Survival after Sublobar Resection for Early-Stage Lung Cancer: Methodological Obstacles in Comparing the Efficacy to Lobectomy

Comparative Study of Indocyanine Green Fluorescence Imaging in Lung Cancer with Near-Infrared-I/II Windows

BACKGROUND

We compare the application of intravenous indocyanine green (ICG) fluorescence imaging in lung cancer with near-infrared-I (NIR-I) and near-infrared-II (NIR-II) windows.

METHODS

From March to December 2022, we enrolled patients who received an intravenous injection of ICG (5 mg/kg) 1 day before the planned lung cancer surgery. The lung cancer nodules were imaged by NIR-I/II fluorescence imaging systems, and the tumor-to-normal-tissue ratio (TNR) was calculated. In addition, the fluorescence intensity and signal-to-background ratio (SBR) of capillary glass tubes containing ICG covered with different thicknesses of lung tissue were measured by NIR-I/II fluorescence imaging systems.

RESULTS

In this study, 102 patients were enrolled, and the mean age was 59.9 ± 9.2 years. A total of 96 (94.1%) and 98 (96.1%) lung nodules were successfully imaged with NIR-I and NIR-II fluorescence, and the TNR of NIR-II was significantly higher than that of NIR-I (3.9 ± 1.3 versus 2.4 ± 0.6, P < 0.001). In multiple linear regression, solid nodules (P < 0.001) and squamous cell carcinoma (P < 0.001) were independent predictors of a higher TNR of NIR-I/II. When capillary glass tubes were covered with lung tissue whose thickness was more than 2 mm, the fluorescence intensity and the SBR of NIR-II were significantly higher than those of NIR-I.

CONCLUSIONS

We verified the feasibility of NIR-II fluorescence imaging in intravenous ICG lung cancer imaging for the first time. NIR-II fluorescence can improve the TNR and penetration depth of lung cancer with promising clinical prospects.

Wedge resection versus lobectomy in T1 lung cancer patients: a propensity matched analysis

OBJECTIVES

Performing wedge resection rather than lobectomy for primary lung cancer remains controversial. Recent studies demonstrate no survival advantage for non-anatomical resection compared to lobectomy in patients with early-stage lung cancer. The objective of this study was to investigate whether in patients with T1 tumours, non-anatomical wedge resection is associated with equivalent survival to lobectomy.

METHODS

This was a retrospective cohort study of patients who underwent lung resection at the Lancashire Cardiac Centre between April 2005 and April 2018. Patients were subjected to multidisciplinary team discussion. The extent of resection was decided by the team based on British Thoracic Society guidelines. The primary outcome was overall survival. Propensity matching of patients with T1 tumours was also performed to determine whether differences in survival rates exist in a subset of these patients with balanced pre-operative characteristics.

RESULTS

There were 187 patients who underwent non-anatomical wedge resection and 431 patients who underwent lobectomy. Cox modelling demonstrated no survival difference between groups for the first 1.6 years then a risk of death 3-fold higher for wedge resection group after 1.6 years (HR 3.14, CI 1.98-4.79). Propensity matching yielded 152 pairs for which 5-year survival was 66.2% for the lobectomy group and 38.5% for the non-anatomical wedge group (SMD = 0.58, p = 0.003).

CONCLUSIONS

Non-anatomical wedge resection was associated with significantly reduced 5-year survival compared to lobectomy in matched patients. Lobectomy should remain the standard of care for patients with early-stage lung cancer who are fit enough to undergo surgical 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.

Prognostic role of preoperative carcinoembryonic antigen level in part-solid lung adenocarcinoma

BACKGROUND

Part-solid lung adenocarcinoma appears as a heterogeneous subgroup, and its surgical management is controversial. This study aimed to elucidate whether preoperative carcinoembryonic antigen, a time-honored tumor marker, can be used as a prognostic factor that contributes to its management.

METHODS

We retrospectively reviewed consecutive patients with clinical-T1a-cN0M0 part-solid adenocarcinoma who underwent surgical resection between January 2011 and December 2015 at two institutions.

RESULTS

Overall, 288 patients were identified. The median age was 69 years with 176 patients (61%) being female. The median follow-up time was 5.6 years. Lymph node metastases were found in 6 (15%) of 41 patients with elevated carcinoembryonic antigen levels, while 10 (4.0%) of 247 patients had normal carcinoembryonic antigen levels (P = 0.016). The 5-year overall survival rates in patients with normal and elevated carcinoembryonic antigen levels were 96.9% and 87.2%, respectively (P = 0.006), and the 5-year relapse-free survival rates were 91.8% and 62.8%, respectively (P < 0.001). The multivariable analysis revealed that preoperative carcinoembryonic antigen level was a significant prognostic factor for relapse-free survival (hazard ratio [HR] = 2.92, 95% confidence interval [CI] = 1.63-5.25, P < 0.001). Among the patients with elevated carcinoembryonic antigen levels, the 5-year overall survival rates in those undergoing lobar resection and segmentectomy were 87.0% and 88.9%, respectively (P = 0.59), and the 5-year relapse-free survival rates were 61.7% and 66.7%, respectively (P = 0.84).

CONCLUSIONS

Our data suggest that preoperative carcinoembryonic antigen level appears to be an important predictor of postoperative survival outcomes in early-stage part-solid adenocarcinoma. Further studies are required to optimize management of patients with elevated preoperative carcinoembryonic antigen levels, although segmentectomy appeared acceptable in those patients.

