM was optimal (training: AUC = 0.948; test: AUC = 0.917) and outperformed the respiratory physician and most radiologists.

CONCLUSIONS

The ERM was more helpful than the PRM for identifying PTB and PAC that present as solid nodules or masses, and the CM was the best.

A guide for managing patients with stage I NSCLC: deciding between lobectomy, segmentectomy, wedge, SBRT and ablation-part 3: systematic review of evidence regarding surgery in compromised patients or specific tumors

Background

Clinical decision-making for patients with stage I lung cancer is complex. It involves multiple options [lobectomy, segmentectomy, wedge, stereotactic body radiotherapy (SBRT), thermal ablation], weighing multiple outcomes (e.g., short-, intermediate-, long-term) and multiple aspects of each (e.g., magnitude of a difference, the degree of confidence in the evidence, and the applicability to the patient and setting at hand). A structure is needed to summarize the relevant evidence for an individual patient and to identify which outcomes have the greatest impact on the decision-making.

Methods

A PubMed systematic review from 2000-2021 of outcomes after lobectomy, segmentectomy and wedge resection in older patients, patients with limited pulmonary reserve and favorable tumors is the focus of this paper. Evidence was abstracted from randomized trials and non-randomized comparisons (NRCs) with adjustment for confounders. The analysis involved careful assessment, including characteristics of patients, settings, residual confounding etc. to expose degrees of uncertainty and applicability to individual patients. Evidence is summarized that provides an at-a-glance overall impression as well as the ability to delve into layers of details of the patients, settings and treatments involved.

Results

In older patients, perioperative mortality is minimally altered by resection extent and only slightly affected by increasing age; sublobar resection may slightly decrease morbidity. Long-term outcomes are worse after lesser resection; the difference is slightly attenuated with increasing age. Reported short-term outcomes are quite acceptable in (selected) patients with severely limited pulmonary reserve, not clearly altered by resection extent but substantially improved by a minimally invasive approach. Quality-of-life (QOL) and impact on pulmonary function hasn't been well studied, but there appears to be little difference by resection extent in older or compromised patients. Patient selection is paramount but not well defined. Ground-glass and screen-detected tumors exhibit favorable long-term outcomes regardless of resection extent; however solid tumors <1 cm are not a reliably favorable group.

Conclusions

A systematic, comprehensive summary of evidence regarding resection extent in compromised patients and favorable tumors with attention to aspects of applicability, uncertainty and effect modifiers provides a foundation for a framework for individualized decision-making.

Recurrence dynamics after curative surgery in patients with invasive mucinous adenocarcinoma of the lung

Background

We investigated the patterns and timing of recurrence and death as well as prognostic factors based on clinicopathological and radiological factors in patients who underwent surgical treatment for invasive mucinous adenocarcinoma (IMA).

Methods

We reviewed clinicopathological findings including spread through air spaces (STAS) and CT findings of IMA such as morphology, solidity, margin, well-defined heterogeneous ground-glass opacity, CT angiogram, and air bronchogram signs from 121 consecutive patients who underwent surgical resection. Prognostic factors for disease-free survival (DFS) and overall survival (OS) were identified. Hazard rate analyses were performed for the survival dynamics.

Results

T stage (hazard ratio [HR] = 4.102, p = 0.03), N stage (N2 vs. N0, HR = 7.653, p < 0.001), and consolidative CT morphology (HR = 3.556, p = 0.008) remained independent predictors for DFS. Age (HR = 1.110, p = 0.002), smoking (HR = 12.893, p < 0.001), T stage (HR = 13.005, p = 0.006), N stage (N2 vs. N0, HR = 7.653, p = 0.004), STAS (HR = 7.463, p = 0.008), and consolidative CT morphology (HR = 6.779, p = 0.007) remained independent predictors for OS. Consolidative morphology, higher T and N stage, and presence of STAS revealed initial sharp peaks after steep decline of the hazard rate curves for recurrence or death in follow-up period.

Conclusions

Consolidative morphology, higher T and N stage, smoking, and STAS were indicators of significantly greater risk of early recurrence or death in patients with IMA. Thus, these findings could be incorporated into future surveillance strategies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13244-022-01208-5.

Surgical Issues for Operable Early-Stage Non-Small-Cell Lung Cancer

Surgical care for early stage non-small-cell lung cancer continuously evolves with new procedures, techniques and care pathways. The most obvious recent change was the transition to minimally invasive procedures, but numerous other aspects of care have also been refined to improve safety and tolerability. These care advancements are essential as we move into an era with increased early detection as a result of screening and greater indications for the use of adjuvant and neoadjuvant strategies.

Bibliometric Analysis of 50 Most Cited Articles Comparing Lobectomy with Sublobar Resection

BACKGROUND

 Recent years have seen an increase in the number of studies of the sublobar resection approach in non-small cell lung cancer (NSCLC) surgery. The purpose of this bibliometric analysis is to assess the significance and impact of articles comparing sublobar resection and lobectomy in NSCLC surgery.

MATERIAL AND METHODS

 The Web of Science database was searched to identify studies comparing sublobar resection and lobectomy in NSCLC surgery published between 2005 and 2020 (accessed: September 11, 2020). The 50 most cited articles were analyzed by years, countries, authors, authors' affiliations, journals, journals' addresses, and impact factors.

