Margin Width of Resected Lepidic Lung Cancer Does Not Affect Recurrence After Sublobar Resection

Prediction of programmed death-1 expression status in non-small cell lung cancer based on intratumoural and peritumoral computed tomography (CT) radiomics nomogram

AIMS

This study aimed to predict the expression of programmed death-1 (PD-1) in non-small cell lung cancer (NSCLC) using intratumoral and peritumoral computed tomography (CT) radiomics nomogram.

MATERIALS AND METHODS

Two hundred patients pathologically diagnosed with NSCLC from two hospitals were retrospectively analyzed. Of these, 159 NSCLC patients from our hospital were randomly divided into a training cohort (n=96) and an internal validation cohort (n=63) at a ratio of 6:4, while 41 NSCLC patients from another medical institution served as the external validation cohort. The radiomic features of the gross tumor volume (GTV) and peritumoral volume (PTV) were extracted from the CT images. Optimal radiomics features were selected using least absolute shrinkage and selection operator regression analysis. Finally, a CT radiomics nomogram of clinically independent predictors combined with the best rad-score was constructed.

RESULTS

Compared with the 'GTV' and 'PTV' radiomics models, the combined 'GTV + PTV' radiomics model showed better predictive performance, and its area under the curve (AUC) values in the training, internal validation, and external validation cohorts were 0.90 (95% confidence interval [CI]: 0.83-0.97), 0.85 (95% CI: 0.74-0.96) and 0.78 (95% CI: 0.63-0.92). The nomogram constructed by the rad-score of the 'GTV + PTV' radiomics model combined with clinical independent predictors (prealbumin and monocyte) had the best performance, with AUC values in each cohort being 0.92 (95% CI: 0.85-0.98), 0.88 (95% CI: 0.78-0.97), and 0.80 (95% CI: 0.66-0.94), respectively.

CONCLUSION

The intratumoral and peritumoral CT radiomics nomogram may facilitate individualized prediction of PD-1 expression status in patients with 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.

Does surgical margin affect recurrence and survival after sublobar pulmonary resection for lung cancer?

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was: How does surgical margin distance affect recurrence and survival after sublobar pulmonary resection for lung cancer? Altogether, 172 papers were found using the search strategy, of which 12 studies with 1946 stage I non-small-cell lung cancer (NSCLC) patients using sublobar resection (wedge resection or segmentectomy) represented to be the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers were tabulated. Overall, 11 cohort studies and 1 prospective study were included. Four cohort studies demonstrated positive prognostic significance of surgical margin with specific cut-off points in each paper (ranged from 9 to 15 mm). Two retrospective studies and 1 prospective study found that a margin-to-tumour ratio of ≥1 was associated with better cytology and prognosis results. Other 5 studies showed that larger margin distance provided a favourable prognosis for NSCLC patients with poor-prognostic factors, including solid-dominant type, high invasive component size and Spread through Air Spaces-positive subtype. After reviewing all the included articles, we conclude that the standard of margin distance of >10 mm or margin-to-tumour ratio  ≥ 1 should be recommended for stage I NSCLC patients undergoing sublobar resection, especially in wedge resection. Patients with poor-prognostic factors like solid-predominant tumour or non-lepidic adenocarcinoma may benefit from larger margin distance and the proper margin distance for them still needs to be determined. For Spread through Air Spaces-positive patients, sublobar resection may not be the alternative to lobectomy.

Thoracoscopic Wedge Resection Versus Segmentectomy for cT1N0 Lung Adenocarcinoma

BACKGROUND

The choice between wedge resection and segmentectomy as a sublobar resection method for patients with cT1N0 lung cancer remains debatable. This study aimed to evaluate the clinical outcomes after wedge resection and segmentectomy for patients with cT1N0 lung adenocarcinoma.

METHODS

The study enrolled 1002 consecutive patients with cT1N0 lung adenocarcinoma who underwent sublobar resection at the authors' institution between 2011 and 2017. A propensity score-matching analysis was used to compared the clinical outcomes between the wedge resection and segmentectomy groups.

