What we know about surgical therapy in early-stage non-small-cell lung cancer: a guide for the medical oncologist

Imbalanced Data Correction Based PET/CT Radiomics Model for Predicting Lymph Node Metastasis in Clinical Stage T1 Lung Adenocarcinoma

OBJECTIVES

To develop and validate the imbalanced data correction based PET/CT radiomics model for predicting lymph node metastasis (LNM) in clinical stage T1 lung adenocarcinoma (LUAD).

METHODS

A total of 183 patients (148/35 non-metastasis/LNM) with pathologically confirmed LUAD were retrospectively included. The cohorts were divided into training vs. validation cohort in a ratio of 7:3. A total of 487 radiomics features were extracted from PET and CT components separately for radiomics model construction. Four clinical features and seven PET/CT radiological features were extracted for traditional model construction. To balance the distribution of majority (non-metastasis) class and minority (LNM) class, the imbalance-adjustment strategies using ten data re-sampling methods were adopted. Three multivariate models (denoted as Traditional, Radiomics, and Combined) were constructed using multivariable logistic regression analysis, where the combined model incorporated all of the significant clinical, radiological, and radiomics features. One hundred times repeated Monte Carlo cross-validation was used to assess the application order of feature selection and imbalance-adjustment strategies in the machine learning pipeline. Prediction performance of each model was evaluated using the area under the receiver operating characteristic curve (AUC) and Geometric mean score (G-mean).

RESULTS

A total of 2 clinical parameters, 2 radiological features, 3 PET, and 5 CT radiomics features were significantly associated with LNM. The combined model with Edited Nearest Neighbors (ENN) re-sampling methods showed strong prediction performance than traditional model or radiomics model with the AUC of 0.94 (95%CI = 0.86-0.97) vs. 0.89 (95%CI = 0.79-0.93), 0.92 (95%CI = 0.85-0.97), and G-mean of 0.88 vs. 0.82, 0.80 in the training cohort, and the AUC of 0.75 (95%CI = 0.57-0.91) vs. 0.68 (95%CI = 0.36-0.83), 0.71 (95%CI = 0.48-0.83) and G-mean of 0.76 vs. 0.64, 0.51 in the validation cohort. The combination of performing feature selection before data re-sampling obtains a better result than the reverse combination (AUC 0.76 ± 0.06 vs. 0.70 ± 0.07, p<0.001).

CONCLUSIONS

The combined model (consisting of age, histological type, C/T ratio, MATV, and radiomics signature) integrated with ENN re-sampling methods had strong lymph node metastasis prediction performance for imbalance cohorts in clinical stage T1 LUAD. Radiomics signatures extracted from PET/CT images could provide complementary prediction information compared with traditional model.

Risk of death due to other causes is lower among octogenarians with non-small cell lung cancer after wedge resection than lobectomy/segmentectomy

OBJECTIVE

We aimed to determine the influences of surgical procedures on the postoperative death of octogenarians with clinical Stage IA non-small cell lung cancer excluding cT1mi.

METHODS

We compared overall survival and the cumulative incidence of death due to all and other causes among 1 130 279, and 191 consecutive patients aged ≤79 and ≥80 years after lobectomy, segmentectomy and wedge resection at three institutions. Death due to other causes was defined as death due to any cause except non-small cell lung cancer.

RESULTS

The median followup was 53 months. The 5-year overall survival rates for patients aged ≥ 80 and ≤ 79 years after lobectomy, segmentectomy and wedge resection were respectively, 78.0% (95% confidence interval, 63.8%-87.2%) versus 91.2% (95% confidence interval, 89.0%-92.9%), 68.1% (95% confidence interval, 45.2%-83.1%) versus 90.0% (95% confidence interval, 84.6%-93.5%), and 62.7% (95% confidence interval, 44.0-76.7%) versus 84.4% (95% confidence interval, 76.3%-89.9%) (P < 0.01 for all). The cumulative incidence of death due to other causes after wedge resection was similar between patients aged ≥ 80 and ≤ 79 years (P = 0.45), but significantly higher in those aged ≥ 80, than ≤ 79 years after lobectomy or segmentectomy (P = 0.00015 and 0.00091, respectively).