RESULTS

 The bibliometric analysis revealed that the most cited article had 443 citations, while the total number of citations of all articles was 2,820. The mean number of citations, in turn, was 56.4 ± 75.62 (1-443) times. The highest number of publications over the past 15 years was in 2016, with eight articles. The Annals of Thoracic Surgery (n = 10; 20%) had the highest number of publications on the list. The articles included in the present study were mostly (n = 35, 70%) published in U.S. journals. While multiple subject matters and analyses were presented by many studies, survival was the topic of greatest interest, with 37 (74%) studies.

CONCLUSION

 This study revealed that interest in studies comparing sublobar resection with lobectomy has increased in recent years. It also presents both quantitative and qualitative analyses of the most cited articles in the literature on this topic. Therefore, it can serve as a guide for researchers.

Prediction of lymph node metastasis of clinical stage IA non-small cell lung cancer based on the tumor volume doubling time

PURPOSE

To investigate whether the volume doubling time is a preoperative predictor of lymph node metastasis of clinical stage IA non-small cell lung cancer (NSCLC).

METHODS

The subjects of this retrospective study were 204 patients who underwent lobectomy and mediastinal lymph node dissection for clinical stage IA NSCLC. We analyzed the relationship between lymph node metastasis and clinicopathological factors, including the volume doubling time.

RESULTS

Lymph node metastasis developed in 24 (11.8%) patients. Multivariable analysis identified consolidation diameter (Odds ratio = 1.407; 95% confidence interval, 1.007-1.966, p = 0.046) and the solid-part tumor volume doubling time (Odds ratio = 0.982; 95% confidence interval, 0.973-0.991, p < 0.001) as independent predictors of lymph node metastasis. The combination of a larger consolidation diameter (> 1.9 cm) and a shorter solid-part tumor volume doubling time (< 132 days) had sensitivity, specificity, and accuracy of 79.2%, 94.4%, and 92.6%, respectively.

CONCLUSIONS

The consolidation diameter and solid-part tumor volume doubling time can be useful preoperative predictors of lymph node metastasis of clinical stage IA NSCLC.

Surgical Treatment is Still Recommended for Patients Over 75 Years with IA NSCLC: A Predictive Model Based on Surveillance, Epidemiology and End Results Database

Background

To determine the populations who suitable for surgical treatment in elderly patients (age ≥ 75 y) with IA stage.

Methods

The clinical data of NSCLC patients diagnosed from 2010 to 2015 were collected from the SEER database and divided into surgery group (SG) and no-surgery groups (NSG). The confounders were balanced and differences in survival were compared between groups using PSM (Propensity score matching, PSM). Cox regression analysis was used to screen the independent factors that affect the Cancer-specific survival (CSS). The surgery group was defined as the patients who surgery-benefit and surgery-no benefit according to the median CSS of the no-surgery group, and then randomly divided into training and validation groups. A surgical benefit prediction model was constructed in the training and validation group. Finally, the model is evaluated using a variety of methods.

Results

A total of 7297 patients were included. Before PSM (SG: n = 3630; NSG: n = 3665) and after PSM (SG: n = 1725, NSG: n = 1725) confirmed that the CSS of the surgery group was longer than the no-surgery group (before PSM: 82 vs. 31 months, P < .0001; after PSM: 55 vs. 39 months, P < .0001). Independent prognostic factors included age, gender, race, marrital, tumor grade, histology, and surgery. In the surgery cohort after PSM, 1005 patients (58.27%) who survived for more than 39 months were defined as surgery beneficiaries, and the 720 patients (41.73%) were defined surgery-no beneficiaries. The surgery group was divided into training group 1207 (70%) and validation group 518 (30%). Independent prognostic factors were used to construct a prediction model. In training group (AUC = .678) and validation group (AUC = .622). Calibration curve and decision curve prove that the model has better performance.

Conclusions

This predictive model can well identify elderly patients with stage IA NSCLC who would benefit from surgery, thus providing a basis for clinical treatment decisions.

HRCT features between lepidic-predominant type and other pathological subtypes in early-stage invasive pulmonary adenocarcinoma appearing as a ground-glass nodule

Background

Different pathological subtypes of invasive pulmonary adenocarcinoma (IPA) have different surgical methods and heterogeneous prognosis. It is essential to clarify IPA subtypes before operation and high-resolution computed tomography (HRCT) plays a very important role in this regard. We aimed to investigate the HRCT features of lepidic-predominant type and other pathological subtypes of early-stage (T1N0M0) IPA appearing as a ground-glass nodule (GGN).

Methods

We performed a retrospective analysis on clinical data and HRCT features of 630 lesions in 589 patients with pathologically confirmed IPA (invasive foci > 5 mm) appearing as pure GGN (pGGN) and mixed GGN (mGGN) with consolidation-to-tumor ratio (CTR) ≤0.5 from January to December 2019. All GGNs were classified as lepidic-predominant adenocarcinoma (LPA) and nonlepidic-predominant adenocarcinoma (n-LPA) groups. Univariate analysis was performed to analyze the differences of clinical data and HRCT features between the LPA and n-LPA groups. Multivariate analysis was conducted to determine the variables to distinguish the LPA from n-LPA group independently. The diagnostic performance of different parameters was compared using receiver operating characteristic curves.

Results

In total, 367 GGNs in the LPA group and 263 GGNs in the n-LPA group were identified. In the univariate analysis, the CTR, mean CT values, and mean diameters as well as mixed GGN, deep lobulation, spiculation, vascular change, bronchial change, and tumor–lung interface were smaller in the LPA group than in the n-LPA group (P <  0.05). Logistic regression model was reconstructed including the mean CT value, CTR, deep lobulation, spiculation, vascular change, and bronchial change (P <  0.05). Area under the curve of the logistic regression model for differentiating LPA and n-LPA was 0.840 (76.4% sensitivity, 78.7% specificity), which was significantly higher than that of the mean CT value or CTR.

