Novel Insights Into the International Association for the Study of Lung Cancer Grading System for Lung Adenocarcinoma.

The new grading system for lung adenocarcinoma proposed by the International Association for the Study of Lung Cancer (IASLC) defines prognostic subgroups on the basis of histologic patterns observed on surgical specimens. This study sought to provide novel insights into the IASLC grading system, with particular focus on recurrence-specific survival (RSS) and lung cancer-specific survival among patients with stage I adenocarcinoma. Under the IASLC grading system, tumors were classified as grade 1 (lepidic predominant with <20% high-grade patterns [micropapillary, solid, and complex glandular]), grade 2 (acinar or papillary predominant with <20% high-grade patterns), or grade 3 (≥20% high-grade patterns). Kaplan-Meier survival estimates, pathologic features, and genomic profiles were investigated for patients whose disease was reclassified into a higher grade under the IASLC grading system on the basis of the hypothesis that they would strongly resemble patients with predominant high-grade tumors. Overall, 423 (29%) of 1443 patients with grade 1 or 2 tumors classified based on the predominant pattern-based grading system had their tumors upgraded to grade 3 based on the IASLC grading system. The RSS curves for patients with upgraded tumors were significantly different from those for patients with grade 1 or 2 tumors (log-rank P < .001) but not from those for patients with predominant high-grade patterns (P = .3). Patients with upgraded tumors had a similar incidence of visceral pleural invasion and spread of tumor through air spaces as patients with predominant high-grade patterns. In multivariable models, the IASLC grading system remained significantly associated with RSS and lung cancer-specific survival after adjustment for aggressive pathologic features such as visceral pleural invasion and spread of tumor through air spaces. The IASLC grading system outperforms the predominant pattern-based grading system and appropriately reclassifies tumors into higher grades with worse prognosis, even after other pathologic features of aggressiveness are considered.

Sublobar resection or lobectomy and postoperative respiratory complications in emphysematous lungs.

OBJECTIVES: Pulmonary resection in patients with severe emphysema may impact postoperative respiratory complications. Low-attenuation areas evaluated using three-dimensional computed tomography to assess emphysematous changes are strongly associated with postoperative respiratory complications. Herein, we investigated the relationship between low-attenuation area, the surgical procedure and resected lung volume, which has not been explored in previous studies. METHODS: We retrospectively evaluated patients with primary or metastatic lung cancer who underwent surgical resection. The low-attenuation area percentage (low-attenuation area/total lung area × 100) and resected lung volume were calculated using three-dimensional computed tomography software, and the relationship with postoperative respiratory complications was analysed. RESULTS: Postoperative respiratory complications occurred in 66 patients (17%) in the total cohort (n = 383). We set the median value of 1.1% as the cut-off value for low-attenuation area percentage to predict postoperative respiratory complications, which occurred in 24% and 10% of patients with low-attenuation area >1.1% and <1.1%, respectively (P < 0.001). Postoperative respiratory complications occurred in approximately one-third of the patients with low-attenuation area >1.1%, whose resected lung volume was ≥15.8% or ≥5 resected subsegments. Multivariable analysis revealed that sublobar resection was associated with a significantly lower risk of postoperative respiratory complications in patients with low-attenuation area >1.1% (odds ratio 0.4, 95% confidence interval 0.183-0.875). CONCLUSIONS: Emphysema is a risk factor for postoperative respiratory complications, and lobectomy is an independent predictive risk factor. Preserving more lung parenchyma may yield better short-term prognoses in patients with emphysematous lungs.

Saving Lives in Thoracic Surgery: Balancing Oncological Radicality and Functional Preservation, Transitioning from Standard Pneumonectomy to Targeted Sublobar Resection.

This review chronicles the evolution of thoracic surgical interventions, from the standardized pneumonectomy to the precise approach of sublobar resections. It discusses the emergence and acceptance of minimally invasive and robot-assisted surgical techniques, highlighting their impact on improving outcomes beyond cancer and their influence on the surgical management of early-stage lung cancer. Evaluating historical developments alongside present methodologies, this review underscores the critical need for meticulous surgical planning and execution to optimize both oncological radicality and functional preservation. This evolution portrayed not only technical advancements but also a shift in the clinical approach towards tailored, organ-preserving methodologies, culminating in a contemporary framework promoting sublobar resections as the standard for specific patient profiles, signifying a new era of precision in thoracic surgery.

Segmentectomy-oriented anatomical model for enhanced precision surgery of the left upper lobe.

