Demographics, Safety and Quality, and Prognostic Information in Both the Seventh and Eighth Editions of the TNM Classification in 18,973 Surgical Cases of the Japanese Joint Committee of Lung Cancer Registry Database in 2010

Optimizing lung cancer surgery in the elderly: sublobar resection versus lobectomy for early-stage non-small cell lung cancer patients aged 80 and above

The optimal surgical approach for elderly patients with early-stage non-small cell lung cancer (NSCLC) remains a topic of debate. A retrospective analysis was conducted on patients who underwent pulmonary resection for early-stage NSCLC at our single institution between January 2018 and December 2022. Propensity score matching was used to balance baseline characteristics between the sublobar resection and lobectomy groups. Perioperative outcomes, pulmonary function recovery, postoperative quality of life, and survival were compared between the two groups. A total of 151 patients were included, with 42 undergoing sublobar resection and 109 undergoing lobectomy. After propensity score matching, baseline characteristics were well-balanced between the two groups. Sublobar resection was associated with shorter operative time (125.83 ± 33.56 min vs. 161.14 ± 61.54 min, p = 0.048), less intraoperative blood loss [65 (30, 75) ml vs. 120 (70, 170) ml, p < 0.001], shorter drainage duration [3 (2, 5) days vs. 5 (3, 6) days, p < 0.001], shorter hospital stay [6 (4, 8) days vs. 10 (7, 13) days, p < 0.001], and fewer postoperative complications (11.9% vs. 47.6%, p < 0.001), compared to lobectomy. Moreover, sublobar resection led to better pulmonary function recovery and higher postoperative quality of life scores, with no significant difference in overall and disease-free survival between the groups. Sublobar resection in patients aged 80 and above with early-stage NSCLC offered comparable oncological outcomes to lobectomy while preserving more lung function and providing better postoperative recovery and long-term quality of life. These findings have important implications for treatment decision-making in elderly NSCLC patients.

Clinical outcomes of left upper segmentectomy vs. lobectomy for early non-small-cell lung cancer: a nationwide database study in Japan

PURPOSE

Given that left upper lobe and right upper and middle lobes share a similar anatomy, segmentectomy, such as upper division and lingulectomy, should yield identical oncological clearance to left upper lobectomy. We compared the prognosis of segmentectomy with that of lobectomy for early stage non-small-cell lung cancer (NSCLC) in the left upper lobe.

METHODS

We retrospectively examined 2115 patients who underwent segmentectomy or lobectomy for c-stage I (TNM 8th edition) NSCLC in the left upper lobe in 2010. We compared the oncological outcomes of segmentectomy (n = 483) and lobectomy (n = 483) using a propensity score matching analysis.

RESULTS

The 5-year recurrence-free and overall survival rates in the segmentectomy and lobectomy groups were comparable, irrespective of c-stage IA or IB. Subset analyses according to radiological tumor findings showed that segmentectomy yielded oncological outcomes comparable to those of lobectomy for non-pure solid tumors. In cases where the solid tumor exceeded 20 mm, segmentectomy showed a recurrence-free survival inferior to that of lobectomy (p = 0.028), despite an equivalent overall survival (p = 0.38).

CONCLUSION

Segmentectomy may be an acceptable alternative to lobectomy with regard to the overall survival of patients with c-stage I NSCLC in the left upper lobe.

Prognostic significance of preoperative exercise tolerance in patients with early-stage lung cancer

OBJECTIVE

To investigate the influence of simple preoperative exercise tests as prognostic factors for early-stage lung cancer.

METHODS

This single-institution retrospective study included consecutive patients who underwent pulmonary resection for stage 0 to I lung cancer between April 2017 and December 2019. Before surgery, 7 metabolic equivalents of task in the double Master 2-step test were loaded into the exercise echocardiogram. The relationship between prognosis and exercise stress test results in terms of availability, symptoms, and saturation of percutaneous oxygen was investigated.

RESULTS

This study included 862 patients with pathological stage 0 to I lung cancer. Among the 862 patients, 673 patients (78.1%) who were able to complete 7 metabolic equivalents of task exercise for 3 minutes without assistance were classified into the complete group. The 5-year survival of the complete group was significantly better than that of the incomplete group. Multivariable analysis revealed that age (hazard ratio, 1.06; P = .008), male sex (hazard ratio, 2.23; P = .011), carcinoembryonic antigen level >5 ng/mL (hazard ratio, 2.33; P = .011), and inability to complete 7 metabolic equivalents of task exercise (hazard ratio, 3.90; P < .001) were the prognostic factors. Patients in the older group who had the ability to complete exercise had a better prognosis than those in the younger group without the ability (P = .003).

CONCLUSIONS

Preoperative exercise ability is a prognostic factor for early-stage lung cancer. Patients who can tolerate an exercise load of 7 metabolic equivalents of task, even if they are aged 70 years or older, have a better prognosis than patients younger than age 70 years without exercise tolerance.

Cost-Utility Analysis of Stereotactic Body Radiation Therapy Versus Surgery for Patients With Stage I Non-small Cell Lung Cancer in Japan

PURPOSE

Stereotactic body radiation therapy (SBRT) for patients with operable stage I non-small cell lung cancer (NSCLC) is less invasive than surgery. However, differences in lifetime costs and patient outcomes remain unclear. In this study, a cost-utility analysis of SBRT compared with surgery for Japanese patients with operable stage I NSCLC was conducted.

METHODS AND MATERIALS

A partitioned survival model was constructed using each treatment arm's overall survival (OS) and progression-free survival (PFS) data. The data for the SBRT arm were extracted from the Japanese multicenter cohort study, which enrolled 678 medically operable patients with stage I NSCLC, and patient registry data were used for the surgery arm. The 5-year OS rate was 78.2% for SBRT and 74.8% for surgery from both studies. The 5-year PFS rate was 57.0% for SBRT and 63.4% for surgery. The quality of life values of PFS and progressive disease were obtained from domestic and overseas literature (PFS: 0.74, progressive disease: 0.65). The time horizon was set to 10 years. The expected costs and quality-adjusted life years for each treatment group were calculated. All costs are expressed in Japanese yen converted to US dollars (USD).

RESULTS

SBRT was the dominant strategy, reducing treatment costs by 4,443.8 USD and increasing quality-adjusted life years by 0.131 compared with surgery. According to probabilistic sensitivity analysis, the probability of SBRT being dominant and cost-effective was 50.6% and 72.4%, respectively. Under the budget impact analysis, the total savings for the patients with stage I NSCLC in Japan was 6,252,870.0 USD (n = 1,407).

CONCLUSIONS

SBRT is a more cost-effective option than surgery in patients with medically operable stage I NSCLC in Japan. Large-scale epidemiologic studies that reflect the latest clinical realities, such as OS/PFS, will be needed to validate this study's robustness.

Current Status and Future Perspectives of Preoperative and Intraoperative Marking in Thoracic Surgery

The widespread implementation of lung cancer screening and thin-slice computed tomography (CT) has led to the more frequent detection of small nodules, which are commonly referred to thoracic surgeons. Surgical resection is the final diagnostic and treatment option for such nodules; however, surgeons must perform preoperative or intraoperative markings for the identification of such nodules and their precise resection. Historically, hook-wire marking has been performed more frequently worldwide; however, lethal complications, such as air embolism, have been reported. Therefore, several surgeons have recently attempted to develop novel preoperative and intraoperative markers. For example, transbronchial markings, such as virtual-assisted lung mapping and intraoperative markings using cone-beam computed tomography, have been developed. This review explores various marking methods that have been practically applied for a better understanding of preoperative and intraoperative markings in thoracic surgery. Recently, several attempts have been made to perform intraoperative molecular imaging and dynamic virtual three-dimensional computed tomography for the localization, diagnosis, and margin assessment of small nodules. In this narrative review, the current status and future perspectives of preoperative and intraoperative markings in thoracic surgery are examined for a better understanding of these techniques.

Proton and carbon ion radiotherapy for operable early-stage lung cancer; a prospective nationwide registry

BACKGROUND AND PURPOSE

To investigate the toxicity and survival outcomes of proton and carbon ion radiotherapy for patients with operable early-stage lung cancer who are eligible for lobectomy.

MATERIALS AND METHODS

This multicenter nationwide prospective cohort study included patients with operable early-stage lung cancer. Proton and carbon ion radiotherapy was performed according to the schedule stipulated in the unified treatment policy. Progression-free survival (PFS), overall survival (OS) and treatment-related toxicities were evaluated.

RESULTS

A total of 274 patients were enrolled and included in efficacy and safety analyses. The most common tumor type was adenocarcinoma (44 %), while 105 cases (38 %) were not histologically confirmed or diagnosed clinically. Overall, 250 (91 %) of the 274 patients had tumors that were peripherally situated, while 138 (50 %) and 136 (50 %) patients were treated by proton and carbon ion radiotherapy, respectively. The median follow-up time for all censored patients was 42.8 months (IQR 36.7-49.0). Grade 3 or severe treatment-related toxicity was observed in 4 cases (1.5 %). Three-year PFS was 80.5 % (95 % CI: 75.7 %-85.5 %) and OS was 92.5 % (95 % CI: 89.3 %-95.8 %). Pathological confirmation and clinical stage were factors significantly associated with PFS, while tumor location and particle-ion type were not. Meanwhile, clinical stage was significantly associated with OS, but pathological confirmation, tumor location, and particle-ion type were not.

CONCLUSIONS

Particle therapy for operable early-stage lung cancer resulted in excellent 3-year OS and PFS in each subset. In this disease context, proton and carbon ion beam therapies are feasible alternatives to curative surgery.

