Adjuvant atezolizumab in Japanese patients with resected stage IB-IIIA non-small cell lung cancer (IMpower010).

The global phase 3 IMpower010 study evaluated adjuvant atezolizumab versus best supportive care (BSC) following platinum-based chemotherapy in patients with resected stage IB-IIIA non-small cell lung cancer (NSCLC). Here, we report a subgroup analysis in patients enrolled in Japan. Eligible patients had complete resection of histologically or cytologically confirmed stage IB (tumors ≥4 cm)-IIIA NSCLC. Upon completing 1-4 cycles of adjuvant cisplatin-based chemotherapy, patients were randomized 1:1 to receive atezolizumab (fixed dose of 1200 mg every 21 days; 16 cycles or 1 year) or BSC. The primary endpoint of the global IMpower010 study was investigator-assessed disease-free survival, tested hierarchically first in patients with stage II-IIIA NSCLC whose tumors expressed programmed death-ligand 1 (PD-L1) on ≥1% of tumor cells, then in all randomized patients with stage II-IIIA NSCLC, and finally in the intention-to-treat (ITT) population (stage IB-IIIA NSCLC). Safety was evaluated in all patients who received atezolizumab or BSC. The study comprised 149 enrolled patients in three populations: ITT (n = 117; atezolizumab, n = 59; BSC, n = 58), all-randomized stage II-IIIA (n = 113; atezolizumab, n = 56; BSC, n = 57), and PD-L1 tumor cells ≥1% stage II-IIIA (n = 74; atezolizumab, n = 41; BSC, n = 33). At the data cutoff date (January 21, 2021), a trend toward disease-free survival improvement with atezolizumab vs BSC was observed in the PD-L1 tumor cells ≥1% stage II-IIIA (unstratified hazard ratio [HR], 0.52; 95% confidence interval [CI], 0.25-1.08), all-randomized stage II-IIIA (unstratified HR, 0.62; 95% CI, 0.35-1.11), and ITT (unstratified HR, 0.61; 95% CI, 0.34-1.10) populations. Atezolizumab-related grade 3/4 adverse events occurred in 16% of patients; no treatment-related grade 5 events occurred. Adjuvant atezolizumab showed disease-free survival improvement and a tolerable toxicity profile in Japanese patients in IMpower010, consistent with the global study results.

Insulinoma-associated protein 1 is a prognostic biomarker in pulmonary high-grade neuroendocrine carcinoma.

BACKGROUNDS AND OBJECTIVES: Recent studies have suggested that insulinoma-associated protein 1 (INSM1) is a useful marker for pathological diagnosis of pulmonary neuroendocrine tumors. In the present study, we investigated the association between INSM1 expression and prognosis in patients with pulmonary high-grade neuroendocrine carcinomas (HGNEC) and assessed the usefulness of INSM1 as a prognostic biomarker in these patients. METHODS: Seventy-five consecutive patients with HGNEC who underwent complete surgical resections from January 2000 to December 2018 were enrolled in this study. We classified these patients into two groups: the INSM1-positive group (n = 59) and INSM1-negative group (n = 16). We compared the clinicopathological characteristics, overall survival (OS), and recurrence-free survival (RFS) between the groups. In addition, we performed univariate and multivariate analyses to identify the prognostic factors associated with postoperative survival. RESULTS: Significant differences in tumor diameter and vascular invasion between the groups were found. OS and RFS were significantly poorer in the INSM1-positive group than in the INSM1-negative group. Univariate and multivariate analyses revealed that INSM1 expression was the strongest predictor of poor prognosis for OS and RFS. CONCLUSIONS: INSM1 expression had the greatest influence on the prognosis in patients with HGNEC and may be a prognostic biomarker in these patients.

EWSR1-CREM fusion in pulmonary mesenchymal neoplasm showing distinctive clear cell morphology.

