Long-term outcomes of stage I NSCLC (≤3 cm) patients following segmentectomy are equivalent to lobectomy under analogous extent of lymph node removal: a PSM based analysis

Conditional Survival of Patients With Early-Stage Non-Small Cell Lung Cancer Who Undergo Lobectomy, Segmentectomy, or Wedge Resection Using the NCDB

BACKGROUND AND OBJECTIVES

Randomized clinical trials have shown that sub-lobar resection for clinical stage (cStage) IA non-small cell lung cancer (NSCLC) is non-inferior to lobar resection. We evaluated traditional and conditional survival differences between lobectomy, wedge resection, and segmentectomy in patients with cStage IA NSCLC.

METHODS

The National Cancer Database (2004-2019) was queried for patients with cStage IA (≤ 2 cm) NSCLC who underwent upfront lobectomy, segmentectomy, or wedge resection. Patients were stratified by extent of resection. Propensity-matched traditional (TSA) and conditional (CSA) survival analyses were performed. Propensity score included age, gender, histology, tumor grade, and Charlson-Deyo score. Number of lymph nodes (LN) harvested was also compared between groups.

RESULTS

There were 46 395 patients who met the inclusion criteria, of whom 32 599 (70.3%) received lobectomy, 11 181 (24.1%) wedge resection, and 2615 (5.6%) segmentectomy. Following propensity matching, all groups contained 2615 patients. In the TSA, segmentectomy (hazard ratio [HR]: 1.19, 95% confidence interval [CI]: 1.08-1.32) and wedge resection (HR: 1.41, CI: 1.28-1.56) were associated with worse 5-year survival. This remained significant in CSA at 3- and 5-years post-resection in patients who underwent segmentectomy (HR: 1.24, CI: 1.08-1.43 and HR: 1.23, CI: 1.02-1.49, respectively) and wedge resection (HR: 1.42, CI: 1.24-1.63 and HR: 1.33, CI: 1.11-1.59, respectively). Wedge resection and segmentectomy were associated with a lower number of harvested LN (median = 4 and 6, respectively) compared to lobectomy (8, p < 0.001).

CONCLUSION

Analysis of real-world data suggests that lobectomy is associated with improved traditional and conditional 5-year survival as well as LN harvest.

Segmentectomy vs. Lobectomy in stage IA non-small cell lung cancer: A systematic review and meta-analysis of perioperative and survival outcomes

While recent randomized controlled trials (RCT) have suggested superior overall survival (OS) outcomes with segmentectomy over lobectomy, questions remain regarding the comparability of these surgical procedures for treating early-stage non-small cell lung cancer (NSCLC). This systematic review and meta-analysis aimed to synthetize existing evidence and to compare the survival outcomes observed for stage IA NSCLC following segmentectomy or lobectomy. 40 studies (38 observational, 2 RCTs) encompassing 103,926 patients were analyzed. Primary outcomes included overall survival (OS), disease-free survival (DFS), local recurrences, harvested lymph nodes, postoperative morbidity, and length of hospital stay. Risk of bias was assessed using established tools, and evidence certainty was evaluated using GRADE. Non-RCTs showed an OS HR of 1.10 (95 % CI: 0.94-1.30, p = 0.24) with low certainty, contrasting with RCTs' HR of 0.82 (95 % CI: 0.66-1.02, p = 0.7) with moderate certainty. Local recurrences exhibited OR 1.40 (95 % CI: 0.94-2.08, p = 0.09) in non-RCTs with low certainty, and RR 1.61 (95 % CI: 1.12-2.31, p = 0.01) in RCTs with low certainty. Non-RCTs showed DFS HR 1.13 (95 % CI: 0.95-1.34, p = 0.18) with low certainty, while RCTs yielded HR 1.00 (95 % CI: 0.85-1.18, p = 0.97) with moderate certainty. Lobectomy resulted in more harvested lymph nodes. Postoperative morbidity and length of hospital stay did not differ significantly. While definitive evidence for OS, DFS, and postoperative outcomes differences was inconclusive, a potential increase in local recurrences following lobectomy was noted. Further well-designed studies are warranted to enhance evidence and inform clinical practice in stage I lung cancer surgery.

