Lobectomy Versus Segmentectomy in Radiologically Pure Solid Small-Sized Non-Small Cell Lung Cancer

Is Lobectomy Actually Worse Than Segmentectomy for All Stage I Non-Small Cell Lung Cancer?

INTRODUCTION

The recent results of the JCOG 0802 and CALGB 140503 studies suggest that segmentectomy should be considered instead of lobectomy for patients with peripheral <2 cm node-negative non-small cell lung cancer (NSCLC). This study aimed to test this hypothesis in a retrospective analysis of a larger dataset of patients with stage I NSCLC recorded in the Surveillance, Epidemiology, and End Results database.

METHODS

Patients with all stage I NSCLC (≤4 cm in size) who underwent either segmentectomy or lobectomy from 2000 to 2017 were analyzed. The primary endpoints were overall survival and lung cancer-specific survival, while the secondary endpoints were the 30-day and 90-day mortality.

RESULTS

Overall, 32,673 patients treated by lobectomy and 2166 patients treated by segmentectomy were included in the initial data collection. After 1:1 propensity score matching (PSM), 2016 patients in each group were enrolled in the final analysis with well-balanced baseline characteristics. After PSM, there was no difference between segmentectomy and lobectomy for all stage IA NSCLC (≤3 cm in size) in both overall survival and lung cancer-specific survival (hazard ratio: 0.87 [0.74-1.02], P value: 0.09 and hazard ratio: 0.81 [0.4-1.03], P value: 0.09, respectively). Furthermore, lobectomy had higher 30-day mortality than segmentectomy: 1.1% versus 2.1%, P value: 0.01. However, this difference was not significant for 90-day mortality, even after PSM (3.9% versus 3.0%, P value: 0.17).

CONCLUSIONS

We found no evidence to support the use of lobectomy rather than segmentectomy in stage IA NSCLC in terms of either overall or lung cancer-specific long-term survival. The choice of lobectomy may also be detrimental to early postoperative recovery.

Differential efficacy of segmentectomy and wedge resection in sublobar resection compared to lobectomy for solid-dominant stage IA lung cancer: a systematic review and meta-analysis

BACKGROUND

Currently, the impact of sublobar resection versus lobectomy on the prognosis of solid-dominant stage IA lung cancer is contradictory in different studies, which requires further exploration.

METHODS

The authors analyzed 26 studies, including one randomized controlled trial and retrospective cohort studies. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using fixed-effects or random-effects models based on heterogeneity levels.

RESULTS

The analysis included 12 667 patients, with 3488 undergoing sublobar resections and 9179 receiving lobectomies. The overall analysis revealed no statistically significant difference in overall survival (OS) (HR=1.28, 95% CI: 0.98-1.69) between sublobar resection and lobectomy, but lobectomy was associated with better recurrence-free survival (RFS) (HR=1.39, 95% CI: 1.10-1.75). Subgroup analyses revealed that, for tumors with a diameter ≤2 cm, sublobar resection versus lobectomy showed no significant difference in OS but sublobar resection had lower RFS. For 2-3 cm tumors, both OS and RFS were significantly lower in the sublobar resection group. When consolidation-to-tumor ratio (CTR) ranged from 0.5 to <1, OS did not differ significantly, but RFS was significantly lower in sublobar resection. Lung cancers with CTR=1 showed significantly lower OS and RFS in the sublobar resection group. Segmentectomy provided similar OS and RFS compared to lobectomy, while wedge resection had a detrimental effect on patient prognosis. However, wedge resection may have provided comparable outcomes for patients aged 75 years or older.

CONCLUSION

Our findings suggest that segmentectomy and lobectomy yield similar oncological outcomes. However, compared to lobectomy, wedge resection is associated with a poorer prognosis. Nevertheless, for elderly patients, wedge resection is also a reasonable surgical option.

Sublobar resection versus lobectomy for stage IA non-small-cell lung cancer ≤ 2 cm: a systematic review and patient-level meta-analysis

Despite lobectomy being the standard of care for early-stage non-small-cell lung cancer (NSCLC), sublobar resection (segmentectomy or wedge resection) has recently been suggested to achieve similar outcomes. An electronic literature search was conducted to retrieve randomized controlled trials (RCTs) or propensity score-matched studies (PSMs) comparing lobectomy to sublobar resection in stage IA NSCLC ≤ 2 cm in size, with provision of Kaplan-Meier curves for overall survival (OS) and disease-free survival (DFS). A graphical reconstructive algorithm was used to obtain OS and DFS of individual patients, which was then pooled under random-effects individual patient data meta-analysis using Cox models to determine hazard ratios (HRs). Sensitivity analyses for OS and DFS were also performed, restricting to results from RCTs only. Seven studies (2528 patients) were retrieved. There were no significant differences in OS (shared-frailty HR = 0.92, 95% CI = 0.77-1.11, p = 0.378) or DFS (shared-frailty HR = 1.06, 95% CI = 0.90-1.24, p = 0.476) between lobectomy and sublobar resection. This comparison remained non-significant even when restricted to RCTs only. Pooled Kaplan-Meier curves of OS appeared to diverge over time, in favor of sublobar resection. This was confirmed on analysis of restricted mean survival time curves. This patient-level meta-analysis of high-quality studies demonstrates that sublobar resection is equivalent to lobectomy in patients with small stage IA NSCLC. Sublobar resection offers greater down-the-road benefits in patients who experience recurrence or a second primary tumor since the lung-sparing index surgery allows patients to receive further treatment safely. This heralds sublobar resection as the new standard of care in carefully selected early-stage patients.Trial registration: PROSPERO CRD42023385358.

Segmentectomy for patients with early-stage pure-solid non-small cell lung cancer

For decades, lobectomy has been the recommended surgical procedure for non-small cell lung cancer (NSCLC), including for small-sized lesions. However, two recent pivotal clinical trials conducted by the Japanese Clinical Oncology Group/West Japan Oncology Group (JCOG0802/WJOG4607L) and the Cancer and Leukemia Group B (CALGB140503), which compared the survival outcomes between lobectomy and sublobar resection (the JCOG0802/WJOG4607L included only segmentectomy, not wedge resection), demonstrated the efficacy of sublobar resection in patients with early-stage peripheral lung cancer measuring ≤ 2 cm. The JCOG0802/WJOG4607L demonstrated the superiority of segmentectomy over lobectomy with respect to overall survival, implying the survival benefit conferred by preservation of the lung parenchyma. Subsequently, the JCOG1211 also demonstrated the efficacy of segmentectomy, even for NSCLC, measuring up to 3 cm with the predominant ground-glass opacity phenotype. Segmentectomy has become the standard of care for early-stage NSCLC and its indications are expected to be further expanded to include solid lung cancers > 2 cm. However, local control is still a major concern for segmentectomy for higher-grade malignant tumors. Thus, the indications of segmentectomy, especially for patients with radiologically pure-solid NSCLC, remain controversial due to the aggressive nature of the malignancy. In this study, we reviewed previous studies and discussed the efficacy of segmentectomy for patients with such tumors.