Objective: To optimize surgical outcomes and minimize complications in complex segmentectomy of the left upper lobe, we investigated the topographical anatomy of the left upper lobe and developed a segmentectomy-oriented anatomical model. Methods: A state-of-the-art 3-dimensional computed tomography workstation was used to visualize the intersegmental planes and associated veins to categorize the anatomical patterns influencing surgical procedures during left upper lobe segmentectomy. This included the central vein affecting S1+2 (apicoposterior segment) segmentectomy, the transverse S3 (anterior segment) affecting S3 segmentectomy, and other venous branching patterns in 395 patients who underwent thoracic surgery at our institution. Results: The central vein was observed in 32% of the patients, necessitating access from the interlobar area after segmental artery and bronchus division. Transverse S3 incidence was 27%, revealing that only one-third of the patients required complete left upper lobe transection between S4 and S3 during S3 segmentectomy. A significant negative correlation was observed between the presence of transverse S3 and the central vein (<10% of patients with the central vein had transverse S3 and vice versa). In 6% of patients, the lingular segmental veins partially or entirely drained into the inferior pulmonary vein, potentially causing excessive or insufficient resection during surgery. Conclusions: This study offers valuable insights into the topographic anatomy of the left upper lobe and presents a segmentectomy-oriented anatomical model for complex segmentectomies. Our approach enables a more precise and individualized surgical planning for patients undergoing segmentectomy based on their unique anatomy, which could thereby lead to improved patient outcomes.

Predicting 1-year non-cancer-related adverse events after lung resection.

OBJECTIVES: Assessing the risk for non-cancer-related outcomes following lung cancer surgery is crucial for high-risk patients. This study examined non-cancer-related adverse events within 1 year after lung resection, emphasizing the role of resected lung volume and postoperative atrial fibrillation (POAF). METHODS: We conducted a retrospective analysis of 460 patients who underwent anatomical lung resection for malignant lung tumours. We assessed perioperative factors, such as the number of resected subsegments and POAF, as potential predictors of 1-year non-cancer-related adverse events. Additionally, we validated a previously published nomogram for predicting POAF. RESULTS: One-year non-cancer-related adverse events occurred in 20% of patients. Multivariable analysis identified higher age, lower percentage-predicted forced expiratory volume in 1 second, greater number of resected subsegments and POAF as independent predictors of these adverse events. The incidence of POAF was 8.5%, with higher age, history of atrial fibrillation, and open thoracotomy as independent predictors. A temporal link between POAF and other severe postoperative complications was observed, as 71% of POAF cases preceded other complications. The nomogram's predicted risk for POAF was associated well with the actual incidence. CONCLUSIONS: Resected lung volume and POAF are statistically significant factors associated with non-cancer-related outcomes after lung resection. Minimizing resected lung volume when oncologically and technically feasible, along with identifying patients at risk for POAF, may contribute to improved postoperative outcomes. Our results have implications for risk stratification and preoperative decision-making in lung cancer surgery.

Harnessing 3D-CT Simulation and Planning for Enhanced Precision Surgery: A Review of Applications and Advancements in Lung Cancer Treatment.

The clinical application of three-dimensional computed tomography (3D-CT) technology has rapidly expanded in the last decade and has been applied to lung cancer surgery. Two consecutive reports of large-scale prospective clinical trials from Japan and the United States have brought a paradigm shift in lung cancer surgery and may have led to a rapid increase in sublobar lung resections. Sublobar resection, especially segmentectomy, requires a more precise understanding of the anatomy than lobectomy, and preoperative 3D simulation and intraoperative navigation support it. The latest 3D simulation software packages are user-friendly. Therefore, in this narrative review, we focus on recent attempts to apply 3D imaging technologies, particularly in the sublobar resection of the lung, and review respective research and outcomes. Improvements in CT accuracy and the use of 3D technology have advanced lung segmental anatomy. Clinical applications have enabled the safe execution of complex sublobar resection through a minimally invasive approach, such as video-assisted thoracoscopic surgery and robotic surgery. However, currently, many facilities still render 3D images on two-dimensional monitors for usage. In the future, it will be challenging to further spread and advance intraoperative navigation through the application of 3D output technologies such as extended reality.

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.

Personalized Medicine in Thoracic Surgery: The Role and Future of Robotic-Assisted Techniques.

The advent of robotic-assisted thoracic surgery (RATS) has revolutionized the field of thoracic surgery, offering a new paradigm for personalized, precision, and individualized medicine [...].

Successful resection after first-line lenvatinib therapy in an advanced thymic carcinoma.