The Change Trend of Cause of Death in Patients With Stage I Non-Small Cell Lung Cancer After Surgery in US: A Long-Term Follow-Up Study Based on SEER Database

There are few studies on the cause of death in patients with stage I non-small cell lung cancer after surgery. Our aim is to study the trend of cause of death and risk factors affecting prognosis in the patients. We retrospectively reviewed patients in Surveillance, Epidemiology and End results database from 2004 to 2015. The change trend between cause of death and follow-up time was studied by calculating the proportion of cause of death at different periods and analyzing the cumulative risk. COX risk regression model was performed by univariate and multivariate analyses for survival analysis. Finally, 23,652 patients were enrolled. In the whole cohort, lung cancer accounted for 18.68% of deaths, followed by other causes (9.57%), heart disease (5.12%) and COPD (3.89%). With the increasing of follow-up time, the cumulative incidence of lung cancer was always the highest, but the growth rate in the late follow-up period was slower than that caused by heart disease and COPD. The proportion of death due to lung cancer decreased from 53.1%-73.1% in 0-30 months after follow-up to 7.8%-41.4% in 90 months after follow-up, while the proportion of deaths due to heart disease and COPD increased. Age was an independent risk factor for lung cancer-, heart disease- and COPD-specific survival, while lobectomy resection was a protective factor, even in patients older than 70 years old. In conclusion, during the follow-up period, lung cancer was still the main cause of death, but the proportion of patients died of heart disease and COPD increased gradually, especially in elderly. Furthermore, age was an important independent factor affecting prognosis, particularly for heart disease- and COPD-related mortality. The application of wedge resection in elderly patients needs further exploration.

Assessing Differences in Lymph Node Metastasis Based Upon Sex in Early Non-Small Cell Lung Cancer

BACKGROUNDS

Whether sex has any impact on the risk of lymph node (LN) metastasis (LNM) in patients with early-stage non-small cell lung cancer (NSCLC) remains controversial. Therefore, we aimed to objectively compared the risk of LNM between female and male patients with early-stage NSCLC so as to figure out whether sex-different extent of surgery may be justified for treating these patients.

METHODS

We retrospectively collected clinical data of patients undergoing lobectomy or segmentectomy with systematic hilar and mediastinal LN dissection for clinical stage IA peripheral NSCLC from June 2014 to April 2019. Both multivariate logistic regression analysis and propensity score-matched(PSM) analysis were applied to compare the risk of LNM between female and male patients.

RESULTS

We finally included a total of 660 patients for analysis. In the analysis of unmatched cohorts, there was no significant different rate of LNM (12.4% Vs 13.9%, P=0.556), hilar/intrapulmonary LNM (8.4% Vs 10.7%, P=0.318) and mediastinal LNM(7.9% Vs 7.5%, P=0.851) between female and male patients. In the multivariate analysis, sex was not found to be an independent predictor of LN in these patients. Moreover, in the analysis of well-matched cohorts generated by PSM analysis, there was still no significant different rate of LNM (13.8% Vs 13.4%, P=0.892), hilar/intrapulmonary LNM (9.1% Vs 11.2%, P=0.442) and mediastinal LNM (9.1% Vs 6.5%, P=0.289) between female and male patients.

CONCLUSIONS

Sex was not an independent predictor of LNM in early-stage NSCLC and there is no sufficient evidence justifying for sex-different extent of surgical resection for these patients.

Is the size of the lepidic component negligible when measuring the size of the tumor to determine the stage of lung adenocarcinoma?

Background

After applying the 8th edition of the TNM staging system, the invasive component size, not total tumor size, began to be used as a T descriptor for the stage. The aim of this study was to evaluate whether the size of the lepidic component can be negligible when using only the invasive component size as the T descriptor.

Methods

From 2010 to 2018, 613 consecutive patients were diagnosed as having stage IA lung adenocarcinoma and underwent anatomical lobectomy at a tertiary hospital. Pathologic specimens and medical records were reviewed retrospectively. Statistical analyses were conducted to find out whether the recurrence of stage IA lung adenocarcinoma was more affected by total tumor size (including lepidic component size) or invasive component size.

Results

The 5-year recurrence-free survival (RFS) rates of stage 0, stage IA1, stage IA2, and stage IA3 were 100%, 98.4%, 89.1%, and 81.7%, respectively. In multivariate analysis, total tumor size was not a risk factor for recurrence, whereas invasive component size was a significant risk factor for recurrence (Hazard ratio =1.658, P=0.043). In subgroup analysis, 5-year RFS rates of large lung adenocarcinoma (total tumor size >3 cm) and others (total tumor size ≤3 cm) in the same invasive component size group (stage IA2 and stage IA3) were not statistically different.

Conclusions

Invasive component size was a risk factor for recurrence of stage IA lung adenocarcinoma, while total tumor size was not a risk factor. Therefore, it seems to be appropriate to ignore the size of the lepidic component.

Prognosis of wide wedge resection in patients with stage IA1 and IA2 lung adenocarcinoma with total tumor size including the lepidic component greater than 2 cm: a single center retrospective study

Background

Stage I lung adenocarcinoma with a lepidic component has a good prognosis after sublobar resection. The purpose of this study is to evaluate the prognosis of wide wedge resection in patients diagnosed with stage IA1 and IA2 lung adenocarcinoma (based on the eighth edition of the TNM staging system) in which the total tumor size, including the lepidic component, is more than 2 cm.