Segmentectomy versus lobectomy for deep clinical T1a-bN0M0 non-small cell lung cancer

OBJECTIVES

Whether segmentectomy could yield similar oncological outcomes with lobectomy for cT1a-bN0M0 non-small cell lung cancer (NSCLC) in the deep lung parenchyma remained unclear. This study aimed to compare the long-term prognosis of segmentectomy and lobectomy for deep NSCLC.

MATERIALS AND METHODS

We retrospectively screened cT1a-bN0M0 NSCLC patients who underwent segmentectomy or lobectomy between 2012 and 2019. The 3D multiplanar reconstruction software was used to determine the tumor location. Log-rank test, Cox hazard proportional regression, and propensity score matching analyses were adopted for prognostic evaluation.

RESULTS

In total, 321 patients with segmentectomy and 239 subjects undergoing lobectomy with a median follow-up time of 48.2 months remained. All the patients had a R0 resection, and no 30-day or 90-day mortality was observed. The 5-year overall survival and disease-free survival were 99.0% and 96.6% for patients undergoing segmentectomy. No significant survival differences existed between segmentectomy and lobectomy after adjusting other factors (disease-free survival, DFS: HR = 1.20, 95%CI: 0.49-2.99, P = 0.688; overall survival, OS: HR = 1.09, 95%CI: 0.30-3.95, P = 0.892). After propensity score matching, patients with segmentectomy (n = 128) had a similar OS (P = 0.870) and DFS (P = 0.900) with those receiving lobectomy (n = 128). To further evaluate the outcomes of segmentectomy for deep lung cancer, 557 peripheral lung cancer patients who underwent segmentectomy at the same period were taken as the reference. As expected, segmentectomy for deep lesions achieved equivalent OS (P = 0.610) and DFS (P = 0.580) with the peripheral lesions.

CONCLUSIONS

Segmentectomy could achieve comparable long-term outcomes with lobectomy for deep cT1a-bN0M0 NSCLC with careful preoperative design and 3D navigation.

Segmentectomy versus lobectomy for small-sized pure solid non-small cell lung cancer

BACKGROUND

Segmentectomy has been recommended for ground glass opacity (GGO)-dominant small-sized non-small cell lung cancer (NSCLC) or those with GGO component. Pure solid NSCLC is a special sub-type and has an inferior prognosis. Whether segmentectomy could achieve comparable long-term outcomes with lobectomy for pure solid small-sized NSCLC remained controversial. This study aimed to compare the prognosis of segmentectomy and lobectomy for pure solid NSCLC.

METHODS

NSCLC patients with a pure solid nodule (≤2 cm) who received segmentectomy or lobectomy between January 2010 and June 2019 were retrospectively screened. Log-rank test, univariable, and multivariable Cox regression analyses were used for prognostic comparison. Further, the propensity score matching analysis was adopted to yield a matched cohort.

RESULTS

After screening, 344 pure solid NSCLC patients with a median follow-up time of 56 months were reserved. Among them, 98 patients underwent segmentectomy and the other 246 subjects received lobectomy. The lobectomy group had a larger tumor size, a higher rate of lymph node metastasis than the segmentectomy arm. Generally, patients with segmentectomy had a better disease-free survival (DFS) (p = 0.011) and overall survival (OS) (p = 0.028) than those with lobectomy. However, the multivariable Cox regression analysis indicated that no significant survival difference existed between segmentectomy and lobectomy after adjusting the potential confounding factors (DFS: hazard ratio [HR], 0.72; 95% confidence interval [CI], 0.30-1.77, p = 0.476; OS: HR, 0.36; 95% CI, 0.08-1.59, p = 0.178). Consistently, in the propensity score matched cohort, segmentectomy (n = 74) yielded similar DFS (p = 0.960) and OS (p = 0.320) with lobectomy (n = 74).

CONCLUSIONS

Segmentectomy could achieve comparable oncological outcomes with lobectomy for pure solid small-sized NSCLC.

A guide for managing patients with stage I NSCLC: deciding between lobectomy, segmentectomy, wedge, SBRT and ablation-part 2: systematic review of evidence regarding resection extent in generally healthy patients

Background

Clinical decision-making for patients with stage I lung cancer is complex. It involves multiple options (lobectomy, segmentectomy, wedge, stereotactic body radiotherapy, 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 generally healthy patients is the focus of this paper. Evidence was abstracted from randomized trials and non-randomized comparisons with at least some 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 healthy patients there is no short-term benefit to sublobar resection vs. lobectomy in randomized and non-randomized comparisons. A detriment in long-term outcomes is demonstrated by adjusted non-randomized comparisons, more marked for wedge than segmentectomy. Quality-of-life data is confounded by the use of video-assisted approaches; evidence suggests the approach has more impact than the resection extent. Differences in pulmonary function tests by resection extent are not clinically meaningful in healthy patients, especially for multi-segmentectomy vs. lobectomy. The margin distance is associated with the risk of recurrence.

Conclusions

A systematic, comprehensive summary of evidence regarding resection extent in healthy patients with attention to aspects of applicability, uncertainty and effect modifiers provides a foundation on which to build a framework for individualized clinical decision-making.

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.

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.

A localization-independent approach for invisible and impalpable ground-glass opacity nodules detection in an in vitro lung specimen: two case reports

A growing number of ground-glass opacity (GGO) nodules are screened out in lungs. Small GGOs are frequently neither visible nor palpable, thus undetectable during operation. Various nodule localization techniques have been developed to facilitate the intraoperative detection of GGO nodules; however, general localization techniques are infeasible or inappropriate in some cases. The detection of small GGO is a great challenge, even within a surgical specimen in the absence of preoperative localization. A localization-independent approach for GGO detection is urgently needed. Herein, we report two cases with invisible and impalpable small GGO which were not appropriate for preoperative localization. The lesions were anatomically resected under the guidance of three-dimensional (3D) reconstruction and got an adequate margin distance. A vessel (artery, vein, or bronchus) which had advanced into or immediately adjacent to the nodule was assigned as a reference vessel. By dissecting and tracing the reference vessel from proximal to distal, the GGO lesions were successfully detected in the surgical specimens, to the eventual obtainment of an accurate pathological diagnosis. Via the two case reports, we introduced an easily handled approach, namely dissecting and tracing a reference vessel, for GGO detection. The novel approach was first described. Combined with precise anatomical segmentectomy guided by 3D reconstruction, it provides an alternative scheme for GGO resection with no need for preoperative localization.

Lymph node metastasis and predictive factors in clinical stage IA squamous cell carcinoma of the lung based on radiological findings

OBJECTIVES

We aimed to clarify the incidence of lymph node (LN) metastasis and its predictive factors in clinical stage IA squamous cell carcinoma (SqCC) based on radiological classification to provide surgical indications for segmentectomy.