Surgically resected sarcomatoid carcinoma of the lung: a nationwide retrospective study in 2010

BACKGROUND

Sarcomatoid carcinoma of the lung is a rare histological type of non-small cell lung cancer with a poor prognosis. We aimed to investigate the clinicopathological characteristics and prognostic factors of surgically resected sarcomatoid carcinoma of the lung.

METHODS

We retrospectively reviewed 14999 patients who underwent surgical resection for non-small cell lung cancer accumulated by the Japanese Joint Committee of Lung Cancer Registry in 2010. Clinicopathological characteristics and survival were compared between the sarcomatoid carcinoma and other non-small cell cancer groups. The prognostic factors in the sarcomatoid carcinoma group were identified using a multivariate Cox proportional hazard model.

RESULTS

Patients with sarcomatoid carcinoma comprised 1.4% of all patients. The sarcomatoid carcinoma group demonstrated a more aggressive pathology with presentation at more advanced stages, requiring more frequent extensive surgical resections. The sarcomatoid carcinoma group had remarkably poorer overall and recurrence-free survival than the other non-small cell lung cancer group. Adjuvant chemotherapy was associated with improved survival for pathological stage II-III sarcomatoid carcinoma cases rather than for pathological stage I disease. In the multivariate analysis, larger tumor size, lymphatic permeation, and no adjuvant chemotherapy were associated with the sarcomatoid carcinoma group's overall and recurrence-free survival.

CONCLUSIONS

Surgically resected sarcomatoid carcinoma of the lung has a higher aggressive and metastatic potential and a worse prognosis than other non-small cell lung cancers. Adjuvant chemotherapy, which was associated with enhanced survival in patients with pathological stage II-III of the disease, could be considered for treating patients with pathological stage II-III sarcomatoid carcinoma of the lung.

Pathological Pleural Invasion is a Risk Factor for Late Recurrence in Long-Term Survivors of Non-small Cell Lung Cancer after Complete Resection

BACKGROUND

Information regarding late recurrence after pulmonary resection for non-small cell lung cancer (NSCLC) is limited. This study aimed to analyze the risk factors for late recurrence after surgery for NSCLC in the current era.

PATIENTS AND METHODS

We conducted a retrospective study of patients who underwent complete resection for pathological I-III NSCLC between 2006 and 2015. Late recurrence was defined as a recurrence that met the following conditions: (1) the patient underwent chest computed tomography (CT) at or after 54 months after surgery and recurrence was not detected at that time, and (2) recurrence that occurred more than 5 years after surgery. The factors influencing late recurrence, relapse-free survival (RFS), and overall survival (OS) after surgery were analyzed.

RESULTS

A total of 1275 with 5-year relapse-free survival after surgery were enrolled in this study. The mean age of the patients was 66.4 years and 54% of the patients were men. The median interval between surgery and the latest follow-up examination was 98 months. In total, 35 patients (2.7%) experienced late recurrence and 138 patients have died thus far. The cumulative recurrence, RFS, and OS rates at 10 years were 3.9%, 84.9%, and 86.3%, respectively. A multivariate analysis revealed that pleural invasion was an independent risk factor for late recurrence. Pleural invasion was a poor prognostic factor for both RFS and OS.

CONCLUSIONS

Pleural invasion was a predictor of late recurrence. Age > 67 years, preoperative serum carcinoembryonic antigen (CEA) > 5 ng/ml, non-adenocarcinoma, and pleural invasion were poor prognostic factors for RFS.

Significance of preoperative evaluation of modified advanced lung cancer inflammation index for patients with resectable non-small cell lung cancer

OBJECTIVES

Body composition and systemic inflammation/nutrition have been identified as important clinical factors in cancer patients. The modified advanced lung cancer inflammation index (mALI), which combines body composition and systemic inflammation/nutrition, is defined as appendicular skeletal muscle index × serum albumin/neutrophil-lymphocyte ratio. This retrospective study aimed to investigate associations between preoperative mALI and surgical outcomes in non-small cell lung cancer (NSCLC) patients.

METHODS

We examined 665 patients with resectable stage I-III NSCLC who underwent pulmonary resection. Patients were divided into low-mALI (n = 168) and high-mALI (n = 497) based on the lower quartile. Kaplan-Meier curves and Cox regression analysis were used to assess the prognostic value of mALI. We then performed 1:1 propensity score matching (PSM) for high- and low-mALI to further investigate impacts on survival.

RESULTS

Overall survival (OS) and recurrence-free survival (RFS) were both significantly poorer in the low-mALI group than in the high-mALI group (58.2% vs. 79.6%, P < 0.001; 48.8% vs. 66.7%, P < 0.001, respectively). Multivariate analysis revealed low-mALI as an independent predictor of OS (hazard ratio [HR], 2.116; 95% confidence interval (CI) 1.458-3.070; P < 0.001) and RFS (HR, 1.634; 95% CI 1.210-2.207; P = 0.001). After PSM, low-mALI remained as an independent predictor of OS (HR, 2.446; 95% CI 1.263-4.738; P = 0.008) and RFS (HR 1.835; 95% CI 1.074-3.137; P = 0.026).

CONCLUSION

Preoperative mALI appears to offer an independent predictor of poor surgical outcomes as a simple, routinely available, and inexpensive biomarker in patients with resectable NSCLC.

Association between recovery from desaturation after stair climbing and postoperative complications in lung resection

OBJECTIVE

The stair-climbing test (SCT) is used as a surrogate for cardiopulmonary exercise testing, which measures maximal oxygen uptake, and considered a useful method for assessing exercise capacity in thoracic surgery. This study aims to investigate whether the recovery time of percutaneous oxygen saturation (SpO2) after stair climbing is a predictor of postoperative complications after lobectomy.

METHODS

We retrospectively identified 54 patients who performed SCT and underwent lobectomy between January 2015 and February 2023 at Shizuoka Cancer Center. The SpO2 recovery time was defined as the time required to recover from the minimum to resting value after stair climbing. The association between SpO2 recovery time and early postoperative pulmonary complications within 30 days after surgery was analyzed.

RESULTS

Eleven patients (20.4%) had postoperative pulmonary complications (≥ Clavien-Dindo Classification Grade 2). The cutoff value of SpO2 recovery time obtained from the receiver operating characteristic curve analysis was 90 s [sensitivity, 81.8%; specificity, 72.1%; AUC, 0.77 (95% confidence interval, 0.64-0.90)]. The occurrence of postoperative pulmonary complications was 42.9% in the delayed recovery time (DRT; SpO2 recovery time ≥ 90 s) group and 6.1% in the non-DRT (SpO2 recovery time < 90 s) group (p = 0.002). DRT was a predictor of postoperative pulmonary complications (odds ratio, 11.60; 95% CI 2.19-61.80).

CONCLUSIONS

DRT of SpO2 after stair climbing is a predictor of postoperative pulmonary complications following lobectomy in borderline patients who require exercise capacity assessment. SpO2 monitoring after stair climbing may be useful as one of the preoperative assessments in patients undergoing lobectomy.

Treatment patterns and clinical outcomes of resectable clinical stage III non-small cell lung cancer in a Japanese real-world setting: Surgery cohort analysis of the SOLUTION study

BACKGROUND

To elucidate the treatment and surgery outcomes with or without perioperative therapies in Japanese patients with clinical stage III non-small cell lung cancer (NSCLC) in real-world settings.

METHODS

We performed subset analyses of the SOLUTION study, a multicenter, noninterventional, observational study of Japanese patients diagnosed with clinical stage III NSCLC, for those who started first-line treatment (surgery±perioperative therapy) between January 2013 and December 2014 (study registration: UMIN000031385). Follow-up data were obtained using medical records from diagnosis to March 1, 2018.

RESULTS

Of 149 eligible patients, 67 underwent surgery alone (median age 71 years) and 82 underwent surgery+perioperative therapy (median age 63 years). Lung resection was performed in 137 patients and the others underwent exploratory thoracotomy or other procedures. Perioperative therapies included adjuvant therapy only (n = 41), neoadjuvant therapy only (n = 24), and neoadjuvant+adjuvant therapy (n = 17). The median overall survival (OS) and 3-year OS rate were 29.3 months and 44.0%, respectively, in patients who underwent surgery alone, and not reached and 61.1%, respectively, in patients who underwent surgery+perioperative therapy. The 3-year progression-free survival (PFS) and disease-free survival (DFS) rates were 42.4% and 47.1%, respectively, in patients who underwent surgery+perioperative therapy and 28.5% and 28.9%, respectively, in patients who underwent surgery alone. In multivariable Cox regression, perioperative therapy was associated with improved OS (hazard ratio [95% confidence interval] 0.49 [0.29-0.81]), PFS (0.62 [0.39-0.96]), and DFS (0.62 [0.39-0.97]) versus surgery alone.

CONCLUSIONS

Our study suggested that perioperative therapy may be associated with better survival among patients undergoing surgical treatment of clinical stage III NSCLC.

Long-term survival outcomes and quality of life of image-guided proton therapy for operable stage I non-small cell lung cancer: A phase 2 study

BACKGROUND AND PURPOSE

This study evaluated long-term efficacy, safety, and changes in quality of life (QOL) of patients after image-guided proton therapy (IGPT) for operable stage I non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

This single-institutional prospective phase 2 study enrolled patients with operable histologically confirmed stage IA or IB NSCLC (7th edition of UICC). The prescribed dose was 66 Gy relative biological effectiveness equivalents (GyRBE) in 10 fractions for peripheral lesions, or 72.6 GyRBE in 22 fractions for central lesions. The primary endpoint was the 3-year overall survival (OS). The secondary endpoints included disease control, toxicity, and changes in QOL score.

