Features of anaplastic lymphoma kinase rearrangement in early-stage lung cancer: Analysis of a nationwide Japanese database.

BACKGROUND AND OBJECTIVES: Anaplastic lymphoma kinase (ALK) rearrangement is a representative driver mutation in lung cancer. However, the biology of early-stage ALK-rearranged lung cancer remains unclear. We aimed to assess the clinicopathological features, prognostic implications, and influence of ALK rearrangement on the postoperative course in surgically resected lung cancer. METHODS: We retrospectively analyzed data from the Japanese Joint Committee of Lung Cancer Registry database. Of the 12 730 patients with lung adenocarcinoma, 794 (6.2%) were tested for ALK rearrangement and were included. RESULTS: ALK rearrangements were detected in 76 patients (10%). The 5-year overall survival (OS) rate was significantly higher in the ALK rearrangement-positive group than in the ALK rearrangement-negative group (p = 0.030). Multivariable analysis revealed that ALK rearrangement was an independent prognostic factor for improved OS (hazard ratio, 0.521; 95% confidence interval, 0.298-0.911; p = 0.022). Regarding the postrecurrence state, there was no difference in the initial recurrence sites between both groups. Administration of ALK-tyrosine kinase inhibitors (TKIs) improved postrecurrence survival in any treatment lines. CONCLUSION: In one of the largest national surveys, ALK rearrangement was associated with improved long-term outcomes in surgically resected patients. ALK-TKIs may be an important treatment strategy for ALK rearrangement-positive lung adenocarcinoma in the postrecurrence state.

Outcomes of lung oligometastasis in pancreatic cancer.

OBJECTIVE: Pancreatic cancer with lung oligometastasis may have favourable overall survival. The aim of this study was to evaluate outcomes of pancreatic cancer with lung oligometastases including both synchronous and metachronous metastases. METHODS: Consecutive pancreatic cancer patients with lung metastasis treated at our institution between February 2015 and December 2021 were identified from our prospectively maintained database. Clinical characteristics and outcomes were compared and analysed according to the extent of lung metastases. Predictors for overall survival were analysed using the Cox proportional hazards model. RESULTS: A totoal of 171 patients were included (oligometastasis/polymetastasis/multi-organ metastasis: 34/50/87). Patients with oligometastases were more likely to undergo surgical resection (41% vs. 0% vs. 2%) and showed a longer median overall survival (41.3 vs. 17.6 vs. 13.1 months) compared with those with other types of metastases. Oligometastasis (hazard ratio, 0.43; 95% confidence interval, 0.24-0.76; P = 0.004) was identified as an independent factor predicting favourable overall survival in patients with lung-only metastasis. Disease status (synchronous vs. metachronous) was not associated with survival in patients with oligometastasis (29.4 vs. 41.3 months, P = 0.527) and polymetastasis (17.9 vs. 16.7 months, P = 0.545). Selected patients who underwent surgical resection showed a median overall survival of 52.7 months. CONCLUSIONS: Patients with lung oligometastases presented a favourable prognosis. Surgical resection in selected patients was associated with a long median overall survival.

Initial perioperative outcomes of robot-assisted thoracoscopic lobectomy using a confronting setting.

PURPOSE: Most robot-assisted thoracoscopic surgery (RATS) is performed from the vertical view. This study evaluates the initial outcomes of our novel confronting RATS technique, in which the patient was viewed horizontally, as in open thoracotomy. METHODS: We reviewed data on patients who underwent thoracoscopic lobectomy between January, 2019 and April, 2022. Perioperative outcomes were compared between RATS and video-assisted thoracoscopic surgery (VATS), using propensity-score matching. RESULTS: RATS and VATS were performed for 83 and 571 patients, respectively. After propensity-score matching, data on 81 patients from each of the two groups were retrieved. The operative time was significantly longer for RATS than for VATS (199 ± 44 min vs. 173 ± 37 min, p < 0.001). There was no mortality or conversion to thoracotomy in either of the groups. The rates of overall complications and prolonged air leak did not differ significantly between the groups. The serum creatine phosphokinase level on postoperative day 4 was higher after RATS than after VATS. The number of resected lymph nodes and the rates of nodal upstaging did not differ significantly between the groups. CONCLUSION: The initial perioperative outcomes of RATS using the confronting settings were comparable to those of VATS.