METHODS

We retrospectively reviewed 192 patients with clinical stage IA SqCC who underwent complete resection with lobectomy and LN dissection at our institution between 2003 and 2019. To evaluate the incidence of LN metastasis from the perspective of indications for segmentectomy, we classified them into outer and inner groups based on the location of the tumor in the radiological findings.

RESULTS

Regarding tumor location, 123 patients had tumors in the outer location and 69 patients had tumors in the inner location. The incidence of LN metastasis was 6% in clinical stage IA SqCC, which included 6% in the outer location and 7% in the inner location (p = 0.669). In the outer location, all LN metastases were in N1 (6%); whereas in the inner location, the incidence of N1 and N2 metastasis were 6% and 1%, respectively. Only tumors sized > 2.0 cm were found to be significantly associated with LN metastasis in clinical stage IA SqCC.

CONCLUSIONS

We demonstrated that the incidence of LN metastasis in clinical stage IA SqCC was comparable to that of the previously reported clinical stage IA NSCLC. The incidence of LN metastasis in the outer location was similar to that in the inner location. Tumor size was only a significant factor affecting LN metastasis in clinical stage IA SqCC.

Prognostic impact of tumour spread through air space in radiological subsolid and pure solid lung adenocarcinoma

OBJECTIVES

The aim of the study was to investigate the relationship between ground-glass opacity (GGO) and tumour spread through air space (STAS), as well as their joint influence on the prognosis of stage I lung adenocarcinoma.

METHODS

A total of 620 consecutive patients with surgically resected lung adenocarcinoma between January 2011 and December 2012 were reviewed retrospectively. The relevance of STAS and GGO was analysed by logistic regression, and their prognostic significance was investigated via the Kaplan-Meier method and Cox regression models. Furthermore, to determine the magnitude of the prognostic impact of GGO and STAS, we respectively performed survival analysis in subgroups according to the presence of STAS and GGO.

RESULTS

Of all 620 cases, 26.7% were positive for STAS, and 32.9% had a GGO component. STAS was present in 10.8% of part-solid lesions and 34.9% of pure solid nodules (P < 0.001). Lepidic-predominant histologic subtype, GGO component and pathological T stage exhibited significant relevance to the presence of STAS. For the whole population, STAS and GGO component were each revealed as independent predictors for overall survival and recurrence-free survival (each with P < 0.001). Interestingly, in the GGO-present subgroup, STAS failed to significantly stratify prognosis. However, in the STAS-positive subgroup, the presence of a GGO component was independently associated with favourable oncological results.

CONCLUSIONS

STAS is associated with a GGO component, and each factor was a significant predictor for the prognosis of stage I lung adenocarcinoma. Moreover, the favourable prognostic impact of a GGO component was greater than the adverse prognostic influence of STAS, indicating that GGO is a more reliable prognostic predictor in stage I lung adenocarcinoma.

Segmentectomy or lobectomy for early-stage non-small-cell lung cancer: a systematic review and meta-analysis

OBJECTIVES

The role of segmentectomy in early-stage non-small-cell lung cancer (NSCLC) remains a matter of debate. We performed a meta-analysis to evaluate the oncological outcomes following segmentectomy versus lobectomy for stage I, stage IA only and stage IA <2 cm only.

METHODS

We systematically searched the literature for articles reporting on overall survival (OS), cancer-specific survival (CSS) or recurrence-free survival (RFS). The hazard ratios (HRs) were retrieved and pooled using an inverse variance-weighted approach.

RESULTS

Twenty-eight studies were included in the analysis. In stage I, segmentectomy was found to be inferior to lobectomy for all 3 outcomes with HR: 1.25 (P = 0.01) for OS, 1.59 (P = 0.02) for CSS and 1.40 (P < 0.001) for RFS. In stage IA, the differences were significant for OS and CSS, though not for RFS with HR: 1.31 (P = 0.04), 1.56 (P = 0.02) and 1.22 (P = 0.11), respectively. In stage IA <2 cm, no significant differences were found between segmentectomy and lobectomy with HR: 1.13 (P = 0.37) for OS, 1.02 (P = 0.95) for CSS and 1.24 (P = 0.11) for RFS.

CONCLUSIONS

For stages I and IA, lobectomy showed superior results whereas for tumours <2 cm, our study did not find significant differences in oncological outcomes between both groups. These results suggest that segmentectomy might be a valuable alternative to lobectomy for NSCLC in tumours <2 cm.

The learning curve for uniportal video-assisted thoracoscopic anatomical segmentectomy

OBJECTIVES

The aim of this study is to evaluate the time course and caseload required to achieve proficiency by plotting the learning curve of uniportal thoracoscopic segmentectomy.

METHODS

We retrospectively analyzed the first 238 and 159 cases of uniportal thoracoscopic segmentectomy performed by two surgeons (A and B). The learning curves were assessed using cumulative sum analysis. Perioperative outcomes were evaluated as the learning curve developed. Two subtypes of this surgical approach, simple and complex segmentectomy, were separately analyzed.

RESULTS

Based on the learning curve, the inflection points occurred at 64 and 90 cases for surgeon A, 71 and 100 cases for surgeon B. Significantly longer operative time (p = .013), length of stay (p = .002), and drainage duration (p = .039) were observed between phase I and phase II compared to phase III for surgeon A. Operative times (p = .001) were significantly reduced for surgeon B. Furthermore, 26-28 and 52-56 cases were necessary to master the simple and complex segmentectomy, respectively.

CONCLUSIONS

A total 64-71 cases were required to master uniportal thoracoscopic segmentectomy and 90-100 cases were necessary to achieve proficiency.

Robotic Surgery and Anatomic Segmentectomy: An Analysis of Trends, Patient Selection, and Outcomes

BACKGROUND

It is unclear whetherrobotic segmentectomies are advantageous. We describe our experience with the robot, comparing patient populations and outcomes with videoscopic thoracic surgery (VATS) and open resection.

METHODS

Patients who received anatomic segmentectomy from 2004-2019 were reviewed. Resection methods were categorized as robotic, VATS, or open. Segmentectomies were categorized as simple or complex. Baseline characteristics and perioperative outcomes were analyzed from 2015-2019 due to implementation of ERAS protocol.

RESULTS

Since 2004, there has been an increase in segmentectomies, including robotic and complex segmentectomies. There were 222 segmentectomies from 2015-2019, of which 77(35%) were robotic, 40(18%) VATS, and 105(47%) open. Complex segmentectomies were higher in the robotic group compared to VATS and open (45% vs. 15% vs. 22%; p<0.001), operative time for robotic resections were also longer compared to VATS and open (205 vs. 147 vs. 147 minutes; p<0.001), but had lower blood loss (50 vs. 75 vs. 100 ml; p<0.001), shorter chest tube days (2 vs. 2 vs. 3 days; p=0.004) and length of stay (3 vs. 3 vs. 4 days; p<0.001). Perioperative mortality was low in all groups. No robotic segmentectomy converted to open compared to 7.5% for VATS (p=0.038). Prolonged air leak was lower for robotic compared to open (4% vs. 13%; p=0.038).

