Peripheral Non-small Cell Lung Cancer Research Articles

Standard lobectomy versus anatomic sublobar resection for peripheral T1-2N0M0 non-small cell lung cancer: comparative assessment of the survival-resection volume relationship

Standard lobectomy versus anatomic sublobar resection for peripheral T1-2N0M0 non-small cell lung cancer: comparative assessment of the survival-resection volume relationship

Segmentectomy Versus Lobectomy in Small-Sized Peripheral Non-Small Cell Lung Cancer (JCOG0802/WJOG4607L): A Multicentre, Randomised, Controlled, Phase 3 Trial

Background: Lobectomy is the standard of care for early-stage non-small cell lung cancer (NSCLC). The survival and clinical benefits of segmentectomy have not been investigated in a randomized trial setting. We conducted a randomized controlled noninferiority trial comparing segmentectomy and lobectomy for small-sized peripheral NSCLC. Methods: Patients with clinical stage IA NSCLC (tumor diameter ≤2 cm; consolidation/tumor ratio > 0·5) were randomly assigned to undergo either lobectomy or segmentectomy. The primary endpoint was overall survival (OS). The secondary endpoints included postoperative respiratory function, relapse-free survival (RFS), proportion of local relapse, and adverse events. Findings: Between August 10, 2009 and October 21, 2014, 1106 patients (lobectomy, n = 554; segmentectomy, n = 552) were enrolled. Patient baseline clinicopathological factors were well balanced. At a median follow-up of 7·3 years, the 5-year OS was 94·3% for segmentectomy and 91·1% for lobectomy. Superiority as well as noninferiority in OS were confirmed using a stratified Cox regression model (hazard ratio [HR], 0·663; 95% confidence interval [CI], 0·474–0·927; one-sided P < 0·0001 for noninferiority; P = 0·0082 for superiority). Improved OS was observed consistently across all predefined subgroups in the segmentectomy arm. The significant differences at 1 year in the reduction of median forced expiratory volume in 1 second at 1 year between the two arms was 3·5% ( P < 0·0001), which did not reach the predefined threshold of 10%. The 5-year RFS was 88·0% for segmentectomy and 87·9% for lobectomy (HR, 0·998; 95% CI, 0·753–1·323). The proportions of local relapse were 10·5% and 5·4% for segmentectomy and lobectomy, respectively ( P = 0·0018). Fifty-two (63%) of 83 patients and 27 (47%) of 58 patients died of other diseases after lobectomy and segmentectomy, respectively. Interpretation: This was the first phase 3 trial to demonstrate the benefits of segmentectomy in OS. Segmentectomy should be the standard surgical procedure for patients with small-sized peripheral NSCLC. Trial Registration: University Hospital Medical Information Network–Clinical Trial Registry Number: UMI02317. Funding: Ministry of Health, Labor and Welfare of Japan and the Japan Agency for Medical Research and Development Declaration of Interest: All authors declare no competing interests for this study. Ethical Approval: The study protocol was approved by the JCOG and WJOG Protocol Review Committees and the institutional review boards of all participating hospitals.

Effect of MU-weighted multi-leaf collimator position error on dose distribution of SBRT radiotherapy in peripheral non-small cell lung cancer.

