Consolidation/Tumor Ratio on Chest Computed Tomography as Predictor of Postoperative Nodal Upstaging in Clinical T1N0 Lung Cancer

Mediastinal lymph node dissection in segmentectomy for peripheral c-stage IA (≤2 cm) non-small-cell lung cancer

OBJECTIVE

Although recent trials on intentional segmentectomy have made mediastinal lymph node dissection (MLND) mandatory, the necessity of MLND in segmentectomy remains uncertain. We conducted a retrospective study to evaluate the necessity of MLND in segmentectomy for patients with peripheral stage IA (≤2 cm) non-small cell lung cancer.

METHODS

Of the 5222 surgical cases for non-small cell lung cancer from 3 institutions between 2010 and 2021, 1457 patients met the JCOG0802 trial eligibility criteria. Initially, we analyzed 574 patients who underwent lobectomy with MLND to identify preoperative risk factors for cN0-pN2 occurrence (cohort 1). Subsequently, we evaluated the relationship between these factors and the cumulative postoperative recurrence in 390 patients who underwent segmentectomy (cohort 2).

RESULTS

In cohort 1, risk factors for cN0-pN2 occurrence were consolidation-to-tumor ratio = 1.0 and maximum standardized uptake value ≥2.0. When classifying patients into 3 groups (group A, without any factors, group B, with either factor, and group C, with both factors), the occurrence of cN0-pN2 was significantly greater in group C than in the other groups (0.9%, 3.4%, and 8.4%, respectively, P = .005). When classifying patients in cohort 2 using the classification identified in cohort 1 (117, 131, and 142 were categorized into group A, group B, and group C, respectively), the 5-year cumulative incidence of recurrence rate was significantly greater in group C than in others (2.0%, 2.0%, and 15.9%, respectively, P < .001).

CONCLUSIONS

MLND is unlikely to be beneficial in intentional segmentectomy for patients with tumors showing consolidation-to-tumor ratio <1.0 and maximum standardized uptake value <2.0.

The Relationship Between Nodal Metastases and Primary Location in Stage I Non-Small Cell Lung Cancer

INTRODUCTION

This study examines the relationship between location of the primary tumor and specific nodal metastases in clinical stage 1 non-small cell lung cancer (NSCLC) patients undergoing lobectomy.

METHODS

We retrospectively analyzed all lobectomies performed at a single institution, between January 2005 and December 2019, for clinical stage I NSCLC patients. Patients selected for this study were clinically node negative (cN0) by positron emission tomography-computed tomography scan and selectively by endobronchial ultrasound or mediastinoscopy. Cases of postoperative pathologic nodal upstaging were identified among these patients. For each patient upstaged, the specific lymph node stations found to be positive were recorded. Descriptive statistics, chi-squared tests, and Fisher's exact test were utilized to identify independent risk factors for upstaging to specific N1 and N2 lymph node stations. All clinical and pathologic staging information was retrospectively normalized to the International Association for the Study of Lung Cancer 8th Edition TNM Classification.

RESULTS

The research cohort included 645 patients. The mean age was 68 years (standard deviation ± 9.2), 54% were female, and 88% were White, 11% Black, and 1% other. Twelve percent (n = 75) were upstaged from cN0 to pN1 or pN2 upon final pathologic examination: 41 to pN1 (54.7%) and 34 to pN2 (45.3%). The primary tumor location with the highest rate of nodal upstaging was the left upper lobe (LUL) (12.8%). Tumors in the right middle lobe had the lowest rate of unsuspected nodal metastases (8.8%). Out of all upstaged patients, there were no positive level eight lymph nodes, and only 1 patient with a positive level nine lymph node. Lymph node levels five and six were only positive in LUL primary tumors, a relationship that approached statistical significance (P = 0.0797). No patients with a LUL primary tumor had a positive level seven lymph node. Upstaging at station 12 was significantly associated with the location of the primary tumor, occurring less often in tumors originating in the right upper lobe in comparison to other lobes (P = 0.0288).

CONCLUSIONS

We identified relationships between the location of a primary tumor and specific nodal upstaging in patients with clinical stage I NSCLC who undergo lobectomy. We found the following: 1) only 1 patient had a positive level eight or nine lymph node out of 645 patients; 2) only LUL primary tumors demonstrated upstaging to level five or six lymph nodes; and 3) right upper lobe tumors were significantly less likely to be associated with a positive level 12 lymph node.