Impact of postoperative complications on the long-term outcome in lung cancer surgery.

PURPOSE: Postoperative complications have a significant impact on perioperative outcomes; however, their association with the long-term prognosis remains unclear. We evaluated the impact of postoperative complications on the long-term outcomes after curative surgery in lung cancer patients. METHODS: This study included 1129 patients with primary lung cancer who underwent lobectomy between April 2011 and March 2017. Univariate and multivariate analyses were performed to assess the association of postoperative complications with the overall and recurrence-free survival. RESULTS: Postoperative complications were observed in 147 (13.0%) patients over a median follow-up period of 5-years. Compared to patients without complications, those with complications showed had worse long-term outcomes, including the 5-year overall survival (75.3% vs. 86.1%, p < 0.001) and 5-year recurrence-free survival (64.2% vs. 74.4%, p = 0.004). A multivariate analysis revealed that the incidence of postoperative complications was significantly associated with the overall survival (hazard ratio = 1.665, p = 0.006) and recurrence-free survival (hazard ratio = 1.416, p = 0.025) in all patients. The prognostic influence was greater in patients with pathological stages II and III cancer (overall survival: hazard ratio = 2.019, p = 0.005; recurrence-free survival: hazard ratio = 1.90, p = 0.001) than in those with pathological stage I cancer. CONCLUSION: Postoperative complications are independent predictors of the overall and recurrence-free survival in lung cancer patients, especially advanced-stage cancer patients.

Comparison of local therapy in patients with lung oligo-recurrence of non-small-cell lung cancer.

BACKGROUND AND OBJECTIVES: The effectiveness of local therapy has been reported in non-small-cell lung cancer (NSCLC) patients with oligo-recurrence. However, there is still no clear consensus on the choice of local therapy. We aimed to examine the choice of local therapy in NSCLC patients with lung oligo-recurrence. METHODS: Among 1760 consecutive NSCLC patients who underwent complete resection between 1990 and 2008, 535 patients developed recurrence. Lung oligo-recurrence was defined as 1-5 metachronous recurrences limited to the lungs only; such recurrence was found in 97 patients. We examined the differences in the prognosis of each therapy for these patients. RESULTS: The 5-year postrecurrence survival (PRS) rates in patients who underwent local therapy (n = 54) and those who did not (n = 43) were 55.6% and 31.1%, respectively; it was significantly higher in patients who underwent local therapy (p = 0.004). Among 47 patients who underwent resection or radiation therapy, the 5-year PRS rates were 61.5% and 47.6% (p = 0.258), and the 5-year postrecurrence progression-free survival rates were 30.3% and 24.7% (p = 0.665), respectively, without any significant difference. CONCLUSIONS: Patients with lung oligo-recurrence should consider local therapy individually, depending on their general condition.

Permissible Outcomes of Lobe-Specific Lymph Node Dissection for Elevated Carcinoembryonic Antigen in Non-Small Cell Lung Cancer.

Background and Objectives: Lobe-specific nodal dissection (L-SND) is currently acceptable for the dissection of early-stage non-small cell lung cancer (NSCLC) but not for cancers of more advanced clinical stages. We aimed to assess the efficacy of L-SND, compared to systemic nodal dissection (SND). Materials and Methods: We retrospectively collected the clinical data of patients with carcinoembryonic antigen (CEA) abnormality who underwent complete resection of NSCLC via lobectomy or more in addition to either SND or L-SND at two cancer-specific institutions from January 2006 to December 2017. Results: A total of 799 patients, including 265 patients who underwent SND and 534 patients who underwent L-SND, were included. On multivariate analysis, thoracotomy, more than lobectomy, cN1-2, advanced pathological stage, adjuvant treatment, and EGFR or ALK were strongly associated with SND. No significant differences were found in overall survival, disease-free survival, and overtime survival after propensity adjustment (p = 0.09, p = 0.11, and p = 0.50, respectively). There were no significant differences in local (p = 0.16), regional (p = 0.72), or distant (p = 0.39) tumor recurrence between the two groups. Conclusions: SND did not improve the prognosis of NSCLC patients with CEA abnormality. Complete pulmonary resection via L-SND seems useful for NSCLC patients with CEA abnormality.