Conclusions

Deep lobulation, spiculation, vascular change, and bronchial change, CT value > − 472.5 HU and CTR > 27.4% may indicate nonlepidic predominant invasive pulmonary adenocarcinoma in GGNs.

Virtual randomized study comparing lobectomy and particle beam therapy for clinical stage IA non-small cell lung cancer in operable patients

To the best of our knowledge there have been no randomized controlled trials comparing lobectomy-a standard treatment for patients with early-stage non-small cell lung cancer (NSCLC)-and particle beam therapy (PBT), the best performing existing radiotherapy. We conducted a virtual randomized trial in medically operable patients with stage IA NSCLC to compare lobectomy and PBT effectiveness. A Markov model was developed to predict life expectancy after lobectomy and PBT in a cohort of patients with stage IA NSCLC. Ten thousand virtual patients were randomly assigned to each group. Sensitivity analyses were performed as model variables and scenarios changed to determine which treatment strategy was best for improving life expectancy. All estimated model parameters were determined using variables extracted from a systematic literature review of previously published articles. The preferred strategy differed depending on patient age. In young patients, lobectomy showed better life expectancy than that of PBT. The difference in life expectancy between lobectomy and PBT was statistically insignificant in older patients. Our model predicted lobectomy as the preferred strategy when operative mortality was under 5%. However, the preferred strategy changed to PBT if operative mortality post lobectomy was over 5%. For medically operable patients with stage IA NSCLC, our Markov model revealed the preferred strategy of lobectomy or PBT regarding operative mortality changed with varying age and comorbidity. Until randomized controlled trial results become available, we hope the current results will provide a rationale background for clinicians to decide treatment modalities for patients with stage IA NSCLC.

Propensity-matched Comparison of VATS Left Upper Tri-segmentectomy and Lobectomy

BACKGROUND

This study aims to investigate the oncological outcomes of video-assisted thoracoscopic (VATS) left upper tri-segmentectomy (LTS) versus left upper lobectomy (LUL) for patients presenting with stage I non-small-cell lung cancer (NSCLC).

METHODS

A retrospective analysis identified 1543 consecutive patients presenting to Shanghai Pulmonary Hospital with NSCLC for VATS-LTS or LUL from 2013-2017. After propensity-score matching for patient demographics and tumor characteristics, 273 pairs were identified. Disease-free survival (DFS) and overall survival (OS) were estimated by the Kaplan-Meier method and compared using the Log-rank test.

RESULTS

The median follow-up time was 51.5 months. There were no significant differences in operative duration (2.11±0.64 versus 2.49±5.96 h, p=0.30), total blood loss (106.19±170.83 versus 97.07±149.34 mL, p=0.51) and operation complications (10% versus 8%, p=0.37) between LUL and LTS. Patients undergoing LUL had longer postoperative hospital stay (5.55±3.00 versus 4.87±2.33 days, p=0.003), greater tumor margin distance (3.3±1.2 versus 3.1±0.9 cm, p＜.001) and greater number of lymph nodes harvested (8.0±3.2 versus 6.8±3.3, p＜.001) than LTS, but the margin/tumor ratio was not statistically different (2.5±1.6 versus 2.3±1.1, p=0.11). Median DFS (49.5 versus 54.3 months, p=0.77) and OS (49.5 versus 55.0 months, p=0.88) were not significantly different between patients undergoing LTS and LUL, and similar outcomes were noted across subgroups of patients stratified by tumor stages, pathological type, and radiographic manifestations.

CONCLUSIONS

VATS-LTS and LUL had comparable oncological outcomes for stage I NSCLC, regardless of tumor pathological types and radiological findings, as long as negative margins were confirmed.

DNA methylation patterns at and beyond the histological margin of early-stage invasive lung adenocarcinoma radiologically manifested as pure ground-glass opacity

Background

Early-stage lung cancers radiologically manifested as ground-glass opacities (GGOs) have been increasingly identified, among which pure GGO (pGGO) has a good prognosis after local resection. However, the optimal surgical margin is still under debate. Precancerous lesions exist in tumor-adjacent tissues beyond the histological margin. However, potential precancerous epigenetic variation patterns beyond the histological margin of pGGO are yet to be discovered and described.

Results

A genome-wide high-resolution DNA methylation analysis was performed on samples collected from 15 pGGO at tumor core (TC), tumor edge (TE), para-tumor tissues at the 5 mm, 10 mm, 15 mm, 20 mm beyond the tumor, and peripheral normal (PN) tissue. TC and TE were tested with the same genetic alterations, which were also observed in histologically normal tissue at 5 mm in two patients with lower mutation allele frequency. According to the difference of methylation profiles between PN samples, 2284 methylation haplotype blocks (MHBs), 1657 differentially methylated CpG sites (DMCs), and 713 differentially methylated regions (DMRs) were identified using reduced representation bisulfite sequencing (RRBS). Two different patterns of methylation markers were observed: Steep (S) markers sharply changed at 5 mm beyond the histological margin, and Gradual (G) markers changed gradually from TC to PN. S markers composed 86.2% of the tumor-related methylation markers, and G markers composed the other 13.8%. S-marker-associated genes enriched in GO terms that were related to the hallmarks of cancer, and G-markers-associated genes enriched in pathways of stem cell pluripotency and transcriptional misregulation in cancer. Significant difference in DNA methylation score was observed between peripheral normal tissue and tumor-adjacent tissues 5 mm further from the histological margin (p < 0.001 in MHB markers). DNA methylation score at and beyond 10 mm from histological margin is not significantly different from peripheral normal tissues (p > 0.05 in all markers).