Distinct impacts of radiological appearance on lymph node metastasis and prognosis based on solid size in clinical T1 non-small cell lung cancer

BACKGROUND

Solid nodules (SN) had more aggressive features and a poorer prognosis than part-solid nodules (PSN). This study aimed to evaluate the specific impacts of nodule radiological appearance (SN vs. PSN) on lymph node metastasis and prognosis based on solid size in cT1 non-small cell lung cancer (NSCLC).

METHODS

Patients with cT1 NSCLC who underwent anatomical resection between 2010 and 2019 were retrospectively screened. Univariable and multivariable logistic regression analyses were adopted to evaluate the associations between nodule radiological appearance and lymph node metastasis. The log-rank test and Cox regression analyses were applied for prognostic evaluation. The cumulative recurrence risk was evaluated by the competing risk model.

RESULTS

There were 958 and 665 NSCLC patients with PSN and SN. Compared to the PSN group, the SN arm had a higher overall lymph node metastasis rate (21.7% vs. 2.7%, P < 0.001), including nodal metastasis at N1 stations (17.7% vs. 2.1%), N2 stations (14.0% vs. 1.6%), and skip nodal metastasis (3.9% vs. 0.6%). However, for cT1a NSCLC, no significant difference existed between SN and PSN (0 vs. 0.4%, P = 1). In addition, the impacts of nodule radiological appearance on lymph node metastasis varied between nodal stations. Solid NSCLC had an inferior prognosis than part-solid patients (5-year disease-free survival: 79.3% vs. 96.2%, P < 0.001). The survival inferiority only existed for cT1b and cT1c NSCLC, but not for cT1a. Strikingly, even for patients with nodal involvement, SN still had a poorer disease-free survival (P = 0.048) and a higher cumulative incidence of recurrence (P < 0.001) than PSN. Specifically, SN had a higher recurrence risk than PSN at each site. Nevertheless, the distribution of recurrences between SN and PSN was similar, except that N2 lymph node recurrences were more frequent in solid NSCLC (28.21% vs. 7.69%, P = 0.041).

CONCLUSION

SN had higher risks of lymph node metastasis and poorer prognosis than PSN for cT1b and cT1c NSCLC, but not for cT1a. SN exhibited a greater proportion of N2 lymph node recurrence than PSN. SN and PSN needed distinct strategies for nodal evaluation and postoperative follow-up.

Rate and Predictors of Unforeseen PN1/PN2-Disease in Surgically Treated cN0 NSCLC-Patients with Primary Tumor > 3 cm: Nationwide Results from Italian VATS-Group Database

Background. Since no robust data are available on the real rate of unforeseen N1-N2 disease (uN) and the relative predictive factors in clinical-N0 NSCLC with peripheral tumours > 3 cm, the usefulness of performing a (mini)invasive mediastinal staging in this setting is debated. Herein, we investigated these issues in a nationwide database. Methods. From 01/2014 to 06/2020, 15,784 thoracoscopic major lung resections were prospectively recorded in the “Italian VATS-Group” database. Among them, 1982 clinical-N0 peripheral solid-type NSCLC > 3 cm were identified, and information was retrospectively reviewed. A mean comparison of more than two groups was made by ANOVA (Bonferroni correction for multiple comparisons), while associations between the categorical variables were estimated with a Chi-square test. The multivariate logistic regression model and Kaplan–Meyer method were used to identify the independent predictors of nodal upstaging and survival results, respectively. Results. At pathological staging, 229 patients had N1-involvement (11.6%), and 169 had uN2 disease (8.5%). Independent predictors of uN1 were SUVmax (OR: 1.98; CI 95: 1.44–2.73, p = 0.0001) and tumour-size (OR: 1.52; CI: 1.11–2.10, p = 0.01), while independent predictors of uN2 were age (OR: 0.98; CI 95: 0.96–0.99, p = 0.039), histology (OR: 0.48; CI 95: 0.30–0.78, p = 0.003), SUVmax (OR: 2.07; CI 95: 1.15–3.72, p = 0.015), and the number of resected lymph nodes (OR: 1.03; CI 95: 1.01–1.05, p = 0.002). Conclusions. The unforeseen N1-N2 disease in cN0/NSCLCs > 3 cm undergoing VATS resection is observable in between 12 and 8% of all cases. We have identified predictors that could guide physicians in selecting the best candidate for (mini)invasive mediastinal staging.

