Lobectomy and limited resection in small-sized peripheral non-small cell lung cancer

Limited resection is comparable to lobectomy for tumor size ≤ 2 cm pulmonary invasive mucinous adenocarcinoma

OBJECTIVES

Invasive mucinous adenocarcinoma (IMA) has a rare incidence with better prognosis than nonmucinous adenocarcinoma. We aimed to investigate the prognosis between limited resection and lobectomy for patients with clinical stage IA IMA ≤ 2 cm.

METHODS

Data were taken from two cohorts: In Shanghai Pulmonary Hospital (SPH) corhort, we identified 403 patients with clinical stage IA IMA who underwent surgery. In the SEER corhort, 480 patients with stage T1 IMA who after surgery were included. Recurrence-free survival (RFS) for SPH corhort, lung cancer-specific survival (LCSS) for the SEER corhort and overall survival (OS) for both corhort were compared between patients undergoing lobectomy and limited resection by Log-rank and Cox proportional hazard regression model.

RESULTS

In SPH corhort, patients who underwent limited resection had equivalent prognosis than those underwent lobectomy (5-year RFS: 79.3% versus. 82.6%, p = 0.116; 5-year OS: 86.2% versus. 88.3%, p = 0.235). However, patients with IMA > 2 to 3 cm had worse prognosis than those with IMA ≤ 2 cm (5-year RFS: 73.7% versus. 86.1%, p = 0.007). In the analysis of IMA > 2 to 3 cm subgroup, multivariate analysis showed that limited resection was an independent risk factor of RFS (hazard ratio, 2.417; 95% confidence interval, 1.157-5.049; p = 0.019), while OS (p = 0.122) was not significantly different between two groups. For IMA ≤ 2 cm, limited resection was not a risk factor of RFS (p = 0. 953) and OS (p = 0.552). In the SEER corhort, IMA ≤ 2 cm subgroup, limited resection was equivalent prognosis in LCSS (p = 0.703) and OS (p = 0.830).

CONCLUSIONS

Limited resection could be a potential surgical option which comparable to lobectomy in patients with clinical stage IA IMA ≤ 2 cm.

Sublobar resection versus lobectomy for stage IA non-small-cell lung cancer: A systematic review and meta-analysis of randomized controlled trials

Surgical resection is the first-line treatment for early-stage lung cancer, with lobectomy being the standard choice since the 1960s. Nevertheless, recent studies have shown controversies about whether sublobar resection or lobectomy is the optimal surgical approach today. In this sense, this meta-analysis aims to compare these techniques. PubMed, EMBASE, and Cochrane databases were searched for randomized controlled trials (RCTs) comparing sublobar resection with lobectomy for stage IA non-small-cell lung cancer (NSCLC) and reporting any of the following outcomes: (1) Overall survival (OS); (2) disease-free survival (DFS); and (3) total disease recurrences. Sublobar resection encompassed wedge resection and segmentectomy techniques. A total of 1975 patients from four studies were included, of whom 978 (49.5%) underwent sublobar resection and 973 (49.3%) were male. All tumors were smaller than 2 cm. Follow-up ranged from 5 to 7.3 years. Mean age was 62.8 ± 37.0 years, and 1353 (68.5%) patients had a known smoking history. OS (HR 0.79; 95% CI 0.60-1.05; p = 0.11) and DFS (HR 1.02; 95% CI 0.86-1.22; p = 0.80) did not significantly differ between the sublobar resection and lobectomy groups. Similarly, no significant statistical difference was observed in total disease recurrences (RR 1.17; 95% CI 0.93-1.46; p = 0.17). Subgroup and isolated sublobar resection techniques analyses were not possible due to the lack of data. Sublobar resection and lobectomy have similar OS, DFS, and disease recurrence rates for stage IA NSCLC. These findings underline the need for new RCTs investigating these outcomes in specific patient subgroups and isolated sublobar resection techniques.

