The Role of Emphysema on Postoperative Prognosis in Early-Stage Nonsmall Cell Lung Cancer.

BACKGROUND: Emphysema is generally considered a poor prognostic factor for patients with nonsmall cell lung cancer; however, whether the poor prognosis is due to highly malignant tumors or emphysema itself remains unclear. This study was designed to determine the prognostic value of emphysema in patients with early-stage nonsmall cell lung cancer. METHODS: A total of 721 patients with clinical stage IA nonsmall cell lung cancer who underwent complete resection between April 2007 and December 2018 were retrospectively analyzed regarding clinicopathological findings and prognosis related to emphysema. RESULTS: The emphysematous and normal lung groups comprised 197 and 524 patients, respectively. Compared with the normal lung group, lymphatic invasion (23.9% vs. 14.1%, P = 0.003), vascular invasion (37.6% vs. 17.2%, P < 0.001), and pleural invasion (18.8% vs. 10.9%, P = 0.006) were observed more frequently in the emphysema group. Additionally, the 5-year overall survival rate was lower (77.1% vs. 91.4%, P < 0.001), and the cumulative incidence of other causes of death was higher in the emphysema group (14.0% vs. 3.50%, P < 0.001). Multivariable Cox regression analysis of overall survival revealed that emphysema (vs. normal lung, hazard ratio 2.02, P = 0.0052), age > 70 years (vs. < 70 years, hazard ratio 4.03, P < 0.001), and SUVmax > 1.8 (vs. ≤ 1.8, hazard ratio 2.20, P = 0.0043) were independent prognostic factors. CONCLUSIONS: Early-stage nonsmall cell lung cancer with emphysema has a tendency for the development of highly malignant tumors. Additionally, emphysema itself may have an impact on poor prognosis.

Risk factors for long-term decline in post-operative pulmonary function after lung resection.

OBJECTIVES: The study aimed to examine the risk factors for long-term decline in pulmonary function after anatomical resection for lung cancer and the effects of the decrease on survival. METHODS: We retrospectively examined 489 patients who underwent anatomical resection for lung cancer between 2010 and 2020. Pulmonary function tests were performed preoperatively and at 1, 3, 6 and 12 months after surgery. The lower interquartile medians of the reduction rates of forced expiratory volume in 1 s and vital capacity at 12 months after surgery were taken as the cut-off values of risk factors for the decrease in post-operative pulmonary function. RESULTS: Forced expiratory volume in 1 s and vital capacity decreased the most in the first month after surgery and then gradually recovered. Vital capacity continued to increase even after 6 months post-surgery, whereas forced expiratory volume in 1 s stabilized. Multivariable logistic analysis showed that the number of resected segments (odds ratio, 2.09; 95% confidence interval, 1.12-3.89; P = 0.019) was a risk factor for the decrease in forced expiratory volume in 1 s at 12 months, and the numbers of resected segments (odds ratio, 1.36; 95% confidence interval, 1.13-1.63; P < 0.001) and post-operative complications (odds ratio, 2.32; 95% confidence interval, 1.01-5.35; P = 0.047) were independent risk factors for decrease in vital capacity. Multivariate cox regression analysis showed that the decrease in vital capacity at 12 months was significantly associated with overall survival (hazard ratio, 2.02; 95% confidence interval, 1.24-3.67; P = 0.004). CONCLUSIONS: Long-term decrease in vital capacity, which was influenced by the number of resected segments and post-operative complications, adversely affected survival.

Classification based on skeletal muscle mass and the severity of lung emphysema impacts on clinical outcomes after anatomical resection for lung cancer.

OBJECTIVES: Both sarcopenia and lung emphysema are prognostic factors in lung cancer and can be easily assessed using the psoas muscle index and Goddard score, respectively. We investigated the clinical significance of the classification based on psoas muscle index and Goddard score in non-small cell lung cancer. METHODS: A total of 303 consecutive patients who underwent anatomical resection for non-small cell lung cancer were retrospectively analyzed. The psoas muscle at the level of the third lumbar vertebrae and Goddard score were measured on preoperative computed tomography. The psoas muscle was adjusted by height as the psoas muscle index (cm2/m2). We divided patients into three groups: low-, middle- and high-risk, using cut-off values of psoas muscle index < 6.36 cm2/m2 for males and 3.92 cm2/m2 for females and Goddard score higher than 7. The predictors of postoperative complications and prognosis were examined. RESULTS: High-, middle- and low-risk were present in 30 (10%), 164 (54%) and 109 (36%) patients, respectively. High risk was significantly associated with male sex, low pulmonary function, more comorbidities and increased postoperative complications. High-risk patients showed poorer overall survival than middle- and low-risk patients (P < 0.001). Multivariable analysis revealed that high risk was an independent risk factor for postoperative complications and unfavorable prognostic factors (P = 0.011, P = 0.014, respectively). CONCLUSIONS: Classification based on psoas muscle index and Goddard score is significantly associated with short- and long-term outcomes in patients with lung cancer. This method can be easily assessed for patients and may help select patients for nutritional support and rehabilitation before surgery.

Segmentectomy Versus Lobectomy for Radiologically Pure Solid Clinical T1a-bN0M0 Lung Cancer.