Computed tomography radiomics in growth prediction of pulmonary ground-glass nodules

PURPOSE

Individualized follow-up of pulmonary ground-glass nodules (GGNs) remains challenging in clinical practice. Accurate prediction of the growth or long-term stability of persistent GGNs is essential to optimize the follow-up intervals.

METHODS

In this retrospective study, 253 patients with 1115 computed tomography (CT) images were recruited. In total, 1115 CT images were randomized into training (70%) and validation sets (30%). We developed models for the growth or long-term stable prediction of GGNs using radiomics and clinical features. We evaluated the prediction accuracy of the models using receiver operating characteristic (ROC) curve analysis, and the areas under the curve (AUCs) were established. The ROC curves of the models were compared using the DeLong method.

RESULTS

The growth and stable groups contained 535 and 580 GGNs, respectively. Traditional radiographic features have limited value in the prediction of growth or long-term stability of GGNs. The prediction nomogram model combining radiomics and clinical features (size, location, and age) yielded the best AUC in both the training and validation sets (AUC = 0.843 and 0.824, respectively). The radiomics model outperformed the clinical model in both sets (AUC: 0.836 vs 0.772 and 0.818 vs 0.735, respectively). The radiomics signature and nomogram model achieved similar AUCs (Delong test, training set: P = 0.09; validation set: P = 0.37).

CONCLUSIONS

We developed and validated a nomogram model combining radiomics signature, size, age, and location to predict the growth or long-term stability of GGNs. The model achieved good performance and may provide a basis for the improvement of follow-up management of GGNs.

Comparison of outcomes following lobectomy, segmentectomy, and wedge resection based on pathological subtyping in patients with pN0 invasive lung adenocarcinoma ≤1 cm

PURPOSE

We sought to analyze the prognostic significance of lung adenocarcinoma classification for patients with pathological N0 (pN0) lung invasive adenocarcinomas ≤1 cm who underwent surgical resection and investigate the optimal surgical procedure according to lung adenocarcinoma classification.

METHODS

A total of 1409 consecutive patients with resected pN0 invasive lung adenocarcinoma ≤1 cm were retrospectively reviewed. Comprehensive histologic subtyping was determined according to IASLC/ATS/ERS lung adenocarcinoma classification. Recurrence-free survival (RFS) and overall survival (OS) were compared between patients receiving lobectomy, segmentectomy, and wedge resection.

RESULTS

RFS and OS favored lobectomy and segmentectomy compared with wedge resection in the entire cohort. Five-year RFS rates were 100%, 98.2%, 97.3%, 77.8%, and 82.8% (p < 0.001) for lepidic, acinar, papillary, micropapillary, and solid predominant subtypes, while 5-year OS rates were 100%, 98.4%, 98.1%, 88.9%, and 96.5% (p < 0.001), respectively. Multivariate analysis showed that adenocarcinoma predominant pathological subtype and CT appearance were independent prognostic factors for RFS, and surgical procedure was independent factor for both RFS and OS. Specifically, wedge resection showed worse survival compared with anatomical resection in patients with papillary, micropapillary, or solid predominant subtypes, whereas in patients with lepidic predominant and acinar predominant subtypes, wedge resection showed comparable RFS with anatomical resection.

CONCLUSIONS

Anatomical resection showed better survival for patients with pN0 invasive lung adenocarcinoma ≤1 cm. For patients with invasive adenocarcinoma ≤1 cm in whom anatomical resection is not feasible, wedge resection could provide similar oncological effect when tumor is lepidic predominant or acinar predominant.

CT-guided Percutaneous Cryoablation in Patients with Lung Nodules Mainly Composed of Ground-Glass Opacities

PURPOSE

To assess the safety and efficacy of cryoablation in patients with lung nodules mainly composed of ground-glass opacities (GGOs).

MATERIALS AND METHODS

In this retrospective study, 50 patients (mean age, 65.0 ± 12.3; 28 women) diagnosed with lung GGO nodules who underwent cryoablation were included (from June 2016-June 2021). The local recurrence rate, the incidence of regional metastases to lymph nodes, the incidence of distant metastases, adverse events, and the lung function condition were analyzed.