CONCLUSIONS

Robotic segmentectomy has increased in our institution, with concurrent rise in atypical segmentectomies. Despite performing more complex procedures, there were no conversions, and low perioperative morbidity and mortality. Our results suggest that the robotic platform can facilitate performance of complex anatomic segmentectomies.

A bibliometric analysis of segmentectomy versus lobectomy for non-small cell lung cancer research (1992-2019)

BACKGROUND

This study intends to create a series of scientific maps to quantitatively estimate hot spots and emerging trends in segmentectomy versus lobectomy for non-small cell lung cancer (NSCLC) research with bibliometric methods.

METHODS

Articles published on segmentectomy versus lobectomy for NSCLC were extracted from the Web of Science Core Collection (WoSCC). Extracted information was analyzed quantitatively using bibliometric analysis by CiteSpace to find hot spots and frontiers in this research area.

RESULTS

A total of 362 scientific articles on segmentectomy versus lobectomy for NSCLC were collected, and the annual publication rate increased over time from 1992 to 2019. The leading country and the leading institution were the United States and University of Pittsburgh, respectively. Furthermore, the most prolific researchers were, namely, James D. Luketich, Rodney J. Landreneau, Matthew J. Schuchert, Morihito Okada, and David O. Wilson. The analysis of keywords pointed out that carcinoma, bronchogenic carcinoma, limited resection, segmental resection, and morbidity are hot spots and lymph node dissection, minimally invasive surgery, impact, epidemiology, and high risk are research frontiers in this field.

CONCLUSION

Publications related to segmentectomy versus lobectomy for NSCLC have made great achievements based on bibliometric analysis in recent years. However, further research and global collaboration are still required. Finally, we find that segmentectomy for the treatment of NSCLC is receiving much more attention from researchers globally compared with lobectomy in this research area.

The Effect of Resection Margin Distance and Invasive Component Size on Recurrence After Sublobar Resection in Patients With Small (≤2 Cm) Lung Adenocarcinoma

BACKGROUND

When performing sublobar resection for lung cancer, the margin distance should exceed the tumor size. However, instead of total tumor size, the 8th edition TNM staging system has adopted the size of invasive component for the T stage. The aim of this study was to determine whether the prognosis was satisfactory when the resection margin distance was greater than the invasive component size instead of the total tumor size.

METHODS

From 2008 to 2017, 193 consecutive patients were diagnosed with lung adenocarcinoma (invasive component size ≤2 cm) and underwent sublobar resection. We analyzed risk factors for recurrence using clinicopathological factors including margin/invasive component ratio (resection margin distance/invasive component size).

RESULTS

Mean tumor size was 1.4 (±0.5) cm and the mean invasive component size was 0.8 cm (±0.5). In the multivariate analysis, neither resection margin distance (cm) nor margin/tumor ratio (resection margin distance/tumor size) was significant risk factors for recurrence. On the other hand, the margin/invasive component ratio (hazard ratio =0.035, p = 0.043) and the SUVmax (hazard ratio =1.993, p = 0.033) were significant risk factors for recurrence.

CONCLUSIONS

When sublobar resection is performed for small (invasive component size ≤2 cm) adenocarcinomas of the lung, the resection margin distance should be larger than the invasive component size. Sublobar resection is not an appropriate treatment for lung adenocarcinoma with high SUVmax.

[Progress in Survival Prognosis of Segmentectomy for Early-stage Non-small Cell Lung Cancer]

Surgery is currently the most appropriate treatment for early-stage non-small cell lung cancer (NSCLC). Increasing unilateral or bilateral multiple primary lung cancer being found, segmentectomy has attracted wide attention for its unique advantages in the treatment for such tumors. Ground glass opacity dominant early-stage NSCLC is associated with a good prognosis and can be cured by segmentectomy, however, the treatment of solid-dominant NSCLC remains controversial owing to the invasive nature. With the in-depth study on the lymph node metastasis pathway, radiological characteristics and molecular biology of NSCLC, a large part of solid nodules with certain characteristics can also be cured by segmentectomy. This paper reviews the research status and progress about the indication of segmentectomy.
.

Comparison of sublobar resection and lobectomy for patients with small (≤2cm) second primary non-small-cell lung cancer

BACKGROUND

This study aimed to investigate whether sublobar resection (SR) is equivalent to lobectomy for small (≤ 2 cm) second primary lung cancer (SPLC).

METHODS

We identified 834 patients with T1aN0M0 SPLC from the Surveillance, Epidemiology, and End Results (SEER) database during 2000-2016. Overall survival (OS) was compared between lobectomy and SR after propensity-score matching. A total of 228 patients with SPLC were identified from three institutions in China as the validation set.

RESULTS

SR was an independent risk factor for patients with 1 to 2 cm SPLC (SR vs Lob: hazard ratio [HR], 1.593; 95% confidence interval [CI], 1.186-2.141; P = .002) but not for patients with SPLC ≤ 1 cm (SR vs Lob: HR, 1.206; 95% CI, 0.790-1.841; P = .385). Subgroup analysis on the SEER data indicated that OS favored lobectomy compared with SR for contralateral SPLC ≤ 2 cm but not for ipsilateral ones (ipsilateral: P = .692; contralateral: P = .030). Our multi-institutional data also revealed that SR was equivalent to lobectomy for patients with ≤2 cm ipsilateral SPLC.

CONCLUSIONS

SR is equivalent to lobectomy for SPLC ≤ 1 cm but not for SPLC > 1 to 2 cm. SR might be recommended for patients with ipsilateral small SPLC considering the difficulty in reoperations.

Procedure-specific prognostic impact of micropapillary subtype may guide resection strategy in small-sized lung adenocarcinomas: a multicenter study

Background:

Limited resection has gradually become an acceptable treatment for lung adenocarcinomas (ADCs) presenting as ground-glass nodules (GGNs). However, its role in lung ADCs presenting as pure solid nodules (PSN) remains unclear. In this study, we aimed to identify potential candidates for limited resection in lung ADCs presenting as PSN.

Methods:

We retrospectively reviewed 772 patients from seven hospitals with lung ADCs ⩽2 cm, presenting as PSN on computed tomography scans, who had undergone surgery between 2009 and 2013. Histological subtypes were listed in 5% increments. To investigate the value of histological subtypes in surgical decision making, five pathologists prospectively evaluated the feasibility of identifying histological subtypes using frozen section (FS) in two cohorts.