Methods

From 2010 to 2018, 180 consecutive patients were diagnosed with stage IA1 and IA2 lung adenocarcinoma with a total tumor size (including the lepidic component) of more than 2 cm, and they underwent wide wedge resection or lobectomy at a hospital in Korea. The patients were determined as stage IA1 or stage IA2, and their clinicopathological characteristics and prognosis were compared between the wedge resection group and the lobectomy group.

Results

The clinicopathological characteristics were not statistically different between the wedge resection group and the lobectomy group. There were no recurrences and cancer-related deaths during the follow-up period for patients with stage IA1 lung adenocarcinoma in the wedge resection group and the lobectomy group. However, the 5-year recurrence-free survival rates of the wedge resection group and the lobectomy group were statistically different (73.9% and 90.8%, respectively; P=0.031) in stage IA2 lung adenocarcinoma. In a multivariate analysis of risk factors for recurrence, wedge resection [hazard ratio (HR) =15.883; P=0.026] and lymphovascular invasion (HR =13.854; P=0.023) were significant risk factors for recurrence in patients with stage IA2 lung adenocarcinoma.

Conclusions

In the cases of lung adenocarcinoma with a total tumor size (including the lepidic component) of more than 2 cm, a good prognosis can be expected with wide wedge resection in stage IA1, but not an appropriate surgical choice for the cases in stage IA2.

CT-guided hook-wire localization of malignant pulmonary nodules for video assisted thoracoscopic surgery

Objectives

Video assisted thoracoscopic surgery (VATS) can currently be used to diagnose and treat pulmonary nodules. However, intraoperative location of pulmonary nodules in VATS is challenging due to their small diameter and deep location in the pulmonary parenchyma. The purpose of this study was to report the clinical safety and effectiveness of CT-guided hook-wire for preoperative localization of malignant pulmonary nodules smaller than 1 cm in diameter.

Methods

From February 2017 to January 2018, we collected the data of 80 patients with malignant pulmonary nodules less than 1 cm in diameter who underwent CT-guided hook-wire preoperative localization and VATS surgery. The effectiveness of preoperative localization was evaluated based on surgical duration, success rate of VATS surgery, and localization-related complications.

Results

The diameter of pulmonary nodules were 0.85 ± 0.17 mm with a distance to the pleural surface of 19.66 ± 14.10 mm. The length of the hook-wire in the lung parenchyma was 29.17 ± 13.14 mm and hook-wire dislodgement occurred in 2 patients. Complications included 27 cases of minor pneumothorax and 18 cases of mild parenchymal hemorrhage. A significant correlation was observed between the length of the hook-wire in the lung parenchyma and mild parenchymal hemorrhage (P = 0.044). The average time of hook-wire localization was 9.0 ± 2.6 min and the average operation time for VATS was 89.02 ± 23.35 min without conversion thoracotomy.

Conclusions

CT-guided hook-wire localization of the lesion during VATS resection is safe for malignant pulmonary nodules with diameter less than 1 cm.

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.

Survival outcomes of resection for pulmonary malignancies including non-small cell lung cancer and pulmonary metastasis after esophagectomy for esophageal carcinoma

OBJECTIVES

This study investigated survival outcomes of resection for pulmonary malignancies after esophagectomy for esophageal carcinoma, comparing non-small cell lung cancer and pulmonary metastases.

METHODS

We retrospectively reviewed consecutive patients who underwent resection for pulmonary malignancies after esophagectomy for esophageal carcinoma between 2009 and 2018. The overall survival and relapse-free survival rate were assessed using Kaplan-Meier analysis.

RESULTS

Eleven patients had non-small cell lung cancer and eight patients had pulmonary metastases from esophageal carcinoma. The 5-year overall survival rate was 92.9% in all patients with a median follow-up period of 50.4 (range: 9.1-130.2) months. While the 5-year overall survival rate was 100.0% in patients with non-small cell lung cancer, it was 85.7% in patients with pulmonary metastases from esophageal carcinoma. The 5-year relapse-free survival rate was 85.7% in patients with non-small cell lung cancer.

CONCLUSIONS

Our data suggest that resection for pulmonary malignancies after esophagectomy for esophageal carcinoma is associated with favorable survival outcomes and should be considered in selected patients.

Prognostic impact of lymphadenectomy on outcomes of sublobar resection for non-small cell lung cancer ≤1 or >1 to 2 cm

Background

Lymphadenectomy is an important part of surgical treatment for non-small cell lung cancer (NSCLC). However, the prognostic impact of lymph node (LN) dissection for patients with NSCLC ≤1 and >1 to 2 cm who underwent sublobar resection is still unclear.

Methods

A group of patients numbering 7,627 with NSCLC 2 cm or less who underwent sublobar resection were identified from the Surveillance, Epidemiology, and End Results (SEER) database between January 2010 and November 2015. The overall survival (OS) and lung cancer-specific survival (LCSS) were evaluated among patients who had undergone dissection of ≥4 LNs, 1 to 3 LNs or who had no-LN dissection; log-rank and Cox proportional-hazards regression analyses were used for the evaluation.