RESULTS

Follow-up computed tomography (CT) was performed an average of 33 months (range, 3-60 months) after the cryoablation procedure. Outcomes were only evaluated in 30 patients. A total of 20 patients were excluded: 10 patients had no cancer detected at histopathological analysis and were diagnosed with CT scan or positron emission tomography-CT (PET/CT), and the other 10 patients had nodules with a diameter of less than 10 mm and a consolidation-to-tumor ratio (CTR) of more than 0.25, and thus histopathological analysis was not performed due to small nodule size and patients were diagnosed with CT or PET/CT. The local recurrence rate was 0% (0 of 30). Evidence of regional metastases of the lymph nodes was not found in any patients (0%; 0 of 30), and the incidence of distant metastases was 0% (0 of 30). No major complications were noted. Lung function recovered to normal within one month after cryoablation in all patients.

CONCLUSION

Cryoablation may serve as a safe and feasible option for the treatment of lung nodules mainly composed of GGOs.

Validation of completion lobectomy after wedge resection for ≤20 mm non-small cell lung cancer

Background

Completion lobectomy after wedge resection is occasionally performed when final histopathology shows an unexpected primary lung cancer even though the primary lesion has already been resected. The objective of this study was to assess the necessity of completion lobectomy after wedge resection for ≤20 mm non-small cell lung cancer (NSCLC).

Methods

Between 2006 and 2016, a total of 112 patients with NSCLC underwent wedge resection in our department. After exclusions, 40 patients were analyzed. Of these, 17 patients underwent completion lobectomy and 23 patients underwent wedge resection alone. Age, sex, tumor size, histology, other malignant diseases and final surgical procedure were used as prognostic variables. Survival analyses were confirmed using the Kaplan-Meier method and log-rank test.

Results

Median follow-up was 70.4 months. No significant difference in 5-year overall survival (OS) and relapse-free survival (RFS) were seen in patients who underwent wedge resection alone compared to the completion lobectomy group (OS: 72.6% vs. 62.5%, P=0.34; RFS: 64.2% vs. 50.0%, P=0.35). Multivariate analysis identified age (>65 years old) and male sex as independent prognostic factors for OS and RFS.

Conclusions

Completion lobectomy after wedge resection did not impact OS or RFS compared with wedge resection alone in patients with ≤20 mm NSCLC. These findings suggested that selected patients may not require resection of the remaining lobe or lymph node dissection after initial wedge resection.

Managing screening-detected subsolid nodules-the Asian perspective

The broad application of low-dose computed tomography (CT) screening has resulted in the detection of many small pulmonary nodules. In Asia, a large number of these detected nodules with a radiological ground glass pattern are reported as lung adenocarcinomas or premalignant lesions, especially among female non-smokers. In this review article, we discuss controversial issues and conditions involving these subsolid pulmonary nodules that we often face in Asia, including a lack or insufficiency of current guidelines; the roles of preoperative biopsy and imaging; the location of lesions; appropriate selection of localization techniques; the roles of dissection and sampling of frozen sections and lymph nodes; multifocal lesions; and the roles of non-surgical treatment modalities. For these complex issues, we have tried to present up-to-date evidence and our own opinions regarding the management of subsolid nodules. It is our hope that this article helps surgeons and physicians to manage the complex issues involving ground glass nodules (GGNs) in a balanced manner in their daily practice and provokes further discussion towards better guidelines and/or algorithms.

Risk Factors for Occult Lymph Node Metastasis in Peripheral Non-Small Cell Lung Cancer with Invasive Component Size 3 cm or Less

BACKGROUND

In the seventh edition TNM staging system for lung cancer, a high maximum standardized uptake value (SUVmax) on positron emission tomography was regarded as a risk factor for occult lymph node metastasis in clinical T1N0 non-small cell lung cancer (NSCLC). However, in the eighth edition TNM classification, tumors are classified according to the size of the invasive component only, and those with invasive component size ≤3 cm are diagnosed as stage T1. The aim of this study was to reassess the risk factors for occult lymph node metastasis under the eighth edition TNM classification for lung cancer.

METHODS

From 2010 to 2017, 553 patients with clinical N0 peripheral NSCLC with invasive component size ≤3 cm underwent anatomical lobectomy with systematic lymph node dissection. We analyzed these cases retrospectively to identify risk factors for postoperative nodal upstaging.

RESULTS

Among 553 study patients, 54 (9.8%) had nodal upstaging after surgery. In multivariate analysis adopting the eighth edition TNM classification for lung cancer, serum carcinoembryonic antigen (CEA) level (hazard ratio [HR] = 1.113, p = 0.002), invasive component size (HR = 2.398, p = 0.004), visceral pleural invasion (HR = 2.901, p = 0.005), and lymphatic invasion (HR = 9.336, p < 0.001) were significant risk factors for nodal upstaging, but SUVmax was not.