Comparison of lobectomy and sublobar resection for stage I non-small cell lung cancer: a meta-analysis based on randomized controlled trials

Background

This meta-analysis aimed to compare the prognostic between lobectomy and sublobar resection in patients with stage I non-small cell lung cancer (NSCLC).

Methods

We conducted a detailed search in PubMed, Embase, Web of Science, and the Cochrane Library for randomized controlled trials (RCTs) comparing the prognosis of lobectomy and sublobar resection for stage I NSCLC, with the primary outcomes being overall survival (OS) and disease-free survival (DFS).

Results

A total of 2222 patients were included in the 5 RCTs. The results showed no statistical difference in OS (HR=0.87, p=0.445) and DFS (HR=0.99, p=0.918) between patients who underwent lobectomy and sublobar resection during the total follow-up period. In terms of dichotomous variables, there were no statistical differences in OS (relative ratio [RR]=1.05, p=0.848) and DFS (RR=1.21, p=0.075) between the two groups during the total follow-up period, as well as 5-year OS (RR=0.96, p=0.409) and 5-year DFS (RR=0.95, p=0.270). In addition, subgroup analysis showed a better prognosis for non-adenocarcinoma patients with sublobar resection than lobectomy (HR=0.53, p=0.037), but also an increased cause of cancer death (not limited to lung cancer) (RR=1.56, p=0.004).

Conclusion

Our results showed that for stage I NSCLC, lobectomy is usually not a justified operation.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023407301, identifier CRD42023407301.

Segmentectomy versus lobectomy. Which factors are decisive for an optimal oncological outcome?

Low-dose computed tomography is being used for lung cancer screening in high-risk groups. Detecting lung cancer at an early stage improves the chance of optimal treatment and increases overall survival. This article compares segmentectomy vs. lobectomy as surgical options, in the case of stage I non-small cell lung carcinoma, ideally IA. To compare the 2 previously referred strategies, data were collected from articles (40 studies were reviewed), reviews, and systematic analyses in PubMed Central, as well as reviewing recent literature. Segmentectomy could be an equal alternative to lobectomy in early-stage NSCLC (tumour < 2 cm). It could be preferred for patients with a low cardiopulmonary reserve, who struggle to survive a lobectomy. As far as early-stage NSCLC is concerned, anatomic segmentectomy is an acceptable procedure in a selective group of patients. For better tumour and stage classification, a systematic lymph node dissection should be performed.

"Separated" precise subsegmentectomy: Single-port thoracoscopic noncombined subsegmentectomy in one lung lobe

BACKGROUND

In clinical practice, combined segmental resection (CSS) can avoid resection of multiple segments to preserve lung function. When two or more distant lung segments or subsegments of the same lobe present with a ground glass opacity (GGO) that meets the indications for sublobar resection, conventional CSS or wedge resection could not remove all the nodules, and lobectomy is performed in most of these patients. For these particular types of nodules, we perform a single lobe noncombined subsegmental resection, or "separated" precise subsegmentectomy, to preserve more lung tissue. This study was designed to initially assess the feasibility and safety of "separated" precise subsegmentectomy.

METHODS

Selected cases of specific GGO were subjected to "separated" precise subsegmentectomy and the results of general clinical data, perioperative operative time, bleeding, length of stay, computed tomography (CT) review, lung function and its dynamic changes were collected and analyzed in these patients.

RESULTS

"Separated" precise subsegmentectomy was performed in 12 patients and successfully completed. The median operation time, bleeding amount, and length of hospital stay were 96 min, 50 ml and 4 days, respectively. There was one case of pulmonary infection and one case of persistent air leakage, no death or pulmonary torsion, bronchopleural fistula and other pulmonary complications occurred. After 3 months, the median percentage of lung function retention was 91.7%, and the CT scan showed that the reserved lung tissue of 12 patients was well inflated and there was no obvious imaging manifestation of atelectasis.