PurposePosition accuracy of the multi‐leaf collimator (MLC) is essential in stereotactic body radiotherapy (SBRT). This study is aimed to investigate the dosimetric impacts of the MU‐weighted MLC positioning uncertainties of SBRT for patients with early stage peripheral non‐small cell lung cancer (NSCLC).MethodsThree types of MLC position error were simulated: Type 1, random error; Type 2, system shift, in which both MLC banks shifted to the left or right direction; and Type 3, in which both MLC banks moved with same magnitudes in the opposite directions. Two baseline plans were generated: an automatic plan (AP) and a manually optimized plan (MP). Multi‐leaf collimator position errors were introduced to generate simulated plans with the preset MLC leaf position errors, which were then reimported into the Pinnacle system to generate simulated plans, respectively. The dosimetric parameters (CI, nCI, GI, etc.) and gEUD values of PTV and OARs were calculated. Linear regression between MU‐weighted/unweighted MLC position error and gEUD was performed to obtain dose sensitivity.ResultsThe dose sensitivities of the PTVs were −4.93, −38.94, −41.70, −55.55, and 30.33 Gy/mm for random, left shift, right shift, system close, and system open MLC errors, respectively. There were significant differences between the MU‐weighted and the unweighted dose sensitivity, which was −38.94 Gy/mm vs −3.42 Gy/mm (left shift), −41.70 Gy/mm vs −3.56 Gy/mm (right shift), −55.55 Gy/mm vs −4.84 Gy/mm (system close), and 30.33 vs 2.64 Gy/mm (system open). For the system open/close MLC errors, as the PTV volume became larger, the dose sensitivity decreased. APs provided smaller dose sensitivity for the system shift and system close MLC errors compared to the conventional MPs.ConclusionsThere was significant difference in dose sensitivity between MU‐weighted and unweighted MLC position error of SBRT radiotherapy in peripheral NSCLC. MU is suggested to be included in the dosimetric evaluation of the MLC misalignments, since it is much closer to clinical radiotherapy.

Lobectomy is superior to segmentectomy for peripheral high grade non-small cell lung cancer ≤2 cm.

BackgroundCurrent practice guidelines recommend the following criteria for segmentectomy for non-small cell lung cancer (NSCLC): size ≤2 cm, margins ≥2 cm and no lymph node involvement. We sought to further stratify the selection criteria for segmentectomy for small peripheral high-grade tumors.MethodsThis retrospective database study was conducted using the Surveillance, Epidemiology and End Results (SEER) database. We queried for patients with high-grade (poorly differentiated/undifferentiated) pathological (p)T1a/b peripheral NSCLC (tumor size ≤2 cm), who underwent either lobectomy or segmentectomy between 2004 and 2015. Patients with node-positive disease or those who received any form of induction or adjuvant treatments were excluded.ResultsA total of 4,332 patients met the inclusion criteria, with 3,977 patients (91.8%) treated with lobectomy and 355 patients (8.2%) who underwent segmentectomy. In a propensity matched pair analysis of 640 patients, lobectomy (n=320) showed significantly improved 5-year survival of 45.9% vs. 33.8% for segmentectomy (n=320), P<0.01. In a multivariate Cox regression analysis, lobectomy was associated with significantly improved survival (HR: 0.84, 95% CI: 0.714–0.989, P=0.036). Interestingly, married status, adenocarcinoma histology, number of lymph nodes sampled were associated with better survival (P<0.05), while advanced age and male gender had worse survival outcomes (P<0.05).ConclusionsFor small peripheral NSCLC ≤2 cm and high grades of tumor differentiation, lobectomy is associated with better long-term survival outcomes as compared to segmentectomy. Additional data is needed to further stratify various NSCLC histologies with their respective grades to allow for better selection for segmentectomy.

A Clinical Study on Microwave Ablation in Combination with Chemotherapy in Treating Peripheral IIIB-IV Non-Small Cell Lung Cancer.

Background: This study investigated the efficacy and complications of microwave ablation in combination with chemotherapy in treating peripheral IIIB-IV non-small cell lung cancer (NSCLC). Materials and Methods: A total of 100 patients with peripheral IIIB-IV NSCLC were randomly divided into two groups: combination group (n = 52) and chemotherapy group (n = 48). Patients in the combination group were treated with microwave ablation, radiotherapy, and chemotherapy, whereas the patients in the chemotherapy group were treated with pemetrexed disodium or gemcitabine hydrochloride, cisplatin chemotherapy, and conventional radiotherapy. Results: The effectiveness and disease control rates were significantly higher in the combination group than in the chemotherapy group (p < 0.05). The second- and third-year survival rates were significantly higher in the combination group than in the chemotherapy group (p < 0.05). However, patients in the combination group had no serious complications, and there were no intraoperative and perioperative deaths. Conclusions: Microwave ablation is safe and effective. Combination chemotherapy is superior to chemotherapy in treating peripheral IIIB-IV NSCLC in terms of effectiveness rate, disease control rate, and extended patient survival time.