Development and external validation of a nomogram for predicting lymph node metastasis in 1-3 cm lung adenocarcinoma

Aim: This study aimed to investigate the risk factors for lymph node metastasis in 1-3 cm adenocarcinoma and develop a new nomogram to predict the probability of lymph node metastasis.Materials & methods: This study collected clinical data from 1656 patients for risk factor analysis and an additional 500 patients for external validation. The logistic regression analyses were employed for risk factor analysis. The least absolute shrinkage and selection operator regression was used to select variables, and important variables were used to construct the nomogram and an online calculator.Results: The nomogram for predicting lymph node metastasis comprises six variables: tumor size (mediastinal window), consolidation tumor ratio, tumor location, lymphadenopathy, preoperative serum carcinoembryonic antigen level and pathological grade. According to the predicted results, the risk of lymph node metastasis was divided into low-risk group and high-risk group. We confirmed the exceptional clinical efficacy of the model through multiple evaluation methods.Conclusion: The importance of intraoperative frozen section is increasing. We discussed the risk factors for lymph node metastasis and developed a nomogram to predict the probability of lymph node metastasis in 1-3 cm adenocarcinomas, which can guide lymph node resection strategies during surgery.

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.

Survival outcomes of segmentectomy and lobectomy for early stage non-small cell lung cancer: a systematic review and meta-analysis

BACKGROUND

The question of whether segmentectomy and lobectomy have similar survival outcomes for patients with early-stage non-small cell lung cancer (NSCLC) is a matter of debate.

METHODS

A cohort study and randomized controlled trial were included, comparing segmentectomy and lobectomy, by utilizing computerized access to the Pubmed, Web of Science, and Cochrane Library databases up until July 2022. The Cochrane Collaboration tool was used to evaluate the randomized controlled trials, while the Newcastle-Ottawa Scale (NOS) was used to evaluate the cohort studies. Sensitivity analyses were also carried out.

RESULTS

The analysis incorporated 17 literature studies, including one randomized controlled trial and 16 cohort studies, and was divided into a segmentectomy group (n = 2081) and a lobectomy group (n = 2395) based on the type of surgery the patient underwent. Each study was followed up from 27 months to 130.8 months after surgery. Over survival (OS): HR = 1.14, 95%CI(0.97,1.32), P = 0.10; disease-free survival (DFS): HR = 1.13, 95%CI(0.91,1.41), P = 0.27; recurrence-free survival (RFS): HR = 0.95, 95%CI(0.81,1.12), P = 0.54.

CONCLUSION

The results of the study suggest that the survival outcomes of the segmentectomy group were not inferior to that of the lobectomy group. Segmentectomy should therefore be considered as a treatment option for early stage NSCLC.

Sublobar Resection of Non-Small-Cell Lung Cancer: Wedge Resection vs. Segmentectomy

Lung cancer is the most common cause of cancer death. The mainstay treatment for non-small-cell lung cancer (NSCLC), particularly in the early stages, is surgical resection. Traditionally, lobectomy has been considered the gold-standard technique. Sublobar resection includes segmentectomy and wedge resection. Compared to lobectomy, these procedures have been viewed as a compromise procedure, reserved for those with poor cardiopulmonary function or who are poor surgical candidates for other reasons. However, with the advances in imaging and surgical techniques, the subject of sublobar resection as a curative treatment is being revisited. Many studies have now shown segmentectomy to be equivalent to lobectomy in patients with small (<2.0 cm), peripheral NSCLC. However, there is a mix of evidence when it comes to wedge resection and its suitability as a curative procedure. At this time, until more data can be found, segmentectomy should be considered before wedge resection for patients with early-stage NSCLC.

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.

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.

Systematic review and meta-analysis of segmentectomy vs. lobectomy for stage IA non-small cell lung cancer

Background

Whether segmentectomy is appropriate for stage IA non-small cell lung cancer (NSCLC), especially for stage IA NSCLC with a tumor size of 2-3 cm, remains controversial. Thus, we conducted this meta-analysis to compare segmentectomy and lobectomy for stage IA NSCLC with a tumor size of 2-3 cm and IA ≤2 cm NSCLC.

Methods

A systematic screening of online databases (PubMed, Embase, Web of Science, and Cochrane Library) was conducted regarding the terms of perioperative outcomes, overall survival (OS), recurrence-free survival (RFS), and disease-free survival (DFS). The inverse-variance and Mantel-Haenszel approaches were used to pool effect sizes for survival outcomes and perioperative outcomes.