CONCLUSION

"Separated" precise subsegmentectomy is a novel and safe surgical method that provides a more optimized way for patients with specific multiple nodules to preserve lung function. Further prospective large studies are needed to verify this finding.

Comparison Between Wedge Resection and Lobectomy/Segmentectomy for Early-Stage Non-small Cell Lung Cancer: A Bayesian Meta-analysis and Systematic Review

BACKGROUND

Surgery has become an accepted method for the treatment of early-stage non-small cell lung cancer (NSCLC). The purpose of this Bayesian meta-analysis was to compare the overall survival (OS), disease-free survival (DFS), and relapse-free survival (RFS) between wedge resection and lobectomy/segmentectomy for treatment of early-stage NSCLC.

METHODS

Eligible studies were retrieved from Web of Science, PubMed, MEDLINE, Cochrane Library, EMBASE, CNKI, and WanFang up to July 2021 and screened based on established selection criteria. The Bayesian meta-analysis was performed with the combination of the reported survival outcomes of the individual studies using a random-effect model. The OS, DFS, and RFS of the wedge resection group was compared with the lobectomy/segmentectomy group. The hazard ratio (HR) and standard error were extracted or calculated for each study using the Kaplan-Meier method.

RESULTS

This study was registered with PROSPERO (INPLASY202080090).The pooled OS hazard ratio between segmentectomy and lobectomy was 1.1 [95% confidence interval (CI) 0.92-1.4], the pooled HR between lobectomy and wedge resection was 0.71 [95% CI 0.52-0.96], and the pooled HR between segmentectomy and wedge was 0.80 [95% CI 0.56-1.10]. The pooled HR of DFS or RFS was not statistically significant among the three surgical approaches.

CONCLUSIONS

Patients with early-stage NSCLC received lobectomy had the lowest hazard ratio of OS than patients received wedge resection, indicating that the overall survival of patients received lobectomy was higher than patients received wedge resection. However, regarding DFS and RFS, the three surgical approaches showed no significant difference.

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.

Pulmonary function after segmentectomy versus lobectomy in patients with early-stage non-small-cell lung cancer: a meta-analysis

Objective

Segmentectomy is widely performed for early-stage lung cancer. However, the effects of segmentectomy versus lobectomy on pulmonary function remain unclear. We performed a meta-analysis with the aim of comparing segmentectomy and lobectomy in terms of preservation of pulmonary function in patients with early-stage non-small-cell lung cancer (NSCLC).

Methods

We conducted a literature search of PubMed using the terms ‘pulmonary function’ AND ‘segmentectomy’ AND ‘lobectomy’. The primary outcomes of interest were the forced expiratory volume in 1 second (FEV1), FEV1 as percent of predicted (%FEV1), change in FEV1 (Δ%FEV1), and the ratio of postoperative to preoperative FEV1.

Results

Thirteen studies comprising 2027 patients met the inclusion and exclusion criteria and were included for analysis, including 787 patients in the segmentectomy group and 1240 patients in the lobectomy group. Patients in the segmentectomy group showed significantly better preservation of FEV1 and %FEV1 compared with the lobectomy group. The reduction in FEV1 after surgery was significantly less in the segmentectomy group compared with the lobectomy group, and Δ%FEV1 was significantly higher in the segmentectomy group than in the lobectomy group.

Conclusion

Segmentectomy results in better preservation of pulmonary function compared with lobectomy in patients with early-stage NSCLC.

Identifying Lung Cancer Patients Suitable for Segmentectomy: A Brief Review

Background: In 1995, a clinical randomized controlled study (RCT) conducted by the Lung Cancer Study Group (LCSG) pointed out that the lobectomy was the gold standard for treating early lung cancer. However, with the development of technology, the results of several retrospective studies have shown that the efficacy of pulmonary segmentectomy is equivalent to that of lobectomy. Currently, it is still controversial whether segmental resection or lobectomy should be performed for early lung cancer. Thus, we aim to summarize the indications of segmentectomy.

