Sublobar resection versus lobectomy in solid-type, clinical stage IA, non-small cell lung cancer

Survival and pulmonary function in stage IA non-small cell lung cancer after sublobar resection versus lobectomy: An updated meta-analysis

Traditionally, lobectomy was standard for stage IA non-small-cell lung cancer (NSCLC). Recent RCTs suggest sublobar resection's comparable outcomes. Our meta-analysis, incorporating 30 studies (including four RCTs), assessed sublobar resection's efficacy. Employing a random-effects model and I2 statistics for heterogeneity, we found sublobar resection reduced DFS (HR 1.31, p < 0.01) and OS (HR 1.27, p < 0.01) overall. However, RCT subgroup analysis showed no significant differences in DFS (p = 0.28) or OS (p = 0.62). Sublobar resection is a viable option for well-selected patients.

Differential efficacy of segmentectomy and wedge resection in sublobar resection compared to lobectomy for solid-dominant stage IA lung cancer: a systematic review and meta-analysis

BACKGROUND

Currently, the impact of sublobar resection versus lobectomy on the prognosis of solid-dominant stage IA lung cancer is contradictory in different studies, which requires further exploration.

METHODS

The authors analyzed 26 studies, including one randomized controlled trial and retrospective cohort studies. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using fixed-effects or random-effects models based on heterogeneity levels.

RESULTS

The analysis included 12 667 patients, with 3488 undergoing sublobar resections and 9179 receiving lobectomies. The overall analysis revealed no statistically significant difference in overall survival (OS) (HR=1.28, 95% CI: 0.98-1.69) between sublobar resection and lobectomy, but lobectomy was associated with better recurrence-free survival (RFS) (HR=1.39, 95% CI: 1.10-1.75). Subgroup analyses revealed that, for tumors with a diameter ≤2 cm, sublobar resection versus lobectomy showed no significant difference in OS but sublobar resection had lower RFS. For 2-3 cm tumors, both OS and RFS were significantly lower in the sublobar resection group. When consolidation-to-tumor ratio (CTR) ranged from 0.5 to <1, OS did not differ significantly, but RFS was significantly lower in sublobar resection. Lung cancers with CTR=1 showed significantly lower OS and RFS in the sublobar resection group. Segmentectomy provided similar OS and RFS compared to lobectomy, while wedge resection had a detrimental effect on patient prognosis. However, wedge resection may have provided comparable outcomes for patients aged 75 years or older.

CONCLUSION

Our findings suggest that segmentectomy and lobectomy yield similar oncological outcomes. However, compared to lobectomy, wedge resection is associated with a poorer prognosis. Nevertheless, for elderly patients, wedge resection is also a reasonable surgical option.

Discordance between clinical and pathologic staging and the timeliness of care of non-small cell lung cancer patients diagnosed with operable tumors

AIM

This study was performed to evaluate concordance between clinical and pathologic staging of non-small cell lung cancer (NSCLC) in our hospital network.

METHODS

We retrospectively reviewed records of 417 patients with NSCLC who received curative surgery and whose pathology was evaluated in our hospital between 2016 and 2021. Cytology, tissue pathology, and associated clinical, surgical, and imaging information were retrieved from hospital digital records.

RESULTS

The cohort included 214 female and 203 male patients aged 20.6-85.8 years. Median times among staging computed tomography and surgery (105 days [interquartile range (IQR) 77.0-143.0]), positron emission tomography and surgery (78.5 days [IQR 56.0-109.0]), and endobronchial ultrasound-guided transbronchial needle aspiration and surgery (59 days [IQR 42-94]) indicated that Australian guidelines of <42 days between original referral and commencement of treatment were not being met in the majority of cases. Discordance between clinical TNM (cTNM) and pathologic TNM staging was 25.9%, including 18.4% cases that were clinically understaged and two patients with undetected stage IVA disease. cTNM understaging was significantly associated with time between the final staging investigation and surgery (p = .023), pleural (p < .05) and vessel (p < .05) invasion, and diagnosis of high-grade adenocarcinoma (p = .001).

CONCLUSION

Discordance between clinical and pathologic staging of NSCLC is associated with tumor histopathologic characteristics and treatment delays. Although tumor factors that lead to discordant staging cannot be controlled, reduced time to surgery may have resulted in better outcomes for some patients in this potentially curable lung cancer cohort.