Results

Patients with NSCLC ≤2 cm who underwent ≥4 LNs dissection had better OS and LCSS compared with those who underwent dissection of 1 to 3 LNs or who had no-LN dissection after sublobar resection. Subgroup analysis showed that dissection of ≥4 LNs had better OS and LCSS than those of 1 to 3 LNs dissection in NSCLC >1 to 2 cm, whereas had similar OS and LCSS in NSCLC ≤1 cm. Multivariate Cox analysis showed that dissection of 1 to 3 LNs was not an independent risk factor of OS and LCSS than dissection of ≥4 LNs in NSCLC ≤1 cm after sublobar resection.

Conclusions

The extent of LN dissection is associated with the survival outcomes in patients with NSCLC ≤2 cm after sublobar resection. Dissection of ≥4 LNs should be recommended for NSCLC >1 to 2 cm, whereas surgeons can rely on surgical skills and patient profiles to decide ≥4 LNs or 1 to 3 LNs dissection for NSCLC ≤1 cm during sublobar resection.

Surgical Choice for Clinical Stage IA Non-Small Cell Lung Cancer: View From Regional Lymph Node Metastasis

BACKGROUND

We aimed to investigate the pattern of regional lymph node (LN) metastasis of early-stage non-small cell lung cancer (NSCLC) to provide novel rationale for surgical choice (lobectomy, segmentectomy, or wedge resection) for these patients.

METHODS

We retrospectively collected clinical data of patients undergoing lobectomy with systematic mediastinal LN dissection or sampling for cT1N0M0 peripheral NSCLC from January 2015 to December 2018. The regional LN metastasis pattern was analyzed based on tumor size.

RESULTS

We included a total of 354 patients for analysis. The rate of hilar or intrapulmonary LN metastasis was 13.6%. When stratified by tumor size, NSCLC less than or equal to 1 cm had no hilar or intrapulmonary LN metastasis (0%) while NSCLC greater than 2 cm but less than or equal to 3 cm had a significantly high rate of hilar or intrapulmonary LN metastasis (18.4%) and the rates of hilar, interlobar, and peripheral LN metastasis were also relatively high (5.4%, 5.4%, and 12.2%, respectively). NSCLC greater than 1.5 cm but less than or equal to 2 cm also had relatively high rates of hilar (6.5%) and peripheral (18.3%) LN metastasis, while NSCLC greater than 1 cm but less than or equal to 1.5 cm had significantly low rates of hilar or intrapulmonary (2.5%) and peripheral (2.5%) LN metastasis. Radiographic feature and histology were found to be independent predictors of regional LN metastasis.

CONCLUSIONS

The pattern of regional LN metastasis in clinical stage IA peripheral NSCLC was significantly influenced by tumor size, which may provide evidence on surgical choice (lobectomy, segmentectomy, or wedge resection) for these early-stage NSCLC patients based on tumor size.

[Clinical Characteristics and Prognosis of Sub-centimeter Lung Adenocarcinoma]

背景与目的

随着肺癌筛查的逐渐推广，越来越多的患者被确诊为亚厘米(直径≤1 cm)肺腺癌。亚厘米肺腺癌多为早期肺癌，但目前关于亚厘米肺腺癌的研究仍不充分。本研究针对亚厘米肺腺癌患者临床特征及预后进行分析，为该类患者的诊疗提供依据。

方法

回顾性分析2012年1月-2016年12月北京大学人民医院经胸腔镜手术病理确诊为亚厘米肺腺癌患者的临床及预后资料。根据结节影像学特征将患者分为纯磨玻璃结节(pure ground-glass nodules, pGGN)、混杂性磨玻璃结节(mixed ground-glass nodules, mGGN)和实性结节(solid nodules, SN)组，对比三组患者临床特征并对不同直径结节行亚组分析。此外，通过多因素分析筛选亚厘米肺浸润性腺癌的独立危险因素。

结果

本组共182例患者，中位年龄54(27-75)岁。男性57例，女性125例。女性亚厘米肺腺癌患者无吸烟史比例显著高于男性(P < 0.001)。所有1 mm-10 mm pGGN、1 mm-5 mm mGGN及1 mm-5 mm SN患者术后病理除原发灶外无其他阳性发现。46例6 mm-10 mm mGGN患者中有3例侵犯胸膜，1例发现脉管癌栓。39例6 mm-10 mm SN患者中有5例侵犯胸膜，2例发现脉管癌栓，2例出现淋巴结转移。侵犯胸膜、发现脉管癌栓或淋巴结转移的患者其病理类型均为浸润性腺癌。多因素Logistic回归分析发现吸烟史、既往肿瘤病史、mGGN、SN和肿瘤直径 > 5 mm是病理为肺浸润性腺癌的独立危险因素。中位随访时间44(22-82)个月，全组患者5年无复发生存率100.0%，总生存率98.9%。

结论

亚厘米肺腺癌患者发病年龄相对较小。影像学表现为6 mm-10 mm mGGN和6 mm-10 mm SN的亚厘米肺浸润性腺癌患者存在侵犯胸膜或淋巴结转移可能。吸烟史、既往肿瘤病史、mGGN、SN和肿瘤直径 > 5 mm为亚厘米肺浸润性腺癌的独立危险因素。对于亚厘米肺腺癌患者，早期发现并采取合适且有效的外科干预可获得良好的预后。

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.

