Sublobar Resection Margin Width Does Not Affect Recurrence of Clinical N0 Non-small Cell Lung Cancer Presenting as GGO-Predominant Nodule of 3 cm or Less

Intentional wedge resection versus segmentectomy for ≤2 cm ground-glass-opacity-dominant non-small cell lung cancer: a real-world study using inverse probability of treatment weighting

BACKGROUND

Whether wedge resection is oncological suitable for ground glass opacity (GGO)-dominant non-small cell lung cancer (NSCLC) ≤2 cm is still debatable. The aim of this study is to investigate the short-term and long-term outcomes of intentional wedge resection and segmentectomy for those patients.

MATERIALS AND METHODS

This was a real-world study from one of the largest thoracic surgery centers in West China. Patients who underwent intentional wedge resection or segmentectomy for ≤2 cm CTR (consolidation-to-tumor) ≤0.5 NSCLC were consecutively included between December 2009 and December 2018. Data were prospectively collected and retrospectively reviewed. Inverse probability of treatment weighting (IPTW) was used to balance baseline characteristics. Long-term outcomes, including overall survival (OS), recurrence-free survival (RFS), and lung cancer-specific survival (LCSS), were analyzed using Cox proportional model.

RESULTS

A total of 1209 patients were included (497 in the wedge resection group, 712 in the segmentectomy group). Compared to segmentectomy, wedge resection had a significantly lower rate of complications (3.8 vs. 7.7%, P =0.008), a shorter operating time (65 min vs. 114 min, P <0.001), and a shorter postoperative stay (3 days vs. 4 days, P <0.001). The median follow-up was 70.1 months. The multivariate Cox model indicated that wedge resection had survival outcomes that were similar to segmentectomy in terms of 5-year OS (98.8 vs. 99.6%, HR=1.98, 95% CI: 0.59-6.68, P =0.270), 5-year RFS (98.8 vs. 99.5%, HR=1.88, 95% CI: 0.56-6.31, P =0.307) and 5-year LCSS (99.9 vs. 99.6%, HR=1.76, 95% CI: 0.24-13.15, P =0.581).

CONCLUSION

Intentional wedge resection is an appropriate choice for ≤2 cm GGO-dominant NSCLC.

Quantification of Resection Margin following Sublobar Resection in Lung Cancer Patients through Pre- and Post-Operative CT Image Comparison: Utilizing a CT-Based 3D Reconstruction Algorithm

Sublobar resection has emerged as a standard treatment option for early-stage peripheral non-small cell lung cancer. Achieving an adequate resection margin is crucial to prevent local tumor recurrence. However, gross measurement of the resection margin may lack accuracy due to the elasticity of lung tissue and interobserver variability. Therefore, this study aimed to develop an objective measurement method, the CT-based 3D reconstruction algorithm, to quantify the resection margin following sublobar resection in lung cancer patients through pre- and post-operative CT image comparison. An automated subvascular matching technique was first developed to ensure accuracy and reproducibility in the matching process. Following the extraction of matched feature points, another key technique involves calculating the displacement field within the image. This is particularly important for mapping discontinuous deformation fields around the surgical resection area. A transformation based on thin-plate spline is used for medical image registration. Upon completing the final step of image registration, the distance at the resection margin was measured. After developing the CT-based 3D reconstruction algorithm, we included 12 cases for resection margin distance measurement, comprising 4 right middle lobectomies, 6 segmentectomies, and 2 wedge resections. The outcomes obtained with our method revealed that the target registration error for all cases was less than 2.5 mm. Our method demonstrated the feasibility of measuring the resection margin following sublobar resection in lung cancer patients through pre- and post-operative CT image comparison. Further validation with a multicenter, large cohort, and analysis of clinical outcome correlation is necessary in future studies.

What Is an Adequate Margin During Sublobar Resection of ≤3 cm N0 Subsolid Lung Adenocarcinomas?

BACKGROUND

Sublobar resection offers noninferior survival vs lobectomy for ≤2 cm non-small cell lung cancer and is commonly used for subsolid tumors. Although data exist for solid tumors, the minimum adequate margin of resection for subsolid adenocarcinomas remains unclear.