Results

A total of 10 articles were included in the analysis. The perioperative morbidity [risk ratio (RR): 0.90, P=0.10], mortality (RR: 0.94, P=0.84), intraoperative blood loss [mean difference (MD): 3.07, P=0.86] and operative time (MD: 18.99, P=0.13) were comparable between the segmentectomy and lobectomy groups. The number of lymph nodes harvested was statistically less in segmentectomy than in lobectomy (MD: -5.71, P=0.02). In stage IA patients with a tumor size of 2-3 cm, lobectomy showed superior survival outcomes compared to segmentectomy, with a pooled hazard ratio (HR) of 1.39 (P=0.01) for OS and 1.38 (P=0.06) for RFS or DFS. In stage IA ≤2 cm, lobectomy and segmentectomy had comparable survival outcomes with pooled HRs of 1.18 (P=0.29) for OS and 1.18 (P=0.12) for RFS or DFS.

Conclusions

When a patient is in stage IA and the tumor size is less than 2 cm, segmentectomy should be performed. If the tumor size is between 2 and 3 cm, lobectomy is recommended.

Sublobar resection versus lobectomy in the treatment of synchronous multiple primary lung cancer

OBJECTIVE

Although synchronous multiple primary lung cancers (sMPLCs) are common in clinical practice, the choice of surgical modalities for the main lesion is still at the stage of exploration. This study is designed to analyze the prognosis of sMPLCs and single primary lung cancers with similar tumor stages and to explore whether sublobar resection has a similar prognosis as lobectomy for sMPLCs.

METHODS

One-hundred forty-one cases of sMPLCs were selected, including the following: 65 cases underwent lobectomy for main lesions, and 76 cases underwent sublobar resection for main lesions. One thousand one hundred forty-four cases of single primary lung cancer were matched at 1:1 by propensity score matching. Then, the patients with sMPLCs were divided into a lobectomy group and a sublobar group according to the first tumor stage. Ninety-eight cases of patients with sMPLCs were matched. The short-term perioperative effect, 5-year disease-free survival (DFS) rate, and 5-year overall survival (OS) rate between the two groups were compared.

RESULTS

There was no significant difference in OS between sMPLCs and single primary lung cancer after lobectomy (77.1% vs. 77.2%, P = 0.157) and sublobar resection (98.7% vs. 90.7%, P = 0.309). There was no significant difference in OS (86.7% vs. 83.9%, P = 0.482) or DFS (67.6 vs. 87.7%, P = 0.324) between the lobectomy group and sublobar group with sMPLCs. The sublobar resection group obtained a lower incidence of postoperative complications (40.8% vs. 16.3%, P = 0.007) and shorter postoperative hospital stay (11.22 vs. 9.27, P = 0.049).

CONCLUSION

The prognosis of patients with sMPLCs generally depends on the main tumor state, which has no statistical difference regardless of sublobar resection or lobectomy, and the perioperative period of sublobar resection is safer than that of lobectomy.

A Comparative Evaluation of Mediastinal Nodal SUVmax and Derived Ratios from 18F-FDG PET/CT Imaging to Predict Nodal Metastases in Non-Small Cell Lung Cancer

18F-FDG positron emission tomography with computed tomography (PET/CT) is a standard imaging modality for the nodal staging of non-small cell lung cancer (NSCLC). To improve the accuracy of pre-operative staging, we compare the staging accuracy of mediastinal lymph node (LN) standard uptake values (SUV) with four derived SUV ratios based on the SUV values of primary tumours (TR), the mediastinal blood pool (MR), liver (LR), and nodal size (SR). In 2015-2017, 53 patients (29 women and 24 men, mean age 67.4 years, range 53-87) receiving surgical resection have pre-operative evidence of mediastinal nodal involvement (cN2). Among these, 114 mediastinal nodes are resected and available for correlative PET/CT analysis. cN2 status accuracy is low, with only 32.5% of the cN2 cases confirmed pathologically. Using receiver operating characteristic (ROC) curve analyses, a SUVmax of N2 LN performs well in predicting the presence of N2 disease (AUC, 0.822). Based on the respective selected thresholds for each ROC curve, normalisation of LN SUVmax to that for mediastinum, liver and tumour improved sensitivities of LN SUVmax from 68% to 81.1-89.2% while maintaining acceptable specificity (68-70.1%). In conclusion, normalised SUV ratios (particularly LR) improve current pre-operative staging performance in detecting mediastinal nodal involvement.

Lobectomy Demonstrates Superior Survival Than Segmentectomy for High-Grade Non-Small Cell Lung Cancer: The National Cancer Database Analysis

BACKGROUND

Current recommendations for segmentectomy for non-small cell lung cancer (NSCLC) include size ≤2 cm, margins ≥ 2 cm, and no nodal involvement. This study further stratifies the selection criteria for segmentectomy using the National Cancer Database (NCDB).