Outcomes after thoracoscopic surgery in octogenarian patients with clinical N0 non-small-cell lung cancer.

OBJECTIVE: The number of surgeries for elderly patients with lung cancer is increasing. In our institute, thoracoscopic lobectomy and hilar lymph node dissection are the standard procedure for octogenarian patients with clinical N0 non-small-cell lung cancer. The aim of this study was to determine the outcome of our strategy for octogenarian patients. METHODS: Seventy octogenarian patients with clinical N0 non-small-cell lung cancer who underwent surgery were enrolled (O group). As a control group, 205 septuagenarian patients were also enrolled (S group). We compared several clinicopathological factors and outcomes. RESULTS: The median age of the O group was 82. There was no significant difference in the comorbidity ratio between the two groups. The 5-year overall survival ratio for the O group (72.8%) was significantly worse than that for the S group (88.3%). However, multivariate analysis proved age was not an independent predictor of outcome. The rates of recurrences involving ipsilateral mediastinal lymph nodes were equal in the two groups. After propensity score matching, clinical T1 patients were dominant (85%) in two matched group and no statistically significant differences were observed in the 5-year overall survival between the two groups. CONCLUSIONS: Our strategy for octogenarian patients with non-small-cell lung cancer, including omission of mediastinal lymph node dissection, was determined to be feasible, in particularly with cT1N0 disease.

Recent fluorescence imaging technology applications of indocyanine green in general thoracic surgery.

Thoracic surgeons perform a wide variety of cancer operations, which are often associated with high morbidity and mortality. Thus, thoracic surgery involves many special challenges that require innovative solutions. The increased utilization of minimally invasive practices, poor overall cancer survival, and significant morbidity of critical operations remain key obstacles to overcome. Fluorescence imaging technology (FIT), involving the implementation of fluorescent dyes and imaging systems, is currently used as an adjunct for general thoracic surgery in many situations and includes sentinel lymph node mapping, pulmonary intersegmental plane identification, pulmonary nodule identification, pulmonary bullous lesion detection, evaluation of the anastomotic perfusion after tracheal surgery, and thoracic duct imaging for postoperative chylothorax. This technology enhances the surgeon's ability to perform operations, and has specific advantages. We review some of the key studies that demonstrate the applications of FIT in the field of general thoracic surgery, focusing on the use of indocyanine green.

[Completion Pneumonectomy and Perioperative Managements].

Completion pneumonectomy (CP) is the complete removal of lung tissue remaining after an initial ipsilateral partial pulmonary resection and is one of the most invasive operations in the field of general thoracic surgery. Mortality and morbidity rates are higher after CP than standard pneumonectomy. CP is a highly demanding procedure, usually due to major pleural and sometimes pericardial dense adhesions from previous surgery or infection. Intra-pericardial control of the pulmonary artery and veins is recommended to avoid vessel injury. Therefore, this operative intervention should be performed only by experienced thoracic surgeons on carefully selected patients in order to improve postoperative outcomes. Preoperative pulmonary and cardiac functions are decreased by the previous procedure. In addition, the rate of complications is high because of excessive operative invasiveness. Therefore, preoperative assessment, surgical indication, low invasive surgical technique, and good postoperative management are very important elements when CP is performed. On the other hands, CP may be a reasonable option for postoperative lung cancer recurrence or new primaries only in carefully selected patients, in whom the potential oncological benefits overweigh the surgical risk. This article reviews these operative knack and pitfalls.

Efficiency of thoracoscopic palpation in localizing small pulmonary nodules.

PURPOSE: The thoracoscopic localization of small and deep pulmonary nodules can be challenging. We conducted this study to evaluate the efficiency of thoracoscopic palpation in tumor detection. METHODS: The subjects of this study were 229 patients with a collective 267 indeterminate pulmonary nodules ≤ 15 mm in diameter, in the outer third of the lung field. The nodules were localized by palpation using the forefinger or a metal suction probe. Based on the distance from the pleura-to-tumor size ratio (D/S), the nodules were classified into group A (D/S = 0), group B (0 < D/S ≤ 1), and group C (D/S > 1). RESULTS: The median tumor diameter was 10 mm. All 267 nodules were palpable and resected with negative margins via thoracoscopic wedge resection. The majority of the deep nodules had no pleural change (11%, 86%, and 100% in groups A, B, and C, respectively; P < 0.01). The median margins were 15, 16, and 14 mm in groups A, B, and C, respectively. In four patients (1.5%) with relatively short margins (2-7 mm), an additional intraoperative wedge resection was performed. CONCLUSION: Thoracoscopic palpation was effective for tumor detection when the nodules were located in the outer third of the lung.