METHODS

This was a retrospective review of 1101 adenocarcinoma resections at our institution from 2006 to 2022. Inclusion criteria were tumors ≤3 cm with ≥10% radiographic ground glass, excised by sublobar resection. Exclusions were positive nodes or positive or unreported margin. The primary outcome was the rate of local recurrence (LR) at multiple thresholds of margin distance. The relationship between margin distance and solid component size was also explored.

RESULTS

Inclusion criteria were met by 194 patients. Median (interquartile range) tumor diameter and margin distance were 12 mm (9-17 mm) and 10 mm (5-17 mm), respectively. Median follow-up was 42.5 months. There was a progressive increase in LR with diminishing margin (0.1-cm decrements) from 1.5 cm to 0.5 cm. The difference in the rate of LR between "over" (n = 143) and "under" (n = 51) was most significant at 0.5 cm (8 of 51 [15.7%] vs 6 of 143 [4.2%]; P = .01) but did not reach α adjusted for multiple comparisons. On Cox regression for LR-free survival, margin ≤0.5 cm (P = .19) and solid component percentage (P = .14) trended to significance. Combining these using a ratio of margin distance-to-solid component size, a ratio of ≤1 showed a significantly higher rate of LR (7 [14.3%] vs 2 [2.0%], P = .009). Treatment of LRs provided at least intermediate-term survival in 87% of recurrences (median postrecurrence follow-up was 44 months).

CONCLUSIONS

During sublobar resection of subsolid lung adenocarcinomas, a margin distance-to-solid component size ratio of >1.0 appears to be a more reliable factor than margin distance alone to minimize local recurrence. Local recurrence, however, may not impact survival in patients with subsolid adenocarcinomas if timely treatment is administered.

Clinical and non-contrast computed tomography characteristics and disease development in patients with benign pulmonary subsolid nodules with a solid component ≤ 5 mm

OBJECTIVES

To evaluate the clinical and non-contrast computed tomography (CT) features of patients with benign pulmonary subsolid nodules (SSNs) with a solid component ≤ 5 mm and their development trends via follow-up CT.

METHODS

We retrospectively collected 436 data from patients who had SSNs with a solid component ≤ 5 mm, including 69 with absorbable benign SSNs (AB-SSNs), 70 with nonabsorbable benign SSNs (NB-SSNs), and 297 with malignant SSNs (M-SSNs). Models 1, 2, and 3 for distinguishing the different types of SSNs were then developed and validated.

RESULTS

Patients with AB-SSNs were younger and exhibited respiratory symptoms more frequently than those with M-SSNs. The frequency of nodules detected during follow-up CT was in the following order: AB-SSNs > NB-SSNs > M-SSNs. NB-SSNs were smaller than M-SSNs, and ill-defined margins were more frequent in AB-SSNs than in NB-SSNs and M-SSNs. Benign SSNs exhibited irregular shape, target sign, and lower CT values more frequently compared to M-SSNs, whereas the latter demonstrated bubble lucency more commonly compared to the former. Furthermore, AB-SSNs showed more thickened interlobular septa and satellite lesions than M-SSNs and M-SSNs had more pleural retraction than AB-SSNs (all p < 0.017). The three models had AUCs ranging 0.748-0.920 and 0.790-0.912 in the training and external validation cohorts, respectively. A follow-up CT showed nodule progression in four benign SSNs.

CONCLUSIONS

The three SSN types have different clinical and imaging characteristics, with some benign SSNs progressing to resemble malignancy.

CRITICAL RELEVANCE STATEMENT

A good understanding of the imaging features and development trends of benign SSNs may help reduce unnecessary follow-up or interventions. This retrospective study explores the CT characteristics of benign SSNs with a solid component ≤ 5 mm by comparing AB-SSNs, NB-SSNs, and M-SSNs and delineates their development trends via follow-up CT.

KEY POINTS

1. Different subsolid nodule types exhibit distinct clinical and imaging features. 2. A miniscule number of benign subsolid nodules can progress to resemble malignancy. 3. Knowing the clinical and imaging features and development trends of benign subsolid nodules can improve management.