RESULTS

We enrolled 43 patients (median age: 68 years; range, 47-79 years) between July 2013 to January 2021, of whom 41 (95 %) had peripheral lesions and 27 (63 %) were stage IA. OS, local control, and progression-free survival rates were 95 % (95 % CI: 83-99), 95 % (82-99), and 86 % (72-94), respectively, at 3 years, and 83 % (66-92), 95 % (82-99), and 77 % (60-88), respectively, at 7 years. Four patients (9 %) developed grade 2, and one patient (2 %) developed grade 3 radiation pneumonitis. No other grade 3 or higher adverse events were observed. In the QOL analysis, global QOL remained favorable; however, approximately 40 % of patients reported dyspnea at 3 and 24 months.

CONCLUSION

Our findings suggest that IGPT provides effective disease control and survival in operable stage I NSCLC, particularly for peripheral lesions. Moreover, toxicity associated with IGPT was minimal, and patients reported favorable QOL.

Pathologic Response and Survival after Neoadjuvant Chemotherapy with Bevacizumab Followed by Surgery for Clinical Stage II/IIIA Nonsquamous Non-Small-Cell Lung Cancer: Results from a Phase II Feasibility Study (NAVAL)

The objective of this study was to evaluate the relationship between pathologic response and survival in patients with clinical stage II/IIIA nonsquamous non-small-cell lung cancer (NSCLC) who intended to undergo neoadjuvant chemotherapy with bevacizumab, followed by surgery. In this phase II NAVAL study evaluating the feasibility of neoadjuvant chemotherapy with cisplatin (75 mg/m2), pemetrexed (500 mg/m2), and bevacizumab (15 mg/kg), followed by surgery, progression-free survival (PFS) and overall survival (OS) were assessed as the secondary endpoints. Patients were categorized based on the proportion of residual viable primary tumor in the resected specimen after neoadjuvant chemotherapy: those with residual tumor in less than one-third were classified as pathologic responders, the rest as nonresponders. Of the 30 patients, 25 underwent surgical resection after three cycles of neoadjuvant chemotherapy with bevacizumab; 5 did not undergo surgery. Among all 30 patients, the rates of 2- and 5-year PFS were 41.5% and 34.6%, respectively, and the rates of 2- and 5-year OS were 70.0% and 60.0%, respectively. A total of 6 patients (20%) were classified as pathologic responders; the other 24 (80%), as nonresponders. The five-year PFS differed significantly between pathologic responders (100%) and nonresponders (17.5%; p = 0.002). The five-year OS also differed significantly between pathologic responders (100%) and nonresponders (43.5%; p = 0.006). Pathologic response seems to be a predictor of survival. Long-term survival after surgery is expected for pathologic responders, whereas additional therapy is needed for nonresponders.

Long term outcomes beyond 5 years after pulmonary resection for non-small-cell lung cancer

OBJECTIVES

We investigated the incidence of late recurrence beyond 5 years after pulmonary resection and aimed to identify candidates for long-term surveillance.

METHODS

We retrospectively reviewed the medical records of 978 non-small-cell lung cancer patients who underwent pulmonary resection between 2002 and 2015 and survived without recurrence for 5 years. Clinicopathological factors associated with recurrence-free survival beyond 5 years after surgery were investigated using univariate and multivariate analyses. The development of late metachronous malignancies was also investigated.

RESULTS

The median follow-up period from 5 years post-surgery was 27 months in the whole cohort. Late recurrence occurred in 37 (3.8%) patients. Late metachronous malignancies were diagnosed in 116 patients (11.9%), including 57 (5.8%) with lung cancer. One-, three-, and five-year recurrence-free survival rates beyond 5 years after surgery were 97.6%, 94.7%, and 94.7%, respectively. The recurrence-free survival of patients with pN1-2 was significantly poorer than that of patients with pN0 disease. Multivariate analysis revealed that adenocarcinoma and pN1-2 status were significantly associated with poor recurrence-free survival beyond 5 years post-surgery (P = 0.009 and 0.007, respectively).

CONCLUSIONS

Non-adenocarcinoma histology and pN0 status were significant favorable factors for recurrence-free survival beyond 5 years post-surgery. The efficacies of long-term surveillance for the detection of late recurrence were considered limited for these populations. Twelve percent of the patients experienced late metachronous malignancies after pulmonary resection.

Real-world efficacy of adjuvant therapy for totally resected stage I lung adenocarcinoma patients with pathological high-risk factors: propensity score analysis

BACKGROUND

We investigated the real-world efficacy of adjuvant therapy for stage I lung adenocarcinoma patients with pathological high-risk factors.

METHODS

Study participants were enrolled from November 1, 2016 and December 31, 2020. Clinical bias was balanced by propensity score matching. Disease-free survival (DFS) outcomes were compared by Kaplan-Meier analysis. The Cox proportional hazards regression was used to identify survival-associated factors. p ≤ 0.05 was the threshold for statistical significance.

RESULTS

A total of 454 patients, among whom 134 (29.5%) underwent adjuvant therapy, were enrolled in this study. One hundred and eighteen of the patients who underwent adjuvant therapy were well matched with non-treatment patients. Prognostic outcomes of the treatment group were significantly better than those of the non-treatment group, as revealed by Kaplan-Meier analysis after PSM. Differences in prevention of recurrence or metastasis between the targeted therapy and chemotherapy groups were insignificant. Adjuvant therapy was found to be positive prognostic factors, tumor size and solid growth patterns were negative.

CONCLUSIONS

Adjuvant therapy significantly improved the DFS for stage I lung adenocarcinoma patients with high-risk factors. Larger prospective clinical trials should be performed to verify our findings.

Phase II Trial of Adjuvant Atezolizumab Therapy in Elderly Patients with Completely Resected Stage II/III Non-Small Cell Lung Cancer: RELIANCE Trial

INTRODUCTION

Atezolizumab following platinum chemotherapy and complete pulmonary resection has become the new standard of adjuvant care for patients with stage II-III non-small cell lung cancer (NSCLC) expressing programmed death-ligand 1 (PD-L1). However, the efficacy and safety of postoperative adjuvant therapy and subsequent atezolizumab in patients aged 75 and older have not been established.

METHODS

Patients with completely resected stage II-III NSCLC aged 75 and older will be prospectively registered in this single-arm phase II study. The enrolled patients will receive cisplatin plus vinorelbine (CDDP + VNR) followed by atezolizumab for up to 12 months. PD-L1 expression in at least 1% of cells will be confirmed by immunohistochemical staining. We plan to enroll 33 patients over 1 year at 25 institutions in Japan. The primary endpoint is the completion rate of adjuvant treatment (CDDP + VNR initiation to atezolizumab completion).

CONCLUSION

The present study represents the first prospective trial of the tolerability of postoperative adjuvant therapy with immune checkpoint inhibitors in elderly individuals. The results of this trial might help promote postoperative adjuvant immunotherapy in the future for the elderly.

So Now We Know-Reflections on the Extent of Resection for Stage I Lung Cancer

Lobectomy has been the standard treatment for stage I lung cancer in healthy patients, largely based on a randomized trial published in 1995. Nevertheless, research has continued regarding the role of sublobar resection. Three additional randomized trials addressing resection extent in healthy patients have recently been published. These 4 trials involve differences in design, eligibility, interventions, and intraoperative processes. Patients were ineligible if intraoperative assessment demonstrated stage > IA or inadequate resection margins. All trials consistently show no differences in perioperative morbidity, mortality, and postoperative changes in lung function between sublobar resection and lobectomy-consistent with other nonrandomized evidence. Long-term outcomes are generally encouraging of lesser resection, but some inconsistencies are apparent. The 2 larger recent trials demonstrated no overall survival difference while the others suggested better survival after lobectomy versus sublobar resection. Recurrence-free survival was found to be the same after lobectomy versus sublobar resection in 3 trials, despite higher locoregional recurrences after sublobar resection. The low 5-year recurrence-free survival (64%, regardless of resection extent) in 1 recent trial highlights the need for further optimization. Thus, there is high-level evidence that sublobar resection is a reasonable alternative to lobectomy in healthy patients. However, variability in long-term results suggests that aspects of patients, tumors and interventions need to be better understood. Therefore, we propose to apply sublobar resection cautiously; especially because there are no short-term benefits. Sublobar resection requires careful attention to intraoperative details (nodes, margins), and may be best suited for less aggressive (eg, ground glass, slow growing) tumors.

Real-World Treatment Patterns and Survival Outcomes for Patients with Non-Metastatic Non-Small-Cell Lung Cancer in Sweden: A Nationwide Registry Analysis from the I-O Optimise Initiative

Non-small-cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide, with ~40-50% of patients diagnosed with non-metastatic disease (stages IA-IIIC). The treatment landscape is evolving rapidly as immunotherapies and targeted therapy are introduced in the non-metastatic setting, creating a need to assess patient outcomes prior to their introduction. This real-world study using Swedish National Lung Cancer Registry data examined outcomes (overall survival (OS) and time to next treatment or death (TTNTD)) and treatment patterns for adults diagnosed with non-metastatic NSCLC. Baseline characteristics and OS from diagnosis were described for all patients; OS, treatment patterns, and TTNTD from treatment start were described for the treatment subgroup (patients diagnosed from 2014 onwards), stratified by disease stage and initial treatment. OS and TTNTD were described using the Kaplan-Meier estimator. The overall population (2008-2019) included 17,433 patients; the treatment subgroup included 5147 patients. Median OS (interquartile range) overall ranged from 83.3 (31.6-165.3) months (stage I patients) to 10.4 (4.3-24.2) months (stage IIIB patients). Among the treatment subgroup, median OS and TTNTD were longest among patients receiving surgery versus other anticancer treatments. These findings provide a baseline upon which to evaluate the epidemiology of non-metastatic NSCLC as newer treatments are introduced.