CONCLUSIONS

The influence of wedge resection on death due to other causes was lower than that of lobectomy or segmentectomy in patients with non-small cell lung cancer aged ≥ 80 years. Wedge resection might be a useful option for octogenarians even if they can tolerate lobectomy/segmentectomy to avoid postoperative death due to causes other than non-small cell lung cancer.

Integrative nomogram of intratumoral, peritumoral, and lymph node radiomic features for prediction of lymph node metastasis in cT1N0M0 lung adenocarcinomas

Radiomics studies to predict lymph node (LN) metastasis has only focused on either primary tumor or LN alone. However, combining radiomics features from multiple sources may reflect multiple characteristic of the lesion thereby increasing the discriminative performance of the radiomic model. Therefore, the present study intends to evaluate the efficiency of integrative nomogram, created by combining clinical parameters and radiomics features extracted from gross tumor volume (GTV), peritumoral volume (PTV) and LN, for the preoperative prediction of LN metastasis in clinical cT1N0M0 adenocarcinoma. A primary cohort of 163 patients (training cohort, 113; and internal validation cohort, 50) and an external validation cohort of 53 patients with clinical stage cT1N0M0 were retrospectively included. Features were extracted from three regions of interests (ROIs): GTV; PTV (5.0 mm around the tumor) and LN on pre-operative contrast enhanced computed tomography (CT). LASSO logistic regression method was used to build radiomic signatures. Multivariable regression analysis was used to build a nomogram. The performance of the nomogram was assessed with respect to its calibration, discrimination, and clinical usefulness. The discriminative performance of nomogram was validated both internally and externally. The radiomic signatures using the features of GTV, PTV and LN showed a good ability in predicting LN metastasis with an area under the curve (AUC) of 0.74 (95% CI 0.60–0.88), 0.72 (95% CI 0.57–0.87) and 0.64 (95% CI 0.48–0.80) respectively in external validation cohort. The integration of different signature together further increases the discriminatory ability: GTV + PTV (GPTV): AUC 0.75 (95% CI 0.61–0.89) and GPTV + LN: AUC 0.76 (95% CI 0.61–0.91) in external validation cohort. An integrative nomogram of clinical parameters and radiomic features demonstrated further increase in discriminatory ability with AUC of 0.79 (95% CI 0.66–0.93) in external validation cohort. The nomogram showed good calibration. Decision curve analysis demonstrated that the radiomic nomogram was clinically useful. The integration of information from clinical parameters along with CT radiomics information from GTV, PTV and LN was feasible and increases the predictive performance of the nomogram in predicting LN status in cT1N0M0 adenocarcinoma patients suggesting merit of information integration from multiple sources in building prediction model.

Influence of enhanced recovery after surgery (ERAS) on patients receiving lung resection: a retrospective study of 1749 cases

BACKGROUND

The study aimed to evaluate the outcomes following the implementation of enhanced recovery after surgery (ERAS) for patients undergoing lung cancer surgery.

METHOD

A retrospective cohort study involving 1749 patients with lung cancer undergoing pulmonary resection was conducted. The patients were divided into two time period groups for analysis (routine pathway and ERAS pathway). Logistic regression analysis was performed to assess the risks of developing postoperative pulmonary complications.

RESULTS

Among the 1749 patients, 691 were stratified into the ERAS group, and 1058 in to the routine group. The ERAS group presented with shorter postoperative in-hospital length of stay (LOS) (4.0 vs 6.0, P < 0.001), total LOS (10.0 vs. 13.0 days, P < 0.001), and lower total in-hospital costs (P < 0.001), including material (P < 0.001) and drug expenses (P < 0.001). Furthermore, the ERAS group also presented with a lower occurrence of postoperative pulmonary complications (PPCs) than the routine group (15.2% vs. 19.5%, P = 0.022). Likewise, a significantly lower occurrence of pneumonia (8.4% vs. 14.2%, P < 0.001) and atelectasis (5.9% vs. 9.8%, P = 0.004) was found in the ERAS group. Regarding the binary logistic regression, the ERAS intervention was the sole independent factor for the occurrence of PPCs (OR: 0.601, 95% CI 0.434-0.824, P = 0.002). In addition, age (OR: 1.032, 95% CI 1.018-1.046), COPD (OR: 1.792, 95% CI 1.196-2.686), and FEV1 (OR: 0.205, 95% CI 0.125-0.339) were also independent predictors of PPCs.