EWSR1-CREM gene fusions were recently discovered in several mesenchymal and epithelial tumors, including myxoid mesenchymal tumors of the central nervous system, rare cases of soft tissue clear cell sarcoma and angiomatoid fibrous histiocytoma, and hyalinizing clear cell carcinoma, which implicates the potential phenotypic diversities of tumors harboring an EWSR1-CREM fusion. We herein present an exceedingly indolent pulmonary mesenchymal tumor showing distinctive clinicopathological features. This tumor histologically displayed a small nest and alveolar pattern consisting of monomorphic clear cells intermingled with dilated anastomosing vasculature. Immunophenotypically, tumor cells were positive for vimentin and focally positive for synaptophysin, but negative for many immunohistochemical panels including keratins, EMA, desmin, mesothelial markers, melanotic markers, smooth muscle actin, inhibin and S-100 protein. Interestingly, RNA sequencing identified an in-frame EWSR1-CREM fusion, which was confirmed by subsequent real-time/reverse transcription polymerase chain reaction and fluorescence in situ hybridization assay. Clinical follow-up showed no evidence of recurrence and metastasis. Our pathological findings further expand the phenotypic spectrum of tumors associated with EWSR1-CREM fusions, implying the emergence of a possible novel tumor entity.

[Left Paraganglioma in the Posterior Mediastinum].

A 69-year-old man with hypertension was referred for an abnormal shadow detected on chest computed tomography(CT) at a medical checkup. Enhanced CT showed a highly enhanced posterior mediastinal tumor of 34×27 mm. Magnetic resonance imaging (MRI) revealed a low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. Thus, a neurogenic tumor was suspected and the surgery was performed. The tumor was carefully dissected as it was hyper-vascular and hemorrhagic. Immediately after tumor resection, the patient's blood pressure rapidly decreased, and phenylephrine hydrochloride was needed to maintain the blood pressure. The pathological diagnosis was paraganglioma.

The Outcomes of a Limited Resection for Non-Small Cell Lung Cancer Based on Differences in Pathology.

OBJECTIVE: A precise preoperative diagnosis of in situ or minimally invasive carcinoma may identify patients who can be treated by limited resection. Although some clinical trials of limited resection for lung cancer have started, it will take a long time before the results will be published. We have already reported a large-scale study of limited resection. We herein report the data for a subclass analysis according to differences in pathology. METHODS: Data from multiple institutions were collected on 1710 patients who had undergone limited resection (segmentectomy or wedge resection) for cT1N0M0 non-small cell carcinoma. The disease-free survival (DFS) and recurrence-free proportion (RFP) were analyzed. Small cell carcinomas and carcinoid tumors were excluded from this analysis. Adenocarcinomas were sub-classified into four groups using two factors, the ratio of consolidation to the tumor diameter (C/T) and the tumor diameter alone. RESULTS: The median patient age was 64 (20-75) years old. The mean maximal diameter of the tumors was 1.5 ± 0.5 cm. The DFS and RFP at 5 years based on the pathology were 92.2 and 94.7 % in adenocarcinoma (n = 1575), 76.3 and 82.4 % in squamous cell carcinoma (SqCC) (n = 100), and 73.6 and 75.9 % in patients with other tumors (n = 35). The prognosis of adenocarcinoma in both groups A (C/T ≤0.25 and tumor diameter ≤2.0 cm) and B (C/T ≤0.25 and tumor diameter >2.0 cm) was good. In SqCC, only segmentectomy was a favorable prognostic factor. In the groups with other pathologies, large cell carcinomas were worse in prognosis (the both DFS and RFP: 46.3 %). CONCLUSION: Knowing the pathological diagnosis is important to determine the indications for limited resection. Measurement of the tumor diameter and C/T was useful to determine the indications for limited resection for adenocarcinoma. Limited resection for adenocarcinomas is similar with a larger resection, while the technique should be performed with caution in squamous cell carcinoma and other pathologies.

Significant role of Psf3 expression in non-small-cell lung cancer.

The GINS complex associates with cell division cycle (Cdc) protein 45 and mini-chromosome maintenance (Mcm) proteins 2-7 to form the Cdc45-Mcm-GINS (CMG) complex, which is essential for DNA duplication. One member of the GINS complex is Psf3. We previously found that increased Psf3 expression was strongly associated with poor survival in lung adenocarcinoma. Here, we investigated the role of Psf3 expression in non-small-cell lung cancer (NSCLC). We verified Psf3 expression in human NSCLC tissues (180 patients) and cell lines. Immunohistochemical analysis revealed that the overexpression of Psf3 was significantly associated with vessel invasion (P = 0.016), lymphatic invasion (P = 0.002), and pleural invasion (P = 0.036). The overall survival rate in patients with Psf3 overexpression was significantly lower than that in patients without Psf3 overexpression (P = 0.006). Multivariate survival analysis revealed Psf3 expression to be an independent risk factor for an unfavorable outcome (P = 0.049). A proximal ligation assay showed interactions between Psf3 and other CMG components (such as Mcm2 and Cdc45) in both NSCLC specimens and cell lines, indicating that Psf3 acted as the CMG complex, which could lead to excessive proliferation. Knockdown of Psf3 inhibited the proliferation of both cell lines by delaying the S phase, which revealed that Psf3 played an important role in cancer proliferation. Thus, Psf3 acted as the CMG complex, promoting excessive proliferation. These results suggest that Psf3 inhibition might be a therapeutic target for NSCLC with Psf3 overexpression.