Application of intrapulmonary wire combined with intrapleural fibrin glue in preoperative localization of small pulmonary nodules

OBJECTIVE

This study aims to investigate the accuracy of the preoperative localization of small nodules by computerized tomography (CT)-guided placing wire and intrapleural fibrin glue near the nodules at 3 days before the operation.

METHODS

From October 2015 to December 2017, a total of 79 patients, who received preoperative localization of small pulmonary nodules and surgical treatment in the Department of Thoracic Surgery of Hohhot First Hospital, were enrolled into this study. These patients were randomly divided into 2 groups: methylene blue localization group (n = 47), and modified localization group (n = 32), where the patients received preoperative localization of the small nodules by CT-guided placing wire and intrapleural fibrin glue near the nodule at 3 days before the operation. Localization accuracy, operation time and difficulty in postoperative seeking for pathological specimens were compared between these 2 groups.

RESULTS

In the methylene blue localization group, 3 patients had localization failure due to the intrathoracic diffusion of methylene blue, and the success rate was 93.61%. In the modified localization group, all 32 patients succeeded in the localization, and the success rate was 100%. Operation time and difficulty of finding the specimen was significantly lower in the modified localization group than in the methylene blue localization group (P < .05).

CONCLUSION

The application of preoperative localization of small nodules by placing wire and intrapleural fibrin glue improves the success rate of resection, reduces operation time and the risk of the operation, and lowers the difficulty of finding pathological specimens after the operation. Hence this operative procedure is worthy of popularization.

The impact of PRDX4 and the EGFR mutation status on cellular proliferation in lung adenocarcinoma

Background: Oxidative stress plays key roles in the progression of lung adenocarcinoma. Recently, we reported that peroxiredoxin 4 (PRDX4), an antioxidant enzyme, can be a prognostic marker of lung adenocarcinoma (LUAD). In the present study, we aimed to further investigate the relationship among the PRDX4 expression, epidermal growth factor receptor (EGFR) mutations and cell proliferation in LUAD. Methods: The expression of PRDX4 was immunohistochemically analyzed and the EGFR mutation status was examined in 127 paraffin-embedded human surgical specimens from patients with stage I LUAD. The PRDX4 expression was considered to be high when >40% of the adenocarcinoma cells were positively stained. In vitro, using plasmid transfection methods, PRDX4 plasmid DNAs were transfected into human lung adenocarcinoma cell lines, A549 (EGFR-wild) or PC-9 (EGFR mutant). The viability of these cells was analyzed using a Cell Counting Kit-8 kit. Results: The number of cases with high PRDX4 expression levels among patients with LUAD with EGFR mutations was significantly larger than that in patients with EGFR wild-type. The combination of the PRDX4 expression level with the EGFR mutation status was closely associated with the prognosis of patients with stage I LUAD. Viability assays showed that the proliferation of A549 cells was significantly suppressed after PRDX4 plasmid transfection, while the overexpression of PRDX4 had no effect on the proliferation of EGFR-mutant PC-9 cells. Conclusions: The PRDX4 expression and EGFR mutation status were significantly associated with the prognosis of patients with stage I LUAD, and EGFR mutations affected the role of PRDX4 in the proliferation of LUAD cells.

Persistence of racial disparities in early-stage lung cancer treatment

OBJECTIVE

Although the incidence of lung cancer has decreased over the past decades, disparities in survival and treatment modalities have been observed for black and white patients with early-stage non-small cell lung cancer, despite the fact that surgical resection has been established as the standard of care. Possible contributors to these disparities are stage at diagnosis, comorbidities, socioeconomic factors, and patient preference. This study examines racial disparities in treatment, adjusting for clinicodemographic factors.

METHODS

The Surveillance, Epidemiology, and End Results-Medicare dataset was queried to identify patients diagnosed with primary stage I non-small cell lung cancer between 1992 and 2009. Multivariable logistic regressions were performed to assess the association between race and treatment modalities within 1 year of diagnosis, adjusted for clinical and demographic factors. Adjusted Cox proportional hazards models were performed to evaluate disparities in survival, accounting for mode of treatment.

RESULTS

We identified 22,724 patients; 21,230 (93.4%) white and 1494 (6.6%) black. Black patients were less likely to receive treatment (odds ratio [OR]_adj, 0.62; 95% confidence interval [CI], 0.53-0.73) and less likely to receive surgery only when treated (OR_adj, 0.70, 95% CI, 0.61-0.79). Although univariate survival for black patients was worse, when accounting for treatment mode, there was no difference in survival (hazard ratio_adj, 0.97; 95% CI, 0.90-1.04 for all patients, hazard ratio_adj, 0.98; 95% CI: 0.90-1.06 for treated patients).

CONCLUSIONS

Treatment disparities persist, even when adjusting for clinical and demographic factors. However, when black patients receive similar treatment, survival is comparable with white patients.

[Expression and Clinical Significance of LC-3 and P62 in Non-small Cell Lung Cancer]

BACKGROUND

LC-3 and P62, two of important autophagy-related proteins, were reported highly expressed in many kinds of human malignancies and associated with outcomes of the patients. The purpose of this study was to investigate the expression status of LC-3 and P62 in non-small cell lung cancer patients and define the clinical-pathologic features.

METHODS

66 cases of non-small cell lung cancer patients were employed. The expression of LC-3 and P62 were detected by immunohistochemistry.