CONCLUSION

Implementation of an ERAS pathway shows improved postoperative outcomes, including shortened LOS, lower in-hospital costs, and reduced occurrence of PPCs, providing benefits to the postoperative recovery of patients with lung cancer undergoing surgical treatment.

Video-Assisted Thoracoscopic Segmentectomy for Deep and Peripheral Small Lung Cancer

Background  We aimed to retrospectively compare the long-term prognosis and recurrence after segmentectomy between nonsmall cell lung cancer (NSCLC) patients with deep and peripheral lesions.

Methods  Data were extracted for 85 lobectomy-tolerable NSCLC patients with tumors measuring ≤2 cm, who underwent video-assisted thoracoscopic segmentectomy with curative intent during January 2006 to December 2014. Tumor location was determined by the surgeon using thin-slice (1 mm) and three-dimensional computed tomography. Overall and recurrence-free survival was compared between patients with peripheral and deep lesions using univariate and multivariate Cox proportional hazard models. The indications for segmentectomy included NSCLC measuring ≤2 cm and consolidation/tumor ratio ≤20%, solid NSCLC ≤1 cm, and indeterminate nodule ≤1.5 cm.

Results  No recurrence of peripheral and deep lesions was noted. The 5-year overall survival was 96.4% for all patients, and 100 and 95.3% for patients with deep and peripheral lesions, respectively. There was no significant difference between the overall survival rates associated with the deep and peripheral lesions (95% confidence interval [CI], 89.5–98.8, nonsignificant, 86.4–98.4, respectively; p  = 0.189). In a multivariate analysis, the American Society of Anesthesiologists score (hazard ratio [HR], 13.30; 95% CI, 1.31–210.36; p  = 0.028) and histology (HR, 0.03; 95% CI, 0.00–0.32; p  = 0.037) were independent prognostic factors for overall survival; tumor location was not a prognostic factor.

Conclusions  When video-assisted thoracoscopic segmentectomy with curative intent was performed with sufficient surgical margins, the location of small NSCLC did not affect recurrence risk and prognosis. Video-assisted thoracoscopic segmentectomy for small NSCLC is acceptable, regardless of the tumor location.

Interventional Bronchoscopy

For over 150 years, bronchoscopy, especially flexible bronchoscopy, has been a mainstay for airway inspection, the diagnosis of airway lesions, therapeutic aspiration of airway secretions, and transbronchial biopsy to diagnose parenchymal lung disorders. Its utility for the diagnosis of peripheral pulmonary nodules and therapeutic treatments besides aspiration of airway secretions, however, has been limited. Challenges to the wider use of flexible bronchoscopy have included difficulty in navigating to the lung periphery, the avoidance of vasculature structures when performing diagnostic biopsies, and the ability to biopsy a lesion under direct visualization. The last 10-15 years have seen major advances in thoracic imaging, navigational platforms to direct the bronchoscopist to lung lesions, and the ability to visualize lesions during biopsy. Moreover, multiple new techniques have either become recently available or are currently being investigated to treat a broad range of airway and lung parenchymal diseases, such as asthma, emphysema, and chronic bronchitis, or to alleviate recurrent exacerbations. New bronchoscopic therapies are also being investigated to not only diagnose, but possibly treat, malignant peripheral lung nodules. As a result, flexible bronchoscopy is now able to provide a new and expanding armamentarium of diagnostic and therapeutic tools to treat patients with a variety of lung diseases. This State-of-the-Art review succinctly reviews these techniques and provides clinicians an organized approach to their role in the diagnosis and treatment of a range of lung diseases.