Conclusions

According to the methylation pattern observed in our study, it was implied that methylation alterations were not significantly different between tissues at or beyond P10 and distal normal tissues. This finding explained for the excellent prognosis from radical resections with surgical margins of more than 15 mm. The inclusion of epigenetic characteristics into surgical margin analysis may yield a more sensitive and accurate assessment of remnant cancerous and precancerous cells in the surgical margins.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01140-3.

Survival Outcomes of Lobectomy Versus Segmentectomy in Clinical Stage I Non-Small Cell Lung Cancer: A Meta-Analysis

INTRODUCTION

The gold standard surgical therapy for patients with clinical stage I non-small cell lung cancer (NSCLC) is lobectomy with mediastinal lymph node dissection. Meanwhile, segmentectomy has emerged as an alternative choice with the advantage of fewer postoperative complications. The acceptance of this procedure remains controversial, and conflicting results exist in the retrospective trials.

OBJECTIVES

The aim of this meta-analysis was to analyze the survival outcomes of lobectomy versus segmentectomy in clinical stage I NSCLC.

METHODS

A computerized literature search was done on published trials in PubMed, Embase, and the Cochrane Library to June 2019 to identify clinical trials. Lung cancer-specific survival (LCSS) and overall survival (OS) were measured as outcomes. Statistical analysis was performed in the Meta-analysis Revman 5.3 software.

RESULTS

A systematic literature search was conducted including seven studies. In this meta-analysis, the LCSS and OS in the lobectomy group were linked to a markedly lower trend in comparison to the segmentectomy group without significant statistical difference (P > 0.05), indicating that lobectomy confers an equivalent survival outcome compared with segmentectomy.

CONCLUSION

No significant differences were found in survival outcomes between lobectomy and segmentectomy. Further large-scale, prospective, randomized trials are needed to explore reasonable surgical treatments for early-stage lung cancer.

Complex segmentectomy in the treatment of stage IA non-small-cell lung cancer

OBJECTIVES

Although segmentectomy for lung cancer has been widely accepted, complex segmentectomy, which creates several, intricate intersegmental planes, remains controversial. Potential arguments include risk of incurability and 'failure of cancer control'. We compared the outcomes of complex segmentectomy versus lobectomy and evaluated its use in lung cancer treatment.

METHODS

We retrospectively reviewed clinical stage IA lung cancer patients who underwent complex segmentectomy (n = 99) or location-adjusted lobectomy (n = 94) between April 2009 and December 2017. Clinicopathological and postoperative results were compared. Factors affecting survival were assessed by the Kaplan-Meier method and the Cox regression analysis.

RESULTS

No significant differences were detected in 30-day mortality (0% vs 0%), overall complications (26.3% vs 21.3%) and prolonged air leakage (11.1% vs 9.6%) rates between the 2 groups, respectively. Comparable results were obtained for 5-year overall (93.5% vs 96.4%, respectively; P = 0.21) or recurrence-free (92.3% vs 88.5%, respectively; P = 0.82) survivals after complex segmentectomy or lobectomy. There were 2 (2.0%) recurrences after complex segmentectomy and 7 (7.5%) after lobectomy (P = 0.094), with 0 (0%) margin relapses in each group. Multivariable Cox regression analysis revealed that complex segmentectomy and lobectomy had a numerically similar impact on recurrence-free survival (hazard ratio 0.93, 95% confidence interval 0.32-2.69; P = 0.90).

CONCLUSIONS

Complex segmentectomy can provide acceptable short- and long-term outcomes in lung cancer treatment.

Should resection extent be decided by total lesion size or solid component size in ground glass opacity-containing lung adenocarcinomas?

BACKGROUND

Indication for sublobar resections in early-stage lung adenocarcinomas has been controversial. The purpose of this study was to find appropriate selection criteria for sublobar resections in ground glass opacity (GGO)-containing early-stage lung adenocarcinomas.

METHODS

We retrospectively studied 985 consecutive patients with clinical stage IA, peripheral GGO-containing lung adenocarcinomas ≤3 cm in size. According to their radiological appearance, they were divided into a pure GGO group and a part-solid nodule (PSN) group. The PSN group was further divided into a GGO-predominant subgroup and a solid-predominant subgroup. Propensity-score matching (PSM) was conducted first in PSNs with similar total lesion size and then in those with similar solid component size to eliminate potential confounders. Histological characteristics and prognosis were compared between matched patients to investigate the prognostic value of total lesion size and solid component size. Then solid component size was chosen as the selection criterion to compare the prognosis of patients receiving lobectomy or sublobar resections.

RESULTS

Comparing to PSNs, pure GGO lesions had significantly more favorable histological characteristics and prognosis, with 100% 5-year overall survival (OS), even though 33.3% of patients with pure GGO lesions >20 mm in total lesion size received sublobar resections. For 157 pairs of PSNs with similar total lesion size but different solid component size after the first PSM, the solid-predominant subgroup had significantly worse histological characteristics and prognosis than the GGO-predominant subgroup. After the second PSM, histological characteristics and prognosis were comparable between 73 pairs of PSNs with similar solid component size but different total lesion size. Multivariable analysis showed that solid component size, rather than total lesion size or consolidation-to-tumor ratio (CTR), was an independent prognostic factor. For PSNs containing solid component size ≤2 cm, relapse-free survival (RFS) was similar after sublobar resections or lobectomy (95.0% vs. 93.6%, P=0.592). The results remained similar for PSNs of total lesion size >2 cm but solid component size ≤2 cm (88.9% vs. 90.0%, P=0.893).