Intratumoral hyperthermic chemotherapy injection in peripheral non-small cell lung cancer

BackgroundIntratumoral chemotherapy (ITC) has been used by many groups; the combination of heat and cytotoxic drugs increases the ability to destroy the malignant cells. The aim of this study was to assess the efficacy and safety of percutaneous injection of hyperthermic chemotherapy in conjunction with systemic chemotherapy as a palliative management of peripheral inoperable non-small cell lung cancer (NSCLC) compared to conventional systemic chemotherapy.ResultsThere was a statistically significant improvement in quality of life score in group A and B, but deterioration in group C after 6 months. As regards radiology, after 6 months in group A, one patient (10%) showed complete response, 6 patients (60%) showed partial response, one patient (10%) stable response, and two patients (20%) showed progression; in group B, 6 patients (60%) showed partial response, two patients (20%) showed stable response, and two patients (20%) showed progression; and in group C, 7 patients (70%) showed progression, two patients (20%) showed partial response, and one patient (10%) showed stable response. There were few controllable complications. Median survival in group A was 16 months, in group B was 15 months, and in group C was 8 months.ConclusionIntratumoral hyperthermic chemotherapy is a promising, effective, harmless palliative therapy for inoperable peripheral NSCLC.

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

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 ≤ 3cm, aiming to provide evidences for surgical choice for early-stage peripheral right middle lobe NSCLC. We retrospectively investigated the clinical and pathological data of patients diagnosed with peripheral right middle lobe NSCLC ≤ 3cm between January 2015 and December 2019. The LNM patterns were analyzed by tumor size. A total of 60 patients were included for analysis. The tumor size was preoperatively divided as follows: ≤ 1cm (13 patients); > 1cm but ≤ 2cm (36 patients); > 2cm but ≤ 3cm (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. For the right middle lobe peripheral NSCLC ≤ 1cm, sublobar resection with lymph node sampling may be a feasible treatment. For cancers > 1cm but ≤ 2cm, lobectomy with lobe-specific lymph node dissection (especially station 2R and 4R) may be a preferred choice. For tumors > 2cm but ≤ 3cm, lobectomy with systematic lymph node dissection may still be the standard of care.

Age-different extent of resection for clinical IA non-small cell lung cancer: analysis of nodal metastasis

Whether age has any impact on the risk of lymph node (LN) metastasis in patients with early-stage non-small cell lung cancer (NSCLC) remains controversial. Therefore, we aimed to objectively compare the risk of LN metastasis between elderly and young patients so as to justify for age-different extent of surgical resection for treating these patients. 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 January 2015 to December 2018. Both multivariate logistic regression analysis and propensity score-matched (PSM) analysis were applied to compare the risk of LN metastasis between elderly (>65 years old) and young (≤65 years old) patients. We finally included a total of 590 patients for analysis (142 elderly patients and 448 young patients). In the analysis of unmatched cohorts, young patients tended to have higher rates of hilar/intrapulmonary LN (13.4% VS 9.2%) and mediastinal LN metastasis (10.5% VS 6.3%) than elderly patients. In the multivariate analysis, age was found to be an independent predictor of both hilar/intrapulmonary (Odds ratio(OR) = 2.065, 95%confidence interval(CI): 1.049–4.064, P = 0.036) and mediastinal (OR = 2.400, 95%CI: 1.083–5.316, P = 0.031) LN metastasis. Moreover, in the analysis of well-matched cohorts generated by PSM analysis, young patients had significantly higher rates of hilar/intrapulmonary (18.8% VS 9.4%, P = 0.039) and mediastinal LN metastasis (17.1% VS 6.0%, P = 0.008) than elderly patients. Therefore, age remains to be an independent predictor of LN metastasis in early-stage NSCLC and age-different extent of surgical resection may be justified for these patients.

Clinical significance of PET/CT uptake for peripheral clinical N0 non-small cell lung cancer.