METHODS

The NCDB was queried for patients with high-grade (poorly/undifferentiated) T1a/b peripheral NSCLC (tumor size ≤2 cm), who underwent either lobectomy or segmentectomy. Patients with pathologic node-positive disease or who received neoadjuvant/adjuvant treatments were excluded. Propensity score analysis was used to adjust for differences in pretreatment characteristics.

RESULTS

11 091 patients were included with 10 413 patients (93.9%) treated with lobectomy and 678 patients (6.1%) underwent segmentectomy. In a propensity matched pair analysis of 1282 patients, lobectomy showed significantly improved median survival of 88.48 months vs 68.30 months for segmentectomy, P = .004. On multivariate Cox regression, lobectomy was associated with significantly improved survival (hazard ratio (HR): .81, 95% CI .72-.92, P = .001). Subgroup analysis of propensity score matched patients with a Charlson-Deyo comorbidity score (CDCC) of 0 also demonstrated a trend of improved survival with lobectomy.

DISCUSSION

Lobectomy may confer significant survival advantage over segmentectomy for high-grade NSCLC (≤2 cm). More work is needed to further stratify various NSCLC histologies with their respective grades allowing more comprehensive selection criteria for segmentectomy.

National trends in the quality of segmentectomy for lung cancer

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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 of operative and postoperative characteristics and outcomes between thoracoscopic segmentectomy and lobectomy for non-small-cell lung cancer: a propensity score matching study from the Italian VATS Group Registry

OBJECTIVES

Only few studies compared the surgical morbidity and mortality of thoracoscopic segmentectomy versus lobectomy for non-small-cell lung cancer, in particular, by relating the segmental resections with the corresponding anatomical lobes.

METHODS

We enrolled a total of 7487 patients who underwent VATS lobectomy (7269) or segmentectomy (218) from January 2014 to July 2019. A propensity score matching approach was used to account for potential confounding factors between the 2 groups. After matching, 349 lobectomies and 208 segmentectomies were included in the analysis. We analysed the operative and postoperative outcomes of video-assisted anatomical segmentectomy compared with video-assisted lobectomy and, in details, the results of segmentectomy with its corresponding lobectomy in a large cohort of patients from the Italian VATS Group Registry.

RESULTS

The overall conversion rate to thoracotomy was not statistically different between the groups (27 patients 8% vs 7 patients 3%, P = 0.1). The lobectomy group had a greater number of resected lymph nodes (median 11 vs 8, P = 0.006). No significant differences were detected in 30-day mortality (1.4%, 5 patients vs 0.9%, 2 patients), overall complications (18%, 62 patients vs 14%, 29 patients) and prolonged air leakage (31 patients, 9% vs 12 patients, 6%) between lobectomy and segmentectomy, respectively. No statistical differences were found regarding the median duration of drainage (3.2 days, P = 1) and the overall median length of hospital stay (6.4 days, P = 0.1) between the 2 groups. In the context of segmentectomy versus corresponding lobectomy, the right upper lobectomy compared with right upper segmentectomy showed a higher number of resected lymph nodes (P = 0.027). No statistical differences were reported in terms of conversion rate and postoperative complication and mortality.

CONCLUSIONS

Segmentectomy could be considered a safe procedure without significant differences compared to thoracoscopic lobectomy in terms of postoperative morbidity and mortality.

Thoracoscopic segmentectomy and lobectomy assisted by three-dimensional computed-tomography bronchography and angiography for the treatment of primary lung cancer

BACKGROUND

Anatomical segmentectomy has been proposed as a substitution for lobectomy for early-stage lung cancer. However, it requires technical meticulousness due to the complex anatomical variations of segmental vessels and bronchi.

AIM

To assess the safety and feasibility of three-dimensional computed-tomography bronchography and angiography (3D-CTBA) in performing video-assisted thoracoscopic surgery (VATS) for lung cancers.

METHODS

In this study, we enrolled 123 patients who consented to undergo thoracoscopic segmentectomy and lobectomy assisted by 3D-CTBA between May 2017 and June 2019. The image data of enhanced computed tomography (CT) scans was reconstructed three-dimensionally by the Mimics software. The results of preoperative 3D-CTBA, in combination with intraoperative navigation, guided the surgery.