CONCLUSIONS

Solid component size better predicts histological characteristics and prognosis than total lesion size in early-stage GGO-containing lung adenocarcinomas. Instead of total lesion size, solid component size ≤2 cm may be a more appropriate selection criterion for sublobar resections in such patients.

Complex Segmentectomy for Hypermetabolic Clinical Stage IA Non-Small Cell Lung Cancer

BACKGROUND

Due to its invasiveness, the indications for "complex segmentectomy" for radiologically hypermetabolic (high maximum standard uptake value [SUV max]) non-small cell lung cancer (NSCLC) remains controversial. This study compared the outcomes after complex segmentectomy and lobectomy in these patients.

METHODS

We retrospectively reviewed 717 patients with radiologically hypermetabolic (SUV max ≥ 2.5), clinical Stage IA NSCLC who underwent complex segmentectomy (n = 61) or "location-adjusted" lobectomy (n = 656) at three institutions from 2010 to 2019. Postoperative outcomes were analyzed for all patients and their propensity score-matched pairs. Factors affecting oncologic outcomes were assessed by Kaplan-Meier estimates and Cox proportional hazards regression analyses.

RESULTS

The prognosis of patients undergoing complex segmentectomy was not significantly different from that of patients undergoing lobectomy [5-year cancer specific survival (CSS) rate, 89.9% vs. 91.1%, P = 0.98 and 5-year recurrence-free interval (RFI) rates, 83.0% vs. 77.5%, P = 0.62] in non-adjusted cohort. In 55 propensity score-matched pairs, oncologic outcomes were not significantly different between patients undergoing complex segmentectomy (5-year CSS, 89.9%; 5-year RFI, 83.0%) and lobectomy (5-year CSS, 83.6%; 5-year RFI, 82.5%). Multivariable Cox regression analysis for RFI revealed no significant differences between oncologic outcomes associated with complex segmentectomy and lobectomy (hazard ratio, 0.84; 95% confidence interval, 0.25-2.14; P = 0.74).

CONCLUSIONS

Oncologic outcomes of complex segmentectomy and lobectomy were not significantly different in those with radiologically hypermetabolic, clinical Stage IA NSCLC patients. Complex segmentectomy can treat high SUV max, clinical Stage IA lung cancers without compromising oncologic results.

Management of pulmonary ground-glass opacities: a position paper from a panel of experts of the Italian Society of Thoracic Surgery (SICT)

OBJECTIVES

A significant gap in our knowledge of how to manage pulmonary ground-glass opacities (GGOs) still exists. Accordingly, there is a lack of consensus among clinicians on this topic. The Italian Society of Thoracic Surgery (Società Italiana di Chirurgia Toracica, SICT) promoted a national expert meeting to provide insightful guidance for clinical practice. Our goal was to publish herein the final consensus document from this conference.

METHODS

The working panel of the PNR group (Pulmonary Nodules Recommendation Group, a branch of the SICT) together with 5 scientific supervisors (nominated by the SICT) identified a jury of expert thoracic surgeons who organized a multidisciplinary meeting to propose specific statements (n = 29); 73 participants discussed and voted on statements using a modified Delphi process (repeated iterations of anonymous voting over 2 rounds with electronic support) requiring 70% agreement to reach consensus on a statement.

RESULTS

Consensus was reached on several critical points in GGO management, in particular on the definition of GGO, radiological and radiometabolic evaluation, indications for a non-surgical biopsy, GGO management based on radiological characteristics, surgical strategies (extension of pulmonary resection and lymphadenectomy) and radiological surveillance. A list of 29 statements was finally approved.

CONCLUSIONS

The participants at this national expert meeting analysed this challenging topic and provided a list of suggestions for health institutions and physicians with practical indications for GGO management.

Introduction of robotic surgery leads to increased rate of segmentectomy in patients with lung cancer

Background

Pulmonary segmentectomy provides an anatomic lung resection while avoiding removal of excess normal lung tissue. This may be beneficial in patients with minimal pulmonary reserve who present with early-stage non-small cell lung cancer (NSCLC). However, the operative performance of a segmentectomy using a video-assisted thoracoscopic approach can be technically challenging. We hypothesized that introduction of the robotic surgical system would facilitate the performance of a segmentectomy as measured by an increase in the proportion of segmentectomies being pursued.

Methods

We completed a retrospective analysis of thoracoscopic and robotic anatomic lung resections, including lobectomies and segmentectomies, performed in patients with primary lung cancer from the time of initiation of the robotic thoracic surgery program in November 2017 to November 2019. We compared the proportion of thoracoscopic and robotic segmentectomies performed during the first year compared to the second year of the data collection period.

Results

A total of 138 thoracoscopic and robotic anatomic lung resections were performed for primary lung cancer. Types of lung cancer resected (adenocarcinoma, squamous cell carcinoma, or other), tumor size based on clinical T staging (T1–T4), and tumor location were not significantly different between years (P=0.44, P=0.98, and P=0.26, respectively). The proportion of segmentectomies increased from 8.6% during the first year to 25.0% during the second year (P=0.01). One out of 6 (16.7%) segmentectomies were performed using the robot during the first year versus 15 out of 17 (88.2%) during the second year (P=0.003).

Conclusions

Use of the robot led to a significant increase in the number of segmentectomies performed in patients undergoing anatomic lung resection. With increasing lung cancer awareness and widely available screening, a greater number of small, early-stage tumors suitable for segmentectomy will likely be detected. We conclude that robotic-assisted surgery may facilitate the challenges of performing a minimally invasive segmentectomy.