Thymic carcinoma is a highly malignant tumor and treatment options are limited. Lenvatinib, a novel multitargeted kinase inhibitor, has recently been approved for the treatment of unresectable thymic carcinoma. There are no reports of complete surgical resection after the administration of first-line lenvatinib in advanced thymic carcinoma. A 50-year-old man visited our hospital because a computed tomography (CT) scan of the chest showed a large thymic squamous cell carcinoma. We suspected malignant pericardial effusion, invasion of the left upper lobe of the lung, and left mediastinal lymph node metastases. The patient was diagnosed with WHO classification stage IVb disease. Lenvatinib therapy was started at 24 mg/day as first-line therapy. Gradual dose reduction to 16 mg/day was required because of hypertension, diarrhea, and palmar-plantar erythrodysesthesia syndrome as side effects. Chest CT findings after 6 months of lenvatinib therapy showed reduction of the main tumor, disappearance of the mediastinal lymph node metastases, and pericardial effusion. Complete salvage resection was successfully performed a month after discontinuation of lenvatinib. The patient has been disease-free for 1 year without adjuvant therapy. Lenvatinib therapy is one of the promising therapeutic options for thymic carcinoma and may make salvage surgery increasingly useful for advanced thymic carcinoma.

Clinical features of recurrent spontaneous pneumomediastinum.

Background: Spontaneous pneumomediastinum recurrence is rare, and its clinical presentation is unclear. We investigated the clinical features of and predisposing factors for spontaneous pneumomediastinum recurrence. Methods: We retrospectively investigated 30 consecutive patients treated for new-onset spontaneous pneumomediastinum at Shinshu Ueda Medical Center between 2012 and 2021. We evaluated the patient background characteristics, trigger activity, radiological findings, and clinical course of spontaneous pneumomediastinum, including those of recurrent cases. Predisposing factors for spontaneous pneumomediastinum recurrence were evaluated by comparing patients with and without recurrence. Results: Most patients were male (87%). The median age of the patients was 16 years (range, 12-26 years). Among the 30 patients, five experienced at least one recurrence of spontaneous pneumomediastinum. All recurrences occurred within 1 year after new-onset spontaneous pneumomediastinum. Clinical presentations associated with spontaneous pneumomediastinum recurrence, including vital signs, laboratory data, length of hospital stay, and radiological extent of spontaneous pneumomediastinum, were similar to or less aggressive than those associated with new-onset spontaneous pneumomediastinum. Patients with recurrence were more likely to have a medical history of preexisting lung diseases, such as asthma, than those without recurrence (60% vs. 8%; P=0.022). Only one of five patients with recurrence had trigger activity at spontaneous pneumomediastinum onset (20%); however, 60% of patients without recurrence had trigger activity (P=0.15). Conclusions: Spontaneous pneumomediastinum recurrence may have a similar or less aggressive clinical presentation than new-onset spontaneous pneumomediastinum. The presence of preexisting lung diseases may increase the risk of spontaneous pneumomediastinum recurrence.

Port Placement Variations for Robotic Lung Resection: Focusing on Their History, Conventional Look-Up-View and Horizontal Open-Thoracotomy-View Techniques, and More.

This is a narrative review that summarizes the variations in approaches and port placements used for performing robotic lung resections on the da Vinci Surgical Platforms. Currently, the four-arm, look-up-view method, in which the intrathoracic cranial side is viewed from the caudal side, is considered the mainstream approach worldwide. Several variations were devised from this conventional technique, including the so-called horizontal open-thoracotomy-view techniques in which the intrathoracic craniocaudal axis is aligned with the horizontal direction of the console monitor, and fewer port and incision techniques. In September 2022, 166 reports were surveyed using a PubMed English literature search, and this review finally included 30 reports describing the approaches. We categorized the variations into four-phase groups considering advent histories: (I) early era, three-arm technique with utility incisions; (II) four-arm, total port technique without robotic staplers; (III) four-arm technique using robotic staplers; (IV) maximizing the functional features of the Xi, significant alterations in viewing directions, and reducing ports, including the ultimate uniport technique. To comprehensibly visualize these variations for practical use, we created elaborate illustrations based on the literature. The familiarity of thoracic surgeons with the variations and characteristics allows them to choose the optimal procedure that best suits each patient and their preferences.

Micropapillary and Solid Histologic Patterns in N1 and N2 Lymph Node Metastases Are Independent Factors of Poor Prognosis in Patients With Stages II to III Lung Adenocarcinoma.

