Prognostic significance of combined radiologic imaging modalities for prognosis of clinical IA adenocarcinomas

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.

Survival benefit of immune checkpoint inhibitor monotherapy in patients with non-small cell lung cancer recurrence after completely pulmonary resection

Background

Selected patients in non-small cell lung cancer (NSCLC) responded to the treatment of immune checkpoint inhibitors (ICIs) have the survival benefit for advanced stages or metastatic status.

Methods

We investigated whether a response to ICI monotherapy since 2016 influences the survival of NSCLC patients with recurrence after completely pulmonary resection between 2009 and 2017. Disease control rate (DCR) was calculated as complete plus partial response plus stable disease during more than 6 months.

Results

Thirty-five patients (mean age 67 years, range 46–79 years, 60% male) were included in the study. The most frequent histology and pathological stage were adenocarcinoma (60%) and IIB (45.7%), respectively. ICI was used at a median of second-line treatment. The DCR and median progression-free survival were 42.8% and 2.5 (95% CI: 1.6–3.4) months, respectively. The therapeutic outcome from recurrence was 47.5%. Multivariate analysis revealed a significant impact of DCR on favorable therapeutic outcome (P=0.04). A serial increase (pre- to post-surgery to ICI initiation) of C-reactive protein (CRP) and prognostic nutritional index (PNI) was associated with treatment response (both P=0.01).

Conclusions

These results suggest that a response to ICI monotherapy significantly contributes to a survival benefit regardless of therapeutic lines in NSCLC patients with recurrence after completely pulmonary resection, and the therapeutic response is strongly associated with a serial increase in CRP or decrease in prognostic nutritional index.

Narrative review of optimal prognostic radiological tools using computed tomography for T1N0-staged non-small cell lung cancer

Various radiological tools can predict the prognosis of non-small cell lung cancer (NSCLC). In this study, we evaluated the prognostic effect of different radiological tools such as whole tumor size (WTS), consolidation size (CS), consolidation tumor ratio (CTR), tumor disappearance ratio (TDR), mediastinal diameter (MD), and ground glass opacity (GGO) using high-resolution computed tomography (HRCT). We reviewed recent retrospective studies on the predictive effect of these radiological tools on disease-free survival (DFS) and overall survival (OS) in patients with T1N0-staged NSCLC. We searched PubMed and the British Library databases for the English literature published from January 2010 to December 2020 and generated a total of 32 publications (NSCLC, n=16; adenocarcinoma, n=16). The TNM classification version 7 was used in 18 studies, and version 8 in 14 studies. The evaluated radiological parameters were WTS, CS including T category, CTR, TDR, MD, presence of GGO, GGO ratio, and pure GGO. This review suggested that CS, MD, and the presence of GGO are optimal prognostic radiological tools for cT1N0-Staged NSCLC. CTR or TDR for part solid nodules (PSNs) is not a well-accepted prognostic factor. Further investigations are required to differentiate between benign scars and malignant components on HRCT and evaluate the prognosis of PSNs (1< CS ≤2 cm) with large WTS in the future.

Subsegmental resection preserves regional pulmonary function: A focus on thoracoscopy

Background

The aim of this study was to evaluate regional postoperative preserved pulmonary function (PPPF) and three‐dimensional (3D) volumetric changes according to the number of resected subsegments and investigate the factors that most affected pre‐/post PPPF.

Methods

Patients who underwent thoracoscopic lobectomy (n = 73), and segmentectomy (n = 87) were eligible for inclusion in the study. They were classified according to the number of resected subsegments which ranged from 1 to 10. The percentage of pre‐/postoperative forced expiratory volume in 1 s (FEV1) was used for comparison. Furthermore, lung volumetric changes were calculated using 3D computed tomography (CT) volumetry.

Results

The percentage of pre‐/postoperative EFV1 between 4 and 5–7 and between 5–7 and 10 were significant (p = 0.03 and p < 0.01, respectively), but not between 1–2 to 4 (p = 0.99). The difference between volumetric changes in the left lower lobe of patients with a number of resected subsegments was significant (p < 0.01). On univariate and multivariate analyses, chronic inflammation was significant for decrease in recovery percentages. When the PPPF was compared among resected subsegments, it gradually decreased with an increase in the number of patients without a postoperative procrastination of inflammation (p < 0.01).

Conclusions

Segmentectomy is feasible and useful for PPPF. Even a relatively large‐volume resection procedure where 5–7 subsegments are resected can preserve pulmonary function. Chronic inflammation was statistically identified as a risk factor for postoperative preserved pulmonary function.

Key points

 

How preserved regional pulmonary function after thoracoscopic segmentectomy in clinical stage I non-small cell lung cancers in right upper lobe

OBJECTIVE

To investigate the efficacy of regional respiratory preservation after pulmonary resection for clinical stage I non-small cell lung cancer (NSCLC) in right upper lobe.