Segmentectomy or Wedge Resection in Stage IA Lung Squamous Cell Carcinoma and Adenocarcinoma?

Objectives: We performed this study to compare survival outcomes of segmentectomy (SG) and wedge resection (WR) in stage IA lung squamous cell carcinoma (SQCC) and lung adenocarcinoma (AD). Methods: Using the Surveillance, Epidemiology, and End Results registry (SEER), we identified 1529 and 4070 patients with stage IA SQCC and AD, respectively, who had complete clinical information between 2004 and 2015. We used Kaplan-Meier analysis to determine the propensity score for patients with limited resection based on the preoperative characteristics of patients. Lung cancer-specific survival (LCSS) was compared in patients treated with WR and SG after adjusting, stratifying, or matching lung cancer patients according to propensity score. Results: Kaplan-Meier analysis demonstrated that there was a statistically significant difference in survival curves (log rank P=0.01) for patients with stage IA SQCC between SG and WR. But there was no statistically significant difference in survival curves (log rank P>0.05) in patients with stage IA AD between the two limited resections. Compared with the WR, The hazard ratios (95% confidence intervals) of SG were 0.689 (0.519-0.914) and 0.896 (0.752-1.067) in patients with stage IA SQCC and AD, respectively. Conclusion: This study suggests that SG can yield superior survival outcome compared with WR in patients with stage IA SQCC. However, the survival outcomes of SG and WR are generally equivalent in patients with stage IA AD.

Feasibility of limited resection for peripheral small-sized non-small cell lung cancer: a retrospective single-center-based study

PURPOSE

This study aimed to establish new criteria for limited resection of non-small cell lung cancer (NSCLC) based on computed tomography findings and maximum standardized uptake value (SUVmax).

METHODS

Between December 2007 and December 2015, 611 patients underwent lung cancer surgery; of these, 70 with cT1aN0M0 who underwent limited resection were enrolled. Criteria for undergoing intentional limited resection (ILR) were (1) tumor ground-glass opacity (GGO) ratio of ≥ 0.75 and (2) tumor SUVmax ≤ 1.5. Patients who met criteria (1) and (2) underwent partial resection, and those who only met criteria (2) underwent segmentectomy as ILR. The control group was subjected to limited surgery without meeting the criteria.

RESULTS

Overall, 45 and 25 patients who met the criteria were included in the ILR and control groups, respectively. In the ILR group, 13 patients underwent partial resection, and 32 underwent segmentectomy; in the control group, 18 patients underwent partial resection and 7 underwent segmentectomy. According to our criteria, no relapsed cases occurred in the ILR group, although six patients showed recurrence of lung cancer in the control group. The 5-year overall survival (OS) rates in the ILR and control groups were 100% and 67.7%, respectively, and the relapse-free survival (RFS) rates were 100% and 61.6%, respectively. The log-rank test showed that this difference was statistically significant (OS: P < 0.0001, RFS: P < 0.0001).

CONCLUSIONS

SUVmax may serve as a predictive marker of recurrence to determine the treatment strategy for patients with NSCLC. Patients with low GGO ratio and low SUVmax may be cured by limited resection.

Clinical Outcomes of Proton Beam Therapy for Ground-Glass Opacity-Type Lung Cancer

Purpose

Surgery is the standard treatment for early-stage non-small cell lung cancer (NSCLC), including ground-glass opacity (GGO)-type lung cancer. However, some patients are inoperable or refuse to undergo surgery. To explore whether proton beam therapy (PBT) can be an alternative to surgical resection in these patients, this study aimed to examine the retrospective treatment outcomes of patients with GGO-type lung cancer who underwent PBT.

Patients and Methods

Patients with stage I NSCLC and GGOs who underwent PBT at the Medipolis Proton Therapy and Research Center (Kagoshima, Japan) between April 2011 and September 2015 were included. Patients were treated with a total dose of 66 GyE delivered in 10 fractions. Survival curves were calculated using the Kaplan–Meier method, and treatment-related adverse events (AEs) were assessed.

Results

A total of 48 patients (median age: 70.9 ± 9.2 years; men: 54.2%) were analyzed, among whom 53 tumors were observed. The 3-year overall survival rate after PBT was 91.7% (95% confidence interval [CI], 79.3–96.8%), the 3-year disease-free survival rate was 85.4% (95% CI: 71.8–92.8%), and the 3-year local control rate among 53 tumors was 92.5% (95% CI: 81.1–97.1%). During the 3-year follow-up period, 4 patients died, and 3 survived despite recurrence or metastasis. Common AEs were radiation pneumonitis (89.6%), rib fracture (27.1%), and cough (27.1%). None of the patients developed grade ≥3 treatment-related AEs.

Conclusion

The results of this study suggest that PBT may be a promising alternative for patients with GGO-type lung cancer when surgical resection is not feasible, with excellent survival outcomes and tolerable treatment-related AEs.

Comparison of cancer control between segmentectomy and wedge resection in patients with clinical stage IA non-small cell lung cancer

OBJECTIVE

The study objective was to compare cancer control between segmentectomy and wedge resection in patients with clinical stage IA non-small cell lung cancer.

METHODS

Between 2010 and 2015, 457 patients with clinical stage IA (8th edition) non-small cell lung cancer undergoing wedge resection or segmentectomy were identified at 3 institutions. Propensity scores were calculated on the basis of the extent of resection (wedge resection or segmentectomy) and included adjustment for confounding variables, such as age, sex, smoking status, pulmonary functions, laterality, tumor size, maximum standardized uptake value on ¹⁸F-fluorodeoxyglucose positron emission tomography, presence of ground-glass opacity on high-resolution computed tomography, histology, and visceral pleural invasion for multivariable analysis and matching. The primary end point was cumulative incidence of recurrence.