Analysis of Segmental Lymph Node Metastasis and Clinical Features in cT1N0M0 Lung Adenocarcinoma

The progression of lung adenocarcinoma through lymph node metastasis has been well established; however, the process of segmental lymph node (LSN) metastasis in cT1N0M0 lung adenocarcinoma remains unclear. We aimed to elucidate the markers of lymph node metastasis to different segments in early-stage lung adenocarcinoma and identify new indications for segmentectomy. A total of 200 patients were enrolled in this study. These patients were diagnosed with cT1N0M0 lung adenocarcinoma after positron emission tomography/computed tomography and received lobectomy and lymph node dissection surgeries. Lymph nodes retrieved from each station were sorted. The metastatic status of the isolated (i) LSNs and several characteristics were analyzed. Patients with ground-glass nodules (GGNs) (P=0.025), AIS/MIA/lepidic adenocarcinoma (P=0.038), nodules with a maximum diameter ≤1 cm (P=0.017), maximum standardized uptake value (SUV_max) < 2.5 (P=0.029), serum carcinoembryonic antigen (CEA) levels ≤4.5 ng/ml (P=0.036), and no N1 lymph nodes metastasis (P=0.036) had significantly lower iLSN metastasis rates than those without these characteristics. Pure GGNs, CEA levels ≤4.5 ng/ml, SUV_max < 2.5, tumors with a maximum diameter of ≤1 cm, or those confirmed to be adenocarcinoma in situ, minimally invasive adenocarcinoma, or invasive lepidic-predominant adenocarcinoma by frozen section may indicate segmentectomy. However, segmentectomy is not suitable for patients with metastasis to the N1 lymph nodes.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Hook-wire localization versus lipiodol localization for patients with pulmonary lesions having ground-glass opacity

OBJECTIVES

Accurate and safe preoperative localization is useful for video-assisted thoracic surgery of small pulmonary lesions with ground-glass opacity (GGO). However, the optimal localization method is unclear. The aim of this study was to compare the usefulness and safety of the lipiodol and hook-wire localization techniques for video-assisted thoracic surgery of GGO lesions.

METHODS

This prospective, non-randomized comparative study was conducted between April 2014 and December 2016 at 8 qualifying university teaching hospitals. Two-hundred-fifty patients with pulmonary lesions having GGO were included. Patients were assigned in a 1:1 ratio to either the lipiodol (n = 125, 4 hospitals) or hook-wire group (n = 125, 4 hospitals) for preoperative localization procedures. Participants underwent preoperative localization via the lipiodol or hook-wire technique followed by thoracoscopic surgery. The primary endpoint was the procedure success rate.

RESULTS

The procedure success rates (hook-wire vs lipiodol group) were 94.40% versus 99.16% (P = .08). Localization-related complications occurred in 53.60% versus 48.33% of patients (P = .49). Hemorrhage rates were significantly greater in the hook-wire group than in the lipiodol group (21.6% vs 5.83%, P < .001). The lipiodol procedure time was significantly longer than that of the hook-wire technique (20.69 ± 9.34 vs 17.15 ± 7.91 minutes, P = .001). The initially positive surgical resection margin was significantly greater in the hook-wire group than in the lipiodol group (10.89% vs 2.38%, P = .02).

CONCLUSIONS

There was no significant difference in success rate between the hook-wire and lipiodol methods. However, the hemorrhage rate was significantly greater in the hook-wire group, whereas the hook-wire group showed greater initially positive surgical resection margins.

Achievements and futures of immune checkpoint inhibitors in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) has been threatening human health for years. Cytotoxicity-based chemotherapy seems to reach plateau in NSCLC treatment. Immunotherapy with immune checkpoint inhibitors (ICIs) against programmed cell death 1 (PD-1/L1) axis are to provide long-term survival benefits for wild-type advanced NSCLC patients with acceptable adverse effects. Though beneficiary population is limited from monotherapy, combination strategies are expanding indicators. Retrospective evidences suggested ICIs are also potentially useful for brain metastasis. Furthermore, the combination of ICIs and surgery are to prolong progression free survival time for local advanced patients. Additionally, novel agents targeting in immune checkpoints other than PD-1/L1 demonstrated potential values in anticancer immunity. Herein, we summarize the novel therapies of checkpoint inhibitors in NSCLC treatment and some other potential immunotherapy to provide a conspectus for novel immunotherapy in NSCLC and perspective for the future in anti-cancer treatment.

Can peritumoral radiomics increase the efficiency of the prediction for lymph node metastasis in clinical stage T1 lung adenocarcinoma on CT?

OBJECTIVES

To evaluate the efficiency of radiomics model on CT images of intratumoral and peritumoral lung parenchyma for preoperative prediction of lymph node (LN) metastasis in clinical stage T1 peripheral lung adenocarcinoma patients.