[Thoracoscopic Segmentectomy Using Three-dimensional Computed Tomography and Indocyanine-green Fluorescence Navigation].

BACKGROUND: We investigated the feasibility and efficacy of thoracoscopic segmentectomy using 3-dimensional computed tomography( 3D-CT) and indocyanine-green( ICG) fluorescence navigation. METHODS: ICG fluorescence-navigated thoracoscopic segmentectomy was performed in 149 patients during 2013 and 2017. Each patient underwent preoperative evaluation by thin-section enhanced CT, which provided 3-dimensional simulations of vascular and bronchial structures. During the procedure, low-dose ICG( 0.15~0.25 mg/kg) was injected systemically after the target segmental pulmonary arteries and bronchus were divided. Under near-infrared thoracoscopic guidance, an intersegmental plane was clearly observed as a border between dark target region and bright residual region. The ICG fluorescent line was marked by electrocautery, followed by division of lung parenchyma along the line by endoscopic staples. RESULTS: An intersegmental line was visible in 98% of patients by ICG fluorescence navigation. No ICG-related adverse events occurred. No operative mortality was observed and morbidity rate was 8.7%. The 5-year overall survival rate and the 5-year recurrence free probability of 101 patients with primary lung cancer were 92% and 98%, respectively. Local recurrence at the resected site occurred in no patient with lung cancer and 1 patient with pulmonary metastasis. CONCLUSION: Thoracoscopic segmentectomy using 3D-CT and ICG fluorescence navigation is a useful therapeutic option.

High expression of programmed cell death 1 ligand 1 in lung adenocarcinoma is a poor prognostic factor particularly in smokers and wild-type epidermal growth-factor receptor cases.

A clinical implication of programmed cell death 1 ligand 1 (PD-L1) expression in lung adenocarcinoma has not been well established. We evaluated PD-L1 expression immunohistochemically on 296 surgically resected lung adenocarcinomas to investigate a clinical implication of PD-L1 expression especially in terms of smoking history and epidermal growth-factor receptor (EGFR) mutation status. Patients were classified into high- and low-PD-L1 expression groups. The high-expression group (n = 107) showed a significantly higher proportion of smokers and poor differentiation compared with the low-expression group (n = 189). Survival analysis showed that the prognosis of the high-expression group was worse in overall survival than that of the low-expression group (3-year overall survival 85 vs. 94%, P = 0.005). Stratified survival analyses showed that the prognoses of the high-expression group were worse than those of the low-expression group in both strata of smokers and wild-type EGFR (P = 0.009 and P = 0.007, respectively). We found that high PD-L1 expression was a poor prognostic factor in the smokers or the patients with wild-type EGFR, whereas it was not the case in those who never smoked or those with EGFR mutation, implying the importance of adenocarcinoma driver mutations and etiology.

Prognostic impact of bulky swollen lymph nodes in cN1 non-small cell lung cancer patients.

OBJECTIVE: The aim of this study was to analyze clinicopathological backgrounds and prognosis of clinical N1 non-small cell lung cancer and clarify the difference between bulky and non-bulky cN1 diseases. METHODS: We reviewed 110 patients with completely resected cN1 non-small cell lung cancer and examined the prognostic impact of lymph node size. We classified the swollen lymph nodes into two groups based on their size on chest computed tomography: short-axis diameter ≥20 mm (=bulky group) or <20 mm (=non-bulky group). RESULTS: The bulky group consisted of 10 patients, and the non-bulky group comprised 100 patients. There was no significant difference in the upstaging rate to pathological N2 between the bulky and non-bulky groups (31% vs. 30%; P = 0.63). The 5-year recurrence-free survival rate and 5-year overall survival rate of both groups did not differ significantly (P = 0.36, P = 0.30, respectively). Our results suggested the possibility that the size of the swollen lymph nodes had no impact on the prognosis in cN1 non-small cell lung cancer patients. In comparison of surgical procedure, pneumonectomy was performed in the bulky group more frequently than the non-bulky group (70% vs. 19%; P < 0.01). CONCLUSIONS: Bulky cN1 disease was not different from non-bulky disease in the prognosis and the upstaging rate to pN2. Curative resection should be indicated to resectable bulky cN1 disease as with non-bulky disease, with careful pre-operative evaluation and preparation considering the possibility of pneumonectomy.