A case of concurrent follicular lymphoma and lung cancer requiring differentiation from lymph node metastasis

Lung cancer complicated by follicular lymphoma has rarely been reported in the literature. A 69-year-old male with an abnormal shadow on a chest radiograph was referred to our hospital. A mass in the right lung was seen on chest computed tomography (CT). Positron emission tomography-CT showed fluorodeoxyglucose accumulation in the esophagus and multiple intra-abdominal lymph nodes, in addition to the right lung lesion. The lung lesion was diagnosed as a pulmonary adenocarcinoma after biopsy. Upper and lower gastrointestinal endoscopies did not reveal the presence of a tumor. Open lymph node biopsy was performed to determine the course of treatment, leading to a diagnosis of follicular lymphoma. The patient finally underwent radical resection for lung cancer; the follicular lymphoma was judged to be low-grade and was followed up. When complications involving other organs are detected during systemic examination of a patient with lung cancer, it is necessary to distinguish between metastasis to other organs and complications of other malignant diseases, as this will greatly influence the treatment strategy.

Risk Factors for Recurrence of Stage I Epidermal Growth Factor Receptor Mutated Lung Adenocarcinoma

BACKGROUND

We aimed to clarify the risk factors for postoperative recurrence in patients with epidermal growth factor receptor (EGFR)-mutated stage I lung adenocarcinoma, using EGFR wild-type adenocarcinoma as a comparator, to select optimal candidates for adjuvant therapy with EGFR tyrosine kinase inhibitor (TKI).

METHODS

Data of patients with pathologic stage I EGFR-mutated (n = 713) and wild-type (n = 673) adenocarcinoma who did not receive adjuvant therapy were retrospectively analyzed. The cumulative incidence of recurrence (CIR) was estimated using Gray's method, and multivariable Fine-Gray competing risk models identified independent risk factors associated with recurrence.

RESULTS

The CIR did not differ significantly between patients with EGFR-mutated and wild-type adenocarcinoma (P = .32). Multivariable analysis revealed that greater size (cm) of invasive tumor (hazard ratio 1.539; 95% CI, 1.077-2.201), lymphovascular invasion (hazard ratio 5.180; 95% CI, 2.208-12.15), pleural invasion (hazard ratio 3.388; 95% CI, 1.524-7.533), and high-grade histologic subtype (hazard ratio 4.295; 95% CI, 1.539-11.99) were independent risk factors for recurrence in patients with EGFR-mutated adenocarcinoma. The 5-year CIR was significantly higher among patients with these factors (tumor size greater than 2 cm, 15.9%; lymphovascular invasion, 26.9%; pleural invasion, 39.3%; and high-grade subtype, 44.4%) than among patients without them (4.4%, 2.2%, 3.9%, and 5%, respectively; P < .001). For patients with EGFR wild-type adenocarcinoma, independent risk factors for recurrence were invasive tumor size, lymphovascular invasion, and pleural invasion, but not histologic subtypes.

CONCLUSIONS

Even for patients with EGFR-mutated stage I lung adenocarcinoma, recurrence risk is stratified. Adjuvant therapy may be considered if they have high-risk factors for recurrence.

Prognosis and prognostic factors of lung cancer complications in patients with rheumatoid arthritis

AIM

To clarify the prognosis and prognostic factors for lung cancer in patients with rheumatoid arthritis (RA).

METHODS

In this retrospective longitudinal study, we investigated the medical records of patients with RA among 1422 patients diagnosed with lung cancer and registered in a hospital-based cancer registry between January 2013 and May 2022. The Kaplan-Meier method and Cox proportional hazards model were used to analyze survival and identify predictive factors.

RESULTS

Of 26 patients with RA complicated with lung cancer (median age, 69 years), the 2-year overall survival rates for stages I-II were 90%-100%, and those for stages III-IV were 20%, respectively. Positivity of anti-citrullinated protein/peptide antibody, smoking history, interstitial lung disease, poorly controlled RA, stage III and IV lung cancer, histological types other than adenocarcinoma and squamous cell carcinoma, and RF ≧ 50 IU/mL were associated with increased mortality. After the surgical resection of stage I and II lung cancer, 5 of the 16 patients experienced cancer recurrence after resumption of RA treatment, and the histology of the recurrent cancers was mostly squamous cell carcinoma.

CONCLUSIONS

Early detection of lung cancer is needed, especially in patients with RA who have a history of smoking, seropositivity, or interstitial lung disease. Even after surgical resection, it should be noted that squamous cell carcinoma is prone to recurrence.

Five-Year Survival Outcomes After Carbon-Ion Radiotherapy for Operable Stage I NSCLC: A Japanese National Registry Study (J-CROS-LUNG)

INTRODUCTION

The standard therapy for stage I NSCLC is surgery, but some operable patients refuse this option and instead undergo radiotherapy. Carbon-ion radiotherapy (CIRT) is a type of radiotherapy. The Japanese prospective nationwide registry study on CIRT began in 2016. Here, we analyzed real-world clinical outcomes of CIRT for operable patients with stage I NSCLC.

METHODS

All patients with operable stage I NSCLC treated with CIRT in Japan between 2016 and 2018 were enrolled. The dose fractionations for CIRT were selected from several options approved by the Japanese Society for Radiation Oncology. CIRT was delivered to the primary tumor, not to lymph nodes.

RESULTS

The median follow-up period was 56 months. Among 136 patients, 117 (86%) had clinical stage IA NSCLC and 19 (14%) had clinical stage IB NSCLC. There were 50 patients (37%) diagnosed clinically without having been diagnosed histologically. Most tumors (97%) were located in the periphery. The 5-year overall survival, cause-specific survival, progression-free survival, and local control rate were 81.8% (95% confidence interval [CI]: 75.1-89.2), 91.2% (95% CI: 86.0-96.8), 65.9% (95% CI: 58.2-74.6), and 95.8% (95% CI: 92.3-99.5), respectively. Multivariate analysis identified age as a significant factor for overall survival (p = 0.018), whereas age and consolidation/tumor ratio (p = 0.010 and p = 0.004) were significant factors for progression-free survival. There was no grade 4 or higher toxicity. Grade 3 radiation pneumonitis occurred in one patient.

CONCLUSIONS

This study reports the long-term outcomes of CIRT for operable NSCLC in the real world. CIRT for operable patients has been found to have favorable outcomes, with tolerable toxicity.

Robotic Versus Thoracoscopic Sub-lobar Resection for Octogenarians with Clinical Stage IA Non-small Cell Lung Cancer: A Propensity Score-Matched Real-World Study

BACKGROUND

Minimally invasive sub-lobectomy is sufficient in treating small early-stage non-small cell lung cancer (NSCLC). However, comparison of the feasibility and oncologic efficacy between robot-assisted thoracoscopic surgery (RATS) and video-assisted thoracoscopic surgery (VATS) in performing sub-lobectomy for early-stage NSCLC patients age 80 years or older is scarce.

METHODS

Octogenarians with clinical stage IA NSCLC (tumor size, ≤ 2 cm) undergoing minimally invasive wedge resection or segmentectomy at Shanghai Chest Hospital from 2011 to 2020 were retrospectively reviewed from a prospectively maintained database. Propensity score-matching (PSM) with a RATS versus VATS ratio of 1:4 was performed. Perioperative and long-term outcomes were analyzed.

RESULTS

The study identified 594 patients (48 RATS and 546 VATS patients), and PSM resulted in 45 cases in the RATS group and 180 cases in the VATS group. The RATS patients experienced less intraoperative bleeding (60 mL [interquartile range (IQR), 50-100 mL] vs. 80 mL [IQR, 50-100 mL]; P = 0.027) and a shorter postoperative hospital stay (4 days [IQR, 3-5 days] vs. 5 days [IQR, 4-6 days]; P = 0.041) than the VATS patients. The two surgical approaches were comparable concerning other perioperative outcomes and postoperative complications (20.00% vs. 26.11%; P = 0.396). Additionally, during a median follow-up period of 66 months, RATS and VATS achieved comparable 5-year overall survival (90.48% vs. 87.93%; P = 0.891), recurrence-free survival (83.37% vs. 83.18%; P = 0.782), and cumulative incidence of death. Further subgroup comparison also demonstrated comparable long-term outcomes between the two approaches. Finally, multivariate Cox analysis indicated that the surgical approach was not independently correlated with long-term outcomes.

CONCLUSIONS

The RATS approach shortened the postoperative hospital stay, reduced intraoperative bleeding by a statistically notable but clinically insignificant amount, and achieved long-term outcomes comparable with VATS in performing sub-lobectomy for octogenarians with early-stage small NSCLC.

Genomic characteristics and immune landscape of super multiple primary lung cancer

BACKGROUND

In recent years, a growing number of patients with multiple primary lung cancer (MPLC) are being diagnosed, and a subset of these patients is found to have a large number of lesions at the time of diagnosis, which are referred to as 'super MPLC'.

METHODS

Here, we perform whole exome sequencing (WES) and immunohistochemistry (IHC) analysis of PD-L1 and CD8 on 212 tumor samples from 42 patients with super MPLC.

FINDINGS

We report the genomic alteration landscape of super MPLC. EGFR, RBM10 and TP53 mutation and TERT amplification are important molecular events in the evolution of super MPLC. We propose the conception of early intrapulmonary metastasis, which exhibits different clinical features from conventional metastasis. The IHC analyses of PD-L1 and CD8 reveal a less inflamed microenvironment of super MPLC than that of traditional non-small cell lung cancer (NSCLC). We identify the potentially susceptible germline mutations for super MPLC.

INTERPRETATION

Our study depicts the genomic characteristics and immune landscape, providing insights into the pathogenesis and possible therapeutic guidance of super MPLC.

FUNDING

A full list of funding bodies that supported this study can be found in the Acknowledgements section.