ObjectiveIn this cohort study, we determined the clinical value of the maximum standardized uptake value (SUVmax) of primary tumors in non‐small cell lung cancer (NSCLC).Study DesignA retrospective review of NSCLC patients was performed from January 2011 to December 2017. Peripheral cN0 NSCLC patients with tumor size ≤2 cm were included. SUVmax was calculated as a continuous variable for semiquantitative analyses. A receiver operating characteristic curve was analyzed to assess the cutoff threshold of SUVmax on pathological (p) nodal metastasis. We further evaluated the clinical relevance of SUVmax in peripheral cN0 NSCLC patients.ResultsA total of 670 peripheral NSCLC patients with tumor size ≤2 cm were deemed cN0 by preoperative PET/CT scan. Statistical analyses suggested significant correlations of SUVmax with smoking status (P = .026), tumor volume (P = .001), pathology type (P = .008), tumor differentiation (P < .001), vessel invasion (P = .001), plural invasion (P < .001), pT stage (P < .001), nodal involvement (P < .001), and pathological tumor node metastasis stage (P < .001). A cutoff point of SUVmax of 3.8 (P < .001) could be used to predict pathological nodal metastasis. Multivariable analyses indicated that preoperative SUVmax >3.8 (odds ratio, 12.149; P < .001) was an independent predictor of nodal metastasis. Overall survival analyses further suggested that SUVmax was an independent prognostic indicator (hazard ratio, 2.050; P = .017).ConclusionPreoperative SUVmax is a predictor of pathological nodal metastasis and prognosis for peripheral cN0 NSCLC patients with tumor size ≤2 cm. Our results indicate that assessment of PET SUVmax could improve stratification of these patients.

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

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 ≤3cm 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. From 2010 to 2017, 553 patients with clinical N0 peripheral NSCLC with invasive component size ≤3cm underwent anatomical lobectomy with systematic lymph node dissection. We analyzed these cases retrospectively to identify risk factors for postoperative nodal upstaging. 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. SUVmax is not a predictor of nodal upstaging in clinical N0 peripheral NSCLC with invasive component size ≤3cm 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.

Feasibility and effectiveness of thoracoscopic pulmonary segmentectomy for non-small cell lung cancer.

The outcomes of minimally invasive thoracoscopic pulmonary segmentectomy for non-small cell lung cancer (NSCLC) still need to be defined. This study aimed to investigate the feasibility and effectiveness of thoracoscopic pulmonary segmentectomy in patients with early peripheral NSCLC.This was a retrospective study of patients with early peripheral NSCLC admitted between January 2013 and January 2017. Patients were divided into the segmentectomy and lobectomy groups (40/group), according to the surgery they underwent. Blood loss, operation time, removal of drainage tube time, inflammatory response after operation, postoperative complications, postoperative lung function, local recurrence, and survival were compared.Blood loss and removal of drainage tube time were not significantly different between the 2 groups (all P > .05). Operation time in the segmentectomy group was longer than in the lobectomy group (P < .001). The postoperative interleukin-6, procalcitonin, and C-reactive protein changes in the segmentectomy group were significantly lower than in the lobectomy group (all P < .001). The pulmonary function at 2 weeks was significantly reduced in the 2 groups (all P < .001), but it was better in the segmentectomy group than in the lobectomy group (all P < .05). The 1- and 3-year local recurrence disease-free, and overall survival rates were not significantly different between the 2 groups (P > .05). The multivariable analysis could not identify any factor associated with local recurrence or survival (all P > .05).Thoracoscopic pulmonary segmentectomy and lobectomy are both acceptable for the treatment of early peripheral NSCLC, but segmentectomy was associated with lower postoperative inflammation and better postoperative pulmonary function than lobectomy.

The D-dimer level predicts the postoperative prognosis in patients with non-small cell lung cancer.

Carcinoma cells often modulate coagulation and fibrinolysis among cancer patients. Plasma dimerized plasmin fragment D (D-dimer) has been reported as a prognostic marker of various types of malignancies, including non-small cell lung cancer (NSCLC). However, the associations between the plasma D-dimer level and peripheral small NSCLC remain unclear. Three hundred and sixty-two patients with NSCLC who underwent radical surgery were retrospectively reviewed. Patients who received anticoagulation therapy before surgery or who lacked preoperative D-dimer data were excluded. The other 235 patients were divided into a high D-dimer (over 1.0 μg/mL) group (HDD group, n = 47) and a normal D-dimer group (NDD group, n = 188) and investigated for their clinical characteristics, computed tomography (CT) findings, pathological findings, and clinical outcomes. The mean D-dimer levels was 2.49±2.58 μg/ml in the HDD group and 0.42±0.23 μg/ml in the NDD group. The HDD group was characterized by a predominance of male gender, older age, pure solid appearance on chest CT, vascular invasion in pathology, and a large solid part of the tumor. The HDD group showed a worse overall survival, disease-free survival, and disease-specific survival than the NDD group (p<0.001, <0.001, <0.001, respectively). These survival features were also observed in p-Stage IA disease. There was no marked survival difference when tumors showed ground-glass opacity on CT. In NSCLC patients with a solid tumor appearance on CT, high D-dimer levels predict a poor survival and early recurrence.