Prognostic impact of adjuvant therapy for cisplatin-unfit patients with non-small-cell lung cancer: A multicenter analysis.

INTRODUCTION: No evidence exists for postoperative adjuvant therapy in elderly or renal dysfunction patients with non-small-cell lung cancer (NSCLC) who are unfit to receive cisplatin (CDDP). Herein, we evaluated the efficacy of postoperative adjuvant therapy for CDDP-unfit patients. MATERIALS AND METHODS: We defined CDDP-unfit patients as those aged ≥75 years or with renal dysfunction based on criteria established by expert panels and from prospective studies. CDDP-fit patients comprised all others. Between 2010 and 2020, among 1,423 patients with pathological stage II-III (8th edition of the AJCC-TNM Classification) NSCLC, 454 were identified as unfit for CDDP. Following propensity score matching in CDDP-unfit patients with and without postoperative adjuvant therapy, we analyzed the overall survival (OS) and disease-free survival (DFS) of each group and assessed the impact of adjuvant therapy on survival. RESULTS: OS was significantly better in patients who received adjuvant therapy than in those who did not (5-year OS rate: 76.1 % vs. 50.0 %, p < 0.01) among 255 propensity score-matched patients. DFS was also significantly better in patients who received adjuvant therapy than in those who did not (5-year OS: 54.6 % vs. 35.1 %, p < 0.01). CONCLUSIONS: Our findings suggest that postoperative adjuvant therapy could be beneficial for CDDP-unfit patients aged ≥75 years or with renal dysfunction. Future studies for CDDP-unfit patients should be designed based on the results of this study to determine the potential benefits of adjuvant therapy.

Utility of visualization and quantification of surgical techniques using motion analysis software for thoracoscopic surgery.

In this era of endoscopic surgery, feedback from recorded surgical videos is useful and efficient; therefore, effective methods of obtaining this feedback are needed. We analyzed surgical videos using motion analysis software and verified the usefulness of visualizing and objectively evaluating surgical procedures. We measured the grasping and traction angles of the vascular sheath when using forceps and the trajectory of the forceps tip for the upper pulmonary vein during right upper lobectomy during video-assisted thoracoscopic surgery performed by three trainers and trainees. Compared with the trainers, the trainees exhibited insufficient traction of the vascular sheath, performed many slow and unnecessary manipulations, and sometimes performed sudden and fast movements. By visualizing the surgical procedures, the trainee will be better able to identify dangerous or futile movements. It may also make it easier to objectively recognize improvements in one's technique. Motion analysis software could allow for efficient surgical education and self-learning.

Accuracy of thoracic nerves recognition for surgical support system using artificial intelligence.

We developed a surgical support system that visualises important microanatomies using artificial intelligence (AI). This study evaluated its accuracy in recognising the thoracic nerves during lung cancer surgery. Recognition models were created with deep learning using images precisely annotated for nerves. Computational evaluation was performed using the Dice index and the Jaccard index. Four general thoracic surgeons evaluated the accuracy of nerve recognition. Further, the differences in time lag, image quality and smoothness of movement between the AI system and surgical monitor were assessed. Ratings were made using a five-point scale. The computational evaluation was relatively favourable, with a Dice index of 0.56 and a Jaccard index of 0.39. The AI system was used for 10 thoracoscopic surgeries for lung cancer. The accuracy of thoracic nerve recognition was satisfactory, with a recall score of 4.5 ± 0.4 and a precision score of 4.0 ± 0.9. Though smoothness of motion (3.2 ± 0.4) differed slightly, nearly no difference in time lag (4.9 ± 0.3) and image quality (4.6 ± 0.5) between the AI system and the surgical monitor were observed. In conclusion, the AI surgical support system has a satisfactory accuracy in recognising the thoracic nerves.