RESULTS

LC-3 was positive stained in 27 out of 66 cases (40.9%) and P62 was positive stained in 43 out of 66 cases (65.2%). LC-3 positive staining was more frequently in squamous cell carcinoma patients (P<0.05); while P62 positive staining was more frequently in late-stage adenocarcinoma patients with metastasis (P<0.05). There was a significant negative correlation between LC-3 and P62 expressions in non-small cell lung cancer tissues (rs=-0.065, P<0.001). Kaplan-Meier analysis showed that patients with positive LC-3 expression had favorable clinical outcomes compared with the patients with negative LC-3 expression (P<0.05).

CONCLUSIONS

LC-3 and P62 showed abnormal expression in non-small cell lung cancer tissues, suggesting that autophagy is involved in the occurrence and development of NSCLC.

Early stage lung cancer survival after wedge resection and stereotactic body radiation

BACKGROUND

The comparative effectiveness of stereotactic body radiation therapy (SBRT) and wedge resection in the treatment of early stage lung cancer is still under debate. This meta-analysis compares the 5-year overall survival (OS) of wedge resection and SBRT in patients with stage I non-small cell lung cancer (NSCLC).

METHODS

Original research articles published between 1995 and 2017 were identified through the National Library of Medicine and National Institutes of Health PubMed database and through the reference lists of reviewed articles. Data were processed and analyzed in R (version 3.4.2) and a summary estimate that accounted for the sample size of each study was calculated. The combined percent survival was calculated using random effect models. Funnel plots were used to assess publication bias. Heterogeneity was tested using the Q statistic and the I2 statistic.

RESULTS

There were 16 studies totaling 1,984 patients with stage I NSCLC treated with wedge resection. The meta-estimate was 74% (95% CI, 66-81%), with significant heterogeneity across studies (Q =172.46, P<0.0001; I2=91.30%). Thirty-six studies including 3,309 patients with stage I NSCLC treated with SBRT/SABR produced a meta-estimate of 44% (95% CI, 38-50%), with significant heterogeneity (Q =423.55, P<0.0001; I2=91.74%). Two articles directly comparing stage I NSCLC patients treated with wedge resection to patients treated with SBRT both reported higher 5-year OS after wedge resection.

CONCLUSIONS

SBRT is a treatment option reserved to medically inoperable patients, but could be an alternative to surgery in medically operable patients who prefer a less invasive treatment. More standardized methods for data collection and reporting are necessary to allow better comparisons across published studies.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

What is the role of wedge resection for T1a lung cancer?

Since 1995, lobar resection became the standard of care for medically fit patients with early stage lung cancer. This was based on the results of a single randomized trial comparing lobectomy and sublobar resection (SLR) in stage I lung cancer conducted by the lung cancer study group between 1982 and 1988. The conclusions of the study included a statistically significant tripling in loco-regional recurrence (LR) after limited resection but no difference between the two arms of the trial in systemic recurrence. Although both overall survival and cancer specific survival favored lobectomy, neither achieved statistical significance. Regardless, this landmark trial established lobectomy as the preferred oncological resection for early stage lung cancer. The practice of thoracic surgery has evolved significantly since the study period of the Lung Cancer Study Group, and this has led some surgeons to question its relevance to contemporary practice. The increased detection of smaller more precisely staged tumors combined with the rising segment of the population that is elderly with limited cardiopulmonary reserve has renewed interest in sub-lobar resection including wedge resection as either a definitive therapeutic strategy or as a compromise approach in patients with poor performance status. The interest in wedge resections is also to some extent further fueled by the emergence and increased utilization of competing technologies of local control such as stereotactic radiation or percutaneous and trans-bronchial ablative techniques. Although the results of the LCSG still cast a long shadow over the soundness of wedge resection as a cancer operation, much literature has been published in the subsequent years on this topic. We present in this review an overview of the conflicting data and offer our perspective on the role of wedge resection in early stage lung cancer.

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

Background

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

Methods

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

Results

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

Conclusion

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

Clinical analysis of the impact of sublobectomy on pulmonary function

The present study investigated and analyzed the clinical impact of sublobectomy on pulmonary functions.Changes in pulmonary function before and after sublobectomy were compared to the changes after lobectomy.Changes in the pulmonary function before and after sublobectomy and lobectomy did not exhibit remarkable differences in long-term effects. Surgery-related indexes of the sublobectomy group were significantly lower than those of the lobectomy group (P < .05). The indexes of pulmonary function both before and after surgery in the sublobectomy group were not associated with a significant decrease in the quality of survival based on pulmonary function as the main index (P > .05).Compared with lobectomy, sublobectomy maximally retained the normal healthy pulmonary tissue, with similar local recurrence rate, 5-year recurrence-free survival rate, and 5-year survival rate. Sublobectomy decreased the impact on respiratory functions to the minimum. After the operation, the quality of survival with pulmonary functions as the main index did not decrease significantly. Therefore, sublobectomy could be an appropriate choice for elderly patients with poor cardiopulmonary function or with chronic diseases.

The Impact of Margins on Outcomes After Wedge Resection for Stage I Non-Small Cell Lung Cancer

BACKGROUND

The relationship between margin distance and recurrence and survival for stage I non-small cell lung carcinoma (NSCLC) less than or equal to 2 cm is not clear.