RESULTS

In all cohorts, postoperative recurrence occurred in 36 of 195 patients (18.5%) undergoing wedge resection and 14 of 262 patients (5.3%) undergoing segmentectomy. Cumulative incidence of recurrence was significantly lower in patients undergoing segmentectomy (5-year cumulative incidence of recurrence, 5.3%) than in those undergoing wedge resection (5-year cumulative incidence of recurrence, 19.1%; P < .001). In propensity score-adjusted multivariable analysis, segmentectomy was identified as an independent favorable prognostic factor for cumulative incidence of recurrence (hazard ratio, 0.47; 95% confidence interval, 0.24-0.90; P = .022). In propensity score matching of 163 pairs, cumulative incidence of recurrence was significantly lower in patients undergoing segmentectomy (5-year cumulative incidence of recurrence, 6.6%) than in those undergoing wedge resection (5-year cumulative incidence of recurrence, 13.2%; P = .041).

CONCLUSIONS

Cancer control was better in segmentectomy than in wedge resection. Segmentectomy is the preferred oncologic procedure as sublobar resection to treat clinical stage IA non-small cell lung cancer.

Prognostic Significance of Lymph Node Count Removed at Sublobar Resection in Pathologic Stage IA Non-Small-cell Lung Cancer: A Population-Based Analysis

BACKGROUND

We sought to elucidate the associations between the examined lymph node (ELN) count and survival after sublobar resection (SLR) in pathologic stage IA non-small-cell lung cancer and assess the survival efficacy for patients undergoing SLR with an adequate ELN count compared with lobar resection (LR).

PATIENTS AND METHODS

The newly released U.S. Surveillance, Epidemiology, and End Results database was queried. The association between the ELN count in SLR and survival was analyzed using Cox regression and propensity score matching analyses. The optimal cutoff for the ELN count in SLR was determined using the Chow test and "segmented" function. Survival differences between SLR with an adequate ELN count and LR were compared using the log-rank test.

RESULTS

A total of 16,630 lobectomies, 3979 wedge resections, and 1119 segmentectomies were included in the present study. The median ELN count was 3 (interquartile range [IQR], 1-7), 1 (IQR, 0-4), and 7 (IQR, 4-12) for segmentectomy, wedge resection, and lobectomy, respectively (P < .001). The optimal cutoff for ELNs was 2.40 (IQR, 2.15-2.65) and 2.59 (IQR, 2.19-3.00) for patients undergoing wedge and segmental resection. SLR patients with ≥ 3 ELNs showed better overall survival and lung cancer-specific survival compared with those with < 3 ELNs. SLR patients with ≥ 3 ELNs had a noninferior prognosis compared with LR patients after matching of potential confounders.

CONCLUSIONS

In SLR, an adequate ELN count (≥ 3) could confer an improved prognosis compared with an inadequate ELN count (< 3). SLR patients with an adequate ELN count had noninferior survival outcomes compared with LR patients when the ELNs were well matched.

Prognostic value of visceral pleural invasion in pure-solid and part-solid lung cancer patients

OBJECTIVE

Visceral pleural invasion (VPI) indicates poor prognosis in non-small cell lung cancer (NSCLC), and is defined as a T2 descriptor for T1-sized tumor. However, whether its prognostic impact differs between pure-solid and part-solid tumors as preoperative diagnostic imaging is controversial. We aimed to elucidate the prognostic difference of VPI in cT1-sized NSCLC according to radiological tumor type (pure-solid or part-solid).

METHODS

We retrospectively reviewed 498 NSCLC patients who underwent complete anatomical lung resection between 2009 and 2014. Patients with node-negative, cT1-sized (consolidation size, ≤ 3 cm) NSCLCs were included. VPI included pathological PL1 and PL2. The prognostic impact of VPI according to radiological tumor type was assessed using multivariate Cox regression analyses.

RESULTS

We evaluated 227 pure-solid and 271 part-solid tumors; median follow-up period was 57 months. VPI was found in 40 (17.6%) and 15 (5.5%) patients with pure-solid and part-solid tumors, respectively (p < 0.001). In pure-solid group, VPI patients showed significantly poorer overall survival (OS) rates than non-VPI patients (p = 0.003). In part-solid group, OS rates did not differ significantly according to VPI (p = 0.770). Multivariate analysis revealed that the adjusted hazard ratio (95% confidence interval) for poor OS was 2.129 (1.048-4.132, p = 0.037) for pure-solid tumors with VPI compared to pure-solid tumors without VPI, and 0.925 (0.050-4.920, p = 0.941) for part-solid tumors with VPI compared to part-solid tumors without VPI.

CONCLUSIONS

VPI had a negative prognostic impact on cT1-sized pure-solid tumors but not on part-solid tumors. Upstaging of the T-category by VPI in cT1-sized NSCLCs may be considered for pure-solid tumors.

Meta-analysis of association between CT-based features and tumor spread through air spaces in lung adenocarcinoma

Objective

Spread through air space (STAS) is a novel invasive pattern of lung adenocarcinoma and is also a risk factor for recurrence and worse prognosis of lung adenocarcinoma after sublobar resection. The aims of this study are to evaluate the association between computed tomography (CT)-based features and STAS for preoperative prediction of STAS in lung adenocarcinoma, eventually, which could help us choose appropriate surgical type.