Survival Outcomes of Sublobectomy and Lobectomy in Elderly Patients with Peripheral Solid-Dominant Non-small Cell Lung Cancer

BACKGROUND

According to the JCOG0802 study, there were many non-cancer-related deaths in the lobectomy group. Meanwhile, the median age of the enrolled patients in the JCOG0802 study was 67 years old. Whether this difference in perioperative outcomes and survival outcomes is related to age remains unknown. We aim to investigate whether the sublobectomy was comparable to lobectomy in elderly (≥ 75 years old) patients with peripheral solid-dominant [50% ≤ consolidation tumor ratio (CTR) ≤ 1] and diameter ≤ 2 cm non-small cell lung cancer (NSCLC).

METHODS

We retrospectively included 10,830 patients who underwent surgery treatment at two large-volume medical centers, Taizhou Hospital of Zhejiang Province and Shanghai Chest Hospital, from January 2016 to January 2018. Of these, 164 patients aged ≥ 75 years, tumor ≤ 2 cm, and 50% ≤ CTR ≤ 1 who received lobectomy or sublobectomy were included in our study. The perioperative outcomes, survival analyses, analysis of death patterns, tumor recurrence patterns, and Cox regression analyses were performed.

RESULTS

On perioperative outcomes, sublobectomy was associated with a shorter operation time (p < 0.001), and in terms of survival outcomes, the 5-year overall survival (OS, p = 0.85) and 5-year disease-free surivial (DFS, p = 0.58) did not differ significantly between the two groups. The Cox regression analyses showed that CTR value, visceral pleural infiltration, and smoking were independent risk factors for worse OS. Furthermore, tumor recurrence pattern and death patterns between the two groups did not differ significantly.

CONCLUSIONS

Sublobectomy could achieve superior perioperative outcomes and equivalent oncological efficacy in comparison with lobectomy in elderly patients (≥ 75 years old) with peripheral solid-dominant and diameter ≤ 2 cm NSCLC.

Sublobar Resections

Sublobar resections are commonly performed operations that have seen an increase in applicability. The sublobar approach, comprising segmentectomy and wedge resections, can provide lung preservation and thus is better tolerated in select patients in comparison to lobectomy. These operations are offered for a variety of benign and malignant lesions. Understanding the indications and technical aspects of these approaches is paramount as improvements in lung cancer screening protocols and the imaging modalities has led to an increase in the detection of early-stage cancer. In this article, we discuss the anatomy, indications, technical approaches, and outcomes for sublobar resection.

Measuring the margin distance in pulmonary wedge resection

BACKGROUND

Margin distance contributes to survival and recurrence during wedge resections for early-stage non-small cell lung cancer. The Initiative for Early Lung Cancer Research on Treatment sought to standardize a surgeon-measured margin intraoperatively.

METHODS

Lung cancer patients who underwent wedge resection were reviewed. Margins were measured by the surgeon twice as per a standardized protocol. Intraobserver variability as well as surgeon-pathologist variability were compared.

RESULTS

Forty-five patients underwent wedge resection. Same-surgeon measurement analysis indicated good reliability with a small mean difference and narrow limit of agreement for the two measures. The median surgeon-measured margin was 18.0 mm, median pathologist-measured margin was 16.0 mm and the median difference between the surgeon-pathologist margin was -1.0 mm, ranging from -18.0 to 12.0 mm. Bland-Altman analysis for margin measurements demonstrated a mean difference of 0.65 mm. The limit of agreement for the two approaches were wide, with the difference lying between -16.25 and 14.96 mm.

CONCLUSIONS

A novel protocol of surgeon-measured margin was evaluated and compared with pathologist-measured margin. High intraobserver agreement for repeat surgeon measurements yet low-to-moderate correlation or directionality between surgeon and pathologic measurements were found.

DISCUSSION

A standardized protocol may reduce variability in pathologic assessment. These findings have critical implications considering the impact of margin distance on outcomes.

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.

Virtual-assisted lung mapping in sublobar resection of small pulmonary nodules, long-term results

OBJECTIVES

The short-term efficacy of virtual-assisted lung mapping (VAL-MAP), a preoperative bronchoscopic multi-spot lung-marking technique, has been confirmed in 2 prospective multicentre studies. The objectives of this study were to analyse the local recurrence and survival of patients enrolled in these studies, long-term.