RESULTS

A total of 59 women and 64 men were enrolled, of whom 57 (46.3%) underwent segmentectomy and 66 (53.7%) underwent lobectomy. The majority of tumor appearance on CT was part-solid ground-glass nodule (pGGN; 55.3%). The mean duration of chest tube placement was 3.5 ± 1.6 d, and the average length of postoperative hospital stay was 6.8 ± 1.8 d. Surgical complications included one case of pneumonia and four cases of prolonged air leak lasting > 5 d. Notably, there was no intraoperative massive hemorrhage, postoperative intensive-care unit stay, or 30-d mortality. Preoperative 3D-CTBA images can display clearly and vividly the targeted structure and the variations of vessels and bronchi. To reduce the risk of locoregional recurrence, the application of 3D-CTBA with a virtual 3D surgical margin help the VATS surgeon determine accurate distances and positional relations among the tumor, bronchial trees, and the intersegmental vessels. Three-dimensional navigation was performed to confirm the segmental structure, precisely cut off the targeted segment, and avoid intersegmental veins injury.

CONCLUSION

VATS and 3D-CTBA worked in harmony in our study. This combination also provided a new pattern of transition from lesion-directed location of tumors to computer-aided surgery for the management of early lung cancer.

Comparative analysis of the long-term outcomes of segmentectomy and lobectomy for stage IA1 lung adenocarcinoma in patients with or without previous malignancy of other organs: a population-based study

BACKGROUND

For early stage non-small cell lung cancer, whether limited resection can yield comparable outcomes to those of lobectomy hasn't been established. We compared Overall survival (OS) and lung cancer-specific survival (LCSS) after segmentectomy or lobectomy in stage IA1 (≤10 mm) lung adenocarcinoma (LUAD) patients.

RESEARCH DESIGN AND METHODS

We retrospectively recruited patients who'd been diagnosed with lung cancer for the first time and treated with segmentectomy or lobectomy, with or without previous other malignancy.

RESULTS

1788 patients were included. After propensity score matching: 5-year OS were 85.6% for segmentectomy and 84.7% for lobectomy (p=0.951); 5-year LCSS were 93.5% for segmentectomy; and 93.0% for lobectomy (p=0.726). Cox regression analysis revealed segmentectomy was comparable to lobectomy in OS and LCSS. Having a second lung cancer later in life was associated with a worse LCSS for lobectomy (p<0.05) rather than segmentectomy. After patients were stratified according to malignancy history, subgroup analyses showed no significant prognosis differences between two surgeries.

CONCLUSIONS

For stage IA1 LUAD patients who were diagnosed with lung cancer for the first time, with or without previous other malignancy, segmentectomy yields comparable outcomes to those of lobectomy. It may provide better outcomes for patients with multiple suspicious nodules.

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

INTRODUCTION

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

[Comparison of Short-term Results of Preoperative Planning Combined with Fluorescence Video-assisted Thoracoscopic Precision Segmentectomy and Traditional Thoracoscopic Segmentectomy in the Treatment of Early Lung Adenocarcinoma]

背景与目的

肺癌的死亡率居所有恶性肿瘤的第一位，但对于早期肺腺癌患者不同的肺段切除术之间手术效果及对肺功能的影响研究较少。本研究旨在评估术前规划联合荧光胸腔镜精准肺段切除术与传统肺段切除术两种手术方式对早期肺腺癌患者肺功能保留程度和近期结果比较。

方法

前瞻性选取2020年1月1日-2020年10月31日于中国科学技术大学附属第一医院胸外科行胸腔镜肺段切除术患者60例，精准组30例，传统组30例，比较两组患者临床病理特征、围手术期资料和术后肺功能情况。

结果

精准组在手术时间上较传统组更短，差异有统计学意义（P < 0.05）。术前肺功能精准组与传统组的用力肺活量（forced vital capacity, FVC）、一秒用力呼气容积（forced expiratory volume in one second, FEV₁）和一氧化碳弥散量（carbon monoxide diffusing capacity, DLCO）分别为：（3.65±0.63）L vs（3.54±0.64）L、（2.72±0.50）L vs（2.54±0.48）L及（20.36±3.02）mL/mmHg/min vs（19.16±3.18）mL/mmHg/min，差异均无统计学意义（P > 0.05）。术后1个月肺功能精准组与传统组的FVC、FEV₁和DLCO分别为：（3.35±0.63）L vs（2.89±0.57）L、（2.39±0.54）L vs（2.09±0.48）L及（17.43±3.10）mL/mmHg/min vs（15.78±2.86）mL/mmHg/min，差异均有统计学意义（P < 0.05）；术后3个月肺功能精准组与传统组的FVC和DLCO分别为：（3.47±0.63）L vs（3.20±0.56）L、（19.38±3.02）mL/mmHg/min vs（17.79±3.21）mL/mmHg/min，差异均无统计学意义（P > 0.05）。