RESULTS

Wedge resection was performed for 810 patients (80.8%), and segmentectomy was performed for 192 patients (19.2%). Wedge resection resulted in better perioperative outcomes than segmentectomy. The multivariate analysis showed that the significant risk factors for poor disease-free survival (DFS) were elevated preoperative serum carcinoembryonic antigen levels, total tumor diameter greater than 2 cm, and a consolidation-to-tumor (C/T) ratio higher than 50%. After propensity-matching, no differences in overall survival or DFS were noted between the two matched groups. However, subgroup analysis showed that segmentectomy was associated with better DFS than wedge resection (p = 0.039) for the patients with a tumor diameter greater than 2 cm and a C/T ratio higher than 50%.

CONCLUSION

Segmentectomy is the appropriate surgical method for sublobar resection in cT1N0 lung adenocarcinoma patients with a tumor diameter greater than 2 cm and a C/T ratio higher than 50%. Wedge resection may be a safe and feasible sublobar resection method for patients with a tumor diameter of 2 cm or smaller or a C/T ratio of 50% or lower.

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.

The prognosis of small-sized non-small cell lung cancer with visceral pleural invasion after sublobar resection

BACKGROUND

Sublobar resection is sometimes performed as a surgical treatment for small peripheral tumors. However, there is a question about whether sublobar resection is adequate treatment when visceral pleural invasion is diagnosed postoperatively. The purpose of this study was to evaluate the prognosis of patients with small-sized stage IB non-small cell lung cancer (NSCLC) after sublobar resection.

METHODS

From January 2010 to December 2018, 227 consecutive patients with eighth edition TNM stage IB NSCLC (per the joint staging system of the International Association for the Study of Lung Cancer and the American Joint Committee on Cancer) underwent curative surgery at a single center. Those patients were reviewed retrospectively. The clinicopathological characteristics and prognosis were compared between the sublobar resection group and the lobectomy group. The sublobar resection group included only small-sized (invasive component size ≤2 cm) NSCLC.

RESULTS

In all study patients, clinicopathological characteristics between the sublobar resection and lobectomy groups were not different except in maximum standardized uptake value (SUVmax) and invasive component size. The 5-year recurrence-free survival (RFS) rate was 80.7% after sublobar resection and 73.4% after lobectomy (P=0.349). The 5-year overall survival (OS) rate was 87.3% after sublobar resection and 84.8% after lobectomy (P=0.503). In patients with small-sized NSCLC, the clinicopathological characteristics were not different between the sublobar resection group and the lobectomy group. The 5-year RFS rate was 80.7% after sublobar resection and 72.3% after lobectomy (P=0.417). The 5-year OS rate was 87.3% after sublobar resection and 91.2% after lobectomy (P=0.956). Sublobar resection was not a risk factor for recurrence in the multivariate analysis.

CONCLUSIONS

The prognosis of sublobar resection in patients with small-sized stage IB NSCLC was comparable with lobectomy. Thus, additional completion lobectomy may not be essential in this setting, despite postoperative upstaging from T1 to T2a.

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

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

Prognosis after wedge resection in patients with 8th edition TNM stage IA1 and IA2 non-small cell lung cancer

Background

According to the 8^th edition TNM classification for non-small cell lung cancer (NSCLC), tumor stage (T) is determined by the maximum size of the invasive component, without the lepidic component, and the T category has been further subdivided. We investigated the indications for wedge resection using the 8^th edition TNM staging system, which measures only the size of the invasive component in tumor size.

Methods

We compared 5-year disease-free survival (DFS) rates in 429 consecutive patients with 8^th edition stage IA1 and IA2 NSCLC who underwent lobectomy or wedge resection from 2007 to 2017. We also analyzed the risk factors for recurrence after surgical resection.

Results

There were no significant differences in clinicopathological factors or 5-year DFS in patients with stage IA1 disease (5-year DFS 95.0%, lobectomy, vs. 91.6%, wedge resection; P=0.435). For patients with stage IA2 tumors, the 5-year DFS was 88.3% after lobectomy and 74.0% after wedge resection (P=0.118). There were significant differences in clinicopathological characteristics between lobectomy and wedge resection groups in stage IA2 NSCLC. On multivariate analysis, serum CEA level [hazard ratio (HR) =1.040, P=0.046] and lymphovascular invasion (HR =2.664, P=0.027), but not wedge resection, were significant risk factors for recurrence in stage IA2 NSCLC. On multivariate analysis for recurrence risk after wedge resection in stage IA1 and stage IA2 NSCLC, only the width of the resection margin was associated with recurrence.

Conclusions

Wedge resection may be an acceptable procedure in stage IA1 NSCLC. When performing wedge resection, it is necessary to ensure a sufficient resection margin distance.