[Anesthetic management of an adult patient with tracheobronchomalacia].

General anesthesia was successfully performed in an 86-year-old woman with severe tracheobronchomalacia Tracheobronchomalacia in adult is a very rare disease, characterized by weakness of the trachea and bronchi, causing luminal narrowing during expiration. The patient had laparoscopic cholecystectomy. We used propofol, remifentanil, and rocuronium for induction of anesthesia. For maintenance of anesthesia, oxygen, air, propofol, fentanyl, and remifentanil were used. After the end of operation, we used sugammadex to reverse neuromuscular blockade by rocuronium. The patient showed spontaneous breathing and good awareness, and we extubated. The patient did well, and was discharged from the hospital 3 days after the operation. In this case, no special care such as postoperative CPAP was necessary, but normally, general anesthesia for a patient with tracheobronchomalacia requires attention. We gave general anesthesia satisfactorily in a patient with tracheobronchomalacia.

The effect of lobar shifting following right upper lobectomy on postoperative pulmonary function.

OBJECTIVES: Lobes occasionally displace after lobectomy, referred to as "lobar shifting". However, the benefits, especially in postoperative pulmonary function, remain controversial. This study aimed to measure the effect of lobar shifting on postoperative pulmonary function especially in the right upper lobe. METHODS: This retrospective study includes 273 right upper lobectomy patients (lobectomy group) and 24 right upper segmentectomy patients (segmentectomy group) from 2012 to 2021. The lobectomy group was further subdivided based on their Synapse Vincent® image: with their postoperative middle lobe bronchus shifted toward the head (shift group: 176 cases) and without (non-shift group: 97 cases). Several factors were examined to determine the cause of lobar shifting. The rate of measured actual postoperative forced expiratory volume in 1 s (FEV1.0) to predicted postoperative FEV1.0 was analyzed and compared among the three groups. RESULTS: Factors that correlated with lobar shifting included age (p < 0.001), a relatively small middle lobe volume (p = 0.03), no adhesions (p < 0.001), and good upper/middle and middle/lower lobulation (p = 0.04, p = 0.02). The rate of measured actual postoperative FEV1.0 to predicted postoperative FEV1 for the shift, non-shift, and segmentectomy groups were 112.5%, 107.9%, and 103.1% (shift vs non-shift: p = 0.04, shift vs segmentectomy: p = 0.02, non-shift vs segmentectomy: p = 0.19). CONCLUSIONS: Lobar shifting after right upper lobectomy is influenced by morphological factors and may have a beneficial impact on postoperative pulmonary function.

The role of Necl-5 in the invasive activity of lung adenocarcinoma.

Nectin-like molecule-5 (Necl-5) is an immunoglobulin-like molecule that was originally identified as a poliovirus receptor and is often upregulated in cancer cells. It has been said that Necl-5 plays a role in not only cell-cell adhesion, but also cell migration, proliferation, and metastasis. In this study, we used a bronchioloalveolar carcinoma (BAC) cell line and fibroblasts to assess the expression of Necl-5 in the development of cancer-stroma communication by using an easy-to-prepare double-layered collagen gel hemisphere (DL-CGH) system that enables visualization of cell migration during invasion. The expression of Necl-5 was higher in BAC cells than in fibroblasts. This tendency didn't change even when the BAC cells were mixed with fibroblasts. To assess the role of Necl-5 in the invasive activity of the BAC cells, we knocked down its expression using RNA interference (RNAi). The invasion assay with DL-CGH revealed that inhibition of Necl-5 expression in the BAC cells was associated with suppressed invasiveness. In addition, Necl-5 knockdown inhibited the movement and proliferation of the BAC cells. Necl-5 expression in lung cancer cells is crucial for their invasiveness in the cancer-stromal interaction, suggesting that Necl-5 could be a favorable molecular target for the suppression of invasiveness in lung adenocarcinoma.