METHODS

Of the 663 patients enrolled in the 2 studies, 559 patients' follow-up data were collected. After excluding those who did not undergo VAL-MAP, whose resection was not for curative intent, who underwent concurrent resection without VAL-MAP, or who eventually underwent lobectomy instead of sublobar resection (i.e. wedge resection or segmentectomy), 422 patients were further analysed.

RESULTS

Among 264 patients with primary lung cancer, the 5-year local recurrence-free rate was 98.4%, and the 5-year overall survival (OS) rate was 94.5%. Limited to stage IA2 or less (≤2 cm in diameter; n = 238, 90.1%), the 5-year local recurrence-free and OS rates were 98.7% and 94.8%, respectively. Among 102 patients with metastatic lung tumours, the 5-year local recurrence-free rate was 93.8% and the 5-year OS rate was 81.8%. Limited to the most common (colorectal) cancer (n = 53), the 5-year local recurrence-free and OS rates were 94.9% and 82.3%, respectively.

CONCLUSIONS

VAL-MAP, which is beneficial in localizing small barely palpable pulmonary lesions and determining the appropriate resection lines, was associated with reasonable long-term outcomes.

SUBJ COLLECTION

152, 1542.

Optimal margins for early stage peripheral lung adenocarcinoma resection

Background

A pathologically confirmed negative margin is required when performing sublobar resection in patients with early stage peripheral lung adenocarcinoma. However, the optimal margin distance to ensure complete tumor resection while preserving healthy lung tissue remains unknown. We aimed to establish a reliable distance range for negative margins.

Methods

A total of 52 intraoperative para-cancer tissue specimens from patients with peripheral lung adenocarcinoma with pathological tumors ≤2 cm in size were examined. Depending on the distance from the tumor edge (D), the para-cancer tissues were divided into the following five groups: D < 0.5 cm (group I); 0.5 cm ≤ D < 1.0 cm (group II); 1.0 cm ≤ D < 1.5 cm (group III); 1.5 cm ≤ D < 2.0 cm (group IV); and D ≥ 2.0 cm (group V). During pathological examination of the specimens under a microscope, the presence of atypical adenomatous hyperplasia or more severe lesions was considered unsafe, whereas the presence of normal lung tissue or benign hyperplasia was considered safe.

Results

Group V, in which the margin was the farthest from the tumor edge, was the safest. There were significant safety differences in between groups I and V (χ² = 26.217, P < 0.001). Significant safety differences also existed between groups II and V (χ² = 9.420, P < 0.005). There were no significant safety differences between group III or IV and group V (P = 0.207; P = 0.610).

Conclusions

We suggest that when performing sublobar resection in patients with early stage peripheral lung adenocarcinoma with pathological tumor sizes ≤2 cm, the resection margin distance should be ≥1 cm to ensure a negative margin.

Long-Term Prognosis of Patients With Resected Adenocarcinoma In Situ and Minimally Invasive Adenocarcinoma of the Lung

INTRODUCTION

The WHO classification of lung tumors defines adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) as cancers with no or limited histologic invasive components. The probability of patients with AIS or MIA being recurrence free for 5 years postoperatively has been found to be 100%. This study aimed to analyze the prognosis of patients with AIS or MIA after more than 5 postoperative years.

METHODS

We reviewed the pathologic findings of 4768 patients who underwent resection for lung cancer between 1998 and 2010. Of these, 524 patients with curative resection for AIS (207 cases, 39.5%) and MIA (317 cases, 60.5%) were included. Postoperative recurrence, survival, and development of secondary primary lung cancer (SPLC) were analyzed.

RESULTS

Of the included patients, 342 (65.3%) were of female sex, 333 (63.5%) were nonsmokers, and 229 (43.7%) underwent sublobar resection. Average pathologic total tumor diameter was 15.2 plus or minus 5.5 mm. Median postoperative follow-up period was 100 months (range: 1-237). No recurrence of lung cancer was observed for either AIS or MIA cases. Estimated 10-year postoperative disease-specific survival rates were 100% and 100% (p = 0.72), and overall survival rates were 95.3% and 97.8% (p = 0.94) for AIS and MIA cases, respectively. Estimated incidence rates of metachronous SPLC at 10 years after surgery were 5.6% and 7.7% for AIS and MIA, respectively (p = 0.45), and these were not correlated with the EGFR mutation status.