METHODS

Three hundred sixty-six peripheral lung adenocarcinoma patients with clinical stage T1 were evaluated using five CT scanners. For each patient, two volumes of interest (VOIs) on CT were defined as the gross tumor volume (GTV) and the peritumoral volume (PTV, 1.5 cm around the tumor). One thousand nine hundred forty-six radiomic features were obtained from each VOI, and then refined for reproducibility and redundancy. The refined features were investigated for usefulness in building radiomic signatures by mRMR feature ranking method and LASSO classifier. Multivariable logistic regression analysis was used to develop a radiomic nomogram incorporating the radiomic signature and clinical parameters. The prediction performance was evaluated on the validation cohort.

RESULTS

The radiomic signatures using the features of GTV and PTV showed a good ability in predicting LN metastasis with an AUC of 0.829 (95% CI, 0.745-0.913) and 0.825 (95% CI, 0.733-0.918), respectively. By incorporating the features of GTV and PTV, the AUC of radiomic signature increased to 0.843 (95% CI, 0.770-0.916). The AUC of radiomic nomogram was 0.869 (95% CI, 0.800-0.938).

CONCLUSIONS

Radiomic signatures of GTV and PTV both had a good prediction ability in the prediction of LN metastasis, and there is no significant difference of AUC between the two groups. The proposed nomogram can be conveniently used to facilitate the preoperative prediction of LN metastasis in T1 peripheral lung adenocarcinomas.

KEY POINTS

• Radiomics from peritumoral lung parenchyma increase the efficiency of the prediction for lymph node metastasis in clinical stage T1 lung adenocarcinoma on CT. • A radiomic nomogram was developed and validated to predict LN metastasis. • Different scan parameters on CT showed that radiomics signature had good predictive performance.

[Advances in Surgical Approach and Resection of Non-small Cell Lung Cancer]

随着疾病谱的改变，肺癌的发病率和死亡率在全球范围内一直居高不下，自从外科干预被应用于肺癌的治疗，其地位日益提高，目前以外科手术为主的综合治疗已成为肺癌治疗的首选方案，外科手术入路和术式种类繁多，并且新的技术不断出现，本文拟总结不同手术方式和手术入路的研究进展。随着手术软硬件技术的发展和微创理念深入人心，胸腔镜微创手术较传统开胸手术为肺癌患者带来了更多的福音，手术方式的改变也可更大限度保留肺组织，提高患者的生存质量，相信随着各类手术适应证和手术方式的进一步规范，微创胸腔镜手术会给肺癌患者带来更多的益处。

Enhanced recovery programs in lung cancer surgery: systematic review and meta-analysis of randomized controlled trials

Background

Enhanced recovery after surgery (ERAS) program is an effective evidence-based multidisciplinary protocol of perioperative care, but its roles in thoracic surgery remain unclear. This systematic review of randomized controlled trials (RCTs) aims to investigate the efficacy and safety of the ERAS programs for lung cancer surgery.

Materials and methods

We searched the PubMed and EMBASE databases to identify the RCTs that implemented an ERAS program encompassing more than four care elements within at least two phases of perioperative care in lung cancer surgery. The heterogeneity levels between studies were estimated by the Cochrane Collaborations. A qualitative review was performed if considerable heterogeneity was revealed. Relative risk (RR) and weighted mean difference served as the summarized statistics for the meta-analyses. Additional analyses were also performed to perceive potential bias risks.

Results

A total of seven RCTs enrolling 486 patients were included. The meta-analysis indicated that the ERAS group patients had significantly lower morbidity rates (RR=0.64; p<0.001), especially the rates of pulmonary (RR=0.43; p<0.001) and surgical complications (RR=0.46; p=0.010), than those of control group patients. No significant reduction was found in the in-hospital mortality (RR=0.70; p=0.58) or cardiovascular complications (RR=1.46; p=0.25). In the qualitative review, most of the evidence reported significantly shortened length of hospital and intensive care unit stay and decreased hospitalization costs in the ERAS-treated patients. No significant publication bias was detected in the meta-analyses.

Conclusion

Our review demonstrates that the implementation of an ERAS program for lung cancer surgery can effectively accelerate postoperative recovery and save hospitalization costs without compromising patients’ safety. A worldwide consensus guideline is urgently required to standardize the ERAS protocols for elective lung resections in the future.