NUF2 Expression in Cancer Tissues and Lymph Nodes Suggests Post-Surgery Recurrence of Non-Small Cell Lung Cancer

In non-small cell lung cancer (NSCLC) cases, detecting potential lymph node metastases is essential to determine the indications for sublobar resection or adjuvant therapy. NUF2 is a tumor-specific antigen that is highly expressed in lung cancer tissues. However, the significance of analyzing NUF2 expression in dissected lymph nodes has not yet been studied. Thus, we investigated the association between NUF2 expression in lung cancer tissues and dissected lymph nodes and early recurrence of NSCLC to determine its usefulness as a marker of lymph node micrometastasis. This retrospective study quantified NUF2 expression in the cancer tissues of 88 patients with NSCLC who underwent complete resection using real-time polymerase chain reaction and investigated its relationship with clinicopathological features and prognosis. We also quantified NUF2 RNA expression in mediastinal lymph nodes from 255 patients with pN0 NSCLC who underwent complete resection with lymph node dissection and analyzed its association with prognosis. NUF2 expression in primary tumors was correlated with lymph node metastasis and unfavorable outcomes in terms of poor recurrence-free and cancer-specific survival. In N0 NSCLC cases, high NUF2 expression in mediastinal lymph nodes indicated poor prognosis, especially in lymph node recurrence. NUF2 emerges as a promising marker for predicting lymph node metastatic recurrence, offering potential utility in guiding post-surgical adjuvant therapy for lung cancer or assisting in intraoperative decisions for sublobar resection.

Neoadjuvant nivolumab plus chemotherapy in resectable non-small-cell lung cancer in Japanese patients from CheckMate 816

In the open-label, phase III CheckMate 816 study (NCT02998528), neoadjuvant nivolumab plus chemotherapy demonstrated statistically significant improvements in event-free survival (EFS) and pathological complete response (pCR) versus chemotherapy alone in patients with resectable non-small-cell lung cancer (NSCLC). Here we report efficacy and safety outcomes in the Japanese subpopulation. Patients with stage IB-IIIA, resectable NSCLC were randomized 1:1 to nivolumab plus chemotherapy or chemotherapy alone for three cycles before undergoing definitive surgery within 6 weeks of completing neoadjuvant treatment. The primary end-points (EFS and pCR) and safety were assessed in patients enrolled at 16 centers in Japan. Of the Japanese patients randomized, 93.9% (31/33) in the nivolumab plus chemotherapy arm and 82.9% (29/35) in the chemotherapy arm underwent surgery. At 21.5 months' minimum follow-up, median EFS was 30.6 months (95% confidence interval [CI], 16.8-not reached [NR]) with nivolumab plus chemotherapy versus 19.6 months (95% CI, 8.5-NR) with chemotherapy; hazard ratio, 0.60 (95% CI, 0.30-1.24). The pCR rate was 30.3% (95% CI, 15.6-48.7) versus 5.7% (95% CI, 0.7-19.2), respectively; odds ratio, 7.17 (95% CI, 1.44-35.85). Grade 3/4 treatment-related adverse events were reported in 59.4% versus 42.9% of patients, respectively, with no new safety signals identified. Neoadjuvant nivolumab plus chemotherapy resulted in longer EFS and a higher pCR rate versus chemotherapy alone in Japanese patients, consistent with findings in the global population. These data support nivolumab plus chemotherapy as a neoadjuvant treatment option in Japanese patients with resectable NSCLC.

NOTCH1 and CREBBP co-mutations negatively affect the benefit of adjuvant therapy in completely resected EGFR-mutated NSCLC: translational research of phase III IMPACT study

The phase III IMPACT study (UMIN000044738) compared adjuvant gefitinib with cisplatin plus vinorelbine (cis/vin) in completely resected epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC). Although the primary endpoint of disease-free survival (DFS) was not met, we searched for molecular predictors of adjuvant gefitinib efficacy. Of 234 patients enrolled in the IMPACT study, 202 patients were analyzed for 409 cancer-related gene mutations and tumor mutation burden using resected lung cancer specimens. Frequent somatic mutations included tumor protein p53 (TP53; 58.4%), CUB and Sushi multiple domains 3 (CSMD3; 11.8%), and NOTCH1 (9.9%). Multivariate analysis showed that NOTCH1 co-mutation was a significant poor prognostic factor for overall survival (OS) in the gefitinib group and cAMP response element binding protein (CREBBP) co-mutation for DFS and OS in the cis/vin group. In patients with NOTCH1 co-mutations, gefitinib group had a shorter OS than cis/vin group (Hazard ratio 5.49, 95% CI 1.07-28.00), with a significant interaction (P for interaction = 0.039). In patients with CREBBP co-mutations, the gefitinib group had a longer DFS than the cis/vin group, with a significant interaction (P for interaction = 0.058). In completely resected EGFR-mutated NSCLC, NOTCH1 and CREBBP mutations might predict poor outcome in patients treated with gefitinib and cis/vin, respectively.

Adjuvant and neo-adjuvant therapy for non-small cell lung cancer without EGFR mutations or ALK rearrangements

Surgical resection is the most effective therapeutic option for the cure in early stage resectable non-small-cell lung cancer (NSCLC). However, despite complete resection, up to 70% of patients die within 5 years mainly due to tumor recurrence in extra-thoracic organs. Adjuvant or neoadjuvant platinum-based chemotherapy may improve postoperative survival, but the absolute survival benefit is modest with an around 5% improvement at 5 years. Recent advance in systemic therapy has changed treatment strategy for advanced unresectable NSCLC, and also has provided a paradigm shift in treatment strategy for resectable NSCLC. For NSCLC without oncogenic driver alterations, immunotherapy using immune-checkpoint inhibitors may improve clinical outcomes in preoperative neoadjuvant setting as well as in postoperative adjuvant setting. Here, we overview recent evidence of adjuvant and neoadjuvant therapy and discuss emerging clinical questions in decision-making of treatment for potentially resectable patients with NSCLC harboring no oncogenic alterations.

The Clinical Relevance of the Expression of SGLT2 in Lung Adenocarcinoma

PURPOSE

We aimed to elucidate the functions and clinical relevance of sodium-glucose cotransporter 2 (SGLT2) in resected lung adenocarcinoma.

METHODS

The protein expression of SGLT2 in tumor samples from 199 patients with lung adenocarcinoma was analyzed by immunohistochemistry, and the protein expression, clinical variables, and survival outcomes were compared.

RESULTS

The median SGLT2 expression was significantly higher in advanced-stage and more aggressive adenocarcinomas. Age ≥70 (p < 0.01), BI ≥600 (p < 0.01), PRDX4 <25 (p < 0.01), and SGLT2 ≥12% (p = 0.03) were significant factors for RFS in multivariate analysis. Significant differences were observed in the RFS rates of the groups divided using the cutoff value of SGLT2 ≥12% (5-year RFS: 72.6% vs. 90%) (p < 0.01).

CONCLUSION

The expression of SGLT2 was more frequently detected in advanced-stage and more aggressive adenocarcinomas with aggressive biological behavior than in their counterparts. The survival analysis revealed that the strong expression of SGLT2 was associated with poorer RFS. The SGLT2 expression predicts postoperative recurrence in lung adenocarcinoma patients.

Risk analysis of visceral pleural invasion in malignant solitary pulmonary nodules that appear touching the pleural surface

BACKGROUND

The preoperative determination of visceral pleural invasion (VPI) in patients with malignant solitary pulmonary nodules (SPNs) is essential for determining the surgical range and selecting adjuvant chemotherapy.

OBJECTIVES

This study aimed to systematically investigate risk factors of VPI in patients with SPN and construct a preoperative predictive model for such patients.

DESIGN

This is a retrospective study. The clinical, radiological, and pathological characteristics of study subjects were reviewed, and the groups with and without VPI were compared.

METHODS

Multivariate logistic analysis was utilized to identify independent risk factors for VPI. Moreover, a predictive nomogram was constructed to assess the likelihood of VPI occurrence.

RESULTS

Of the 364 enrolled cases, SPNs adjacent to the pleura with VPI were found in 110 (30.2%) patients. By incorporating four preoperative variables, including tumor diameter (>2 cm), maximum computed tomography value (>200 Hu), air bronchogram sign, and age, a preoperative predictive nomogram was constructed. The nomogram demonstrated good discriminative ability, with a C-index of 0.736 (95% CI (0.662-0.790)). Furthermore, our data indicated that the air bronchogram sign (odd ratio (OR) 1.81, 95% CI (0.99-3.89), p = 0.048), a maximum diameter >2 cm (OR 24.48, 95% CI (8.43-71.07), p < 0.001), pathological type (OR 5.01, 95% CI (2.61-9.64), p < 0.001), and Ki-67 >30% (OR 2.95, 95% CI (1.40-6.21), p = 0.004) were overall independent risk factors for VPI.

CONCLUSION

This study investigated the risk factors for VPI in malignant SPNs touching the pleural surface. Additionally, a nomogram was developed to predict the likelihood of VPI in such patients, facilitating informed decision-making regarding surgical approaches and treatment protocols.

Benefit of Adjuvant Chemotherapy for Patients Older Than 75 Years With Completely Resected p-Stage II-IIIA Non-Small-Cell Lung Cancer: A Retrospective Cohort Study Using Japanese Nationwide Real-World Data

BACKGROUND

The efficacy of adjuvant chemotherapy (ACT) in elderly patients with completely resected p-stage II-IIIA non-small-cell lung cancer (NSCLC) remains unclear because all previous randomized controlled trials on ACT have been conducted among patients aged <75 years. Thus, this study aimed to evaluate the effectiveness of ACT in elderly patients with completely resected NSCLC.