Methods

Systematic research was conducted to search for studies published before September 1, 2019. The association between CT-based features of radiological tumor size>2 cm、pure solid nodule、 part-solid nodule or Percentage of solid component (PSC)>50% and STAS was evaluated. According to rigorous inclusion and exclusion criteria. Eight studies including 2385 patients published between 2015 and 2018 were finally enrolled in our meta-analysis.

Results

Our results clearly depicted that there is no significant relationship between radiological tumor size>2 cm and STAS with the combined OR of 1.47(95% CI:0.86–2.51). Meta-analysis of 3 studies showed that pure solid nodule in CT image were more likely to spread through air spaces with pooled OR of 3.10(95%CI2.17–4.43). Meta-analysis of 5 studies revealed the part-solid nodule in CT image may be more likely to appear STAS in adenocarcinoma (ADC) (combined OR:3.10,95%CI:2.17–4.43). PSC>50% in CT image was a significant independent predictor in the diagnosis of STAS in ADC from our meta-analysis with combined OR of 2.95(95%CI:1.88–4.63).

Conclusion

In conclusion, The CT-based features of pure solid nodule、part-solid nodule、PSC>50% are promising imaging biomarkers for predicting STAS in ADC and may substantially influence the choice of surgical type. In future, more studies with well-designed and large-scale are needed to confirm the conclusion.

Novel technique for identification of the pulmonary intersegmental plane using manual jet ventilation during pulmonary segmentectomy

Introduction

For successful pulmonary segmentectomy, the identification of boundaries between segments is important. Previous measures include tracing the intersegmental vessels by staining with a dye via the affected pulmonary artery or bronchus and inflating with oxygen via a high frequency ventilator. However, problems with these methods have been reported.

Aim

We developed a novel method using a manual jet ventilator (MJV) and investigated its efficacy in identification of the pulmonary intersegmental plane.

Material and methods

Patients underwent MJV for pulmonary segmentectomy in the period from January 2013 to December 2017 at our institution. The patients’ characteristics, resected segments, availability of clear resection planes, and complications associated with MJV from medical records were investigated. A questionnaire survey was conducted with the surgeons on the effectiveness of lung segment identification using MJV.

Results

Of 199 cases of planned pulmonary segmentectomy, 171 cases with descriptions of identified intersegmental planes were analyzed. Of these, 152 (89%) cases showed a clear boundary. There were 19 cases where the exact boundaries were not clearly identified, but segmentectomy was still performed. Furthermore, we found that identification of the right upper lobes was difficult (p = 0.0028). A subjective questionnaire was answered by the 12 surgeons who performed the procedures. All 12 responded that MJV was very effective or effective regarding clarity, safety, shorter identification time, and shorter resection time.

Conclusions

MJV enabled surgeons to more easily and safely identify the pulmonary intersegmental plane, thereby suggesting that MJV has clinical significance during pulmonary segmentectomy.

Oncologic outcomes of lobectomy vs. segmentectomy in non-small cell lung cancer with clinical T1N0M0 stage: a literature review and meta-analysis

Background

Lobectomy has long been regarded as the standard treatment for operable non-small cell lung cancer (NSCLC). Recent studies suggested that segmentectomy could achieve a good prognosis for early-stage NSCLC and might be an alternative to lobectomy in this cohort. Until now, on the issue of comparison between lobectomy and segmentectomy, there remains no published randomized controlled trial (RCT), and all existing evidence is low. Recently, a categorization of lower-level evidence has been proposed, namely, the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system. The aim of this meta-analysis is to compare the oncologic outcome between lobectomy and segmentectomy in NSCLC with the clinical T1N0M0 stage according to the GRADE system.

Methods

PubMed, the PMC database, EMBASE, Web of Science, and the Cochrane library were searched prior to May 2019 to identify studies that compared the prognosis between lobectomy and segmentectomy for clinical T1N0M0 NSCLC. The evidence level of the included studies was assessed according to the GRADE system, including level IIA, probably not confounded nonrandomized comparison; level IIB, possibly confounded nonrandomized comparison; and level IIC, probably confounded nonrandomized comparison. The predefined outcomes included overall survival (OS) and disease-free survival (DFS). Univariable and multivariable hazard ratios (HRs) with 95% confidence intervals (95% CI) were pooled using a random-effects model.

Results

Twelve nonrandomized studies involving 8,072 participants were included. Of these studies, two were classified as IIA level (16.7%), six as IIB level (50.0%), and four as IIC level (33.3%). When crude HRs were included, compared with lobectomy, segmentectomy was associated with shorter OS but comparable DFS in the entire cohort (OS, pooled HR =1.45, 95% CI, 1.23 to 1.67; DFS, pooled HR =1.03, 95% CI, 0.65 to 1.82) and in patients with nodules ≤2 cm (OS, pooled HR =1.55, 95% CI, 1.33 to 1.80; DFS, pooled HR =0.98, 95% CI, 0.55 to 1.77). When adjusted HRs were included, the impact of segmentectomy on OS and DFS was comparable to that of lobectomy in the entire cohort (OS, pooled HR =1.39, 95% CI, 0.92 to 2.10; DFS, pooled HR =0.83, 95% CI, 0.66 to 1.03) and in patients with nodules ≤2 cm (OS, pooled HR =1.61, 95% CI, 0.87 to 3.00; DFS, pooled HR =0.90, 95% CI, 0.63 to 1.27).

Conclusions

Based on our results, although shorter OS is observed in patients received segmentectomy, it is necessary to wait for more results from RCT to draw a valid conclusion.