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

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. 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. 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. 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.

Safety and clinical outcomes of computed tomography-guided percutaneous microwave ablation in patients aged 80 years and older with early-stage non-small cell lung cancer: A multicenter retrospective study.

BackgroundPrevious studies have documented the therapeutic value of computed tomography (CT)‐guided percutaneous microwave ablation (MWA) for early‐stage non‐small cell lung cancer (NSCLC). However, few studies have focused on patients aged 80 years and older. This retrospective study aimed to evaluate the safety and clinical outcomes of CT‐guided percutaneous MWA in patients aged 80 years and older with early‐stage peripheral NSCLC.MethodsA retrospective analysis of 63 patients aged 80 years and older with cT1a‐2bN0M0 peripheral NSCLC who underwent CT‐guided percutaneous MWA was performed between January 2008 and January 2018 at 11 hospitals in Shandong Province, China.ResultsThe median follow‐up time was 21.0 months. The overall median survival time was 50 months. The cancer‐specific median survival time was not reached in five years. The one‐, two‐, three‐, four‐, and five‐year overall survival rates were 97.1%, 92.6%, 63.4%, 54.4%, and 32.6%, respectively. The one‐, two‐, and three‐year cancer‐specific survival (CSS) rates were 97.9%, 97.9%, and 69.4%, respectively. The four‐ and five‐year CSS rates were not achieved. A total of 14 patients (22.2%) had local progression. The one‐, two‐, three‐, four‐, and five‐year local control rates were 88.8%, 78.8%, 70.3%, 63.9%, and 63.9%, respectively. The mortality rate was 0% within 30 days after the procedure. Major complications included pneumothorax requiring drainage (21.1%), pulmonary infection (4.2%), and pleural effusions requiring drainage (2.8%).ConclusionsCT‐guided percutaneous MWA is a safe and effective modality for treating patients aged 80 years and older with early‐stage peripheral NSCLC.

MODERN APPROACHES TO EARLY RADIOLOGICAL DIAGNOSIS OF BONE AND CEREBRAL METASTASES OF PERIPHERAL NON-SMALL CELL LUNG CANCER

Objective:сonstructive principles development of early diagnosis of bone and cerebral metastases of peripheral non-small cell lung cancer (PNSCLC), is based on the targeted preventive and personalized application of radiological and nuclear diagnostic methods.Materials and methods.There was performed the retrospective analysis of medical cards of 1473 patients with peripheral non-small cell lung cancer for the evaluation of the characteristics and frequency of bones and brain metastases. The frequency and features of bone and brain metastases depending on clinical and morphological features of the primary lung tumor were studied. 118 patients with PNSCLC with bone and brain metastases, regardless of clinical symptoms, were examined using a wide range of modern radiological and nuclear methods.Conclusion:the original algorithm has been developed on the study of the diagnostic significance of medical imaging methods. The application of this algorithm will significantly improve the early diagnosis of bone and cerebral metastases and improve the staging of PNSCLC.

Lobe-Specific Lymph Node Dissection for Clinical Early-Stage (cIA) Peripheral Non-small Cell Lung Cancer Patients: What and How?