PATIENTS

We extracted the nationwide data of 812 patients aged ≥75 years who underwent lobectomy with mediastinal nodal dissection in 2010 and were diagnosed with p-stage II-IIIA NSCLC, from nationwide registry data accumulated in 2016.

METHODS

We classified the 812 patients into 2 groups based on the ACT administration status and analyzed the differences in their postoperative overall survival (OS).

RESULTS

Overall, 295 patients received ACT (36.3%; group A), whereas 517 patients did not (63.70%; group N). Group A showed significantly better OS as a whole (hazard ratio [HR]: 0.650 [95% confidence interval {CI}: 0.526-0.804]), in the p-stage II subset (HR: 0.688 [95% CI: 0.513-0.925]), and p-stage IIIA subset (HR: 0.547 [95% CI: 0.402-0.743]) than group N. Even after propensity score matching, group A showed significantly better OS as a whole (HR: 0.626 [95% CI: 0.495-0.792]), in the p-stage II subset (HR: 0.690 [95% CI: 0.493-0.964]), and p-stage IIIA subset (HR: 0.554 [95% CI: 0.398-0.772]) than group N.

CONCLUSION

ACT is recommended even in elderly patients with completely resected p-stage II-IIIA NSCLC. Hence, physicians should not avoid ACT in patients with completely resected NSCLC based solely on age.

Outcomes of carbon ion radiotherapy compared with segmentectomy for ground glass opacity-dominant early-stage lung cancer

PURPOSE

This study aimed to compare the outcomes of patients with ground-grass opacity (GGO)-dominant non-small cell lung cancer (NSCLC) who were treated with carbon ion radiotherapy (CIRT) versus segmentectomy.

METHODS

A retrospective review of medical records was conducted. The study included 123 cases of clinical stage 0/IA peripheral NSCLC treated with single-fraction CIRT from 2003 to 2012, 14 of which were determined to be GGO-dominant and were assigned to CIRT group. As a control, 48 consecutive patients who underwent segmentectomy for peripheral GGO-dominant clinical stage IA NSCLC were assigned to segmentectomy group.

RESULTS

The patients in CIRT group, compared with segmentectomy group, were significantly older (75 ± 7.2 vs. 65 ± 8.2 years, P = 0.000660), more likely to be male (13/14 vs. 22/48, P = 0.00179), and had a lower forced vital capacity (91 ± 19% vs. 110 ± 13%, P = 0.0173). There was a significant difference in the 5-years overall survival rate (86% vs. 96%, P = 0.000860), but not in the 5-years disease-specific survival rate (93% vs. 98%, P = 0.368).

DISCUSSION

Compared with segmentectomy, CIRT may be an alternative option for patients with early GGO-dominant NSCLC who are poor candidates for, or who refuse, surgery.

Prognostic factors of resected pathological stage I lung adenocarcinoma: evaluating subtypes and PD-L1/CD155 expression

We aimed to compare the prognostic impacts of adenocarcinoma subtypes, programmed death-ligand I (PD-L1), and CD155 expression on patients with resected pathological stage (p-stage) I lung adenocarcinoma. In total, 353 patients with completely resected p-stage I lung adenocarcinomas were retrospectively reviewed. The expression levels of PD-L1 and CD155 in tumour cells from each adenocarcinoma subtype were evaluated using several clinicopathological and histological features, such as the presence of a micropapillary pattern. A total of 52 patients (14.7%) had PD-L1-positive tumours, whereas 128 patients (36.3%) had CD155-positive tumours, with a tumour proportion score of 5% for both PD-L1 and CD155 expression. Compared with patients with other adenocarcinoma subtypes, those with solid-predominant adenocarcinomas were significantly more positive for PD-L1 and CD155. Multivariate analysis showed that PD-L1 expression status was significantly associated with progression-free survival and overall survival, whereas CD155 expression and the presence of a micropapillary pattern were not significantly associated with either parameter. Patients with PD-L1-positive tumours had poorer prognoses than those with CD155-positive tumours. Moreover, PD-L1 and CD155 were significantly expressed in solid-predominant adenocarcinomas. The results of this study suggest that immune checkpoint inhibitors can be used as adjuvants in the treatment of patients with p-stage I adenocarcinoma.

Is adjuvant chemotherapy for completely resected p-stage IA (>2 cm) and stage IB non-small-cell lung cancer beneficial for elderly patients? A large, retrospective cohort study based on real-world data from Japan

OBJECTIVE

The efficacy of tegafur-uracil as adjuvant chemotherapy for patients with completely resected stage I non-small-cell lung cancer is proven; however, its efficacy for elderly patients remains unclear. Herein, we evaluated the effectiveness of adjuvant chemotherapy for elderly patients with completely resected stage I non-small-cell lung cancer based on real-world Japanese data using propensity score matching.

METHODS

This retrospective study extracted data from a nationwide registry study, performed in 2016, on patients ≥75 years who underwent lobectomy with mediastinal nodal dissection for non-small-cell lung cancer in 2010 and were diagnosed with p-stage IA (>2 cm) or stage IB non-small-cell lung cancer. We classified the 1294 patients into two groups-Group A, postoperative adjuvant chemotherapy (n = 295, 22.8%) and Group N, no adjuvant chemotherapy (n = 999, 77.2%)-and analyzed differences in postoperative overall survival between groups.

RESULTS

Group A showed no advantage in overall survival over Group N as a whole (hazard ratio: 0.824 [95% confidence interval: 0.631-1.076]), in p-stage IA (hazard ratio: 0.617 [95% confidence interval: 0.330-1.156]) and in p-stage IB (hazard ratio: 0.806 [95% confidence interval: 0.597-1.088]) subsets. Even after propensity score matching, Group A showed no significant advantage in overall survival over Group N as a whole (hazard ratio: 0.975 [95% confidence interval: 0.688-1.381]), in p-stage IA (hazard ratio: 1.390 [95% confidence interval: 0.539-3.586]) and in p-stage IB (hazard ratio: 0.922 [95% confidence interval: 0.633-1.343]).

CONCLUSIONS

adjuvant chemotherapy for completely resected p-stage IA (>2 cm) and stage IB non-small-cell lung cancer showed no benefit for recommendation for elderly patients; considering the risk of adverse events, we do not recommend adjuvant chemotherapy for elderly patients.

Investigation of uncertainty in internal target volume definition for lung stereotactic body radiotherapy

This study evaluated the validity of internal target volumes (ITVs) defined by three- (3DCT) and four-dimensional computed tomography (4DCT), and subsequently compared them with actual movements during treatment. Five patients with upper lobe lung tumors were treated with stereotactic body radiotherapy (SBRT) at 48 Gy in four fractions. Planning 3DCT images were acquired with peak-exhale and peak-inhale breath-holds, and 4DCT images were acquired in the cine mode under free breathing. Cine images were acquired using an electronic portal imaging device during irradiation. Tumor coverage was evaluated based on the manner in which the peak-to-peak breathing amplitude on the planning CT covered the range of tumor motion (± 3 SD) during irradiation in the left-right, anteroposterior, and cranio-caudal (CC) directions. The mean tumor coverage of the 4DCT-based ITV was better than that of the 3DCT-based ITV in the CC direction. The internal margin should be considered when setting the irradiation field for 4DCT. The proposed 4DCT-based ITV can be used as an efficient approach in free-breathing SBRT for upper-lobe tumors of the lung because its coverage is superior to that of 3DCT.

Creation, evolution, and future challenges of ion beam therapy from a medical physicist's viewpoint (Part 3): Chapter 3. Clinical research, Chapter 4. Future challenges, Chapter 5. Discussion, and Conclusion

Clinical studies of ion beam therapy have been performed at the Lawrence Berkeley Laboratory (LBL), National Institute of Radiological Sciences (NIRS), Gesellschaft für Schwerionenforschung (GSI), and Deutsches Krebsforschungszentrum (DKFZ), in addition to the development of equipment, biophysical models, and treatment planning systems. Although cancers, including brain tumors and pancreatic cancer, have been treated with the Bevalac's neon-ion beam at the LBL (where the first clinical research was conducted), insufficient results were obtained owing to the limited availability of neon-ion beams and immaturity of related technologies. However, the 184-Inch Cyclotron's helium-ion beam yielded promising results for chordomas and chondrosarcomas at the base of the skull. Using carbon-ion beams, NIRS has conducted clinical trials for the treatment of common cancers for which radiotherapy is indicated. Because better results than X-ray therapy results have been obtained for lung, liver, pancreas, and prostate cancers, as well as pelvic recurrences of rectal cancer, the Japanese government recently approved the use of public medical insurance for carbon-ion radiotherapy, except for lung cancer. GSI obtained better results than LBL for bone and soft tissue tumors, owing to dose enhancement enabled by scanning irradiation. In addition, DKFZ compared treatment results of proton and carbon-ion radiotherapy for these tumors. This article summarizes a series of articles (Parts 1-3) and describes future issues of immune ion beam therapy and linear energy transfer optimization.

Effect of Surgical Treatment for N2-Positive c-stage III Non-Small Cell Lung Carcinoma in the "PACIFIC" Era

BACKGROUND

The PACIFIC trial findings drastically changed the c-stage III non-small cell lung cancer (NSCLC) treatment strategy. However, it remains uncertain whether surgery is no longer needed for treatment. We aimed to evaluate the efficacy of surgery and explore the prognostic factors of better outcomes in surgery-treated patients than in PACIFIC regimen-treated patients.

PATIENTS AND METHODS

From 2010 to 2020, 107 patients with clinical N2-stage III NSCLC underwent lung resection in our institute. We analyzed and compared the yearly postoperative overall survival (OS) benchmarks of these patients to those of patients treated in the PACIFIC trial.