The dynamic pulmonary functional change after thoracoscopic lower lobe segmentectomy.

BACKGROUND: The advantages of segmentectomy over lobectomy in sparing pulmonary function remain controversial. Lower lobe segmentectomy is divided into simple segmentectomy, such as segment 6; and complex segmentectomy that includes the basal segments. Here, we compared residual lung function after thoracoscopic segmentectomy versus lobectomy in the lower lobe using the three-dimensional computed tomography volumetric method. METHODS: Between January 2012 and October 2020, 67 patients who underwent thoracoscopic segmentectomy of the lower lobe were matched to 67 patients who underwent thoracoscopic lower lobectomy during the same period using propensity score matching analysis. The postoperative decrease in the rate of forced expiratory volume in 1 s was compared between methods. The regional forced expiratory volume in 1 s of the residual lobe rescued by segmentectomy was measured using volumetric and spirometric analyses and compared to lower lobectomy. The ratio of the actual to predicted postoperative forced expiratory volume in 1 s in the residual lobe was defined as the preservation rate. RESULTS: Of the 67 thoracoscopic segmentectomies, 43 were S6, seven were S8, three were S8 + 9, seven were S10, and seven were S9 + 10. The percentage of postoperative/preoperative forced expiratory volume in 1 s was significantly higher in the segmentectomy versus lobectomy group (90.7% vs. 85.7%, p = 0.001). The preservation rates after simple segmentectomy (n = 43) and complex segmentectomy (n = 24) did not differ significantly (82.2% vs. 80.2%, p = 0.709). CONCLUSIONS: Thoracoscopic lower lobe segmentectomy versus lobectomy preserves postoperative lung function. Even complex segmentectomy exhibited outcomes relevant to simple segmentectomy by sparing the residual lobe.

Uniportal left S1 + 2 segmentectomy.

The left upper lobe is one of the largest lobes of the lung; left upper segmentectomy is well established among thoracic surgeons. In uniportal left S1 + 2 segmentectomy, dissection of the vasculature, bronchus, and intersegmental plane can be performed anteriorly. Given that the fissureless technique is commonly used in uniportal video-assisted thoracoscopic surgery, S1 + 2 segmentectomy exhibits high affinity with the unidirectional approach. We have frequently performed left S1 + 2 segmentectomy for early non-small cell lung cancer located in the apical segment, since this procedure has the potential to preserve pulmonary function over tri-segmentectomy. Herein, we introduce our approach to uniportal left S1 + 2 segmentectomy as a minimally invasive alternative for preserving lung function.

Asia expert consensus on segmentectomy in non-small cell lung cancer: A modified Delphi study.

Objective: Segmentectomy as a parenchymal-sparing surgical approach has been recommended over lobectomy in select patients with early-stage non-small cell lung cancer. This study aimed to address 3 aspects of segmentectomy ("patient indication"; "segmentectomy approaches"; "lymph node assessment") where there is limited clinical guidance. Methods: A modified Delphi approach comprising 3 anonymous surveys and 2 expert discussions was used to establish consensus on the aforementioned topics among 15 thoracic surgeons (2 Steering Committee; 2 Task Force; 11 Voting Experts) from Asia who have extensive segmentectomy experience. Statements were developed by the Steering Committee and Task Force based on their clinical experience, published literature (rounds 1-3), and comments received from Voting Experts through surveys (rounds 2-3). Voting Experts indicated their agreement with each statement on a 5-point Likert scale. Consensus was defined as ≥70% of Voting Experts selecting either "Agree"/"Strongly Agree" or "Disagree"/"Strongly Disagree." Results: Consensus from the 11 Voting Experts was reached on 36 statements (11 "patient indication" statements; 19 "segmentation approaches" statements; 6 "lymph node assessment" statements). In rounds 1, 2, and 3, consensus was reached on 48%, 81%, and 100% of drafted statements, respectively. Conclusions: A recent phase 3 trial reported significantly improved 5-year overall survival rates for segmentectomy compared with lobectomy, proposing thoracic surgeons to consider segmentectomy as a surgical option in suitable patients. This consensus serves as a guidance to thoracic surgeons considering segmentectomy in patients with early non-small cell lung cancer, outlining key principles that surgeons should consider in surgical decision-making.