Results:

The percentage of micropapillary (MIP) subtype had a striking impact on recurrence-free survival (RFS) and overall survival (OS) for lung ADCs ⩽2 cm presenting as PSNs. In multivariable Cox analysis, segmentectomy was significantly associated with worse RFS and OS in patients with MIP >5% than lobectomy, but not in those with MIP ⩽5%. With wedge resection, worse RFS and OS were observed in patients with MIP >5% and those with MIP ⩽5% than lobectomy. The sensitivity and specificity for detecting MIP by FS were 74.2% and 85.6%, respectively, with substantial inter-rater agreement.

Conclusion:

Segmentectomy and lobectomy had similar oncological outcomes in patients with lung ADCs ⩽2 cm presenting as PSN with MIP ⩽5%. Randomized trials are necessary to validate the feasibility of intraoperative FS to choose candidates for 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.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Comparing Segmentectomy and Lobectomy for Clinical Stage IA Solid-dominant Lung Cancer Measuring 2.1 to 3 cm

INTRODUCTION

We aimed to determine the feasibility of segmentectomy for radiologically solid-dominant clinical stage IA lung cancer measuring 2.1 to 3 cm (whole tumor size).

PATIENTS AND METHODS

Data from 197 patients with radiologically solid-dominant clinical stage IA lung cancer measuring 2.1 to 3 cm who underwent lobectomy (n = 154) or segmentectomy (n = 43) were retrospectively analyzed. Recurrence-free survival (RFS) and overall survival (OS) at 5 years were assessed. Finally, propensity score matching was performed by age, gender, radiologic whole tumor size, consolidation to maximum tumor ratio, tumor location, maximum standardized uptake value, and preoperative forced expiratory volume in 1 second (FEV1) and vital capacity (VC).

RESULTS

Only 2 (4.7%) patients in the segmentectomy group were converted to lobectomy because of lymph node metastasis or inadequate surgical margins. Postoperative reductions in VC and FEV1 at 12 months were significantly less in the segmentectomy group (VC, 7.4%; FEV1, 6.9%) than in the lobectomy group (VC, 17.6%; FEV1, 14.4%). RFS was comparable between patients who underwent lobectomy and segmentectomy in both the unmatched (73.4% and 82.7%, respectively; P = .30) and the 37 propensity-matched (79.5% and 80.1%, respectively) patients. Similarly, OS was comparable between patients who underwent lobectomy and segmentectomy in the unmatched (80.0% and 90.6%, respectively; P = .42) and matched (82.9% and 89.3%, respectively) patients.

CONCLUSIONS

Segmentectomy can be feasible in patients with radiologically solid-dominant clinical stage IA lung cancers measuring 2.1 to 3 cm when patients are appropriately selected.

Diagnosis and treatment of early and locally advanced non-small-cell lung cancer: The 2019 AIOM (Italian Association of Medical Oncology) clinical practice guidelines

The Italian Association of Medical Oncology (AIOM) has developed clinical practice guidelines for the diagnosis and treatment of patients with early and locally advanced non-small cell lung cancer. In the current paper a panel of AIOM experts in the field of thoracic malignancies discussed these topics, analyzing available scientific evidences, with the final aim of providing a summary of clinical recommendations, which may guide physicians in their current practice.

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

Background

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

Methods

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

Results

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

Conclusions

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

Key points

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

External validation of the eighth edition of the TNM classification for lung cancer in 3,611 surgically treated patients at a single institution

BACKGROUND

A new revision of the tumor, node, metastasis (TNM) classification for lung cancer has been proposed by the International Association for the Study of Lung Cancer (IASLC), but external validation for it is required. This study aimed to evaluate stage groupings in the 8th edition of the TNM classification in an independent Chinese cohort.

METHODS

We retrospectively analyzed 3,611 patients who were diagnosed as stage I to IV non-small cell lung cancer (NSCLC) and who received surgical treatment at our institute in China between October 2009 and August 2017. Long-rank tests were used to compare survival between two adjacent stage groups.

RESULTS

Based on the 8th edition of the TNM classification, differences between every 2 adjacent stage groups were found to be significant except between Ia1 and Ia2 (P=0.062), and between IIIc and IVa (P=0.063). Significant differences were found between every 2 adjacent categories stratified by the T and N descriptors. Additionally, significant differences were found between M0 and M1a (P<0.001), while no significant difference was observed between M1a and M1b (P=0.092).

CONCLUSIONS

Our study provides an external validation of the stage groupings in the 8th edition of the TNM staging system in surgically treated Chinese patients with NSCLC.

Meta-analysis of segmentectomy versus lobectomy for radiologically pure solid or solid-dominant stage IA non-small cell lung cancer

OBJECTIVE

Whether segmentectomy can be used to treat radiologically determined pure solid or solid-dominant lung cancer remains controversial owing to the invasive pathologic characteristics of these tumors despite their small size. This meta-analysis compared the oncologic outcomes after lobectomy and segmentectomy regarding relapse-free survival (RFS) and overall survival (OS) in patients with radiologically determined pure solid or solid-dominant clinical stage IA non-small cell lung cancer (NSCLC).

METHODS

A literature search was performed in the MEDLINE, EMBASE, and Cochrane Central databases for information from the date of database inception to March 2019. Studies were selected according to predefined eligibility criteria. The hazard ratio (HR) and associated 95% confidence interval (CI) were extracted or calculated as the outcome measure for data combining.

RESULTS

Seven eligible studies published between 2014 and 2018 enrolling 1428 patients were included in the current meta-analysis. Compared with lobectomy, segmentectomy had a significant benefit on the RFS of radiologically determined pure solid or solid-dominant clinical stage IA NSCLC patients (combined HR: 1.46; 95% CI, 1.05-2.03; P = 0.024) and there were no significant differences on the OS of these patients (HR: 1.52; 95% CI, 0.95-2.43; P = 0.08).

CONCLUSIONS

Segmentectomy leads to lower survival than lobectomy for clinical stage IA NSCLC patients with radiologically determined pure solid or solid-dominant tumors. Moreover, applying lobectomy to clinical stage IA NSCLC patients with radiologically determined pure solid or solid-dominant tumors (≤2 cm) could lead to an even bigger survival advantage. However, there are some limitations in the present study, and more evidence is needed to support the conclusion.

Propensity-Matched Analysis Comparing Survival After Sublobar Resection and Lobectomy for cT1N0 Lung Adenocarcinoma

BACKGROUND

The optimal surgical method for cT1N0 lung adenocarcinoma remains controversial.

OBJECTIVE

The aim of this study was to evaluate the differences in clinical outcomes of sublobar resection and lobectomy for cT1N0 lung adenocarcinoma patients.

METHODS

We included 1035 consecutive patients with cT1N0 lung adenocarcinoma who underwent surgery at our institute from January 2011 to December 2016. The surgical approach, either sublobar resection or lobectomy, was determined at the discretion of each surgeon. A propensity-matched analysis incorporating total tumor diameter, solid component diameter, consolidation-to-tumor (C/T) ratio, and performance status was used to compare the clinical outcomes of the sublobar resection and lobectomy groups.