Methods: To conduct the review, previous researches involving indications of segmentectomy were collected from the literature using Pubmed. These articles were published and accepted in English in the medical literature from 2013 to 2020. We have focused on segmentectomy and its indications.

Results: A total of 176 articles were retrieved from the Pubmed database, of which 31 articles included indications for segmentectomy. We summarized the relevant content, and the potential and prospect of segmentectomy for the treatment of lung cancer were emphasized.

Conclusions: These findings have a number of important implications for future practice. Pulmonary segmentectomy is a very vital surgical procedure for select patients with lung cancer, which provides a novel approach for the treatment of lung cancer and the survival of lung cancer patients.

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.

Stapled video-assisted thoracoscopic segmentectomy preserves as much lung volume as nonstapled video-assisted thoracoscopic segmentectomy

BACKGROUND

Two different techniques of performing segmentectomy have been reported in the era of video-assisted thoracosopic surgery (VATS), including stapled segmentectomy (SS) and non-stapled segmentectomy (NSS). Some surgeons favor stapled segmentectomy for better pneumostatic control, while others prefer non-stapled segmentectomy to avoid compromising adjacent pulmonary parenchyma. In this study, we used multidetector computed tomography (MDCT) and spirometry to evaluate lung volume preservation of different segmentectomy techniques.

METHODS

A total of 269 patients undergoing video-assisted thoracic surgery (VATS) segmentectomy between October 2013 and September 2016 in a single institution were reviewed. Perioperative outcomes, the cost of hospital admission, the change in forced expiratory volume in 1 s (FEV1) (ΔFEV1 and ΔFEV1%), and residual ipsilateral volume ratios (RiVR) were compared.

RESULTS

The final study population consisted of 107 patients: 30 patients underwent NSS, and 77 patients underwent SS. The NSS group had significantly longer operative time, more blood loss, longer duration of chest tube placement and postoperative hospitalization than the SS group. The follow-up of RiVR (at 6 months, 12 months, 24 months), ΔFEV1(L), and ΔFEV1(%) demonstrated no significant difference between NSS and SS group.

CONCLUSION

Our study demonstrated that postoperative residual lung volume was not influenced by different segmentectomy techniques.

Lobectomy versus sublobar resection in patients with non-small cell lung cancer: a systematic review

Surgery is the gold standard treatment of lung cancer. The minimally invasive technique does not only concern access to the chest but also the limits of parenchymal resection. The study debates on the safety and oncological adequacy of sublobar resections in bronchogenic carcinoma patients. A systematic analysis of the data in the literature was carried out, comparing the outcomes of patients with resectable non-small lung cancer (NSCLC) who underwent lobectomy or sublobar resection. These last interventions include both segmentectomies and wedge resections taking into consideration the following parameters: complications, relapse rate and overall survival. The complication rate is higher in patients underwent lobectomy compared to sublobar resection, especially in presence of high comorbidity index or octogenarian patients (overall values respectively between 0 and 48% and 0 and 46.6%). Contrarily, the relapse rate (6.2% to 32% vs. 3.6% to 53.4%) and overall survival (50.2% to 93.8% vs. 38.6% to 100%) are more favorable in patients undergoing lobectomy. Sublobar resections are particularly indicated in elderly patients and in patients with high comorbidity index or reduced respiratory functional reserve. However, pulmonary lobectomy still remains the safest and oncologically correct method in patients with good performance status or higher risk of recurrence.

Prognostic impact of lymphadenectomy on outcomes of sublobar resection for non-small cell lung cancer ≤1 or >1 to 2 cm

Background

Lymphadenectomy is an important part of surgical treatment for non-small cell lung cancer (NSCLC). However, the prognostic impact of lymph node (LN) dissection for patients with NSCLC ≤1 and >1 to 2 cm who underwent sublobar resection is still unclear.