INTRODUCTION: High-grade histologic patterns are associated with poor prognosis in patients with primary nonmucinous lung adenocarcinoma (ADC). We investigated whether the presence of micropapillary (MIP), solid (SOL), or both patterns in lymph node (LN) metastases has prognostic value. METHODS: Patients who underwent lobectomy for pathologic stages II to III lung ADC with N1 or N2 LN metastases (N = 360; 2000-2012) were analyzed. We assessed overall survival (OS), lung cancer-specific cumulative incidence of death (LC-CID), and cumulative incidence of recurrence (CIR) between patients with and without MIP/SOL patterns in LN metastases. Multivariable Cox regression analysis was used to quantify the association between MIP/SOL patterns and outcomes. RESULTS: MIP and SOL in LN metastases were associated with a higher incidence of smoking history (p = 0.004), tumor necrosis (p = 0.013), and spread of tumor through air spaces (p < 0.0001), a higher prevalence of MIP or SOL in the primary tumor (p < 0.0001), shorter OS (5-y OS, 40% [95% confidence interval or CI: 29%-56%] versus 63% [48%-83%] for no MIP/SOL in LNs, p = 0.03), higher LC-CID (5-y, 43% [29%-56%] versus 14% [4%-29%], p = 0.013), and higher CIR (5-y, 65% [50%-77%] versus 43% [25%-60%], p = 0.057). MIP and SOL in LN metastases were independently associated with poor outcomes: OS (hazard ratio [HR] = 1.81 [95% CI: 1.00-3.29], p = 0.05), LC-CID (HR = 3.10 [1.30-7.37], p = 0.01), and CIR (HR = 2.06 [1.09-3.90], p = 0.026). CONCLUSIONS: MIP/SOL histologic patterns in N1 or N2 LN metastases are associated with worse outcomes in patients with stages II to III lung ADC. MIP/SOL histologic patterns in LN metastases can stratify patients with high-risk stages II to III lung ADC.

Anatomical resection for right B3 downwards-shifting malformation.

The right B3 downwards-shifting malformation is rare. This malformation often leads to the following complications: abnormal pulmonary arteries that accompany the downward-displaced B3, and complete fusion of the upper and middle lobes into one lobe, with no horizonal fissure. When performing pulmonary anatomical resection in the right upper or middle lobes in patients with this malformation, careful preoperative planning and surgical technique are required, with which the surgeon should be familiar. Herein, we present the anatomical features necessary for anatomical resection of the right B3 downwards-shifting malformation based on our technical experiences with anatomic segmentectomy and lobectomy techniques.

Significance of the evaluation of tracheal length using a three-dimensional imaging workstation.

Background: Limited information is available on the total tracheal length and its other characteristics for tracheal surgery. This study aimed to investigate the reference value of tracheal length and assess its relationship with physiological variables. Methods: We measured the tracheal length of 215 patients (107 men and 108 women) who underwent contrast-enhanced computed tomography before thoracic surgery using a three-dimensional imaging workstation. Pearson correlation analysis and multiple linear regression analysis were performed to investigate the relationship between the total tracheal length (cervical and thoracic) and common physiological parameters. Results: The mean total tracheal length was 11.5±1 cm (range, 8.8-14.4 cm); 8% of the patients had a total tracheal length <10 cm. The cervical trachea was significantly shorter in men than in women (2.9±1.3 vs. 3.8±1.3 cm, P<0.001), whereas the thoracic trachea was significantly longer in men than in women (8.9±1.1 vs. 7.4±1.1 cm, P<0.001). Correlation analysis showed that the total tracheal length was positively associated with height in both sexes, while the height was positively associated with only cervical tracheal length. In the multiple linear regression analysis, the total tracheal length was influenced most by height, while cervical and thoracic tracheal lengths were influenced most by sex. Older age was also an independent contributor to a shorter cervical trachea and longer thoracic trachea in both sexes. Conclusions: The total tracheal length ranged from short to long in individuals, and characteristics of tracheal length varied with height, age, sex, and part of the trachea. We should thus be aware of the tracheal length of each patient for appropriate tracheal management.

Is using a consolidation tumor ratio 0.5 as criterion feasible in daily practice? Evaluation of interobserver measurement variability of consolidation tumor ratio of lung cancer less than 3 cm in size.