CONCLUSIONS

Although the development of metachronous SPLC should be noted, the risk of recurrence is quite low at more than 5 years after resection of AIS and MIA. This finding strengthens the clinical value of distinguishing AIS and MIA from other adenocarcinomas of the lung.

Adjuvant treatment can improve prognosis in patients with non-small cell lung cancer ≤3 cm after sublobectomy: a propensity score analysis

Background

Numerous retrospective studies have reported that sublobectomy has a poorer prognosis than lobectomy in patients with early-stage lung cancer. The purpose of this study was to determine whether adjuvant treatment could improve the prognosis of patients with non-small cell lung cancer (NSCLC) ≤3 cm after sublobectomy.

Methods

We collected data from 17,763 patients with T1N0M0 NSCLC after surgery from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015. Kaplan-Meier curves were generated to compare the overall survival (OS) rates and the lung cancer-specific survival (LCSS) rates. Cox proportional hazards regressions were performed to discover the independent risk factors for both the OS and LCSS rates.

Results

Lobectomy was performed in 12,428 cases and sublobectomy was performed in 5,335 cases. In the sublobectomy group, among the 394 patients treated with adjuvant therapy, larger tumor diameter, a lower number of lymph node dissections, and more wedge resections were observed in the patients treated with adjuvant therapy. In the subsequent survival analysis, the OS and LCSS rates of adjuvant therapy patients showed a significant survival advantage over those treated with sublobectomy alone (P<0.05). The survival analysis was performed again after propensity match scoring, generating similar results (P<0.05). There was still a significant difference in OS between adjuvant therapy and lobectomy alone (P<0.05).

Conclusions

Chemoradiotherapy can improve the OS of patients with NSCLC ≤3 cm after sublobectomy and reduce death caused by tumors. Therefore, when patients cannot tolerate lobectomy or are given inappropriate sublobectomy, adjuvant therapy can improve the prognosis of patients.

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.

Effect of Margin Status on Survival After Resection of Hilar Cholangiocarcinoma in the Modern Era of Adjuvant Therapies

INTRODUCTION

Studies have shown that for patients with hilar cholangiocarcinoma (HC), survival is associated with negative resection margins (R0). This requires increasingly proximal resection, putting patients at higher risk for complications, which may delay chemotherapy. For patients with microscopically positive resection margins (R1), the use of modern adjuvant therapies may offset the effect of R1 resection.

METHODS

Patients at our institution with HC undergoing curative-intent resection between January 2008 and July 2019 were identified by retrospective record review. Demographic data, operative details, tumor characteristics, postoperative outcomes, recurrence, survival, and follow-up were recorded. Patients with R0 margin were compared to those with R1 margin. Patients with R2 resection were excluded.

RESULTS

Seventy-five patients underwent attempted resection with 34 (45.3%) cases aborted due to metastatic disease or locally advanced disease. Forty-one (54.7%) patients underwent curative-intent resection with R1 rate of 43.9%. Both groups had similar rates of adjuvant therapy (56.5% vs. 61.1%, P = .7672). Complication rates and 30 mortality were similar between groups (all P > .05). Both groups had similar median recurrence-free survival (R0 29.2 months vs. R1 27.8 months, P = .540) and median overall survival (R0 31.2 months vs. R1 38.8 months, P = .736) with similar median follow-up time (R0 29.9 months vs. R1 28.5 months, P = .8864).

CONCLUSIONS

At our institution, patients undergoing hepatic resection for HC with R1 margins have similar recurrence-free and overall survival to those with R0 margins. Complications and short-term mortality were similar. This may indicate that with use of modern adjuvant therapies obtaining an R0 resection is not an absolute mandate.

Feasibility of limited resection for peripheral small-sized non-small cell lung cancer: a retrospective single-center-based study

PURPOSE

This study aimed to establish new criteria for limited resection of non-small cell lung cancer (NSCLC) based on computed tomography findings and maximum standardized uptake value (SUVmax).