Methods

A group of patients numbering 7,627 with NSCLC 2 cm or less who underwent sublobar resection were identified from the Surveillance, Epidemiology, and End Results (SEER) database between January 2010 and November 2015. The overall survival (OS) and lung cancer-specific survival (LCSS) were evaluated among patients who had undergone dissection of ≥4 LNs, 1 to 3 LNs or who had no-LN dissection; log-rank and Cox proportional-hazards regression analyses were used for the evaluation.

Results

Patients with NSCLC ≤2 cm who underwent ≥4 LNs dissection had better OS and LCSS compared with those who underwent dissection of 1 to 3 LNs or who had no-LN dissection after sublobar resection. Subgroup analysis showed that dissection of ≥4 LNs had better OS and LCSS than those of 1 to 3 LNs dissection in NSCLC >1 to 2 cm, whereas had similar OS and LCSS in NSCLC ≤1 cm. Multivariate Cox analysis showed that dissection of 1 to 3 LNs was not an independent risk factor of OS and LCSS than dissection of ≥4 LNs in NSCLC ≤1 cm after sublobar resection.

Conclusions

The extent of LN dissection is associated with the survival outcomes in patients with NSCLC ≤2 cm after sublobar resection. Dissection of ≥4 LNs should be recommended for NSCLC >1 to 2 cm, whereas surgeons can rely on surgical skills and patient profiles to decide ≥4 LNs or 1 to 3 LNs dissection for NSCLC ≤1 cm during sublobar resection.

Equivalent Survival Between Lobectomy and Segmentectomy for Clinical Stage IA Lung Cancer

BACKGROUND

The oncologic efficacy of segmentectomy is controversial. We compared long-term survival in clinical stage IA (T1N0) Medicare patients undergoing lobectomy and segmentectomy in The Society of Thoracic Surgeons database.

METHODS

The Society of Thoracic Surgeons General Thoracic Surgery Database was linked to Medicare data in 14,286 lung cancer patients who underwent segmentectomy (n = 1654) or lobectomy (n = 12,632) for clinical stage IA disease from 2002 to 2015. Cox regression was used to create a long-term survival model. Patients were then propensity matched on demographic and clinical variables to derive matched pairs.

RESULTS

In Cox modeling segmentectomy was associated with survival similar to lobectomy in the entire cohort (hazard ratio, 1.04; 95% confidence interval, 0.89-1.20; P = .64) and in the matched subcohort. A subanalysis restricted to the 2009 to 2015 population (n = 11,811), when T1a tumors were specified and positron emission tomography results and mediastinal staging procedures were accurately recorded in the database, also showed that segmentectomy and lobectomy continue to have similar survival (hazard ratio, 1.00; 95% confidence interval, 0.87-1.16). Subanalysis of the pathologic N0 patients demonstrated the same results.

CONCLUSIONS

Lobectomy and segmentectomy for early-stage lung cancer are equally effective treatments with similar survival. Surgeons from The Society of Thoracic Surgeons database appear to be selecting patients appropriately for sublobar procedures.

A novel technique for identification of the segments based on pulmonary artery plane combined with oxygen diffusing discrepancy

Background

Segmentectomy has been widely accepted as a powerful tool to treat small lung nodules. Despite been commonly used, identify the intersegment plane precisely in visual during the operation still being a complex issue. We described a novel method in minimal invasive thoracic surgery utilizing arterial-navigation combined with oxygen diffusing discrepancy based on the variance of oxygen diffusion in target and reserved segments. We perspectively analyzed 24 cases with small lung nodules of T1N0M0 disease to examine the efficacy of the new method.

Methods

From June 2018 to September 2018, 24 patients with small primary lung cancers underwent segmentectomy at The Affiliated Hospital of Qingdao University. All the patients received minimally invasive procedures and standard anatomical segmentectomy. Ligation of the target segment artery followed by observation and the arterial-navigation line gradually appeared by color discrepancy in the visceral pleural surface. The plane was then testified by inflation-deflation method.