Optimal Treatment Strategy for Oligo-Recurrence Lung Cancer Patients with Driver Mutations.

BACKGROUND: The efficacy of local therapies for lung cancer patients with postoperative oligo-recurrence has been reported. However, whether local therapies should be chosen over molecular targeted therapies for oligo-recurrence patients with driver mutations remains controversial. Therefore, we aimed to investigate the optimal initial treatment strategy for oligo-recurrence in lung cancer patients with driver mutations. METHODS: Among 2152 patients with lung adenocarcinoma who underwent surgical resection at our institute between 2008 and 2020, 66 patients with driver mutations who experienced cancer oligo-recurrence after surgery and were treated with local or molecularly targeted therapy as an initial therapy after recurrence were evaluated. Oligo-recurrence was characterized by the presence of 1 to 3 recurrent lesions. These patients were investigated, focusing on their post-recurrence therapies and prognoses. RESULTS: The median follow-up period was 71 months. Local and molecular targeted therapies were administered to 41 and 25 patients, respectively. The number of recurrence lesions tended to be lower in the initial local therapy group than in the molecular targeted therapy group. In the initial local therapy group, 23 patients (56%) subsequently received molecular targeted therapies. The time from recurrence to the initiation of molecular targeted therapy was significantly longer in the local therapy group than in the molecular targeted therapy group (p < 0.001). There was no significant difference in post-recurrence overall survival (hazard ratio, 1.429; 95% confidence interval, 0.701-2.912; log-rank, p = 0.324) and post-recurrence progression-free survival (hazard ratio, 0.799; 95% confidence interval, 0.459-1.390; log-rank, p = 0.426) in the initial local ablative therapy group compared with the initial molecular targeted therapy group. CONCLUSIONS: Local therapies as a first-line treatment did not show statistically significant differences in post-recurrence survival or progression-free survival compared with molecular targeted therapies. However, local therapies as an initial treatment should be considered preferably, as they can cure the recurrence and can delay the start of administration of molecular targeted therapies.

A survival nomogram model for patients with resectable non-small cell lung cancer and lymph node metastasis (N1 or N2) based on the Surveillance, Epidemiology, and End Results Database and single-center data.

Background: The ability to predict survival in patients with lymph node metastasis has long been elusive. After surgery, the basis for decision-making on the combination treatment of patients is not clear. The purpose of this study was thus to build a survival nomogram model to effectively predict the overall survival (OS) of patients with non-small cell lung cancer (NSCLC) and lymph node metastasis. The number of dissected lymph nodes (NDLN), number of positive lymph nodes (NPLN), lymph node ratio (LNR), and log odds of positive lymph nodes (LODDS) were included in this study to determine the risk factors in patients with advanced NSCLC. Methods: The data of 5,132 patients with NSCLC and lymph node metastasis (N1 or N2) were extracted from the Surveillance, Epidemiology, and End Results (SEER) database according to inclusion and exclusion criteria and used as the training cohort. We enrolled 117 patients from the First Affiliated Hospital, Zhejiang University School of Medicine as the external validation cohort. Receiver operating characteristic (ROC) analyses were performed to determine the best cutoff values for predicting the prognosis of patients with NSCLC. Based on the risk factors affecting prognosis, a nomogram was constructed using univariate and multivariate Cox proportional hazard regression models. The discrimination ability of the nomogram was evaluated with the concordance index (C-index) and calibration curves. For the independent risk factors, survival curves were drawn using Kaplan-Meier analysis. Results: ROC curve analysis showed that the optimal NPLN cut-off value was 4, LNR was 0.26, and LODDS was -0.25, respectively. However, LNR was nonsignificant in multivariate analysis, with a P value of 0.274. The novel survival nomogram model included seven independent risk factors, among which were NPLN, LODDS, and chemotherapy. Model 4, which included N stage, NPLN, and LODDS, had a higher likelihood ratio (LR) and C-index than did the other models. The C-index was 0.648 [95% confidence interval (CI): 0.636-0.659] in the training cohort and 0.807 (95% CI: 0.751-0.863) in the external validation cohort, showing good prognostic accuracy and discrimination ability. According to the median risk score, the patients in the training cohort and external validation cohort were divided into high-risk and low-risk groups, between which significant differences in OS were found. In the training cohort, age, sex, T stage, N stage, NPLN, LODDS, and chemotherapy were significantly associated with OS (P<0.001). In the external validation cohort, T stage, NPLN, LODDS, and chemotherapy were found to be correlated with OS. Conclusions: The NPLN and LODDS nomogram is an accurate survival prediction tool for patients with N1 or N2 NSCLC. Patients with lymph node metastasis can benefit from chemotherapy, but no evidence shows that radiotherapy is necessary for patients with resectable NSCLC.