RESULTS

The 1-, 2-, 3-, 4-, and 5-year OS rates of patients were 87.7%, 73.9%, 64.9%, 58.2%, and 55.4%, respectively, all of which were superior to those of PACIFIC regimen-treated patients. However, patients with cT3/T4 tumors and skip, multistation, distant, and bulky N2 metastases, as well as those who underwent bronchoplasty, showed inferior results in several yearly benchmarks than in PACIFIC regimen-treated patients. Multivariate analyses conducted among factors mentioned above showed that cT3/T4 tumor was a worse prognostic factor for surgery-treated patients than for PACIFIC regimen-treated patients (hazard ratio [HR] 1.89, P = .036). Distant N2 metastasis was also a worse prognostic factor, although its effect was not statistically significant (HR 1.81, P = .082).

CONCLUSION

Surgery remains the mainstay of N2-positive c-stage III NSCLC treatment, and the PACIFIC regimen may be suitable only for patients with unresectable disease. However, surgery should be cautiously considered for patients with cT3/4 disease.

Multi-dimensional radiomics analysis to predict visceral pleural invasion in lung adenocarcinoma of ≤3 cm maximum diameter

AIM

To explore the value of radiomics analysis in preoperatively predicting visceral pleural invasion (VPI) of lung adenocarcinoma (LAC) with ≤3 cm maximum diameter and to compare the performance of two-dimensional (2D) and three-dimensional (3D) computed tomography (CT) radiomics models.

MATERIALS AND METHODS

A total of 391 LAC patients were enrolled retrospectively, of whom 142 were VPI (+) and 249 were VPI (-). Radiomics features were extracted from 2D and 3D regions of interest (ROIs) of tumours in CT images. 2D and 3D radiomics models were developed combining the optimal radiomics features by using the logistic regression machine-learning method and radiomics scores (rad-scores) were calculated. Nomograms were constructed by integrating independent risk factors and rad-scores. The performance of each model was evaluated by using the receiver operator characteristic (ROC) curve, decision curve analysis (DCA), clinical impact curve (CIC), and calculating the area under the curve (AUC).

RESULTS

There was no difference in the VPI prediction between 2D and 3D radiomics models (training group: 2D AUC=0.835, 3D AUC=0.836, p=0.896; validation group: 2D AUC=0.803, 3D AUC=0.794, p=0.567). The 2D and 3D nomograms performed similarly regarding discrimination (training group: 2D AUC=0.867, 3D AUC=0.862, p=0.409, validation group: 2D AUC=0.835, 3D AUC=0.827, p=0.558), and outperformed their corresponding radiomics models and the clinical model. DCA and CIC revealed that the 2D nomogram had slightly better clinical utility.

CONCLUSION

The 2D radiomics model has a similar discrimination capability compared with the 3D radiomics model. The 2D nomogram performs slightly better for individual VPI prediction in LAC.

Bidirectional Mendelian randomization analysis of the genetic association between primary lung cancer and colorectal cancer

BACKGROUND

With the development and popularization of low-dose chest CT technology, the diagnosis and survival rates of patients with early lung cancer (LC) have significantly improved. The occurrence of colorectal cancer (CRC) as the second primary cancer (SPC) in primary lung cancer (PLC) survivors has become an essential factor affecting the prognosis of early LC. This study explored the potential association between PLC and CRC genetically, laying a foundation for developing SPC-CRC prevention strategies after primary early LC.

METHODS

Based on a two-sample bidirectional Mendelian randomization (MR) design, this study systematically screened genetic instrumental variables (IVs) based on the genome-wide association studies (GWAS) of PLC and CRC, applied inverse variance weighted (IVW) as the main method to assess the incidence association between the two cancers, and used a variety of other MR methods for supplementary analysis. Finally, the Genetic Risk Scores (GRS) method was used for secondary analysis to verify the results robustness further.

RESULTS

From LC to CRC forward MR analysis, 20 genetic IVs of overall LC, 15 genetic IVs of squamous cell lung carcinoma (LUSC), and 10 genetic IVs of adenocarcinoma of the lung (LUAD) were screened. In the reverse MR analysis from CRC to LC, 47 genetic IVs for overall CRC, 37 for colon cancer, and 25 for rectal cancer were screened. The IVW method and a variety of MR methods all found that overall LC and CRC were significantly associated at the genetic level. Subgroup analysis also showed that LUSC was associated with CRC. And the results of the GRS method were consistent with those of the main analysis, confirming the robustness of the study. Our MR study found an association between LC and CRC, with an increased risk of SPC-CRC following PLC, especially LUSC. Our study provides an essential basis for the precise prevention of SPC-CRC after PLC, suggesting that we should pay more attention to the population with a history of PLC in clinical work, and pay close attention to the incidence of SPC-CRC, and carry out intervention and treatment as soon as possible.

Long-term outcome of patients with peripheral ground-glass opacity-dominant lung cancer after sublobar resections

OBJECTIVE

This study aimed to evaluate the long-term prognosis of patients with peripheral small ground-glass opacity-dominant lung cancer after sublobar resection. We have already reported the 5-year safety and efficacy of sublobar resection and report the long-term outcomes after a 10-year follow-up period.

METHODS

Between May 2009 and April 2011, 333 patients with radiologically noninvasive peripheral lung cancer were enrolled from 51 institutions (median age, 62 years at registration) and followed up until May 6, 2021. Of these patients, sublobar resections with wedge resection as the first choice were performed in 314 patients (258 wedge resections and 56 segmentectomies), conversion lobectomies were performed in 11 patients, and 8 patients were ineligible.

RESULTS

The 10-year relapse-free survival and overall survival for the 314 patients with sublobar resections were 98.6% (95% confidence interval, 96.2-99.5) and 98.5% (95% confidence interval, 96.1-99.4), respectively. There was 1 local recurrence at the resection margin. Among the patients, second cancers were observed in 43 patients (13.4%; 95% confidence interval, 9.8-17.6), of which 18 were second lung cancers (5.8%; 95% confidence interval, 3.5-8.9).

CONCLUSIONS

Peripheral ground-glass opacity-dominant lung cancer is cured by sublobar resection, with wedge resection as the first choice, and the indications for other treatment options should be further investigated. The incidence of second cancer is similar to that in the general Japanese population.

Segmentectomy versus lobectomy for deep clinical T1a-bN0M0 non-small cell lung cancer

OBJECTIVES

Whether segmentectomy could yield similar oncological outcomes with lobectomy for cT1a-bN0M0 non-small cell lung cancer (NSCLC) in the deep lung parenchyma remained unclear. This study aimed to compare the long-term prognosis of segmentectomy and lobectomy for deep NSCLC.

MATERIALS AND METHODS

We retrospectively screened cT1a-bN0M0 NSCLC patients who underwent segmentectomy or lobectomy between 2012 and 2019. The 3D multiplanar reconstruction software was used to determine the tumor location. Log-rank test, Cox hazard proportional regression, and propensity score matching analyses were adopted for prognostic evaluation.

RESULTS

In total, 321 patients with segmentectomy and 239 subjects undergoing lobectomy with a median follow-up time of 48.2 months remained. All the patients had a R0 resection, and no 30-day or 90-day mortality was observed. The 5-year overall survival and disease-free survival were 99.0% and 96.6% for patients undergoing segmentectomy. No significant survival differences existed between segmentectomy and lobectomy after adjusting other factors (disease-free survival, DFS: HR = 1.20, 95%CI: 0.49-2.99, P = 0.688; overall survival, OS: HR = 1.09, 95%CI: 0.30-3.95, P = 0.892). After propensity score matching, patients with segmentectomy (n = 128) had a similar OS (P = 0.870) and DFS (P = 0.900) with those receiving lobectomy (n = 128). To further evaluate the outcomes of segmentectomy for deep lung cancer, 557 peripheral lung cancer patients who underwent segmentectomy at the same period were taken as the reference. As expected, segmentectomy for deep lesions achieved equivalent OS (P = 0.610) and DFS (P = 0.580) with the peripheral lesions.

CONCLUSIONS

Segmentectomy could achieve comparable long-term outcomes with lobectomy for deep cT1a-bN0M0 NSCLC with careful preoperative design and 3D navigation.

Development of artificial intelligence prognostic model for surgically resected non-small cell lung cancer

There are great expectations for artificial intelligence (AI) in medicine. We aimed to develop an AI prognostic model for surgically resected non-small cell lung cancer (NSCLC). This study enrolled 1049 patients with pathological stage I-IIIA surgically resected NSCLC at Kyushu University. We set 17 clinicopathological factors and 30 preoperative and 22 postoperative blood test results as explanatory variables. Disease-free survival (DFS), overall survival (OS), and cancer-specific survival (CSS) were set as objective variables. The eXtreme Gradient Boosting (XGBoost) was used as the machine learning algorithm. The median age was 69 (23-89) years, and 605 patients (57.7%) were male. The numbers of patients with pathological stage IA, IB, IIA, IIB, and IIIA were 553 (52.7%), 223 (21.4%), 100 (9.5%), 55 (5.3%), and 118 (11.2%), respectively. The 5-year DFS, OS, and CSS rates were 71.0%, 82.8%, and 88.7%, respectively. Our AI prognostic model showed that the areas under the curve of the receiver operating characteristic curves of DFS, OS, and CSS at 5 years were 0.890, 0.926, and 0.960, respectively. The AI prognostic model using XGBoost showed good prediction accuracy and provided accurate predictive probability of postoperative prognosis of NSCLC.