Results

The mean identification time of the intersegments plane was 8 minutes. The residual segments collapsed and stayed pink, meanwhile the target parts remained inflated and turned dark. It allowed a clear identification of the intersegments plane on the surface. All operations were successfully completed. There were no perioperative deaths or major complications. The coincidence rate of arterial-navigation and inflation-deflation technique was 22/24.

Conclusions

The arterial-navigation method is safe and feasible to identify the intersegmental plane in small lung tumor resection.

Clinicopathological features of small-sized peripheral squamous cell lung cancer

Recent advances in imaging technology have enhanced the detection rate of small-sized peripheral lung cancers. The present study aimed to identify the clinicopathological differences between patients with small-sized peripheral squamous cell carcinoma (SCC) and adenocarcinoma (ADC). Patients with lung cancer who underwent radical surgical resection at Gunma University Hospital between July 2007 and October 2012 were retrospectively analyzed. Patients who exhibited small-sized peripheral tumors (pathological size, ≤2 cm) located within the outer-third of the lung field on preoperative computed tomography were enrolled in the present study. A total of 26 patients were diagnosed with SCC and 214 with ADC. The results revealed that patients with SCC exhibited higher rates of pleural invasion, vascular invasion and lymphatic invasion compared with ADC patients. Additionally, the rate of postoperative recurrence was higher in patients with SCC compared with ADC patients. Patients with ADC were subsequently into two groups: Solid ADCs (sADC) and non-solid ADCs (nsADC), which included pure ground glass nodules and part-solid ADCs. The results revealed that the incidence of pleural invasion, vascular invasion and lymphatic invasion, and the rate of postoperative recurrence in patients with sADCs were similar to those with SCC, but were also significantly higher when compared with nsADC patients. The present study concluded that patients with SCC and sADC may not be suitable candidates for sublobar resection, despite exhibiting small tumors that are located in the peripheral lung.

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.

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.

[Advances in the Study of the Effects of Video-assisted Thoracoscopic Segmentectomy on Pulmonary Function]

2018年美国国立综合癌症网络关于非小细胞肺癌（non-small cell lung cancer, NSCLC）指南指出，对于早期NSCLC，解剖性肺叶切除为首选方案。随着电视胸腔镜技术的发展，以胸腔镜为代表的胸外科微创手术在临床得到了广泛应用。胸腔镜肺段切除术已经成为早期NSCLC的治疗方案之一。临床研究发现相较于肺叶切除，亚肺叶切除在早期NSCLC治疗中也可取得相似的结果并保留更多的肺功能，但肺段切除术后患者肺功能的改变尚存争议。本文将重点对胸腔镜肺段切除术后患者肺功能改变的研究进展做一综述。

[Difference of Lung Function Retention after Segmentectomy and Lobectomy]

近年来肺癌发病率和检出率逐渐升高，肺段切除术被越来越普遍应用于治疗早期非小细胞肺癌。有学者认为肺段切除术相比肺叶切除术更有利于术后肺功能的保留，也有研究得出两种手术方式在术后肺功能保留方面差异不大，本文就肺段切除术与肺叶切除术术后肺功能变化的相关研究作一综述。

Evaluation of lobar lymph node metastasis in non-small cell lung carcinoma using modified total lesion glycolysis

Background

Volumetric parameters based on 3-dimensional reconstruction have recently been introduced for cancer staging. We aimed to improve the ability to diagnose hilar lymph node metastasis in patients with non-small cell lung cancer.

Methods

We evaluated 142 patients with non-small cell lung cancer who underwent right upper lobectomy and radical lymph node dissection. Metastatic involvement of right upper lobar lymph nodes was assessed using high-resolution computed tomography (HRCT) and 18F-2-floro-2-deoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT).