Predictive Value of 18 F-FDG PET/MRI for Pleural Invasion in Solid and Subsolid Lung Adenocarcinomas Smaller Than 3 cm

BACKGROUND

Positron emission tomography (PET)/MRI combines the characteristics of metabolism imaging and high soft tissue resolution, and could provide high diagnostic efficacy for assessment of pleural invasion (PI) of lung cancer.

PURPOSE

To investigate the application of ¹⁸ F-fluorodeoxyglucose (FDG) PET/MRI for predicting PI of lung cancer with the maximum diameter ≤3 cm.

STUDY TYPE

Prospective.

POPULATION

A total of 44 patients with non-small cell lung cancer (NSCLC), age from 39 to 79 years old, including 19 (56.82%) females.

FIELD STRENGTH/SEQUENCE

A 3-T, hybrid PET/MRI including axial fast spin echo respiratory-triggered T2 fat-suppressed imaging (T2FS) and echo planar imaging diffusion-weighted imaging (DWI).

ASSESSMENT

The maximum standardized uptake value (SUVmax) of all lesions was measured on PET images. Localized effusion outside the contact between the nodules and the pleura on T2FS and signal at the contact between the nodules and the pleura on DWI were evaluated by experienced physicians through visual assessment of the MRI sequences.

STATISTICAL TESTS

Three models (models 1-3) were developed, incorporating CT, CT and PET, PET and MRI features, and Lasso regression was used in feature selection. The receiver operating characteristic (ROC) curve for PI diagnosis was visualized for each model, and the area under the curve (AUC) was calculated. The DeLong test was used to compare the different AUCs. A P value < 0.05 was considered statistically significant.

RESULTS

The AUC of models 1-3 was 0.762, 0.829, and 0.915, respectively. The DeLong test showed a statistically significant difference between the AUCs of model 1 vs. model 3, while the differences between the AUCs of model 1 vs. model 2 (P = 0.253) and model 2 vs. model 3 (P = 0.075) were not statistically significant.

DATA CONCLUSION

¹⁸ F-FDG PET/MRI might show high predictive value for lung adenocarcinoma smaller than 3 cm with PI.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 2.

The prognosis of different types of pleural tags based on radiologic-pathologic comparison

Objectives

There are increasing numbers of studies of pleural tags (PTs). The purpose of this case series was to classify the PTs in patients with peripheral pulmonary adenocarcinoma based on radiologic-pathologic comparison and to study the prognosis.

Methods

The clinical, imaging, pathological and prognostic data of 161 patients with peripheral pulmonary adenocarcinoma in three hospitals were analyzed retrospectively. We classified PTs using computed tomography (CT) for pathologic comparison.

Results

According to the relationship between tumors and pleural on CT images, PTs were classified into four types: type 1, one or more linear pleural tag; type 2, one or more linear pleural tag with soft tissue component at the pleural end; type 3, one soft tissue cord-like pleural tag; type 4, directly abutting the visceral pleura, pulling or pushing the visceral pleura. In these PTs, the incidence of visceral pleural invasion (VPI) was high in type 2 (46.88%) and type 3 (56.41%) of PTs. Our prognostic analysis showed that micropapillary or solid histological subtype (HR = 5.766, 95% CI: 1.435–23.159, P = 0.014) and type 3 of PTs (HR = 11.058, 95% CI: 1.349–90.623, P = 0.025) were two independent risk factors for tumor progression.

Conclusions

PT is a risk factor for poor prognosis in patients with peripheral pulmonary adenocarcinoma, the presence of which on CT images can remind us to provide patients with a more reasonable treatment.

Minimally Invasive and Sublobar Resections for Lung Cancer

Current guidelines for non-small cell lung cancer (NSCLC) recommend segmentectomy over lobectomy for patients with poor pulmonary reserve or for peripheral nodules less than or equal to 2 cm with adenocarcinoma in situ histology, greater than 50% ground-glass opacity on computed tomography, or radiologic doubling time greater than or equal to 400 days. However, emerging data suggest oncologic equivalence of segmentectomy to lobectomy for less than or equal to 2 cm, peripheral stage IA NSCLC regardless of histologic type or radiographic findings.