结论

术前规划联合荧光胸腔镜精准肺段切除术在段间平面识别、解剖血管及术后恢复等方便提供了优势，明显缩短了手术时间，使治疗更为精准。

Outcomes with segmentectomy versus lobectomy in patients with clinical T1cN0M0 non-small cell lung cancer

OBJECTIVE

We hypothesize that segmentectomy is associated with similar recurrence-free and overall survival when compared with lobectomy in the setting of patients with clinical T1cN0M0 non-small cell lung cancer (NSCLC; >2-3 cm), as defined by the American Joint Committee on Cancer 8th edition staging system.

METHODS

We performed a single-institution retrospective study identifying patients undergoing segmentectomy (90) versus lobectomy (279) for T1c NSCLC from January 1, 2003, to December 31, 2016. Univariate, multivariable, and propensity score-weighted analyses were performed to analyze the following endpoints: freedom from recurrence, overall survival, and time to recurrence.

RESULTS

Patients undergoing segmentectomy were older than patients undergoing lobectomy (71.5 vs 68.8, respectively, P = .02). There were no differences in incidence of major complications (12.4% vs 11.7%, P = .85), hospital length of stay (6.2 vs 7 days, P = .19), and mortality at 30 (1.1% vs 1.7%, P = 1) and 90 days (2.2% vs 2.3%, P = 1). In addition, there were no statistical differences in locoregional (12.2% vs 8.6%, P = .408), distant (11.1% vs 13.9%, P = .716), or overall recurrence (23.3% vs 22.5%, P = 1), as well as 5-year freedom from recurrence (68.6% vs 75.8%, P = .5) or 5-year survival (57.8% vs 61.0%, P = .9). Propensity score-matched analysis found no differences in overall survival (hazard ratio [HR], 1.034; P = .764), recurrence-free survival (HR, 1.168; P = .1391), or time to recurrence (HR, 1.053; P = .7462).

CONCLUSIONS

In the setting of clinical T1cN0M0 NSCLC, anatomic segmentectomy was not associated with significant differences in recurrence-free or overall survival at 5 years. Further prospective randomized trials are needed to corroborate the expansion of the role of anatomic segmentectomy to all American Joint Committee on Cancer 8th Edition Stage 1A NSCLC.

Segmental resection is associated with decreased survival in patients with stage IA non-small cell lung cancer with a tumor size of 21-30 mm

Background

The feasibility of segmental resection for early-stage non-small cell lung cancer (NSCLC) is still controversial. This study aimed to compare survival outcomes following lobectomy and segmental resection in patients with pathological T1cN0M0 (tumor size 21-30 mm) NSCLC.

Methods

Patients diagnosed between 1998 and 2016 with pathological stage IA NSCLC and with tumors measuring 21-30 mm were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. The observational outcomes were cancer-specific survival (CSS) and overall survival (OS) at 5 years. Univariate survival analysis was carried out to identify potential prognostic factors of prolonged survival. Cox proportional hazards model was used to adjust for confounding factors. Additionally, pairwise comparisons were conducted between lobectomy and segmental resection for CSS and OS, and forest plots were drawn.

Results

Of the 9,580 patients analyzed, 400 patients (4.2%) underwent segmental resections. Patients with older age (P<0.001), smaller tumors (P<0.001), and left-sided tumors (P=0.002) were more likely to receive segmental resection. No difference was found in the operative mortality rates between the segmental resection group and the lobectomy group (1.0% vs. 1.2%, P=0.707). The CSS (HR, 1.429; 95% CI, 1.166-1.752; P=0.001) and OS (HR, 1.348; 95% CI, 1.176-1.544; P<0.001) in the segmental resection group were significantly worse than those in the lobectomy group. Subgroup analyses by age, year of diagnosis, sex, tumor size, histology, grade, and the number of dissected lymph nodes also confirmed that lobectomy was associated with improved CSS and OS.

Conclusions

Lobectomy and thorough removal of lymph nodes should continue to be the recommended standard of care for patients with surgically resectable stage IA NSCLC with tumor size of 21-30 mm.

Short-term local control after VATS segmentectomy and lobectomy for solid NSCLC of less than 2 cm

Introduction

VATS pulmonary segmentectomy is increasingly proposed as a parenchyma‐sparing resection for tumors smaller than 2 cm in diameter. The aim of this study was to compare short‐term oncological results and local control in solid non‐small cell lung cancers (NSCLCs) <2 cm surgically treated by intentional VATS segmentectomy or lobectomy.