Results

On receiver operating characteristic (ROC) curve analysis, the area under the curves (AUC) for short axis, maximum of standardized uptake value (SUV_max), total lesion glycolysis (TLG) and modified TLG (mTLG) were 0.79, 0.77, 0.76, and 0.87, respectively. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of mTLG, using the optimal cut off value (2.45), for diagnosis of lobar lymph node metastasis were 71%, 88%, 44%, and 96%, respectively. Hilar asymmetric uptake (HAU) of FDG was larger in true-positive cases than in false-negative cases (P<0.01). Furthermore, the size of metastatic foci in the lymph node was smaller in false-negative cases (P=0.012).

Conclusions

Modified TLG is a good parameter to diagnose metastatic right upper lobar lymph nodes. Micrometastasis in the lymph node is difficult to predict using the current diagnostic method. However, more careful evaluation is required in patients with symmetric FDG accumulation at hilar region because hilar lymph nodes respond to various causes such as benign pulmonary diseases.

Early Experience with Video-Assisted Thoracoscopic Anatomic Segmentectomy

BACKGROUND

Anatomic segmentectomy for stage I nonsmall cell lung cancer (NSCLC) has potential advantages such as preserving pulmonary function and reducing postoperative complications. However, many surgeons are deterred from this procedure for its anatomical complexity. Therefore, we presented our early experience with video-assisted thoracoscopic surgery (VATS) anatomic segmentectomy compared with our most recent VATS lobectomy cases.

PATIENTS AND METHODS

Forty patients with cT1aN0M0 (ground-glass opacity [GGO] rate >50%) NSCLC underwent VATS segmentectomy from January 2015 to December 2016. To compare the short-term postoperative outcomes, 47 patients, who underwent VATS lobectomy for cT1aN0M0 NSCLC (GGO rate ≤50% and pure solid nodule) during the same period, were referred to as a control group.

RESULTS

The two groups were similar in age, sex, preoperative pulmonary functional assessment, and associated comorbidities. The tumor size in the segmentectomy group was significantly smaller (median, 0.8 cm versus 1.4 cm, P < .001). Segmentectomy and lobectomy groups had similar operating time, estimated blood loss, duration of chest tube drainage, length of postoperative hospital stay, and postoperative major and minor morbidities. With regard to lymph node evaluation, lobectomy was associated with more lymph nodes (median, 12 versus 9 nodes, P < .001) and mediastinal nodal stations evaluated (median, 3 versus 3 stations, P < .001).

CONCLUSIONS

With acceptable morbidity and mortality, VATS segmentectomy may be an acceptable option for the treatment of cT1aN0M0 (GGO rate >50%) NSCLC.

[Prognostic Analysis of Lobectomy versus Sublobar Resection in Patients Aged ≥60 Years with Stage Ia Small Cell Lung Cancer]

背景与目的

目前，肺叶切除与亚肺叶切除治疗Ia期小细胞肺癌（small cell lung cancer, SCLC）的预后比较鲜有报道。本研究通过对年龄≥60岁的T1N0M0（≤3 cm）SCLC进行回顾性研究，旨在探索肺叶切除与亚肺叶切除治疗Ia期SCLC预后的对比分析。

方法

纳入“监测，流行病学和结果数据库”（Surveillance, Epidemiology and End Results database, SEER）在1992年-2010年间经病理诊断为Ia期SCLC患者共515例，数据使用Kaplan-Meier（Log-rank检验）和Cox模型进行比较统计分析。

结果

肺叶切除组（n=110）、亚肺叶切除组（n=57）、和非手术治疗组（n=348）的中位生存期分别为45个月、23个月和16个月；该三组相应的5年总生存期（OS）分别为44%、30%和14%（Lob vs Sub, χ²=4.851, P=0.028; Sub vs non-surgical, χ²=6.529, P=0.011）。SCLC有、无淋巴结采样/清扫患者的预后无显著差异（P=0.107）；肺叶切除+放化疗组（Lob+CR, n=59）的5年OS为50%。Cox分析证实，手术（肺叶与亚肺叶切除术）方式为独立预后预测因素之一。

结论

年龄≥60岁的Ia期SCLC患者，我们推荐解剖性肺叶切除联合辅助放化疗治疗。