Bibliometric Analysis of 50 Most Cited Articles Comparing Lobectomy with Sublobar Resection

BACKGROUND

 Recent years have seen an increase in the number of studies of the sublobar resection approach in non-small cell lung cancer (NSCLC) surgery. The purpose of this bibliometric analysis is to assess the significance and impact of articles comparing sublobar resection and lobectomy in NSCLC surgery.

MATERIAL AND METHODS

 The Web of Science database was searched to identify studies comparing sublobar resection and lobectomy in NSCLC surgery published between 2005 and 2020 (accessed: September 11, 2020). The 50 most cited articles were analyzed by years, countries, authors, authors' affiliations, journals, journals' addresses, and impact factors.

RESULTS

 The bibliometric analysis revealed that the most cited article had 443 citations, while the total number of citations of all articles was 2,820. The mean number of citations, in turn, was 56.4 ± 75.62 (1-443) times. The highest number of publications over the past 15 years was in 2016, with eight articles. The Annals of Thoracic Surgery (n = 10; 20%) had the highest number of publications on the list. The articles included in the present study were mostly (n = 35, 70%) published in U.S. journals. While multiple subject matters and analyses were presented by many studies, survival was the topic of greatest interest, with 37 (74%) studies.

CONCLUSION

 This study revealed that interest in studies comparing sublobar resection with lobectomy has increased in recent years. It also presents both quantitative and qualitative analyses of the most cited articles in the literature on this topic. Therefore, it can serve as a guide for researchers.

Surgical Consideration Based on Lymph Nodes Spread Patterns in Patients with Peripheral Right Middle Non-small Cell Lung Cancer 3 cm or Less

BACKGROUND

The optimal extent of lung resection and lymph nodes dissection for peripheral early-stage right middle non-small cell lung cancer (NSCLC) still remains controversial. In this study, we analyzed the patterns of lymph nodes metastasis (LNM) of patients with peripheral right middle NSCLC ≤ 3 cm, aiming to provide evidences for surgical choice for early-stage peripheral right middle lobe NSCLC.

METHODS

We retrospectively investigated the clinical and pathological data of patients diagnosed with peripheral right middle lobe NSCLC ≤ 3 cm between January 2015 and December 2019. The LNM patterns were analyzed by tumor size.

RESULTS

A total of 60 patients were included for analysis. The tumor size was preoperatively divided as follows: ≤ 1 cm (13 patients); > 1 cm but ≤ 2 cm (36 patients); > 2 cm but ≤ 3 cm (11 patients). Fifty-four patients were categorized as N0 group, 1 patient as N1 group, and 5 patients as N2 group. In the upper zone, 3 patients were found to have LNM. In the subcarinal zone, another 3 patients had LNM. But the lymph nodes of all these patients were negative in the lower zone. In station 10, 1 patient (1.67%) was found to have LNM, while in station 11-13, 2 patients (3.33%) were found to have LNM.

CONCLUSION

For the right middle lobe peripheral NSCLC ≤ 1 cm, sublobar resection with lymph node sampling may be a feasible treatment. For cancers > 1 cm but ≤ 2 cm, lobectomy with lobe-specific lymph node dissection (especially station 2R and 4R) may be a preferred choice. For tumors > 2 cm but ≤ 3 cm, lobectomy with systematic lymph node dissection may still be the standard of care.

[Early-stage lung cancer: Is there still a role for surgery?]

For a patient with stage I or II non-small cell lung cancer (NSCLC) surgical resection remains the treatment of choice on condition that the patient is functionally operable. A complete resection should be obtained. Often lobectomy is feasible by a minimally invasive approach. For patients with compromised cardiopulmonary function stereotactic radiotherapy is an alternative treatment. For patients who are functionally operable, no definite recommendation can be made as no large, randomised studies have been performed with a sufficient number of patients and long-term follow-up. For this reason, it is important to discuss every patient within a multidisciplinary team with participation of thoracic surgeons and radiation oncologists. To provide personalised advice, the primary tumour, its extension, the patient's comorbidities and his respiratory and cardiac function have to be considered.

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.