Avian-type receptor-binding ability can increase influenza virus pathogenicity in macaques.

The first influenza pandemic of the 21st century was caused by novel H1N1 viruses that emerged in early 2009. An Asp-to-Gly change at position 222 of the receptor-binding protein hemagglutinin (HA) correlates with more-severe infections in humans. The amino acid at position 222 of HA contributes to receptor-binding specificity with Asp (typically found in human influenza viruses) and Gly (typically found in avian and classic H1N1 swine influenza viruses), conferring binding to human- and avian-type receptors, respectively. Here, we asked whether binding to avian-type receptors enhances influenza virus pathogenicity. We tested two 2009 pandemic H1N1 viruses possessing HA-222G (isolated from severe cases) and two viruses that possessed HA-222D. In glycan arrays, viruses possessing HA-222D preferentially bound to human-type receptors, while those encoding HA-222G bound to both avian- and human-type receptors. This difference in receptor binding correlated with efficient infection of viruses possessing HA-222G, compared to those possessing HA-222D, in human lung tissue, including alveolar type II pneumocytes, which express avian-type receptors. In a nonhuman primate model, infection with one of the viruses possessing HA-222G caused lung damage more severe than did infection with a virus encoding HA-222D, although these pathological differences were not observed for the other virus pair with either HA-222G or HA-222D. These data demonstrate that the acquisition of avian-type receptor-binding specificity may result in more-efficient infection of human alveolar type II pneumocytes and thus more-severe lung damage. Collectively, these findings suggest a new mechanism by which influenza viruses may become more pathogenic in mammals, including humans.

A case of acute exacerbation of idiopathic pulmonary fibrosis after proton beam therapy for non-small cell lung cancer.

There have been no reports describing acute exacerbations of idiopathic pulmonary fibrosis after particle radiotherapy for non-small cell lung cancer. The present study describes the case of a 76-year-old Japanese man with squamous cell carcinoma of the lung that relapsed in the left upper lobe 1 year after right upper lobectomy. He had been treated with oral prednisolone 20 mg/day every 2 days for idiopathic pulmonary fibrosis, and the relapsed lung cancer was treated by proton beam therapy, which was expected to cause the least adverse effects on the idiopathic pulmonary fibrosis. Fifteen days after the initiation of proton beam therapy, the idiopathic pulmonary fibrosis exacerbated, centered on the left upper lobe, for which intensive steroid therapy was given. About 3 months later, the acute exacerbation of idiopathic pulmonary fibrosis had improved, and the relapsed lung cancer became undetectable. Clinicians should be aware that an acute exacerbation of idiopathic pulmonary fibrosis may occur even in proton beam therapy, although proton beam therapy appears to be an effective treatment option for patients with idiopathic pulmonary fibrosis.

Resected stage I anaplastic lymphoma kinase-positive lung adenocarcinoma has a negative impact on recurrence-free survival.

BACKGROUND: The clinical and prognostic implications of anaplastic lymphoma kinase (ALK) status in resected lung cancers remain unclear. In this study we analyzed the prognostic and predictive significance of ALK-positive among patients with completely resected lung adenocarcinoma. METHODS: We retrospectively reviewed 197 patients with lung adenocarcinoma who underwent complete surgical resection and had been tested for their ALK status. We investigated the impact of an ALK-positive status on the recurrence-free survival (RFS) and overall survival (OS) and examined the predictive factors for an ALK-positive status. RESULTS: ALK positivity was noted in 36 (18%) out of 197 patients, and when limited to stage I patients, in 24 (19%) out of 124. In the pathological-stage I population, while the OS exhibited no significant difference between ALK-positive and ALK-negative patients (5-year OS rate, 81.2% vs. 89.8%, p = 0.226), the RFS of ALK-positive patients was significantly worse than that of ALK-negative patients (5-year RFS rate, 55.9% vs. 78.8%, p = 0.018). A multivariate analysis showed that ALK-positive status (hazard ratio [HR] 3.431, p = 0.009) was an independent prognostic factor for the RFS. Regarding the relationship between clinicopathological factors and an ALK-positive status, a high-grade histological subtype, including solid and micropapillary subtypes (odds ratio [OR] 5.464, p < 0.001), and never-smokers (OR 4.292, p = 0.018) were associated with ALK-positive. CONCLUSION: A high-grade histological subtype and never-smokers were associated with ALK positivity, and the RFS of ALK-positive patients was worse than that of ALK-negative patients among patients with completely resected stage I lung adenocarcinoma.