METHODS

Patient clinicopathologic data were reviewed from a pooled data set of stage I NSCLC lesions less than or equal to 2 cm resected by wedge resection at Brigham and Women's Hospital (BWH) between 2000 and 2005 and the International Early Lung and Cardiac Action Program (I-ELCAP) between 1999 and 2015. Multivariable models were constructed to evaluate the relationship between margin distance and recurrence and survival, adjusting for patient age, sex, tumor size, and histologic type. Optimal margin distance was determined for recurrence-free and overall survival using maximum χ² values among survival distributions.

RESULTS

Of 182 cases, 138 tumors had margin distance reported (113 BWH and 25 I-ELCAP). The average tumor size was 13.3 mm, and margin distance was 8.3 mm. During a mean follow-up of 49.6 months, there were 33 recurrences and 59 deaths. Increased margin distance was independently associated with lower risk of recurrence (odds ratio [OR], 0.90; 95% confidence interval [CI], 0.83-0.98). Margin distance was also independently associated with longer survival (hazard ratio [HR], 0.94; 95% CI, 0.90-0.98). A margin distance greater than 9 mm was associated with longest recurrence-free survival and a margin distance greater than 11 mm was associated with longest overall survival.

CONCLUSIONS

Increased margin distance was independently associated with lower risk of recurrence and longer overall survival in patients undergoing wedge resection for NSCLC tumors less than or equal to 2 cm. These findings suggest that with a minimum appropriate margin distance, wedge resection may yield outcomes comparable to those of lobectomy.

Computed Tomography Screening for Lung Cancer: Mediastinal Lymph Node Resection in Stage IA Nonsmall Cell Lung Cancer Manifesting as Subsolid and Solid Nodules

OBJECTIVE

To compare long-term survival rates of patients with first, primary, clinical stage IA nonsmall cell lung cancer from a large cohort undergoing computed tomography screening with and without mediastinal lymph node resection (MLNR) under an Institutional Review Board-approved common protocol from 1992 to 2014.

BACKGROUND

Assessing survival differences of patients with and without MLNR manifesting as solid and subsolid nodules.

METHODS

Long-term Kaplan-Meier (K-M) survival rates for those with and without MLNR were compared and Cox regression analyses were used to adjust for demographic, computed tomography, and surgical covariates.

RESULTS

The long-term K-M rates for 462 with and 145 without MLNR was 92% versus 96% (P = 0.19), respectively. For 203 patients with a subsolid nodule, 151 with and 52 without MLNR, the rate was 100%. For the 404 patients with a solid nodule, 311 with and 93 without MLNR, the rate was 87% versus 94% (P = 0.24) and Cox regression showed no statistically significant difference (P = 0.28) when adjusted for all covariates. Risk of dying increased significantly with increasing decades of age (hazard ratio [HR] 2.3, 95% confidence interval [CI] 1.4-3.8), centrally located tumor (HR 2.5, 95% CI 1.2-5.2), tumor size 21 to 30 mm (HR 2.7, 95% CI 1.2-6.0), and invasion beyond the lung stroma (HR 3.0, 95% CI 1.4-6.1). For the 346 patients with MLNR, tumor size was 20 mm or less; K-M rates for the 269 patients with and 169 patients without MLNR were also not significantly different (HR 2.1, P = 0.24).

CONCLUSIONS

It is not mandatory to perform MLNR when screen-diagnosed nonsmall cell lung cancer manifests as a subsolid nodule.

Temporal trends in centralization and racial disparities in utilization of high-volume hospitals for lung cancer surgery

Racial disparities have been suggested in hospital utilization and outcome for lung cancer surgery, but the effect of hospital centralization on closing this gap is unknown. We hypothesized that centralization has increased the utilization of high- or very-high-volume (HV/VHV) hospitals, a proxy for access to high-quality care, over the study period independently from race.Inpatient records were extracted from the New York Statewide Planning and Research Cooperative System database (1995-2012) according to Clinical Modification of the International Classification of Diseases, 9th Revision diagnosis codes 162.* and 165.* and surgical procedure codes 32.2-32.6 (n = 31,931). Patients treated exclusively with surgery of black or white race with a valid zip code were included. Logistic models were performed to determine factors associated with utilization of HV/VHV or low- or very-low-volume (LV/VLV) hospitals; these models were subsequently stratified by race.The percentage of both black and white patients utilizing HV/VHV hospitals increased over the study period (+22.7% and 13.9%, respectively). The distance to the nearest HV/VHV hospital and patient-hospital distance were significantly lower in black compared to white patients, however, blacks were consistently less likely to use HV/VHV than whites (odds ratioadj: 0.26; 95% confidence interval: 0.23-0.29), and were significantly more likely to utilize urban, teaching, and lower volume hospitals than whites. Likelihood of HV/VHV utilization decreased with an increasing distance from a HV/VHV hospital, overall and separately for black and white patients.Although centralization has increased the utilization of HV/VHV for both black and white patients, racial differences in access and utilization of HV hospitals persisted.

[Issues Need to be Considered in Sublobectomy for Early Stage Lung Cancer]

随着医学技术的进步，早期肺癌患者数量逐年增加，亚肺叶切除治疗在早期肺癌个体化治疗的价值逐渐受到重视。目前，在早期肺癌的术式选择上，肺叶切除和亚肺叶切除孰优孰劣尚存在一些争议。本文就当前亚肺叶切除治疗早期肺癌的下述争议点进行了总结：①循证医学证据；②楔形和肺段的适应症选择；③肿瘤直径和切缘距离的权重比较；④老年人的术式选择。

Risk factors for recurrence after sublobar resection in patients with small (2 cm or less) non-small cell lung cancer presenting as a solid-predominant tumor on chest computed tomography

BACKGROUND

Sublobar resection is considered controversial for non-small cell lung cancer (NSCLC) presenting as a solid-predominant nodule. The aim of this study was to identify risk factors related to recurrence in small-sized NSCLC presenting as a solid-predominant nodule.