Less is more in solid-dominant lung cancer? Sublobar resection versus lobectomy for solid-dominant stage IA non-small-cell lung cancer: A meta-analysis study

Although lobectomy is well established as the standard surgical procedure for stage IA non-small-cell lung cancer (NSCLC), sublobar resection is increasingly preferred, particularly in intentional segmentectomy for radiologically less-invasive small NSCLC. However, the indication for sublobar resection of radiologically pure solid or solid-dominant NSCLC remains controversial, owing to its invasive pathological characteristics. Therefore, the present meta-analysis was conducted to compare the efficacy of sublobar resection with lobectomy for treating solid-dominant stage IA NSCLC. An electronic search was conducted using four online databases from their dates of inception to April 2017. The hazard ratio (HR) was used as a summary statistic for censored outcomes and the odds ratio (OR) was used as the summary statistic for dichotomous variables. A total of nine studies met the selection criteria, including a total of 2,265 patients (1,728 patients underwent lobectomy, 425 segmentectomy and 112 wedge resection). From the available data, patients treated with a sublobar resection had a higher risk of local recurrence compared with patients treated with lobectomy [OR=1.89; 95% confidence interval (CI), 1.02–3.50; P=0.04]. However, no obvious difference in local recurrence was found in a subgroup analysis of segmentectomy compared with lobectomy (OR=1.19; 95% CI, 0.68–2.10; P=0.61). Sublobar resection was not associated with a significantly negative impact on distant recurrence (OR=1.09; 95% CI, 0.55–2.16; P=0.796). Patients in the sublobar resection group had no significant differences in recurrence-free survival (RFS; HR=1.43; 95% CI, 0.76–2.69; P=0.27) and overall survival (OS; HR=0.96; 95% CI, 0.75–1.23; P=0.77) compared with those in the lobectomy group. In the subgroup analysis of anatomic segmentectomy compared with lobectomy, there was no significant difference in RFS, with mild inter-study heterogeneity. The current meta-analysis suggested that segmentectomy had a comparable oncologic efficacy to lobectomy for solid-dominant stage IA NSCLC. Therefore, segmentectomy may be a feasible alternative in selected cases of solid-dominant stage IA NSCLC. However, these findings should be confirmed by prospective randomized controlled trials in the future.

[Progress on the Study of Tumor Spread Through Air Spaces in the Clinicopathological Characteristics of Lung Adenocarcinoma and Its Influence on the Surgical Treatment and Prognosis of Lung Cancer]

肿瘤肺泡腔内播散（tumor spread through air spaces, STAS）作为一种新的病理侵袭方式，与诸多临床病理因素紧密相关。在肺腺癌中，微乳头和实体型病理亚型与之关系最为密切；针对早期肺腺癌存在STAS，手术类型的治疗上肺叶切除似乎优于亚肺叶切除而获益，可能上调早期肺癌的病理分期；同时，STAS与鳞癌等非小细胞肺癌（non-small cell lung cancer, NSCLC）关系密切。此外，STAS的术中冰冻切片病理检测困难，亦有争议存在。STAS作为肿瘤复发的独立危险因素，亦是提示预后不良的重要因素，本文将STAS的研究现状和进展作一综述。

18F-fluorodeoxyglucose positron emission tomography/computed tomography in the evaluation of clinically node-negative non-small cell lung cancer

One in four non-small cell lung cancer (NSCLC) patients are diagnosed at an early-stage. Following the results of the National Lung Screening Trial that demonstrated a survival benefit for low-dose computed tomography screening in high-risk patients, the incidence of early-stage NSCLC is expected to increase. Use of 18F-fluorodeoxyglucose positron emission tomography/computed tomography during initial diagnosis of these early-stage lesions has been increasing. Traditionally, positron emission tomography/computed tomography scans have been utilized for mediastinal nodal staging and to rule out distant metastases in suspected early-stage NSCLC. In clinically node-negative NSCLC, the use of sublobar resection and selective lymph node dissection has been increasing as a therapeutic option. The higher rate of locoregional recurrences after limited resection and the significant incidence of occult lymph node metastases underscores the need to further stratify clinically node-negative NSCLC in order to select patients for limited resection versus lobectomy with complete mediastinal lymph node dissection. In this report, we review the published data, and discuss the significance and potential role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography evaluation for clinically node-negative NSCLC. Consequently, the literature review demonstrates that maximum standardized uptake value is a predictive factor for occult nodal metastasis with an accuracy of 55-77%. In addition, maximum standardized uptake value is a predictor for worse overall, as well as disease-free, survival.

