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

The American Association for Thoracic Surgery (AATS) 2023 Expert Consensus Document: Staging and multidisciplinary management of patients with early-stage non-small cell lung cancer

Novel targeted therapy and immunotherapy drugs have recently been approved for use in patients with surgically resectable lung cancer. Accurate staging, early molecular testing, and knowledge of recent trials are critical to optimize oncologic outcomes in these patients.

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.

Nomogram Predicting the Prognosis of Patients with Surgically Resected Stage IA Non-small Cell Lung Cancer

The American Joint Committee on Cancer (AJCC) 8th stage system was limited in accuracy for predicting prognosis of stage IA non-small cell lung cancer (NSCLC) patients. This study aimed to establish and validate two nomograms that predict overall survival (OS) and lung cancer-specific survival (LCSS) in surgically resected stage IA NSCLC patients. Postoperative patients with stage IA NSCLC in SEER database between 2004 and 2015 were examined. Survival and clinical information according to the inclusion and exclusion criteria were collected. All patients were randomly divided into the training cohort and validation cohort with a ratio of 7:3. Independent prognosis factors were evaluated using univariate and multivariate Cox regression analyses, and predictive nomogram was established based on these factors. Nomogram performance was measured using the C-index, calibration plots, and DCA. Patients were grouped by quartiles of nomogram scores and survival curves were plotted by Kaplan-Meier analysis. In total, 33,533 patients were included in the study. The nomogram contained 12 prognostic factors in OS and 10 prognostic factors in LCSS. In the validation set, the C-index was 0.652 for predicting OS and 0.651 for predicting LCSS. The calibration curves for the nomogram-predicted probability of OS and LCSS showed good agreement between the actual observation and nomogram prediction. DCA indicated that the clinical value of the nomograms were higher than AJCC 8th stage for predicting OS and LCSS. Nomogram scores related risk stratification revealed statistically significant difference which have better discrimination than AJCC 8th stage. The nomogram can accurately predict OS and LCSS in surgically resected patients with stage IA NSCLC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13193-022-01700-w.

Prolonged air leak after segmentectomy: incidence and risk factors

Background

We designed this study to investigate the rate and risk factors of prolonged air leak (PAL) in patients undergoing pulmonary segmentectomy in our unit.

Methods

We performed a retrospective cohort study on 191 patients undergoing pulmonary segmentectomy (January 2017-August 2021). A PAL was defined as an air leak >5 days.

Results

One hundred and sixty-eight segmentectomies were performed using video-assisted thoracoscopic surgery (VATS), 13 were open operations and 10 were robotic. PAL occurred in 36 patients (19%). Their average post-operative stay was 2.4 days longer than those without PAL. Logistic regression analysis showed that a low preoperative carbon monoxide lung diffusion capacity (DLCO) (OR 0.98, P<0.001), low body mass index (BMI) (OR 0.95, P=0.002) and the performance of complex segmentectomies (OR 2.2, P<0.001). were significantly associated with PAL.

Conclusions

Pulmonary segmentectomies are associated with a not negligible risk of PAL when using real world data, especially in patients with compromised pulmonary function and after complex segmentectomies. This finding is useful to inform the decision-making process.

Local control and short-term outcomes after video-assisted thoracoscopic surgery segmentectomy versus lobectomy for pT1c pN0 non-small-cell lung cancer

OBJECTIVES

The aim of this study was to compare short-term outcomes and local control in pT1c pN0 non-small-cell lung cancer that were intentionally treated by video-assisted thoracoscopic surgery (VATS) lobectomy or segmentectomy.

METHODS

Multicentre retrospective study of consecutive patients undergoing VATS lobectomy (VL) or VATS segmentectomy (VS) for pT1c pN0 non-small-cell lung cancer from January 2014 to October 2021. Patients' characteristics, postoperative outcomes and survival were compared.

RESULTS

In total, 162 patients underwent VL (n = 81) or VS (n = 81). Except for age [median (interquartile range) 68 (60-73) vs 71 (65-76) years; P = 0.034] and past medical history of cancer (32% vs 48%; P = 0.038), there was no difference between VL and VS in terms of demographics and comorbidities. Overall 30-day postoperative morbidity was similar in both groups (34% vs 30%; P = 0.5). The median time for chest tube removal [3 (1-5) vs 2 (1-3) days; P = 0.002] and median postoperative length of stay [6 (4-9) vs 5 (3-7) days; P = 0.039] were in favour of the VS group. Significantly larger tumour size (mean ± standard deviation 25.1 ± 3.1 vs 23.6 ± 3.1 mm; P = 0.001) and an increased number of lymph nodes removal [median (interquartile range) 14 (9-23) vs 10 (6-15); P < 0.001] were found in the VL group. During the follow-up [median (interquartile range) 31 (14-48) months], no statistical difference was found for local and distant recurrence in VL groups (12.3%) and VS group (6.1%) (P = 0.183). Overall survival (80% vs 80%) was comparable between both groups (P = 0.166).

CONCLUSIONS

Despite a short follow-up, our preliminary data shows that local control is comparable for VL and VS.

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.

Bias Reduction through Analysis of Competing Events (BRACE) Correction to Address Cancer Treatment Selection Bias in Observational Data

BACKGROUND

Cancer treatments can paradoxically appear to reduce the risk of non-cancer mortality in observational studies, due to residual confounding. Here we introduce a method, Bias Reduction through Analysis of Competing Events (BRACE), to reduce bias in the presence of residual confounding.

METHODS

BRACE is a novel method for adjusting for bias from residual confounding in proportional hazards models. Using standard simulation methods, we compared BRACE vs. Cox proportional hazards regression in the presence of an unmeasured confounder. We examined estimator distributions, bias, mean squared error (MSE), and coverage probability. We then estimated treatment effects of high vs. low intensity treatments in 36,630 prostate cancer, 4,069 lung cancer, and 7,117 head/neck cancer patients, using the Veterans Affairs database. We analyzed treatment effects on cancer-specific mortality (CSM), non-cancer mortality (NCM), and overall survival (OS), using conventional multivariable Cox and propensity score (adjusted using inverse probability weighting) models, vs. BRACE-adjusted estimates.

RESULTS

In simulations with residual confounding, BRACE uniformly reduced both bias and MSE. In the absence of bias, BRACE introduced bias toward the null, albeit with lower MSE. BRACE markedly improved coverage probability, but with a tendency toward overcorrection for effective but non-toxic treatments. For each clinical cohort, more intensive treatments were associated with significantly reduced hazards for CSM, NCM, and OS. BRACE attenuated OS estimates, yielding results more consistent with findings from randomized trials and meta-analyses.

CONCLUSIONS

BRACE reduces bias and MSE when residual confounding is present and represents a novel approach to improve treatment effect estimation in non-randomized studies.

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.