We investigated the possible lobe-specific lymph node (LN) metastasis pattern of early-stage peripheral non-small cell lung cancers (NSCLC) and define the extent of lobe-specific LN dissection for them. We retrospectively collected clinical data of patients undergoing lobectomy or segmentectomy with systematic lymphadenectomy for clinical T1N0M0 peripheral NSCLC from January 2015 to December 2018. The LN metastasis pattern was analyzed by tumor lobe location. A total of 590 patients were included for analysis. The mean number of total dissected LNs was 12.3 ± 5.8 and 8.2 ± 4.1 for total dissected mediastinal LNs. The rate of mediastinal LN metastasis was 9.5%. For cases of upper lobe tumor and lower lobe tumor, 8.8% and 6.0% of them respectively metastasized to the upper LN zone (P = 0.274). However, upper lobe tumors hardly metastasized to the subcarinal (0.3%) and lower (0.3%) LN zones while for lower lobe tumors, the rate of LN metastasis was 10.2% and 5.4% respectively (both P < 0.001). However, all cases (100%) metastasizing from lower lobes to the upper LN zone had a tumor size of 2-3cm, whereas cases with a tumor size ≤ 2cm had no metastasis (0%). None of the tumors in the right middle lobe metastasized to the lower LN zone (0%). A lobe-specific LN metastasis pattern was observed in clinical stage IA peripheral NSCLC. For tumors in upper lobes (≤ 3cm), there may be no need to dissect lower mediastinal LNs and for tumors in lower lobes (≤ 2cm), dissecting upper mediastinal LNs may not be required.

P2.17-42 Surgical Choice for Clinical Stage IA Non-Small Cell Lung Cancer: Novel Rationale from Intrapulmonary Lymph Node Metastasis Pattern

Current available surgical resection methods for early-stage NSCLC mainly consisted of lobectomy and sublobar resection (including segmentectomy and wedge resection) with lobectomy being the preferred option, which was established by the only completed RCT study finding that sublobar resection yielded a significantly higher recurrence rate and a trend toward worse survival than lobectomy. However, there are growing interest in observational studies and systematic reviews exploring the efficacy of sublobar resection in treating early-stage NSCLC, aiming to justify for applying sublobar resection as an alternative to lobectomy for treating these patients but with conflicting conclusions. We aimed to investigate the pattern of intrapulmonary lymph node (LN) metastasis of clinical T1N0M0 peripheral non-small cell lung cancer (NSCLC) to provide novel rationale for surgical choice (lobectomy, segmentectomy, or wedge resection) for these patients. We retrospectively collected clinical data of patients undergoing lobectomy with systematic mediastinal LN dissection or sampling for early-stage NSCLC from January 2015 to December 2018. The intrapulmonary LN metastasis pattern was analyzed by tumor size. We included a total of 354 patients for final analysis. The rate of intrapulmonary LN metastasis was 13.6% (Table 1). When stratified by tumor size, NSCLC ≤1cm had no hilar/intrapulmonary LN metastasis while NSCLC >2 but ≤3cm had significantly high rates of hilar/intrapulmonary LN metastasis (18.4%) and the rates of hilar, interlobar and peripheral LN metastasis were relatively high (5.4%, 5.4% and 12.2%, respectively). NSCLC >1.5cm but ≤2cm also had a relatively high rate of hilar (6.5%) and peripheral (18.3%) LN metastasis while NSCLC >1cm but ≤1.5cm had a significantly low rate of hillar/intrapulmonary (2.5%) and peripheral (2.5%) LN metastasis.Table 1Intrapulmonary lymph node metastasis pattern among clinical stage IA (cT1N0M0) peripheral non-small cell lung cancers with different tumor size.CharacteristicsTotal (N=354)Tumor size groupP value≤1cm (N=35)>1cm but ≤2cm (N=172)>2cm but ≤3cm (N=147)Total dissected N1 LN number (Mean±SD)5.6±3.03.6±1.95.4±2.76.3±3.3<0.001Total dissected N2 LN number (Mean±SD)8.1±4.07.0±3.47.6±3.68.8±4.40.008Lymph node metastasis rate16.9% (60/354)0 (0/35)14.5% (25/172)23.8% (35/147)0.002N1 LN metastasis rate (10-14#)13.6%(48/354)0(0/35)12.2%(21/172)18.4%(27/147)0.013Hilar LN metastasis rate (10#)4.2%(15/354)0(0/35)4.1%(7/172)5.4%(8/147)0.348Interlobar LN metastasis rate (11#)3.4%(12/354)0(0/35)2.3%(4/172)5.4%(8/147)0.263*Peripheral LN metastasis rate (12-14#)10.5%(37/354)0(0/35)11.0%(19/172)12.2%(18/147)0.092N2 LN metastasis rate (1-9#)8.8%(31/354)0(0/35)8.1%(14/172)11.6%(17/147)0.088Note: LN=lymph node; SD=standard deviation. *Fisher’s exact test Open table in a new tab Note: LN=lymph node; SD=standard deviation. *Fisher’s exact test Based on the pattern of intrapulmonary LN metastasis, our study provided novel perspectives on surgical choice of lobectomy, segmentectomy, or wedge resection for clinical stage IA peripheral NSCLC: for NSCLC ≤1cm both segmentecotmy and wedge resection could be utilized, and for NSCLC >1cm but ≤1.5cm segmentecotmy could be utilized provided that sufficient resection margin could be achieved; while for NSCLC >1.5cm lobectomy should be the preferred surgical option.