Methods

This study was a single center retrospective study of consecutive patients undergoing VATS lobectomy (VL) or segmentectomy (VS) for solid <2 cm NSCLC from January 2014 to October 2019.

Results

In total, 188 patients with a median age of 65 years (male/female: 99/89) underwent VS (n = 96) or VL (n = 92). Segmentectomies in the upper lobes were performed in 57% and as a single segment in 55% of cases. There was no statistically significant difference between VS and VL in terms of demographics, comorbidities, postoperative outcomes, dissected lymph node stations (2.89 ± 0.95 vs. 2.93 ± 1, P = 0.58), rate of pN1 (2.2% vs. 2.1%, P = 0.96) or pN2 upstaging (1.09% vs. 1.06%, P = 0.98). Adjuvant chemotherapy was given in 15% of patients in the VL and 11% in the VS group. During follow‐up (median: 23 months), no patients presented with local nodal recurrence or on the stapler line (VS group). Three patients on VL and two in VS groups presented with recurrence on the remnant operated lung. New primary pulmonary tumors were diagnosed in 3.3% and 6.3% of patients in the VL and VS groups, respectively.

Conclusions

Despite the short follow‐up, our preliminary data shows that local control is comparable for VATS lobectomy and VATS segmentectomy for patients with NSCLC <2 cm.

Surgery and invasive diagnostic procedures for benign disease are rare in a large low-dose computed tomography lung cancer screening program

OBJECTIVE

Lung cancer screening with low-dose chest computed tomography improves survival. However, concerns about overdiagnosis and unnecessary interventions persist. We reviewed our lung cancer screening program to determine the rate of surgery and invasive procedures for nonmalignant disease.

METHODS

We reviewed all patients undergoing lung cancer screening from January 2012 to June 2017 with follow-up through January 2019. Patients with suspicious findings (Lung CT Screening Reporting and Data System 4) were referred for further evaluation.

RESULTS

Of 3280 patients screened, 345 (10.5%) had Lung CT Screening Reporting and Data System 4 findings. A total of 311 patients had complete follow-up, of whom 93 (29.9%) were diagnosed with lung cancer. Eighty-three patients underwent lung surgery (2.5% of screened patients). Forty patients underwent lobectomy (48.2%), 3 patients (3.6%) underwent bilobectomy, and 40 patients (48.2%) underwent sublobar resection. Fourteen patients underwent surgery for benign disease (0.43% of screened patients). Fifty-four patients, 5 with benign disease, had at least 1 invasive diagnostic procedure but never underwent surgery. The incidence of any invasive intervention for nonmalignant disease was 0.95% (31/3280 patients). There were no postprocedural deaths within 60 days. Twenty-five patients (0.76%) underwent stereotactic body radiation therapy; 19 patients (76%) had presumed lung cancer without pretreatment pathologic confirmation.

CONCLUSIONS

Surgical resection for benign disease occurred in 0.43% of patients undergoing lung cancer screening. The combined incidence of any invasive diagnostic or therapeutic intervention, including surgical resection, for benign disease was only 0.95%. Periprocedural complications were rare. These results indicate that concern over unnecessary interventions is overstated and should not hinder adoption of lung cancer screening. A multidisciplinary team approach, including thoracic surgeons, is critical to maintain an appropriate rate of interventions in lung cancer screening.

A cross-modal 3D deep learning for accurate lymph node metastasis prediction in clinical stage T1 lung adenocarcinoma

OBJECTIVES

The evaluation of lymph node (LN) status by radiologists based on preoperative computed tomography (CT) lacks high precision for early lung cancer patients; erroneous evaluations result in inappropriate therapeutic plans and increase the risk of complications. This study aims to develop a cross-modal 3D neural network based on CT images and prior clinical knowledge for accurate prediction of LN metastasis in clinical stage T1 lung adenocarcinoma.

PATIENTS AND METHODS

Five hundred one lung adenocarcinoma patients with clinical stage T1 were enrolled. Data including: corresponding 3D nodule-centered patches of CT; prior clinical features; and pathological labels of LN status were obtained. We proposed a cross-modal deep learning system, which can successfully incorporate prior clinical knowledge and CT images into a 3D neural network to predict LN metastasis. We trained and validated our system with 401 cases and tested its performance with 100 cases. The result was compared with that of the logistic regression integration model, the single deep learning model without prior clinical knowledge integration, radiomics method, and manual evaluation by radiologists.