METHODS

Between December 2007 and December 2015, 611 patients underwent lung cancer surgery; of these, 70 with cT1aN0M0 who underwent limited resection were enrolled. Criteria for undergoing intentional limited resection (ILR) were (1) tumor ground-glass opacity (GGO) ratio of ≥ 0.75 and (2) tumor SUVmax ≤ 1.5. Patients who met criteria (1) and (2) underwent partial resection, and those who only met criteria (2) underwent segmentectomy as ILR. The control group was subjected to limited surgery without meeting the criteria.

RESULTS

Overall, 45 and 25 patients who met the criteria were included in the ILR and control groups, respectively. In the ILR group, 13 patients underwent partial resection, and 32 underwent segmentectomy; in the control group, 18 patients underwent partial resection and 7 underwent segmentectomy. According to our criteria, no relapsed cases occurred in the ILR group, although six patients showed recurrence of lung cancer in the control group. The 5-year overall survival (OS) rates in the ILR and control groups were 100% and 67.7%, respectively, and the relapse-free survival (RFS) rates were 100% and 61.6%, respectively. The log-rank test showed that this difference was statistically significant (OS: P < 0.0001, RFS: P < 0.0001).

CONCLUSIONS

SUVmax may serve as a predictive marker of recurrence to determine the treatment strategy for patients with NSCLC. Patients with low GGO ratio and low SUVmax may be cured by limited resection.

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.

The Epidemiology of Ground Glass Opacity Lung Adenocarcinoma: A Network-Based Cumulative Meta-Analysis

Introduction: Due to the introduction of low-dose computed tomography (CT) and screening procedures, the proportion of early-stage lung cancer with ground glass opacity (GGO) manifestation is increasing in clinical practice. However, its epidemiological characteristics is still not fully investigated.

Methods: We retrieved all solitary GGO adenocarcinoma lung cancer (ADLC) on the PubMed, Cochrane Library, and Embase databases until January 1, 2019 and extracted the general information to perform the meta-analysis, mainly focusing on age, gender, and smoking status.

Results: A total of 8,793 solitary GGO ADLC patients from 53 studies were included in this analysis. The final pooled analysis showed that the female proportion, average diagnosis age, and non-smoking proportion of solitary GGO ADLC was 0.62 (95% CI, 0.60–0.64), 56.97 (95% CI, 54.56–59.37), and 0.72 (95% CI, 0.66–0.77), respectively. The cumulative meta-analysis and meta-trend analysis confirmed that the average age at diagnosis has been decreasing while the non-smoking proportion significantly increased in the past two decades.

Conclusions: From our epidemiological analysis, it demonstrates that the clinical characteristics of GGO lung cancer patients may be out of the high-risk factors. Therefore, we propose to reconsider the risk assessment and current lung cancer screening criteria.

Prognostic role of positron emission tomography and computed tomography parameters in stage I lung adenocarcinoma

Background

According to the current pathological classification, lung adenocarcinoma includes histological subtypes with significantly different prognoses, which may require specific surgical approaches. The aim of the study was to assess the role of CT and PET parameters in stratifying patients with stage I adenocarcinoma according to prognosis.

Patients and methods

Fifty-eight patients with pathological stage I lung adenocarcinoma who underwent surgical treatment were retrospectively reviewed. Adenocarcinoma in situ and minimally-invasive adenocarcinoma were grouped as non-invasive adenocarcinoma. Other histotypes were referred as invasive adenocarcinoma. CT scan assessed parameters were: ground glass opacity (GGO) ratio, tumour disappearance rate (TDR) and consolidation diameter. The prognostic role of the following PET parameters was also assessed: standardized uptake value (SUV) max, SUVindex (SUVmax to liver SUVratio), metabolic tumour volume (MTV), total lesion glycolysis (TLG).

Results

Seven patients had a non-invasive adenocarcinoma and 51 an invasive adenocarcinoma. Five-year disease-free survival (DFS) and cancer-specific survival (CSS) for non-invasive and invasive adenocarcinoma were 100% and 100%, 70% and 91%, respectively. Univariate analysis showed a significant difference in SUVmax, SUVindex, GGO ratio and TDR ratio values between non-invasive and invasive adenocarcinoma groups. Optimal SUVmax, SUVindex, GGO ratio and TDR cut-off ratios to predict invasive tumours were 2.6, 0.9, 40% and 56%, respectively. TLG, SUVmax, SUVindex significantly correlated with cancer specific survival.