RESULTS

Sublobar resection and lobectomy were performed for 604 (58.4%; wedge resection/segmentectomy: 470/134) and 431 (41.6%) patients, respectively. Patients in the sublobar resection group had smaller total tumor diameters, smaller solid component diameters, lower C/T ratios, and better performance status. More lymph nodes were dissected in the lobectomy group. Patients in the sublobar resection group had better perioperative outcomes. A multivariable analysis revealed that the solid component diameter and serum carcinoembryonic antigen level are independent risk factors for tumor recurrence. After propensity matching, 284 paired patients in each group were included. No differences in overall survival (OS; p = 0.424) or disease-free survival (DFS; p = 0.296) were noted between the two matched groups.

CONCLUSIONS

Sublobar resection is not inferior to lobectomy regarding both DFS and OS for cT1N0 lung adenocarcinoma patients. Sublobar resection may be a feasible surgical method for cT1N0 lung adenocarcinoma.

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

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

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

Background

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

Methods

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

Results

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

Conclusions

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

[A Review on Comparison of Lobectomy and Segmentectomy in the Treatment of Early Stage Non-small Cell Lung Cancer]

Lung cancer is a worldwide malignancy with high morbidity and mortality in the world. With the application of low-dose spiral computed tomography in the screening and diagnosis of lung cancer, more lung cancers are detected at an early stage and cured by surgical treatment. Anatomical lobectomy has long been the standard procedure for the treatment of early stage non-small cell lung cancer. However, whether intentional segmentectomy can be more used remains controversial. And this paper focuses on the question.
.

Postoperative Recurrence and Survival After Segmentectomy for Clinical Stage 0 or IA Lung Cancer

BACKGROUND

Although radical segmentectomy is an accepted treatment option for small-sized lung cancer, the outcomes remain unclear. The present study aimed to elucidate recurrence patterns and to identify predictors of time to recurrence after intentional segmentectomy for early lung cancer.

PATIENTS AND METHODS

Prospectively collected data of 166 patients who could tolerate lobectomy and underwent intentional segmentectomy for clinical stage 0 or IA non-small-cell lung cancer between 2007 and 2016 were retrospectively analyzed. Surgical indication for intentional segmentectomy was clinical stage 0 or IA ground glass opacity-dominant tumor ≤ 3 cm or solid-dominant tumor ≤ 2 cm on high-resolution computed tomography.

RESULTS

The median follow-up duration was 48.8 months, during which 6 (3.6%) patients developed recurrences. The 5-year recurrence-free survival and 5-year overall survival rates were 93.1% (95% confidence interval [CI], 87.9%-96.1%) and 93.5% (95% CI, 87.7%-96.4%), respectively. Two (1.2%) patients who developed local-only recurrences subsequently underwent completion lobectomy; no cancer-related deaths were seen for these patients. In multivariable analysis, consolidation to maximum tumor diameter (C/T) ratio (hazard ratio, 1.07; 95% CI, 1.01-1.22; P = .02) was an independent predictive factor for time to recurrence. All 6 patients with recurrence had a tumor with a C/T ratio of 86% or higher.

CONCLUSIONS

Based on these findings, favorable survival is expected after intentional segmentectomy for selected patients with clinical stage 0 or IA non-small-cell lung cancer. Patients with a higher C/T ratio tumor appear to be at higher risk of recurrence after intentional segmentectomy.

Near-infrared mapping with indocyanine green is associated with an increase in oncological margin length in minimally invasive segmentectomy

BACKGROUND

Near-infrared fluorescence mapping with indocyanine green dye is a recent advancement in minimally invasive segmental resection. This technique has not yet been reproduced, validated, or objectively evaluated in a large prospective case series. We hypothesized that near-infrared fluorescence mapping is associated with an increased oncological margin distance from the tumor, over and above the best judgment of the surgeon.

METHODS

This was a phase 2 prospective cohort trial in patients who are undergoing robotic segmentectomy for lung tumors <3 cm. The predicted intersegmental plane was first identified by consensus between 2 thoracic surgeons. The true plane was then mapped by indocyanine green injection. A 7-item binary rating scale was used for the evaluation of feasibility, reproducibility, and added oncological margin distance from the tumor. The margin distance between the tumor and the true plane was compared with the margin distance between the tumor and the predicted plane.

RESULTS

Fifty-three patients were enrolled between September 2016 and May 2018 and 31 patients (58.4%) received the planned operation with indocyanine green mapping. In 74.2% of cases (23 out of 31), a score of 7 out of 7 was achieved, indicating the true intersegmental plane identified by indocyanine green mapping was different than the predicted plane identified by the surgeon. In 61.2% (19 out of 31) of those cases, the mean additional margin distance from the tumor to the staple line attributable to the indocyanine green mapping was 2.41 ± 1.6 cm. The overall complication rate was 18.5% (10 out of 53) and there were no deaths.

CONCLUSIONS

Near-infrared fluorescence mapping in robotic segmentectomy is associated with increased oncological margin length, over and above the best judgment of the surgeon, in the majority cases where it is used.

Outcomes and predictive factors for pathological node-positive in radiographically pure-solid, small-sized lung adenocarcinoma

OBJECTIVES

The indication of limited resection for radiographically pure-solid, small-sized lung adenocarcinoma is controversial. This study aimed to reveal the long-term outcome of standard surgical treatment and determine the predictive factors for pathological lymph node metastasis in optimal candidates undergoing limited surgical resection for pure-solid, small-sized lung adenocarcinoma.

METHODS

The medical records of 107 consecutive patients were retrospectively reviewed at our hospital between December 2002 and December 2013. Inclusion criteria were histopathological diagnosis of lung adenocarcinoma, radiographically pure-solid tumor, ≤ 2 cm tumor size measured using thin-section computed tomography, clinical N0M0, patients who underwent lobectomy with systematic or lobe-specific lymph node dissection, and R0 resection. Overall and disease-free survival curves were calculated using the Kaplan-Meier method. Clinicopathological factors predicting pathological node-positive metastasis were identified by univariate and multivariate analysis.

RESULTS

The 5-year overall and disease-free survival rates were 91.4% and 87.3%, respectively. Multivariate analysis demonstrated maximum standardized uptake value > 5 as the independent predictor of pathological node-positive metastasis (odds ratio 3.81; 95% confidence interval 1.25-12.3; p = 0.02). In all patients, the pathological node-positive rate was 16.7%; in patients who had a maximum standardized uptake value of ≤ 5, the rate was 7.9%.

CONCLUSION

The long-term outcome of standard surgical treatment was favorable. Maximum standardized uptake value was a significant predictor of pathological node-positive metastasis; however, diagnostic accuracy was not favorable. Therefore, the selection of optimal candidates is difficult, and limited surgical resection may not be applicable in pure-solid, small-sized lung adenocarcinoma.