RESULTS

The model proposed DensePriNet achieved an AUC of 0.926, which is significantly higher than the logistic regression integration model (0.904) single deep learning model (0.880), and radiomics method (0.891). The Matthews Correlation Coefficient (MCC) of DensePriNet (0.705) was significantly higher than manual classification by one senior radiologist (0.534) and one junior radiologist (0.416), respectively.

CONCLUSION

The performance of the single deep learning method is significantly higher than the radiomics method and the radiologists, and integration of prior clinical knowledge into the deep learning model enhance the diagnostic precision of LN status and facilitate the application of precision medicine.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Lobectomy versus sub-lobar resection in patients with stage IA right middle lobe non-small cell lung cancer: a propensity score matched analysis

Background

The aim of the present study was to compare the prognostic outcomes of patients with stage IA right middle lobe non-small cell lung cancers (RML NSCLCs) that underwent either lobectomy (LR) or sub-lobar resection (SLR) after 1:1 propensity score matching (PSM).

Methods

Patients with stage IA RML NSCLC were identified from the Surveillance, Epidemiology and End Results (SEER) database from 2005 to 2015. Cox regression analysis was carried out to compare lung cancer specific survival (LCSS) following LR or SLR before and after PSM. Subgroup analysis of LCSS stratified by tumor size (≤1, 1-2, and 2-3 cm) was also performed.

Results

A total of 1,104 patients met the inclusion criteria. One hundred ninety-eight (17.9%) patients underwent SLR, and 906 (82.1%) underwent LR. There were significant differences between patients of LR and SLR groups with regard to the tumor size and the number of examined lymph nodes. After PSM, 147 matched pairs (n=294) were selected. Multivariable cox regression analysis revealed no difference in the LCSS of patients that underwent either LR or SLR before [hazard ratio (HR): 0.881, 95% CI: 0.547-1.422, P=0.605] and after PSM (HR: 0.778, 95% CI: 0.409-1.480, P=0.444). Subgroup analysis revealed no significant difference in LCSS between patients of LR and SLR groups with regard to the tumor size (all P>0.05).

Conclusions

Similar to lymphadenectomy, the prognostic outcomes in patients with stage IA RML NSCLC were comparable between LR and SLR.

Sublobar resection is associated with better perioperative outcomes in elderly patients with clinical stage I non-small cell lung cancer: a multicenter retrospective cohort study

BACKGROUND

Sublobar resection has emerged as an alternative to lobectomy for management of early-stage non-small cell lung cancer (NSCLC). However, controversy remains as to whether it is adequate for elderly patients. The present study aimed to comparatively study the perioperative outcomes and overall survival of sublobar resection vs. lobectomy for management of elderly patients (≥65 years) with clinical stage I NSCLC.

METHODS

This is a multicenter retrospective cohort study. Clinical stage I NSCLC patients who underwent lobar or sublobar resection (segmentectomy and wedge resection) at the Department of Thoracic Surgery of 10 tertiary hospitals between January 2014 and September 2017 were retrospectively reviewed from the national collaborative prospective lung cancer database (LinkDoc Technology Co, Ltd., Beijing, China). Clinical data on demographic and tumor characteristics, surgical details were collected. Perioperative outcomes and overall survival were analyzed by using propensity score matching to adjust for selection bias. Subgroup analysis was further carried out to explore the potential sources of heterogeneity.

RESULTS

Among the 1,579 eligible patients, 1,164 (73.7%) underwent lobectomy and 415 (26.3%) underwent sublobar resection (106 segmentectomy and 309 wedge resection). Sublobar resection was more frequently performed in patients who were elder, had more comorbidities and smaller, left-sided adenocarcinoma (P<0.001). Propensity-matched analysis showed significant association of sublobar resection with less blood loss, shorter operation time, chest drainage and hospital stay, while with less lymph node removal when compared with lobectomy (P<0.001). Short term survival analysis showed comparable results even after adjusted in the matched analysis. Similar results were obtained when limiting patients to those aged >75 years, at pathologic stage I, and those who smoking or undergoing video-assisted thoracoscopic surgery (VATS) or segmentectomy and lobectomy.

CONCLUSIONS

Sublobar resection was associated with significantly better perioperative outcomes without compromising short term survival in elderly patients with clinical stage I NSCLC. However, the importance of patient selection and management process, as well as accurate lymph node staging must be acknowledged when making the surgical decision (clinical registration number: NCT03429673).

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.