Conclusions

CT and PET scan parameters may differentiate between non-invasive and invasive stage I adenocarcinomas. If these data are confirmed in larger series, surgical strategy may be selected on the basis of preoperative imaging.

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.

Impact of resection margin length and tumor depth on the local recurrence after thoracoscopic pulmonary wedge resection of a single colorectal metastasis

Background

To evaluate the influence of tumor depth on preoperative computed tomography (CT) image, and resection margin length on local recurrence after pulmonary metastasectomy of colorectal cancer.

Methods

Patients undergoing thoracoscopic pulmonary wedge resection for single pulmonary metastasis of colorectal cancer origin from 2007 to 2017 were analyzed. Factors such as resection margin, tumor size and depth were analyzed. The local recurrences of two subgroups based on the pulmonary resection margin (Group 1: resection margin 1-10 mm or shorter than the tumor size, Group 2: resection margin >10 mm or at least greater than the tumor size) were analyzed.

Results

Sixty-five patients were included in this study. The local recurrence rate was 12/65 (18.5%). Median follow up period was 33 months. Median tumor size and depth on preoperative CT were 1.1 and 1.6 cm. Median length of resection margin was 0.5 cm (group 1: 0.4 cm, group 2: 1.0 cm, P<0.001). No difference was noted in 3-year local recurrence-free survival (80.8% vs. 76.7%, P=0.756) between the two subgroups. No significant correlation was noted between the length of resection margin and the tumor size and depth. However, tumor depth was an independent factor related to higher local recurrence on multivariate analysis.

Conclusions

Extent of resection margin in pulmonary metastasectomy does not seem to affect significantly on the local recurrence if complete resection is accomplished. However, preoperative tumor depth on CT image and postoperative distant metastasis seem to affect on local recurrence after pulmonary metastasectomy.

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.

The role of the ground-glass opacity ratio in resected lung adenocarcinoma

OBJECTIVES

The goal of this study was to investigate the role of the ground-glass opacity (GGO) ratio in lung adenocarcinoma in predicting surgical outcomes.

METHODS

Patients who underwent surgical resection for pulmonary adenocarcinoma between January 2004 and December 2013 were reviewed. The clinical data, imaging characteristics of nodules, surgical approaches and outcomes were analysed with a mean follow-up of 87 months.

RESULTS

Of 789 enrolled patients, 267 cases were categorized as having a GGO ratio ≥0.75; 522 cases were categorized as having a GGO ratio <0.75. The gender, tumour differentiation, epidermal growth factor receptor mutation, smoking habits, lymphovascular space invasion, tumour size, maximum standard uptake value and carcinoembryonic antigen levels were significantly different in the 2 groups. In the group with a GGO ratio ≥0.75, 63.3% of the patients underwent sublobar resection (18.8% with a GGO ratio < 0.75, P <0.001). These patients had fewer relapses (2.2% for GGO ratio ≥0.75, 26.8% for GGO ratio <0.75, P < 0.001) and a better 5-year survival rate (95.5% for GGO ratio ≥0.75, 77.4% for GGO ratio <0.75, P < 0.001). None of the patients with a GGO ratio ≥0.75 had lymph node involvement. The multivariable Cox regression analysis revealed that a GGO ratio <0.75 was an independent factor for postoperative relapse with a hazard ratio of 3.96.

CONCLUSIONS

A GGO ratio ≥0.75 provided a favourable prognostic prediction in patients with resected lung adenocarcinoma. Sublobar resection and lymph node sampling revealed a fair outcome regardless of tumour size. However, anatomical resection is still the standard approach for patients with tumours with a GGO ratio <0.75, size >2 cm.

Predictive factors for invasive adenocarcinoma in patients with clinical non-invasive or minimally invasive lung cancer

Background

Pure ground glass opacity (GGO) or part-solid GGO with small solid component (≤5 mm) are likely to be non-invasive or minimally invasive lung cancer. However, those lesions sometimes are diagnosed as invasive adenocarcinoma postoperatively. The aim of this study was to determine the predictors of invasive adenocarcinoma in clinical non- or minimally invasive lung cancer.