METHODS

This retrospective study analysed patients with clinical stage I NSCLC who underwent open thoracotomy lobectomy (OTL, n = 45), thoracoscopic lobectomy (TSL, n = 137), and thoracoscopic segmentectomy (TSS, n = 37) in right upper lobe. The forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) were examined at 3 and 6-12 months after the operation. The pre- and post-operative lung volumes were evaluated by three-dimensional reconstructed computed tomography. The rates of post- and pre-operative FVC, FEV1, and lung volumes were compared amongst the three groups.

RESULTS

Significant differences were found in both FVC and FEV1 at 6-12 months between TSL and OTL (p < 0.01 and p = 0.02, respectively). The respiratory recovery rates of FVC and FEV1 at 6-12 months were significantly higher in TSS (98.6% ± 1.52% and 96.5% ± 1.66%) than in TSL (93.4% ± 0.79% and 90.4% ± 0.86%) (FVC: p < 0.01 and FEV1: p < 0.01). The volumetric changes were greater in TSL than in TSS for the right middle lobe (19.6% ± 2.39% and 9.59% ± 4.66%; p = 0.06) and right lower lobe (48.3% ± 2.84% and 27.9% ± 5.47%; p < 0.01) CONCLUSION: TSS might be superior to TSL or OTL depending on the moderate expansion of the remaining right lobes.

Radiological imaging and pathological findings of small lung adenocarcinoma: a narrative review

The eighth edition of the Lung Cancer Handling Regulations defines the pathological findings of "invasion" in the pathological diagnosis of lung adenocarcinoma and terms it as adenocarcinoma in situ/minimally invasive carcinoma. In addition, the invasion diameter (tumor diameter excluding the lepidic growth region) was adopted as the pT factor, and the classification further reflected prognosis (degree of invasion/progression). Meanwhile, computed tomography imaging-based classification, where the consolidation (nodule) diameter excluding the ground glass shadow area was defined as cT, and the classification reflected the pathological invasion diameter. It is clear that the revision of the eighth edition has reduced discrepancies in the pathological findings of lung adenocarcinoma in CT imaging and assessment of the degree of invasion and progression. At the same time, the 8th edition is not yet accurate enough. Therefore, we will discuss imaging techniques to better predict the extent of adenocarcinoma invasion and progression, based on our own findings and the literature.

Selection of Pathological N0 (pN0) in Clinical IA (cIA) Lung Adenocarcinoma by Imaging Findings of the Main Tumor

OBJECTIVES

We would like to clarify the imaging findings of the main tumor that may omit the requirement for lymph node dissection in clinical IA (cIA) lung adenocarcinoma.

METHODS

A total of 336 patients with cIA lung adenocarcinomas with normal preoperative carcinoembryonic antigen (CEA) who underwent surgical resection were analyzed. We investigated the association between various computed tomography (CT) imaging findings or the maximum standardized uptake value (SUVmax) of fluorodeoxyglucose-position emission tomography (FDG-PET) and lymph node metastasis. The maximum tumor diameter was calculated from the CT images using both the lung window setting (LD) and mediastinal window setting (MD). The diameter of the solid component (CD) was defined as consolidation diameter in lung window setting. The solid component ratio (C/T) was defined as CD/LD.

RESULTS

SUVmax, MD, and C/T were independent factors related to lymph node metastasis, but CD was not (p = 0.38). The conditions required for the positive predictive value (PPV) to reach 100% were 10.6 mm for MD, 12.5 mm for CD, and 0.55 for C/T. SUVmax did not reach 100%.

CONCLUSIONS

In cIA lung adenocarcinoma with CEA in the normal range, we found that it may be possible for lymph node dissection to be omitted by MD, CD, and C/T.

Efficacy of Xenon Light With Indocyanine Green for Intersegmental Visibility in Thoracoscopic Segmentectomy

BACKGROUND

We previously reported useful methods that can be implemented to identify intersegmental boundary lines (IBLs) by using an intravenous indocyanine green (ICG) fluorescence imaging system (ICG-FS) during a thoracoscopic anatomical segmentectomy (TAS). The aim of this study was to evaluate the recently released third-generation ICG-FS that features an emphasizing xenon-light source for IBL identification.

METHODS

We prospectively studied cases involving 106 consecutive patients who underwent TAS. Intraoperatively, we used the third-generation ICG-FS, the conventional ICG methods (CIM) emphasizing xenon-light (CIM-X), and the spectra-A method (SAM) emphasizing xenon-light (SAM-X), for IBL identification. Furthermore, 16 of the 106 patients (15%) could be simultaneously evaluated using old-generation ICG-FSs, CIM, and SAM. All images were completely quantified for illuminance and for three colors, red, green, and blue.

RESULTS

IBLs were successfully identified in all the patients (100%) with no adverse events. The SAM-X significantly increased the illuminance, especially in the resecting segments, compared to the CIM (39.0 versus 22.2, P < 0.01) and SAM (39.0 versus 29.3, P < 0.01), with enhanced red color compared to the CIM (33.1 versus 21.9, P < 0.01) and SAM (33.1 versus 14.0, P < 0.01). Furthermore, the SAM-X significantly increased the illuminance contrast compared to the CIM-X (34.1 versus 15.3, P < 0.01).