P1.17-19 Lobe-Specific Lymph Node Dissection for Clinical Early-Stage (cIA) Peripheral Non-Small Cell Lung Cancer Patients: Feasible and How?

Currently, the extent of lobe-specific lymph node (LN) dissection (L-SLND) for early-stage non-small cell lung cancer (NSCLC) in previous literatures remains controversial without well-recognized agreement on exact definition of L-SLND. We aimed to investigate the possible lobe-specific LN metastasis pattern of clinical T1N0M0 peripheral NSCLC and define the extent of L-SLND for them. We retrospectively collected clinical data of patients undergoing lobectomy or segmentectomy with systematic lymphadenectomy for early-stage NSCLC from January 2015 to December 2018. The LN metastasis pattern of them was analyzed by tumor lobe location. A total of 590 patients were included for analysis. The rate of mediastinal LN metastasis was 9.5% (table 1). For cases in the upper lobes and these in the lower lobes, 8.8% and 6.0% of them respectively metastasized to the upper LN zone (P=0.274). However, cases in the upper lobes hardly metastasized to the subcarinal (0.3%) and lower (0.3%) LN zones while it was 10.2% and 5.4% for cases in the lower lobes, respectively (both P<0.001). When stratified by tumor size, all these cases (100%) metastasizing from lower lobes had a tumor size of 2-3 cm while cases with a tumor size ≤2 cm had no metastasis to upper LN zone. For cases in right middle lobe, none of them metastasized to the lower LN zone.Table 1Lymph node metastasis pattern among non-small cell lung cancers in different lobesCharacteristicsTotal (N=590)Right upper lobe (N=220)Right middle lobe (N=48)Right lower lobe (N=84)Left upper lobe (N=156)Left lower lobe (N=82)P valueTotal dissected LN number (Mean±SD)12.3±5.813.0±4.511.3±5.113.3±6.011.1±5.312.1±5.10.008Total dissected mediastinal LN number (Mean±SD)8.2±4.19.1±4.58.7±3.99.2±4.86.8±3.27.1±3.2<0.001LN metastasis rate83 (14.1%)29 (13.2%)8 (16.7%)13 (15.5%)20 (12.8%)13 (15.9%)0.915Upper zone metastasis rate47 (8.0%)16 (7.3%)4 (8.3%)5 (6.0%)17 (10.9%)5 (6.1%)0.586Subcarinal zone metastasis rate22 (3.7%)1 (0.5%)4 (8.3%)11 (13.1%)0 (0%)6 (7.3%)<0.001Lower zone metastasis rate10 (1.7%)1 (0.5%)0 (0%)4 (4.8%)0 (0%)5 (6.1%)0.001Note: LN=lymph node; SD=standard deviation. Open table in a new tab Note: LN=lymph node; SD=standard deviation. A lobe-specific LN metastasis pattern of early-stage peripheral NSCLC was observed and for cases in the upper lobes (≤3cm), there is no need to dissect lower mediastinal LNs and for cases in the lower lobes (≤2cm), there is no need for dissecting upper mediastinal LNs. Otherwise, systematic LN dissection or sampling instead of L-SLND should be recommended.

MS07.04 Stage I (Resectable) NSCLC: Surgery

MS07.04 Stage I (Resectable) NSCLC: Surgery

IBS16.01 Lung Cancer Screening and Its Effect on Surgery

IBS16.01 Lung Cancer Screening and Its Effect on Surgery