Prediction of pleural invasion using different imaging tools in non-small cell lung cancer

Clinical staging of non-small cell lung cancer (NSCLC) is used for planning therapeutic strategies. In particular, pleural invasion is regarded as an indicator for upstaging to T2 or T3 in the current 8th TNM staging system; patients with pleural invasion should be indicated for lobectomy rather than sublobar resection. Therefore, accurate preoperative prediction of pleural invasion is important for surgical planning. In recent years, different radiological investigations for patients with NSCLC have been widely used, and methods for more precise detection have been developed in the current medical imaging studies. Therefore, several radiological investigation tools have been used for the prediction of pleural invasion. In this article, to identify the imaging modalities for accurate prediction of pleural invasion, we reviewed the different methods used for this purpose and discussed their advantages and limitations.

Lobectomy vs. segmentectomy. A propensity score matched comparison of outcomes

BACKGROUND

Segmentectomy has emerged as a lung parenchymal sparring alternative to the gold standard lobectomy in non-small cell lung cancer (NSCLC) patients. We hypothesized that there is parity between functional, local recurrence and survival outcomes.

PATIENTS AND METHODS

Parenchymal sparring procedures including anatomical segmentectomies were propensity score matched 1:1 with lobectomies (n = 64). The primary outcomes included survival, functional and oncological outcomes. The oncological outcomes were: post-operative histology, clear margins and local recurrence rates. Kaplan Meier survival curves were used to compare the survival. Oncological and functional variables were assessed by Fischer exact test and t-test.

RESULTS

The pre-operative performance status, ASA grade, lung function, risk factors, surgical approach and tumour histology were similar between the groups. The tumour size was significantly higher for lobectomies (32.4 ± 17 vs. 24.6 ± 12 mm, p = 0.01). The tumour staging in the segmentectomy group was similar to the lobectomy group (Ia; 50 vs. 34%; Ib: 29 vs. 37%; IIa 11 vs. 9.3%; IIb 5 vs. 14%; IIIa 5 vs. 4.6%, p = 0.83). The loco-regional recurrence was lower in the segmentectomy group (1.5 vs. 3.1%, p = 0.69). The up-staging and down-staging post-surgery was similar in both groups, while neo-adjuvant therapy was used in 5 lobectomy and 3 segmentectomy cases. The survival was similar at 1 year between the groups (88 vs. 92%, p = 0.65). Between 4 and 5 years, the survival reduced in the parenchymal sparing group to 39% vs. 68% in the lobectomy group (p = 0.04).

CONCLUSION

Surgical selection bias could be an important confounder in the selection of patients undergoing segmentectomy. Similar up and down staging were demonstrated in the two groups. This is one of the first studies to investigate the results of segmentectomy versus lobectomy in stage II/IIIa NSCLC tumours. No significant differences were found in functional outcomes, but the survival decreased after 4 years in the segmentectomy group, which could be explained by lower survival in the stage II/IIIa tumours treated with segmentectomy.

Uniportal video-assisted thoracoscopic anatomic segmentectomy for small-sized lung cancer

Increasing evidences prove video-assisted thoracic surgery (VATS) segmentectomy is accepted as a valid alternative to lobectomy esp. a greater number of small lung nodules have been detected. Uniportal VATS segmentectomy for small-sized lung cancer is more challenging not only for technical issues in simple or complex uniportal segmentectomy, but also considering oncological efficacy in terms of localization, safe margin, the extent of lymph node dissection and pathological analysis. In this work, we evaluated our evolving uniportal experience, the surgical technique and decision-making of uniportal VATS segmentectomy for small-sized lung cancer.

Surgical Treatment for Pulmonary Metastasis of Head and Neck Cancer: Study of 58 Cases

PURPOSE

Although the number of surgeries performed for pulmonary metastasis of head and neck cancer has been increasing, there have been few reports of the surgical effectiveness. We collected the data of surgeries performed in our facility in order to discuss the surgical performance and indication.

METHODS

We retrospectively examined the prognosis and predictors for 58 patients with pulmonary metastasis of head and neck cancer who underwent a surgery in our facility during the 15-year period, from January 2000 to December 2015.

RESULTS

The 3-year and 5-year survival rates were 54.2% and 35.7%, respectively, and the median survival time was 42.2 months. The disease-free interval (DFI) was less than 24 months and patients with oral cavity cancer were poor prognostic factors.