CONCLUSION

SUVmax is not a predictor of nodal upstaging in clinical N0 peripheral NSCLC with invasive component size ≤3 cm under the eighth edition TNM classification for lung cancer. Significant risk factors of occult lymph node metastasis are serum CEA level, tumor invasive component size, visceral pleural invasion, and lymphatic invasion.

The prognosis of stage I non-small cell lung cancer with visceral pleural invasion and whole pleural adhesion after video-assisted thoracoscopic lobectomy: A single center retrospective study

Background

In cases of peripheral lung cancer with visceral pleural invasion and severe pleural adhesion, the question arises as to whether video-assisted thoracoscopic surgery (VATS) is a safe operation. The purpose of this study was to evaluate whether whole pleural adhesion is a risk factor for recurrence of cancer when performing VATS lobectomy for stage I non-small cell lung cancer (NSCLC) with visceral pleural invasion.

Methods

From 2010 to 2018, 123 consecutive patients who were diagnosed as stage I NSCLC with visceral pleural invasion and who underwent VATS lobectomy, were reviewed retrospectively. Those patients with partial pleural adhesion were excluded. The prognoses of the patients in the whole pleural adhesion group were compared with those of the non-adhesion group.

Results

The clinicopathological characteristics were not found to differ between the two groups, with the exception of age. The mean age of the whole pleural adhesion group was found to be greater than that of the non-adhesion group (70.6 vs. 64.4, P=0.002). The 5-year recurrence-free survival rates for the whole pleural adhesion group and the non-adhesion group were 64.8% and 70.9% respectively, and they were not statistically different (P=0.545). In multivariate analysis, the extent of lymph node dissection (hazard ratio =13.854, P=0.023) was a significant risk factor for recurrence. Whole pleural adhesion was not a risk factor for recurrence.

Conclusions

Whole pleural adhesion was not a risk factor for recurrence after VATS lobectomy in stage I NSCLC with visceral pleural invasion. However, the extent of lymph node dissection was identified as an important prognostic factor.

Management of pulmonary ground-glass opacities: a position paper from a panel of experts of the Italian Society of Thoracic Surgery (SICT)

OBJECTIVES

A significant gap in our knowledge of how to manage pulmonary ground-glass opacities (GGOs) still exists. Accordingly, there is a lack of consensus among clinicians on this topic. The Italian Society of Thoracic Surgery (Società Italiana di Chirurgia Toracica, SICT) promoted a national expert meeting to provide insightful guidance for clinical practice. Our goal was to publish herein the final consensus document from this conference.

METHODS

The working panel of the PNR group (Pulmonary Nodules Recommendation Group, a branch of the SICT) together with 5 scientific supervisors (nominated by the SICT) identified a jury of expert thoracic surgeons who organized a multidisciplinary meeting to propose specific statements (n = 29); 73 participants discussed and voted on statements using a modified Delphi process (repeated iterations of anonymous voting over 2 rounds with electronic support) requiring 70% agreement to reach consensus on a statement.

RESULTS

Consensus was reached on several critical points in GGO management, in particular on the definition of GGO, radiological and radiometabolic evaluation, indications for a non-surgical biopsy, GGO management based on radiological characteristics, surgical strategies (extension of pulmonary resection and lymphadenectomy) and radiological surveillance. A list of 29 statements was finally approved.

CONCLUSIONS

The participants at this national expert meeting analysed this challenging topic and provided a list of suggestions for health institutions and physicians with practical indications for GGO management.

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.

Initial experience with uniportal video-assisted thoracoscopic surgery for the treatment of lung cancer performed by a surgeon who did not have previous experience performing multiportal thoracoscopic surgery: a single center retrospective study

Background

The purpose of this study was to evaluate the surgical outcome of uniportal video-assisted thoracoscopic surgery (VATS) for the treatment of non-small cell lung cancer performed by a surgeon who did not have previous experience performing open thoracotomy and multiportal VATS.

Methods

From January 2017 to December 2018, 85 patients underwent uniportal VATS anatomical pulmonary resection performed by one surgeon. The remaining 269 patients underwent multiportal VATS performed by other experienced surgeons. Clinicopathological characteristics and surgical outcomes of the uniportal VATS and multiportal VATS groups were compared.