CONCLUSIONS

The present study suggests that the SAM-X potentially provided images with the highest visibility and colorfulness compared to the older generation ICG-FSs or CIM-X. Secure IBL identification can be more easily and safely performed using the SAM-X.

Clinical adjustability of radiological tools in patients with surgically resected cT1N0-staged non-small-cell lung cancer from the long-term survival evaluation

Background

Various radiological tools have been introduced to determine the malignancy or prognosis of lung carcinomas. We retrospectively summarized the clinical outcomes to evaluate whether radiological tools such as consolidation-to-tumor ratio (CTR), tumor disappearance ratio (TDR), and mediastinal diameter (MD) are suitable for surgically resected non-small-cell lung cancer (NSCLC).

Methods

This retrospective study included 260 patients (128 men and 132 women; median age, 64 years) with cT1N0-staged NSCLC who underwent thoracotomy. Disease-free survival (DFS) and overall survival (OS) outcomes were analyzed using the Kaplan-Meier method and Cox proportional hazards model.

Results

When the adjusted hazard ratios (HRs) with reference to cT1a/1 mi were calculated, significant differences were observed in cT1b and cT1c for DFS (P=0.04 and P<0.01, respectively) and in cT1c for OS (P=0.01). For HRs with reference to CTR (≤0.5), a significant difference was only observed in CTR (>0.5) for DFS (P=0.01). For HRs with reference to TDR (≤25%), significant differences were observed in TDR (>75%) for DFS (P=0.02) and OS (P=0.02). For HRs with reference to MD (≤5 mm), significant differences were observed in 6–20 mm (P=0.04) and >20 mm (P=0.02) for DFS and in >20 mm (P=0.02) for OS.

Conclusions

All radiological tools revealed significant correlations with prognosis in the patients with cT1N0-staged NSCLCs. We recommend the use of MD in a clinical context. However, further investigation of this issue is needed.

Favorable clinical application for segmental bronchial closure based on experiment results

Background

We previously reported the clinical application of powered vascular staple (PVS) for closure of subsegmental or segmental bronchus (SSB). This study aimed to measure breakdown pressure in experiment and to investigate bronchopleural fistula (BPF) after thoracoscopic segmentectomy (TS).

Methods

Part 1: a total of 30 cadaveric pigs were used, and bronchi were categorized into the following four groups: small [S, bronchial outer diameter (BOD) of 4-8 mm, n=8], medium (M, 9-10 mm, n=9), and large (L, >10 mm, n=13). We additionally added a single additional suture to compensate for weak sites with large BOD (group R, n=6). The pressure was slowly increased, and stump breakdown was observed. Part 2: we investigated the morbidity of BPF formation at follow-up of at least 6 months in a total of 217 patients.

Results

Part 1: the mean leak pressure was the highest in M, followed by groups S, R and L'. However, the significant difference was not found between S and R. Part 2: no BPF was observed, clinically.

Conclusions

Based on experimental results and clinical experience, the proper selection of PVS should contribute to the safety, feasibility, and success as SSB closure.

Importance of avoiding surgery delays after initial discovery of suspected non-small-cell lung cancer in clinical stage IA patients

Introduction

The natural history of consolidation on computed tomography (CT) rarely includes invasive cancers, and evidence of the ideal timing for surgical intervention via long-term follow-up studies remains unknown.

Methods

Between January 2012 and June 2017, pulmonary resection was undertaken in 293 clinical IA patients who were followed-up for > 6 months after the first detection of potential non-small-cell lung cancer (NSCLC) opacities. We evaluated the corresponding HRs and compared the recurrence risk with the CT follow-up duration.

Results

HRs calculated for the longest intervals were compared between two patient subsets: a shorter-interval surgery group (SISG: 41.3%; mean follow-up interval, 13.5±5.3 months) and a longer-interval surgery group (58.7%; mean follow-up interval, 54.9±25.6 months). On Cox multivariate regression analyses, CT consolidation (ratio >0.5), an abnormal carcinoembryonic antigen and a triple-negative mutation showed an independent association with an unfavorable prognosis, as measured by disease-free survival after the first detection of potential NSCLC opacities. The longer-interval surgery group fared significantly better than the SISG in terms of 5-year overall survival after the first detection (99.3% vs 93.1%, P<0.01); the 3-year overall survival after the first detection was significantly shorter in the high-risk SISG (presence of two factors from the three) than that in the low-risk SISG (presence of 0 or one factor; 100% vs 73.3%, P<0.01).

Conclusion

Our study indicates that the patients with potential NSCLC opacities who are able to wait for more than 2 years prior to pulmonary resection may be likely to have a favorable prognosis, whereas early judgment for surgical resection should be required for avoiding surgical delays.