Lobectomy Is Associated with Better Outcomes than Sublobar Resection in Spread through Air Spaces (STAS)-Positive T1 Lung Adenocarcinoma: A Propensity Score-Matched Analysis

INTRODUCTION

Spread through air spaces (STAS) is a form of invasion wherein tumor cells extend beyond the tumor edge within the lung parenchyma. In lung adenocarcinoma (ADC), we investigated the (1) association between STAS and procedure-specific outcomes (sublobar resection and lobectomy), (2) effect of surgical margin-to-tumor diameter ratio in STAS-positive patients, and (3) potential utility of frozen sections (FSs) for detecting STAS intraoperatively.

METHODS

We investigated 1497 patients who underwent lobectomy (n = 970) or sublobar resection (n = 527) for T1N0M0 lung ADC after propensity score matching. Outcomes were analyzed by using a competing risks approach. The effect of margin-to-tumor ratio on recurrence pattern (locoregional and distant) was investigated in patients who underwent sublobar resection. Five pathologists evaluated the feasibility of intraoperatively identifying STAS by using FSs (sensitivity, specificity, and interrater reliability).

RESULTS

On multivariable analysis after propensity score matching (349 pairs/procedure), sublobar resection was significantly associated with recurrence (subhazard ratio = 2.84 [p < 0.001]) and lung cancer-specific death (subhazard ratio = 2.63 [p = 0.021]) in patients with STAS but not in those without STAS. Patients with STAS who underwent sublobar resection had a higher risk of locoregional recurrence regardless of margin-to-tumor ratio (for a margin-to-tumor ratio of ≥1 versus <1, the 5-year cumulative incidence of recurrence rates were 16% and 25%, respectively); among patients without STAS, locoregional recurrences occurred in patients with margin-to-tumor ratio lower than 1 (a 5-year cumulative incidence of recurrence rate of 7%). The sensitivity and specificity for detecting STAS by use of FSs were 71% and 92%, with substantial interrater reliability (Gwet's AC1, 0.67).

CONCLUSIONS

In patients with T1 lung ADC with STAS, lobectomy was associated with better outcomes than sublobar resection was. Pathologists can recognize STAS on FSs.

Segmentectomy Is Equivalent to Lobectomy in Hypermetabolic Clinical Stage IA Lung Adenocarcinomas

BACKGROUND

Recent studies have suggested that lobectomy and segmentectomy hold equivalent oncologic outcomes, particularly for small, peripheral, subsolid nodules. However, for hypermetabolic nodules that are frequently associated with high rates of nodal disease, recurrence, or mortality, the optimum oncologic procedure was not assessed. We hypothesize that for hypermetabolic, cT1 N0 adenocarcinoma, lobectomy and segmentectomy are associated with comparable outcomes.

METHODS

A prospectively collected database was queried for patients with clinical stage IA lung adenocarcinoma who underwent lobectomy or segmentectomy (2000 to 2016) for hypermetabolic tumors (maximum standard uptake value [SUVmax] ≥ 3g/dL). To obtain balanced groups of patients, a propensity matching analysis was done.

RESULTS

A total of 414 patients had hypermetabolic tumors and underwent lobectomy or segmentectomy. Patients were propensity matched (4:1) (lobectomy: n = 156, segmentectomy: n = 46). Patients in the lobectomy group had a higher rate of pathologic nodal upstaging (17% versus 7%, p = 0.085) and a higher pathologic upstaging rate (38% versus 26%, p = 0.143) than the segmentectomy group. In addition, the lobectomy group had a higher number of resected lymph nodes than the segmentectomy group (median lymph nodes resected: 14 versus 7, p < 0.001). No differences were found in in 5-year recurrence-free survival (RFS; 72% versus 69%, p = 0.679) or in 5-year cancer-specific survival (CSS; 92% versus 83%, p = 0.557) between patients who underwent lobectomy or segmentectomy, respectively.

CONCLUSIONS

Our data show that lobectomy and segmentectomy are comparable oncologic procedures for patients with carefully staged cT1 N0 lung adenocarcinoma with hypermetabolic tumors (SUVmax ≥ 3g/dL). Although lobectomy was associated with a more thorough lymph node dissection, this did not translate into a higher rate of RFS or CSS compared with segmentectomy.

Feasibility of transumbilical anatomic "Lung" segmentectomy in a canine model

BACKGROUND

Transumbilical approach has been shown to be feasible to perform lung wedge resection and anatomic lobectomy. This study uses a canine model to assess the feasibility of transumbilical segmentectomy.

METHODS

Transumbilical segmentectomy was performed in 10 beagle dogs using a 3-cm umbilical incision combined with a 2.5-cm diaphragmatic incision. We evaluated the surgical outcomes, operative complications, physiologic changes, hemodynamic changes, and inflammatory changes of the procedures.

RESULTS

Transumbilical segmentectomy was successfully completed in eight of ten animals. There was one mortality complication related to lung injury causing hemodynamic collapse. Another animal required conventional thoracotomy to complete the surgery due to limited working space. There were no notable events in the postoperative period for all eight dogs that completed the segmentectomy via the transumbilical approach.

CONCLUSION

This animal study demonstrates that the pulmonary segmentectomy can be performed with current standard endoscopic instruments via a single transumbilical incision.We believe that advancing surgical innovation and good collaboration between multi-disciplinary research teams will further establish clearer roles for transumbilical segmentectomy in thoracic surgery.

Prognosis After Sublobar Resection of Small-sized Non-small Cell Lung Cancer with Visceral Pleural or Lymphovascular Invasion

BACKGROUND

Although standard surgical treatment of stage I non-small cell lung cancer (NSCLC) is lobectomy, sublobar resection may be elected for small-sized (≤2 cm) peripheral tumors. Our aim was examine the need for completion lobectomy in the event of confirmed pleural or lymphovascular invasion after sublobar resection of NSCLC.

METHODS

A total of 271 consecutive patients undergoing curative resection of stage I NSCLC ≤2 cm were reviewed retrospectively, analyzing clinicopathologic findings and survival times of those with invasion-positive (visceral pleural or lymphovascular invasion) or invasion-negative (neither visceral pleural nor lymphovascular invasion) tumors by surgical approach (sublobar resection vs lobectomy).

RESULTS

Aside from age and pulmonary function, clinicopathologic characteristics of the patient subsets did not differ significantly, nor did 5-year recurrence-free survival rates of surgical subsets (sublobar resection vs lobectomy) in respective tumor groups (invasion-positive 78.9 vs 79.8%, p = 0.928; invasion-negative 80.2 vs 85.4%, p = 0.505). In multivariate analysis, dissected lymph node count was the sole parameter significantly impacting recurrence of stage I invasion-positive NSCLC (hazard ratio = 0.914, 95% confidence interval 0.845-0.988; p = 0.023). Sublobar resection was not a risk factor for recurrence.