Methods

From January 2010 to December 2017, 203 patients were diagnosed as clinical adenocarcinoma in situ (AIS) or minimally invasive adenocarcinoma (MIA) identified on chest computed tomography (CT) and they underwent surgical resection. A retrospective study was performed to analyze the prediction of invasive adenocarcinoma in clinical non- or minimally invasive lung cancer.

Results

Of all clinical AIS or MIA patients, invasive adenocarcinoma was diagnosed in 55 patients (27.1%). In clinical AIS, invasive adenocarcinoma was diagnosed in 19 patients (17.9%) and 36 patients (37.1%) were diagnosed as invasive adenocarcinoma in clinical MIA (P=0.002). Tumor diameter and the presence of solid component were confirmed to be significant predictive factors for invasive adenocarcinoma in a multivariate analysis [hazard ratio (HR) 1.071, P=0.037; HR 2.573, P=0.005; respectively].

Conclusions

Large tumor size and the presence of solid component in clinical AIS or MIA are predictive factors for invasive adenocarcinoma. Therefore, early surgical intervention is recommended for those lesions.

[Progress of Lung Margin During Sublobar Resection for Early-staged Non-small Cell Lung Cancer]

近年来随着低剂量计算机断层扫描(low-dose computed tomography, LDCT)、高分辨率CT(high-resolution CT, HRCT)的普及, 早期非小细胞肺癌的发现比率不断上升, 越来越多的胸外科医生探索手术方式的改良, 推动手术切除范围向更加合理的方向进展。临床研究发现肺切缘阴性较阳性有更低的局部肿瘤复发率, 因此亚肺叶切除术治疗早期肺癌术中保证肺切缘阴性具有重要的临床意义, 本文将就这一领域研究现状和进展作一综述。

Prognostic prediction of clinical stage IA lung cancer presenting as a pure solid nodule

Background

Clinical stage IA lung cancer presenting as a ground glass opacity (GGO) on imaging is known to be associated with a good prognosis. Conversely, the prognosis of lung cancer presenting as a pure solid nodule is less favorable. The purpose of this study was to identify the predictive factors affecting prognosis in pure solid nodule lung cancer.

Methods

A total of 328 consecutive patients undergoing curative resection of clinical stage IA pure solid nodule lung cancer were reviewed retrospectively. Recurrence, survival and risk factors for nodal upstaging were analyzed.

Results

Of the 328 patients, 277 patients (84.6%) underwent lobectomy (or greater) and 51 patients (15.6%) underwent sublobar resection. Mediastinal lymph node dissection or sampling was performed in 278 patients (84.8%). The 5-year recurrence-free survival rate was 70.0% and the disease-specific survival rate was 86.5%. Intraoperative mediastinal lymph node dissection was the only significant related factor for recurrence and cancer-related death in a multivariate analysis [hazard ratio (HR) =0.485, P=0.020; HR =0.342, P=0.014]. A total of 217 patients underwent lobectomy with mediastinal lymph node dissection and nodal upstaging occurred in 36 patients (16.6%). There were no significant predictive factors for nodal upstaging in a multivariate analysis. Visceral pleural invasion, lymphovascular invasion, and small cell carcinoma histology were the only identified risk factors for nodal upstaging (HR =3.858, P=0.006; HR =8.792, P<0.001; HR =45.908, P=0.017).

Conclusions

There were no definite factors predictive of prognosis in clinical stage IA pure solid nodule lung cancer. Only accurate pathologic staging and adequate intraoperative lymph node dissection were shown to be related to prognosis.

Planning and marking for thoracoscopic anatomical segmentectomies

Although sublobar resection (SLR) for treating non-small cell lung carcinoma (NSCLC) is still controversial, thoracoscopic segmentectomy is rising. Performing it by closed chest surgery is complex as it means confirming the location of the lesion, identifying vascular and bronchial structures, preserving venous drainage of adjacent segments, severing the intersegmental plane and ensuring an oncological safety margin with no manual palpation and different landmarks. Accurate planning is mandatory. We discuss in this article the interest of 3D reconstruction and mapping technics to enhance safety and reliability of these procedures.