METHODS

We conducted a retrospective chart review of 118 patients who were treated for clinical N0 NSCLC sized ≤2 cm and who underwent sublobar resection with clear resection margins. We assigned them to two groups according to radiologic features: ground glass opacity (GGO)-predominant tumor and solid-predominant tumor. Clinicopathological characteristics and survival were analyzed in both groups. Risk factors for recurrence were analyzed in the solid-predominant tumor group.

RESULTS

Seventy-three patients had a GGO-predominant tumor, and 45 patients had a solid-predominant tumor. Five-year recurrence-free survival (RFS) in the solid-predominant tumor and GGO-predominant tumor groups was 64.9% and 95.5%, respectively. A multivariate analysis was performed to determine factors associated with recurrence after sublobar resection in the solid-predominant tumor group; it indicated that SUVmax [hazard ratio (HR) =1.482, 95% confidence interval (CI): 1.123-1.956, P=0.005] and histologic types other than adenocarcinoma (squamous cell carcinoma, HR =8.789, 95% CI: 1.572-49.134, P=0.013; other types, HR =53.569, 95% CI: 2.616-1096.849, P=0.010) were significant risk factors for recurrence.

CONCLUSIONS

Risk factors in solid-predominant tumors sized ≤2 cm after sublobar resection are a high SUVmax and histologic types other than adenocarcinoma. Thus, lobectomy should be considered for solid-predominant NSCLC sized ≤2 cm with a high SUVmax or non-adenocarcinoma types.

Appropriateness of Surgical Approach in Black Patients with Lung Cancer-15 Years Later, Little Has Changed

INTRODUCTION

Black patients with lung cancer receive an operation less often and have worse survival than white patients. Over the past several decades limited resection has become an acceptable alternative to lobectomy in selected cases, and mediastinal lymph node staging is recommended. The Surveillance, Epidemiology, and End Results database was explored to assess whether the type of surgical approach is similar in black and white patients with lung cancer.

METHODS

All cases of pathologically proven lung cancers within the site code International Classification of Diseases for Oncology, Third Edition, C340 to C349 (67,191 whites and 13,387 blacks), age 64 years or younger, diagnosed between 2007 and 2012 were identified. The odds of treatment (operation or radiation) in blacks versus whites were calculated using multivariable logistic regression, with race as the dependent variable, overall and by disease stage.

RESULTS

Surgical treatment was significantly less likely to be administered to black patients than to white patients overall (OR_adjusted [OR_adj] = 0.69, 95% confidence interval [CI]: 0.65-0.74) and according to stage. Opposite results were observed when radiation was analyzed (OR_adj = 1.1, 95% CI: 1.04-1.12). Stratification by age groups (≤50 years versus >50 years) or insurance status did not influence the results. Among those who underwent a surgical procedure, black patients were less likely to have their lymph nodes resected overall (OR_adj = 0.79, 95% CI: 0.7-0.89) and according to stage.

CONCLUSIONS

Racial disparities in appropriate lung cancer treatment are still observed independently from insurance status.

Therapeutic strategy for small-sized lung cancer

Minimizing the volume of lung resection without diminishing curability has recently become an important issue in primary lung cancer. In this review, we will discuss the current state of the feasibility of sublobar resection and specific issues for a segmentectomy procedure. A previous randomized controlled trial showed that lobectomy must still be considered the standard surgical procedure compared with sublobar resection for T1N0 non-small cell lung cancer with a tumor less than 3 cm in size. Since then, supporting studies for segmentectomy of lung cancer with a tumor less than 2 cm in size were reported. In addition, segmentectomy seems to be feasible for clinical stage I adenocarcinoma less than 2 cm in size, in women younger than 70 years old, with a low tumor 18F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) standardized uptake value (SUV) from propensity-matching studies. In a meta-analysis of sublobar resection vs. lobectomy, intentionally performed sublobar resection showed equivalent outcomes to lobectomy. In the near future, two ongoing prospective, randomized trials will report results. As specific issues for the surgical procedure of segmentectomy, achieving a sufficient surgical margin is an important issue for preventing loco-regional recurrence. More studies regarding the regional lymph node dissection area for segmentectomy are needed. Sublobar resection has the potential to become the standard procedure for peripheral small-sized lung cancer less than 2 cm. However, more information is needed about the characteristics of this cancer and the surgical procedure, including nodal dissection.

Management of CT screen-detected lung nodule: the thoracic surgeon perspective

Implementation of lung cancer CT screening programs will increase the incidence of pulmonary nodules and require multidisciplinary efforts for devising appropriate treatment plans. The role of the thoracic surgeon is paramount in leading the discussion and shaping the treatment strategies. Management of CT screen-detected lung nodules differ from conventional lung cancer nodules given their smaller size, varied histologies and potentially indolent growth. Here we present a brief overview of the thoracic surgeon's perspective on the clinical evaluation, diagnostic tests and surgical approach to these nodules in the setting of a comprehensive lung cancer screening program.