CONCLUSIONS

Survival rates for patients with small-sized (≤2 cm) NSCLC and visceral pleural or lymphovascular invasion did not differ significantly, whether sublobar resection or lobectomy was done. Hence, completion lobectomy is unnecessary in this setting.

Ground glass opacities: Imaging, pathology, and gene mutations

BACKGROUND

Lung cancer can be detected in its early stages with computed tomography (CT). Early lung adenocarcinoma often is displayed as ground glass opacity (GGO), an entity that has been well studied over the past decade. However, few studies have focused on the correlation between CT characteristics and pathologic subtype of GGO. We aimed to explore the correlation between CT characteristics, pathologic subtype, and gene mutation associated with GGO in an effort to aid in the treatment of lung adenocarcinoma.

METHODS

In this retrospective study, patients with GGO who underwent surgery in our institution between 2013 and 2016 were included. Patients were divided into 2 groups on the basis of CT characteristics: group 1, diameter <20 mm and solid component <50%; and group 2, diameter ≥20 mm or solid component ≥50%. Differences in pathologic subtype and gene mutation pattern between groups were compared using the χ² test. The correlation between pathologic subtype and epidermal growth factor receptor (EGFR) mutation was also tested using the χ² test.

RESULTS

A total of 1018 cases (408 in group 1, 610 in group 2) were included; of these, 544 were tested for the EGFR gene mutation. There was a significant difference in predominant subtype (P < .001) and all included subtypes (P = .044) between the groups. Of 59 cases with the pathologic subtype of micropapillary or solid, 57 were in group 2. The EGFR gene mutation rate was significantly higher in group 2 than group 1 (P < .001) and significantly correlated with pathologic subtype (P < .001); adenocarcinoma in situ was the lowest (31.4%) and papillary was the highest (85.7%). EGFR mutation subtype did not significantly differ between groups (P = .499).

CONCLUSIONS

CT characteristics of GGO significantly correlated with pathologic subtype and gene mutation rate. The EGFR mutation rate differed significantly among pathologic subtypes. GGOs with a diameter of <20 mm and with a solid component <50% seldom contain subtypes with poor prognosis (micropapillary and solid) and the EGFR mutation rate was significantly lower.

Appropriate lymphadenectomy significantly reduced recurrence after segmentectomy for patients with non-small cell lung cancer

Background

Segmentectomy has been widely used for small-sized non-small cell lung cancer (NSCLC). The objective of this study is to determine the impact of number of harvested lymph nodes (LNs) on survival for patients undergoing segmentectomy.

Methods

The clinicopathologic data of patients undergoing segmentectomy for NSCLC from July 2011 to December 2014 were retrospectively analyzed. Survival analysis was performed by Kaplan-Meier method and Cox regression analysis.

Results

A total of 259 patients with NSCLC were eligible for analysis. Patients with harvested LN ≥6 had higher frequency of nodal metastasis in pathologic examination (9.4% vs. 1.5%, P=0.005). The 3-year recurrence-free survival (RFS) of patients with harvested LN ≥6 (90.2%) was significantly higher than that of patients with harvested LN <6 (73.7%, log-rank P=0.038). Multivariable Cox analysis identified harvested LN ≥6 as an independent predictor for improved RFS [hazard ratio (HR) =0.35; 95% confidence interval (CI): 0.14-0.90; P=0.029]. There was no significant difference in RFS between patients with harvested LN station ≥3 and <3 (log-rank P=0.34).

Conclusions

The number of harvest LN ≥6 was independently associated with improved RFS for NSCLC patients undergoing segmentectomy, supporting the National Comprehensive Cancer Network (NCCN) guidelines of appropriate LN sampling.

Lobectomy versus Sublobar Resection in Non-Lepidic Small-Sized Non-Small Cell Lung Cancer

Background

Recently, many surgeons have chosen sublobar resection for the curative treatment of lung tumors with ground-glass opacity, which is a hallmark of lepidic lung cancer. The purpose of this study was to evaluate the oncological results of sublobar resection for non-lepidic lung cancer in comparison with lobectomy.

Methods

We conducted a retrospective chart review of 328 patients with clinical N0 non-small cell lung cancer sized ≤2 cm who underwent curative surgical resection from January 2009 to December 2014. The patients were classified on the basis of their lesions into non-lepidic and lepidic groups. The survival rates following lobectomy and sublobar resection were compared within each of these 2 groups.

Results

The non-lepidic group contained a total of 191 patients. The 5-year recurrence-free survival rate was not significantly different between patients who received sublobar resection or lobectomy in the non-lepidic group (80.1% vs. 79.2%, p=0.822) or in the lepidic group (100% vs. 97.4%, p=0.283). Multivariate analysis indicated that only lymphatic invasion was a significant risk factor for recurrence in the non-lepidic group. Sublobar resection was not a risk factor for recurrence in the non-lepidic group.

Conclusion

The oncological outcomes of sublobar resection and lobectomy in small-sized non-small cell lung cancer did not significantly differ according to histological type.

Restrictive ventilatory impairment is associated with poor outcome in patients with cT1aN0M0 peripheral squamous cell carcinoma of the lung

Background

Patients with squamous cell carcinoma (SqCC) of the lung sometimes have a comorbid pulmonary disease such as pulmonary emphysema or an interstitial lung disease (ILD), both of which negatively affect patient outcome. The aim of this study was to determine the outcome of patients in a multicenter database who underwent surgery for cT1aN0M0 peripheral SqCC lung cancer.

Methods

The medical records of a total of 228 eligible patients from seven institutions were reviewed to evaluate the impact of concomitant impaired pulmonary function and other clinicopathological factors on overall survival (OS) and relapse-free survival (RFS).

Results

Six patients with positive or unclear tumor margins were excluded. Of the 222 remaining study patients, 42 (18.9%) and 97 (43.7%) patients were found to have coexisting restrictive or obstructive ventilatory impairment, respectively. Over a median follow-up period of 30.6 months, the 5-year OS and RFS were 69.0% and 62.6%, respectively. By multivariate analysis, ILDs identified on high-resolution computed tomography (HRCT), pulmonary function test results indicating a restrictive ventilatory impairment, and wedge resection were found to be independent risk factors for poor OS. An increased level of serum squamous cell carcinoma antigen (SCC-Ag) (>1.5 ng/mL) and the same risk factors for poor OS were independent risk factors for recurrence. Among patients who underwent anatomical lung resection (lobectomy and segmentectomy, n=173), a restrictive ventilatory impairment was an independent risk factor for poor OS, and increased serum SCC-Ag level, ILDs on HRCT, and restrictive ventilatory impairment were independent risk factors for poor RFS by multivariate analysis. Factors such as visceral pleural invasion, and lymphatic or vascular invasion were not significantly associated with outcome.

Conclusions

A restrictive ventilatory impairment negatively affects the outcome of patients with cT1aN0M0 peripheral SqCC lung cancer.