Segmental volumetric analysis with a ventilated or perfused area: identifying the intersegmental plane.

OBJECTIVES: Two methods are available to identify the intersegmental plane during segmentectomy: the inflation-deflation method, based on the ventilation area, and injection of indocyanine green, based on the pulmonary arterial distribution. However, whether the intersegmental plane created by these 2 methods matches remains unknown. Our goal was to identify the demarcation lines based on bronchial and arterial territories using 3-dimensional computed tomography-based volumetry. METHODS: We collected data from patients who underwent thoracoscopic segmentectomy in our hospital between April 2012 and May 2021. Three-dimensional images were reconstructed from the preoperative contrast-enhanced computed tomography data using the SYNAPSE VINCENT software program. The volume of the affected area and the distance of the tumour from the intersegmental plane were calculated based on each affected artery and bronchus. Each calculated volume was compared to each affected segment using a paired t-test. RESULTS: Of 195 patients, 114 underwent upper lobe segmentectomy, and 81 underwent lower lobe segmentectomy. In upper lobe segmentectomy, the affected arterial segmental volume was smaller than the bronchial volume (505.0 ml vs 539.4 ml, P < 0.001). In lower lobe segmentectomy, there was no significant difference between arterial and bronchial volumes (234.6 ml vs 236.9 ml, P = 0.607). The volume of the affected arterial segmental lung and the distance of the tumour from the intersegmental plane were significantly smaller than the bronchial volume in upper lobe segmentectomies. CONCLUSIONS: As per the results, the affected segmental volume delineated by the indocyanine green method would be underestimated in upper lobe segmentectomy.

The difference in postoperative pulmonary functional change between upper and lower thoracoscopic lobectomy.

OBJECTIVES: Through 3-dimensional lung volumetric and morphological analyses, we aimed to evaluate the difference in postoperative functional changes between upper and lower thoracoscopic lobectomy. METHODS: A total of 145 lung cancer patients who underwent thoracoscopic upper lobectomy (UL) were matched with 145 patients with lung cancer who underwent thoracoscopic lower lobectomy (LL) between April 2012 and December 2018, based on their sex, age, smoking history, operation side, and pulmonary function. Spirometry and computed tomography were performed before and 6 months after the operation. In addition, the postoperative pulmonary function, volume and morphological changes between the 2 groups were compared. RESULTS: The rate of postoperative decreased and the ratio of actual to predicted postoperative forced expiratory volume in 1 s were significantly higher after LL than after UL (P < 0.001 for both). The tendency above was similar irrespective of the resected side. The postoperative actual volumes of the ipsilateral residual lobe and contralateral lung were larger than the preoperatively measured volumes in each side lobectomy. Moreover, the increased change was particularly remarkable in the middle lobe after right LL. The change in the D-value, representing the structural complexity of the lung, was better maintained in the left lung after LL than after UL (P = 0.042). CONCLUSIONS: Pulmonary function after thoracoscopic LL was superior to that after UL because the upward displacement and the pulmonary reserves of the remaining lobe appeared more robust after LL.

Segmentectomy for Inner Location Small-Sized Non-Small Cell Lung Cancer: Is It Feasible?

BACKGROUND: The efficacy of segmentectomy for inner small-sized non-small-cell lung cancer (NSCLC) remains unknown. We aimed to elucidate whether segmentectomy for inner small-sized NSCLC, defined using a novel 3-dimensional measuring method, yields feasible oncologic outcomes compared with segmentectomy for outer lesions. METHODS: We retrospectively analyzed patients with small-sized (<2 cm) cN0 NSCLC who underwent segmentectomy between January 2007 and December 2020. The tumor centrality ratio, which was measured by using 3-dimensional reconstruction software, was evaluated. The location of tumor origin was confirmed pathologically. Cases with a ratio <2:3 and >2:3 were allocated to the inner group and outer group, respectively. Oncologic outcomes were compared between the 2 groups. RESULTS: Our cohort was divided into the inner group (n = 75) and outer group (n = 127). The proximal distance from a tumor was >20 mm in all cases. The tumor centrality ratio was associated with the pathologic origin of a tumor. The rate of unforeseen positive lymph node metastasis was significantly higher in the inner group (P = .04). There were no significant differences in the 5-year recurrence-free survival (91% vs 87%, P = .67). Univariate analysis identified age, consolidation/tumor ratio, the presence of ground-glass opacity, and lymphovascular invasion, but not tumor centrality, as significant prognostic factors for recurrence-free survival. In the multivariate analysis, the presence of ground-glass opacity and lymphovascular invasion remained significant. CONCLUSIONS: Regarding oncologic outcomes, segmentectomy with a safety proximal distance could be feasible, even for inner small-sized NSCLC. Tumor invasiveness, not tumor centrality, may influence tumor recurrence.