Results

The uniportal VATS procedures included 7 segmentectomies, 66 lobectomies, 1 bilobectomy, and 1 pneumonectomy. There was no conversion to multiportal VATS or open thoracotomy. Patients who underwent multiportal VATS surgery were older, more often men, and more often smokers than those who underwent uniportal VATS. Other clinicopathological characteristics were not statistically different between the two groups. The number of dissected lymph nodes was higher in uniportal VATS than in multiportal VATS (16.8 vs. 14.6, P=0.030). Anesthetic time and operative time were shorter in uniportal VATS than in multiportal VATS (both P<0.001). Intraoperative blood loss was also less in the uniportal VATS group than in the multiportal VATS group (P<0.001). There were no statistical between-group differences in chest tube drainage period, hospital stay, postoperative complication rate, and operative mortality rate.

Conclusions

Uniportal VATS for pulmonary anatomical resection of non-small cell lung cancer performed by a surgeon without previous multiportal VATS experience yielded acceptable surgical outcomes.

Prognostic factors in stage IB non-small cell lung cancer according to the 8th edition of the TNM staging system after curative resection

Background

Patients with stage IB non-small cell lung cancer (NSCLC) with poor prognostic factors can be treated selectively with postoperative adjuvant chemotherapy. The aim of this study was to identify the prognostic factors of stage IB NSCLC according to the new 8^th edition of the tumor, node, and metastasis (TNM) staging system.

Methods

From 2005 to 2016, 211 patients who were diagnosed with stage IB NSCLC according to the 8^th edition of the TNM staging system underwent anatomical pulmonary resection (lobectomy or bilobectomy). We analyzed the outcomes of patients receiving adjuvant chemotherapy. The risk factors for prognosis after surgery were also analyzed for NSCLC stage IB.

Results

Differences between the 5-year recurrence-free-survival (RFS) rates (71.4% vs. 60.2%, P=0.173) and the 5-year disease-specific-survival (DSS) rates (88.0% vs. 81.4%, P=0.437) obtained by patients receiving surgical treatment only versus patients receiving both surgery and adjuvant chemotherapy, retrospectively, were not significant. Multivariate analysis was conducted to identify the risk factors for recurrence and cancer-related death. Lymphovascular invasion was an independent risk factor for both recurrence and cancer-related death [hazard ratio (HR) =2.045, P=0.020; HR =3.150, P=0.048, respectively).

Conclusions

Lymphovascular invasion was the only prognostic factor identified in patients with 8^th edition stage IB NSCLC. Adjuvant chemotherapy was not an effective treatment for patients with stage IB NSCLC. The efficacy of adjuvant chemotherapy for stage IB patients with lymphovascular invasion should be evaluated in a future study.

[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 of upstaged N1 and N2 disease after curative resection in patients with clinical N0 non-small cell lung cancer

Background

Nodal upstaging occasionally occurs after curative resection in clinical N0 non-small cell lung cancer (NSCLC). The purpose of this study was to evaluate the prognosis of clinical N0 NSCLC (T1-2, tumor size 5 cm or smaller) after upstaging to pathologic N1 or N2.

Methods

From 2005 to 2015, 676 consecutive patients were diagnosed with clinical T1-2N0 NSCLC and underwent curative resection. Among these, tumors were upstaged to N1 in 46 patients and to N2 in 24 patients. We analyzed the prognosis of upstaged tumors. For comparison of prognosis between nodal upstaging groups and others in the same stage, patients with preoperative pathologically proven N1 (n=31) and N2 (n=55) NSCLC were included in the study.

Results

A total of 70 patients (10.4%) had nodal upstaging after curative resection of clinical N0 NSCLC. Upstaging to N1 occurred in 46 patients and upstaging to N2 occurred in 24 patients. The 5-year disease-specific survival rate was not statistically different between the upstaged and non-upstaged N1/N2 groups in N1 disease (73.3% vs. 70.5%, P=0.247) or in N2 disease (58.9% vs. 50.7%, P=0.283). Multivariate analysis showed that nodal upstaging was not a significant prognostic factor in N1 or N2 NSCLC (hazard ratio =0.385, P=0.235; hazard ratio =0.677, P=0.458).

Conclusions

Postoperative nodal upstaging from clinical T1-2N0 NSCLC was not a significant prognostic factor in the same stage. Therefore, surgical treatment of clinical T1-2N0 lung cancer diagnosed by imaging without preoperative pathologic lymph node staging can be a treatment option.

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.

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.

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.