BACKGROUND: Consolidation tumor ratio (CTR) calculated as the ratio of the tumor consolidation diameter to the tumor maximum diameter on thin-section computed tomography (CT) of lung cancer has been reported as an important prognostic factor. It has also been used for treatment decision-making. This study aimed to investigate the interobserver variability of CTR measurements on preoperative CT and propose a clinically useful CTR-based classification criterion. METHODS: We enrolled 119 patients who underwent surgery for suspected or diagnosed small-sized lung cancer (≤3.0 cm in diameter). Nine doctors reviewed preoperative CT scans to measure CTR. Interobserver variability of CTR measurements was evaluated using the coefficient of variation (CV) and Fleiss' κ. The prognostic effect of the CTR-based classification was assessed using the Kaplan-Meier method. RESULTS: Interobserver variability of CTR measurement was the highest for tumors with the lowest CTR (CTR = 0); it decreased as CTR increased and reached a plateaued level of low variability (CV <0.5) at CTR of 0.5. We proposed a three-group classification based on the findings of CTR interobserver variability (CTR < 0.5, 0.5 ≤ CTR < 1, and CTR = 1). Interobserver agreement of the judgment of the CTR-based classification was excellent (Fleiss' κ = 0.81). The classification significantly stratified patient prognosis (p < 0.001, 5-year overall survival rates with CTR < 0.5, 0.5 ≤ CTR < 1, and CTR = 1 were 100, 88, and 73.8%, respectively). CONCLUSIONS: CTR 0.5 is a clinically relevant and helpful cutoff for treatment decision-making in patients with early-stage lung cancer based on high interobserver agreement and good prognostic stratification.

Adoption of Robotic Core Technology in Minimally Invasive Lung Segmentectomy: Review.

A recent randomized trial demonstrated the survival superiority of lung segmentectomy over lobectomy in patients with early stage, small-sized lung cancer. Hence, there is a pressing need for thoracic surgeons to gain familiarity with lung segmentectomy. However, lung segmentectomy, especially via minimally invasive surgery, is a technically challenging thoracic surgical procedure. The robotic surgery platform helps surgeons to improve their operative performance based on its core technological features: improved dexterity, precision, and visualization. Herein, we have discussed the key issues related to robotic lung segmentectomy, explicitly focusing on the technical features of complex segmentectomy under difficult conditions. We have also introduced our preferred surgical strategy for robotic lung segmentectomy with specific maneuvers.

Three-step strategy for robotic lung segmentectomy.

Lung segmentectomy is a technically challenging procedure when deep hilar dissection and multiple intersegmental plane divisions are required. We demonstrate a 3-step strategy for robotic lung segmentectomy to overcome these challenges.

Epidemiological analysis of lung and mediastinal neuroendocrine neoplasms in Japan based on the national database.

BACKGROUND: Neuroendocrine neoplasms (NENs) are rare and can originate from any body part. However, there are only few epidemiological studies, especially on lung and mediastinal NENs. This study investigated the epidemiological trends and differences between lung and mediastinal NENs in Japan. METHODS: Patients with lung and mediastinal NENs were identified in a national hospital-based cancer registry between 2009 and 2015 in Japan. NENs were subclassified into neuroendocrine tumors (NETs) and neuroendocrine carcinomas (NECs). NECs were further subdivided into large neuroendocrine carcinomas (LCNECs) and small cell carcinomas (SCCs). We examined the patient characteristics: sex, age, histology, year of diagnosis, diagnostic opportunity, and initial treatment. RESULTS: We identified 48,433 patients with 47,888 lung (98.9%) and 545 mediastinal (1.1%) NENs. The commonest subtype of lung NENs was SCCs (87%), followed by LCNECs (10%) and NETs (3%). In the mediastinum, SCCs were also the commonest (48%), followed by NETs (38%) and LCNECs (14%). The number of lung NEN annually increased; however, that of mediastinal NENs did not change over time. The mean age of patients with lung NETs was lower than that of patients with lung LCNECs and SCCs (NETs, 62 ± 14 years; LCNECs, 70 ± 9 years; SCCs, 71 ± 9 years; p < .001). The lung and mediastinal NENs were mainly detected based on symptoms, except for lung NETs. Surgical intervention, including multimodal therapy, was performed for 89.3% of lung NETs (surgery alone: 83.6%), while only 15.6% of lung NECs were treated with surgery. For the mediastinum, 75.9% of NETs were treated with surgery, with 27.1% of cases treated with surgery plus multimodal therapy. Surgery was performed more frequently for mediastinal NECs (37%) than for lung NECs (15.6%). CONCLUSIONS: This study highlights differences in trends of lung and mediastinal NENs. This study's findings support the importance of epidemiological evaluations based on the primary sites and histological subtypes.