Segmentectomy versus lobectomy for inner-located small-sized early non-small-cell lung cancer.

OBJECTIVES: Although segmentectomy is an acceptable alternative to lobectomy for peripheral small-sized non-small-cell lung cancer, the effectiveness of segmentectomy for inner lesions remains unknown. The aim of this study was to examine the feasibility of segmentectomy in comparison with lobectomy for inner lesions. METHODS: We retrospectively analysed 570 patients with small (≤2 cm) cN0 non-small-cell lung cancer who underwent segmentectomy or lobectomy between January 2007 and March 2021. We focused on patients with lesions located in the inner two-thirds, which were determined using three-dimensional computed tomography (n = 227). After propensity score matching analysis based on sex, age, pulmonary function, serum carcinoembryonic antigen level, radiographic tumour findings and tumour location, we compared the surgical and oncological outcomes in patients who underwent segmentectomy (n = 66) and lobectomy (n = 66). RESULTS: Postoperative mortality or morbidity did not differ significantly between the 2 groups. The 5-year recurrence-free and overall survival rates in the segmentectomy and lobectomy groups were 93.6% vs 84.1% and 95.8% vs 87.9%, respectively. The differences between 2 groups were not significant (P = 0.62 and P = 0.23, respectively). The 2 groups also showed no differences in loco-regional recurrence. Multivariable Cox regression analysis revealed that segmentectomy had a comparable impact on recurrence-free survival (hazard ratio, 0.61; 95% confidence interval, 0.17-2.03; P = 0.43). CONCLUSIONS: Segmentectomy for inner-located small-sized non-small-cell lung tumours could be an acceptable treatment in comparison with lobectomy.

Comparison of oncological outcomes between trisegmentectomy and lobectomy for non-small cell lung cancer in the left upper division.

Background: The left upper lobe is one of the largest lobes in the lungs and is divided into two anatomical units: the upper division (segments 1+2 and segment 3) and lingula (segments 4 and 5). This anatomical classification is similar to that used for the right upper and middle lobes. Although bilobectomy is not recommended for right upper or middle lobe tumors close to the interlobar plane, lobectomy is often performed for tumors located close to the intersegmental plane in the left upper division. To aid in establishing trisegmentectomy as a standard treatment for clinical N0 non-small cell lung cancer (NSCLC) in the left upper lobe, we aimed to re-assess its feasibility based on oncological outcomes according to tumor location. Methods: We retrospectively analyzed the data of patients with clinical N0 NSCLC in the left upper division who underwent left upper lobectomy or trisegmentectomy between April 2006 and December 2020. After propensity score matching, oncological outcomes were compared between the trisegmentectomy and lobectomy groups. To verify whether trisegmentectomy was indicated regardless of tumor distance from the intersegmental plane, we compared the recurrence-free survival (RFS) rates following trisegmentectomy between patients with tumors ≤20 and >20 mm from the intersegmental plane. Results: After propensity score matching, 46 patients were included in each group. There was no significant difference in the 5-year RFS rate between the lobectomy and trisegmentectomy groups (75.5% vs. 84.0%, P=0.41). In the trisegmentectomy cohort, the 5-year RFS rate did not significantly differ according to tumor distance from the intersegmental plane (≤20 or >20 mm) measured using three-dimensional computed tomography (79.4% vs. 81.2%, P=0.69). Multivariate analysis indicated that tumor distance from the intersegmental plane was not a significant predictor of RFS (hazard ratio: 1.75, 95% confidence interval: 0.52-5.91, P=0.37). Conclusions: Our analysis suggests that oncological outcomes (i.e., RFS rates) following trisegmentectomy for clinical N0 NSCLC in the left upper division are not significantly inferior to those following lobectomy, even if the tumor is located close to the intersegmental plane.