CONCLUSION

The effectiveness of surgical treatment for pulmonary metastasis of head and neck cancer was suggested.

Management of stage I and II nonsmall cell lung cancer

The incidence of stage I and II nonsmall cell lung cancer is likely to increase with the ageing population and introduction of screening for high-risk individuals. Optimal management requires multidisciplinary collaboration. Local treatments include surgery and radiotherapy and these are currently combined with (neo)adjuvant chemotherapy in specific cases to improve long-term outcome. Targeted therapies and immunotherapy may also become important therapeutic modalities in this patient group. For resectable disease in patients with low cardiopulmonary risk, complete surgical resection with lobectomy remains the gold standard. Minimally invasive techniques, conservative and sublobar resections are suitable for a subset of patients. Data are emerging that radiotherapy, especially stereotactic body radiation therapy, is a valid alternative in compromised patients who are high-risk candidates for surgery. Whether this is also true for good surgical candidates remains to be evaluated in randomised trials. In specific subgroups adjuvant chemotherapy has been shown to prolong survival; however, patient selection remains important. Neoadjuvant chemotherapy may yield similar results as adjuvant chemotherapy. The role of targeted therapies and immunotherapy in early stage nonsmall cell lung cancer has not yet been determined and results of randomised trials are awaited.

Limited resections in high-risk patients

PURPOSE OF REVIEW

The role of limited, sublobar resection in patients with early-stage nonsmall cell lung cancer (NSCLC) remains controversial. Alternative treatments for surgical resection include stereotactic radiotherapy and radiofrequency ablation. In this review, the role of limited resection is discussed in patients presenting a s high-risk for s surgical intervention.

RECENT FINDINGS

Clear definitions of high-risk patients are currently lacking, as well as, randomized prospective studies indicating which treatment to offer in this population. Awaiting results of two major ongoing trials, at this moment the decision-making process is heavily dependent on retrospective analyses. For selected patients sublobar resection may be a valid oncological option for clinical stage IA NSCLC.

SUMMARY

Surgery remains the gold standard for NSCLC. In case of high-risk patients, a multidisciplinary consultation should advise the patient which treatment option to choose. In early-stage NSCLC, sublobar anatomical resection is preferred over nonsurgical procedures to determine nodal status and prognosis. In case of patients unfit for surgery, stereotactic radiotherapy is a good alternative. A randomized prospective study is necessary to determine survival in high-risk patients allocated to surgery (lobectomy or sublobar resection) or radiation-based treatment.

Clinical analysis of sixty-four patients with T1aN2M0 stage non-small cell lung cancer who had undergone resection

Background

The aim of this study was to evaluate the clinical features of T1aN2M0 stage non‐small cell lung cancer (NSCLC).

Method

From November 2008 to May 2013, 498 patients with T1a‐stage NSCLC who visited the Shanghai Cancer Center were included in the study. All patients underwent a lobectomy or segmentectomy with systematic nodal resection for primary lung cancer. Analyses of gender, smoking history, primary tumor site, tumor location, tumor size, pathological classification, cancer gene, pleural invasion, number of positive lymph nodes, skip N2, single or multiple station N2, progression‐free survival (PFS), and overall survival (OS) were performed.

Result

There were significant differences in tumor size, tumor size distribution, adenocarcinoma subgroup, and number of positive lymph nodes between patients at T1aN2M0 and T1aN0M0 stages. The most common histology of the T1aN2M0 subgroup was adenocarcinoma. Epidermal growth factor receptor mutations were the most common gene mutation in T1aN2M0 stage NSCLC. There were significant differences in five‐year OS and PFS rates between patients with T1aN2M0, T1aN0M0, and T1aN1M0 stages. Multivariate analyses of mediastinal lymph node metastasis showed that gender, tumor size distribution, and histology type were significant predictive factors. Multivariate analyses of OS and PFS rates in the T1aN2M0 subgroup showed that the number of positive lymph nodes was a significant predictive factor.

Conclusion

Gender, tumor size distribution, and histology type were independent predictors of mediastinal lymph node metastasis in patients with T1a stage. The number of positive lymph nodes was significantly associated with OS and PFS rates in patients with T1aN2M0 stage NSCLC.