Prognostic impact of ground-glass opacity components in lung cancer with lymph node metastasis.

Background: In early-stage non-small cell lung cancer (NSCLC), the presence of a ground-glass opacity (GGO) component in the primary lesion on high-resolution computed tomography (CT) is recognized as a favorable prognostic factor. Even in NSCLC with a GGO component, lymph node metastases are occasionally detected during or after surgery. However, the prognostic impact of GGO components in these patients has not been clarified. We aimed to examine the prognostic significance of GGO components as radiological findings of primary lesions of completely resected NSCLC with pathological nodal involvement. Methods: This study included 290 patients (11%) with pathological nodal involvement among 2,546 patients who underwent complete resection of NSCLC at our institution. Patients with an unknown primary lesion (T0) or centrally located lung cancer were excluded. The 290 patients were divided into two groups [i.e., the part-solid ("PS") and "Solid" groups] according to the radiological findings of the primary lesion, and their clinicopathological characteristics and prognoses were compared. Furthermore, a multivariate analysis was performed using the Cox proportional hazards model to examine the factors affecting the overall survival (OS). Results: The OS in the PS group (n=58) was significantly longer than that in the Solid group (n=232; P=0.039). However, multivariate analysis only revealed age [hazard ratio (HR) =1.77; 95% confidence interval (CI): 1.15-2.72] and the clinical T factor (HR =1.58; 95% CI: 1.01-2.47), but not the radiological findings of primary lesions, as the independent prognostic factors. Furthermore, the OS did not differ significantly between the PS and Solid groups matched for the clinical T and N factors (n=58 patients each). Conclusions: GGO components in the primary lesion, considered a decisive prognostic factor in early-stage NSCLC, did not affect the prognosis of patients with NSCLC and pathological nodal involvement.

Prediction of Tumor PD-L1 Expression in Resectable Non-Small Cell Lung Cancer by Machine Learning Models Based on Clinical and Radiological Features: Performance Comparison With Preoperative Biopsy.

OBJECTIVE: We investigated if PD-L1 expression can be predicted by machine learning using clinical and imaging features. METHODS: We included 117 patients with c-stage I/II non-small cell lung cancer who underwent radical resection. A total of 3951 radiomic features were extracted by defining the tumor (within tumor contour), rim (contour ±3 mm) and exterior (contour +10 mm) on preoperative contrast computed tomography. After feature selection by Boruta algorithm, prediction models of tumor PD-L1 expression (22C3: ≥1%, <1%) of resected specimens were constructed using Random Forest: radiomics, clinical, and combined models. Their performance was evaluated by 5-fold cross-validation, and AUCs were compared using Delong test. Next, study groups were categorized as patients without biopsy (training set), and those with biopsy (test set). Predictive ability of biopsy was compared to each prediction model. RESULTS: Of 117 patients (66 ± 10 years old, 48% male), 33 (28.2%) had PD-L1≥1%. Mean AUC of PD-L1≥1% for the validation set in radiomics, clinical, and combined models were 0.80, 0.80, and 0.83 (P = .32 vs. clinical model), respectively. The diagnosis of malignancy was made in 22 of 38 (58%) patients with attempted biopsies, and PD-L1 was measurable in 19 of 38 (50%) patients. Diagnostic accuracies of PD-L1≥1% from 19 determinable biopsies and 38 all attempted biopsies were 0.68 and 0.34, respectively. These were out performed by machine learning: 0.71, 0.71, and 0.74 for radiomics, clinical, and combined models, respectively. CONCLUSIONS: Our machine learning could be an adjunctive tool in estimating PD-L1 expression prior to neoadjuvant treatment, particularly when PD-L1 is indeterminable with biopsy.