Recent Advances in Perioperative Immunotherapies in Lung Cancer

Several clinical trials have been revolutionizing the perioperative treatment of early-stage non-small cell lung cancer (NSCLC). Many of these clinical trials involve cancer immunotherapies with antibody drugs that block the inhibitory immune checkpoints programmed death 1 (PD-1) and its ligand PD-L1. While these new treatments are expected to improve the treatment outcome of NSCLC patients after pulmonary resection, several major clinical questions remain, including the appropriate timing of immunotherapy (neoadjuvant, adjuvant, or both) and the identification of patients who should be treated with neoadjuvant and/or adjuvant immunotherapies, because some early-stage NSCLC patients are cured by surgical resection alone. In addition, immunotherapy may induce immune-related adverse events that will require permanent treatment in some patients. Based on this fact as well, it is desirable to select appropriate patients for neoadjuvant/adjuvant immunotherapies. So far, data from several important trials have been published, with findings demonstrating the efficacy of adjuvant atezolizumab (IMpower010 trial), neoadjuvant nivolumab plus platinum-doublet chemotherapy (CheckMate816 trial), and several perioperative (neoadjuvant plus adjuvant) immunotherapies (AEGEAN, KEYNOTE-671, NADIM II, and Neotorch trials). In addition to these key trials, numerous clinical trials have reported a wealth of data, although most of the above clinical questions have not been completely answered yet. Because there are so many ongoing clinical trials in this field, a comprehensive understanding of the results and/or contents of these trials is necessary to explore answers to the clinical questions above as well as to plan a new clinical trial. In this review, we comprehensively summarize the recent data obtained from clinical trials addressing such questions.

Bronchial branching patterns and volumetry in the right upper lobe: impact on segmentectomy planning

OBJECTIVES

The use of segmentectomy is expected to increase. However, understanding of the segmental bronchial branching is limited. Herein, we aimed to investigate bronchial branching pattern complexity and segmental volumetry of the right upper lung lobe to develop an accurate understanding of segmental anatomy and contribute to the advancement of safe and efficient lung segmentectomy.

METHODS

We evaluated chest computed tomography scans of 303 patients and categorized the branching of segmental bronchi (segment 1, apical; segment 2, posterior; and segment 3, anterior) into 4 major types (typical trifurcated, bifurcated non-defective, bifurcated defective and atypical trifurcated) and 11 subtypes. Segmental volumetry was performed to determine the predominant segment in each case (volume difference <5% was considered equal). Branching complexity was evaluated separately for volumetry-predominant and volumetry-non-predominant segments.

RESULTS

Trifurcated non-defective was the most frequent branching type (64.4%), followed by bifurcated non-defective (22.1%), bifurcated defective (8.6%) and trifurcated half-defective (4.0%). In terms of segmental volumetry, most cases had a one-segment-predominant distribution (71%) and only 5% of cases had equal distribution (segment 1 = segment 2 = segment 3). More than half of the cases had a segment 3-predominant distribution (52%). Branching complexity analysis revealed that the volumetry-non-predominant segment was associated with a higher risk of complex branching patterns compared with the volumetry-predominant segment (37% vs 19%, respectively; P < 0.005).

CONCLUSIONS

Volumetric assessment of the right upper lobe showed a heterogeneous segmental volume distribution. Care should be taken during lung segmentectomy of the volumetry-non-predominant segments because of the high risk associated with complex bronchial branching patterns.

CLINICAL TRIAL REGISTRATION

No. 4840.

Sublobar Resection for Non-Small Cell Lung Cancer in Octogenarians: A Prospective, Multicenter Study

BACKGROUND

Segmentectomy is a good surgical option for peripheral, early, non-small cell lung cancer (NSCLC) ≤2 cm. However, the role of sublobar resection including wedge resection and segmentectomy remains unclear for octogenarians with >2-cm but ≤4-cm early-stage NSCLC, for which lobectomy is a standard treatment.

METHODS

By use of a prospective registry, 892 patients aged ≥80 years with operable lung cancer were enrolled at 82 institutions. Of these, we analyzed the clinicopathologic findings and surgical outcomes of 419 patients with NSCLC tumors of 2 to 4 cm during a median follow-up of 50.9 months between April 2015 and December 2016.

RESULTS

Five-year overall survival (OS) was slightly but not significantly worse after sublobar resection than after lobectomy in the entire cohort (54.7% [95% CI, 43.2%-93.0%] vs 66.8% [95% CI, 60.8%-72.1%]; P = .09). Multivariable Cox regression analysis of OS revealed that these surgical procedures were not independent prognostic predictors (hazard ratio, 0.8 [0.5-1.1]; P = .16). The 5-year OS was comparable between 192 patients who could tolerate lobectomy but were treated by sublobar resection or lobectomy (67.5% [95% CI, 48.8%-80.6%] vs 71.5% [95% CI, 62.9%-78.4%]; P = .79). Recurrence after sublobar resection and lobectomy was locoregional in 11 (11%) of 97 and in 23 (7%) of 322 patients, respectively.

CONCLUSIONS

OS might be equivalent between sublobar resection with a secure surgical margin and lobectomy for selected patients aged ≥80 years with peripheral early-stage NSCLC tumors of 2 to 4 cm who can tolerate lobectomy.

The effectiveness of an accelerometer-based physical activity enhancement intervention for patients undergoing lung resection - A pilot randomized controlled trial

OBJECTIVES

Increasing physical activity after lung resection is important for maintaining quality of life. It is unclear whether accelerometer-based exercise instruction contributes to increasing daily physical activity after lung resection. We examine whether accelerometer-based exercise instruction will lead to increased physical activity in patients undergoing lung resection.

MATERIALS AND METHODS

Forty-six patients undergoing lung resection were randomly assigned to either the intervention group (n = 22) or the control group (n = 24). Twelve participants dropped out. Ultimately, 16 participants in the intervention group and 18 participants in the control group were eligible for analysis. Each group allocation was only known to the person in charge of allocation. The physiotherapists and assessors were not blinded in this study. The intervention group participated in a postoperative rehabilitation program and received physical activity instruction preoperatively and at discharge. The control group participated in a postoperative rehabilitation program only. The primary outcomes was physical activity such as the number of daily steps, light intensity physical activity (LPA) and moderate-vigorous intensity physical activity (MVPA) at the two month postoperative follow-up.

RESULTS

Thirty-four participants were enrolled in this study. Sixteen participants in the intervention group and 18 participants in the control group were included for analysis. Although there was no significant difference in physical activity at baseline, the number of daily steps in the intervention group at the two month postoperative follow-up was significantly higher than that in the control group (8039.2 ± 3480.8 vs. 4887.0 ± 2376.5 steps/day, p = 0.004). Compared to the control group, the intervention group also had greater increases in LPA (63.8 ± 25.1 vs. 44.5 ± 24.5 min/day, p = 0.030) and MVPA (20.2 ± 19.6 vs. 9.6 ± 8.6 min/day, p = 0.022).

CONCLUSIONS

This study showed that accelerometer-based exercise instruction led to an increase in physical activity after lung resection in an unsupervised setting.

CLINICAL TRIAL REGISTRATION

The University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMIN trial No. UMIN000039369).

Circ_0001715 accelerated lung adenocarcinoma process by the miR-1322/CANT1 axis

Lung adenocarcinoma (LUAD) is a type of lung cancer, which belongs to non-small cell lung cancer and has seriously endangered the physical and mental health of people. The study of circRNAs (circRNAs) has been increasingly hot in recent years, in which circRNAs also play an important regulatory role in cancer. The aim of this study was to investigate the biological molecular mechanisms of circ_0001715 in the progression of LUAD. The expression of circ_0001715, miR-1322 and calcium-activated nucleotidase 1 (CANT1) in LUAD tissues and cell lines was assessed by quantitative reverse transcription PCR (RT-qPCR) and western bot assay. Clone formation assay, 5-Ethynyl-2'-Deoxyuridine (EDU) assay and wound healing assay were used to verify the proliferation ability of cells. Dual-luciferase reporter assay and RNA pull-down assay were performed to characterize the interactions between the three factors. Finally, a mouse tumor model was constructed to assess the tumorigenicity of circ_0001715. RT-qPCR assay results showed that circ_0001715 expression was significantly increased in LUAD tissues and cell lines. Finally, knockdown of circ_0001715 could inhibit tumor growth in vivo. Circ_0001715 regulated the progression of LUAD through the miR-1322/CANT1 axis. The results of this study provided ideas for understanding the molecular mechanisms of circ_0001715 in LUAD.

Significance of programmed death-ligand 1 expression in resected lung cancer and its relationship with EGFR mutation

BACKGROUND

Several studies have reported that the high expression of programmed death-ligand 1 (PD-L1) within tumor cells predicts a poor prognosis. However, the relationship between the PD-L1 expression and lymph node metastasis or driver mutations in lung cancer remains poorly understood.

METHODS

A total of 356 consecutive patients who underwent surgical resection for primary lung cancer were included in the study. There were 268 adenocarcinomas including 100 EGFR mutations, 67 squamous cell carcinomas (Sq), and 21 other histologies. The high expression of PD-L1 was defined as a tumor proportion score (TPS) of ≥50. The relationship between the PD-L1 expression and clinicopathological factors and recurrence-free survival (RFS) was analyzed.

RESULTS

The PD-L1 expression was high in 75 patients. It was significantly related to smoking history, Sq histology, driver mutation negative, elevated serum carcinoembryonic antigen levels, and lymph node metastasis. Among patients with driver mutations, a high PD-L1 TPS was found in patients with EGFR G719X mutation. A significant difference in RFS was observed in adenocarcinoma patients. A multivariate analysis of adenocarcinoma cases revealed that tumor size and lymph node metastasis were independent prognostic factors for poor RFS, while the PD-L1 expression was not. A logistic regression analysis revealed that the absence of driver mutations, lymph node metastasis, and a history of smoking were significantly associated with the high expression of PD-L1.

CONCLUSION

Lymph node metastasis was positively related with the high expression of PD-L1, resulting in poor RFS. A high PD-L1 TPS was observed in patients with the EGFR G719X mutation.