BACKGROUND: Segmentectomy for radiologically pure solid tumors is still controversial because these tumors are more aggressive in malignancy than those with ground-glass opacity. This study aimed to determine the feasibility of intentional segmentectomy for pure solid small-sized lung cancer. METHODS: We retrospectively analyzed 96 radiologically pure solid tumors in clinical T1a-bN0M0 lung cancer. Patients whose tumor was located at a central region or right middle lobe were excluded. Forty-four patients who underwent lobectomy were compared with 52 those who underwent segmentectomy. Segmentectomy got converted to lobectomy if lymph node metastases or inadequate surgical margin was confirmed. Factors affecting survival were assessed using Cox regression. Propensity score stratification analysis was also performed. RESULTS: Eight patients (8%) were identified as a histological type other than adenocarcinoma or squamous cell carcinoma. Moreover, 14 patients (14%) displayed lymph node metastasis. Among those who underwent segmentectomy, nine patients (16%) were converted to lobectomy due to lymph node metastasis or inadequate surgical margin. The 3-year recurrence-free survival rates were 84.1 and 82.2% in patients who underwent segmentectomy and lobectomy, respectively (P = 0.745). In addition, the recurrence-free survival was not statistically significant between segmentectomy and lobectomy, as determined via multivariable Cox regression analysis (hazard ratio 1.11; 95% confidence interval 0.40-3.06), even after propensity score stratification (hazard ratio 1.17; 95% confidence interval 0.38-3.65). CONCLUSIONS: Segmentectomy with intraoperative assessment of lymph node metastasis and adequate surgical margin may be a feasible surgical procedure for pure solid tumors in clinical T1a-bN0M0 lung cancer.

Is cancer history really an exclusion criterion for clinical trial of lung cancer? Influence of gastrointestinal tract cancer history on the outcomes of lung cancer surgery.

Objective: Exclusion of patients with a history of other cancer treatment except in situ situation has been considered to be inevitable for clinical trials investigating survival outcome. However, there have been few reports confirming these influences on surgical outcome of lung cancer patients ever. Methods: Multi-institutional, individual data from patients with non­small cell lung cancer resected between 2000 and 2013 were collected. The patients were divided into two groups: those with a history of gastrointestinal tract cancer (GI group) and those without any history (non-GI group). We compared the outcomes with well-matched groups using propensity scoring to minimize bias related to the nonrandomness. The influence of gastrointestinal tract cancer stage, disease-free interval, and treatment method for gastrointestinal tract cancer on the surgical outcome of non­small cell lung cancer was examined. Results: We analyzed 196 patients in the GI group and 3732 in the non-GI group. In unmatched cohort, multivariate analyses showed that a history of gastrointestinal tract cancer did not affect overall survival or recurrence-free survival. Independent predictors of poor prognosis included older age, male sex, high carcinoembryonic antigen levels and advanced clinical stage of non­small cell lung cancer. The two groups in the matched cohort demonstrated equivalent overall survival and recurrence-free survival, even in patients with clinical stage I. Gastrointestinal tract cancer stage, disease-free interval and treatment method for gastrointestinal tract cancer were not associated with outcomes. Conclusions: History of early gastrointestinal tract cancer completely resected is not always necessary for exclusion criteria in clinical trial of lung cancer.

[Abdominoperineal Resection for Anal Metastasis of Rectal Cancer].

Anal metastasis of colorectal cancer is rare, and no standardized effective therapeutic strategy exists. We report a case of abdominoperineal resection for anal metastasis of rectal cancer. A 65-year-old man underwent laparoscopic low anterior resection for rectal cancer in August 2013. Histopathological examination revealed a moderately differentiated adenocarcinoma( tub2, pSS, ly3, v2, pN1, H0, P0, M0, Stage III a, Cur A). In February 2015, he complained of anal discomfort, and tumor markers were elevated. Enhanced CT revealed a 15-mm high-density solid tumor in the anal canal. The results of needle biopsy indicated a moderately differentiated adenocarcinoma. This tumor was suspected to be metastasis from rectal cancer, and we performed abdominoperineal resection. Histopathological examination revealed a moderately differentiated adenocarcinoma, which was the same histological type as the primary rectal cancer and was covered with normal anal epithelium. Collectively, the findings indicated anal metastasis from rectal cancer. The patient is alive without recurrence for 18 months after resection. Anal metastasis should be considered as a differential diagnosis in patients with anal discomfort who have a history of colon/rectal cancer. Abdominoperineal resection may be an effective treatment modality for this condition.

Prognostic significance of vascular invasion in intermediate-grade subtype of lung adenocarcinoma.

OBJECTIVES: Although the recent reclassification of histological subtypes of lung adenocarcinoma reflects disease prognosis better, the prognosis of papillary and acinar-predominant adenocarcinoma, which are highly prevalent, is heterogeneity. The present study aimed to identify the prognostic indicators for papillary and acinar-predominant adenocarcinoma. METHODS: This retrospective study included 315 consecutive patients with completely resected pathological N0 lung adenocarcinoma tumors ≤3 cm from two institutions. Tumors were classified according to histologically predominant subtypes as low-grade (adenocarcinoma in situ, minimally invasive adenocarcinoma or lepidic predominant), intermediate-grade (papillary or acinar predominant) or high-grade (solid or micropapillary predominant). Prognostic factors in intermediate-grade group were assessed among clinicopathological factors of age, gender, surgical procedure, tumor size, pleural, lymphatic and vascular invasion using Cox proportion hazards analyses. RESULTS: There were 174 patients in the low-grade group, 109 in the intermediate-grade group and 32 in the high-grade group. The 3-year recurrence-free survival rates were 98.1%, 86.3% and 74.8% for these groups, respectively (P < 0.001). In the intermediate-grade group, the presence of vascular invasion was an independent prognostic factor on multivariate Cox regression analysis of recurrence-free survival (hazard ratio, 3.48; 95% confidence interval, 1.26-9.57, P = 0.01). Classification of intermediate-grade group based on vascular invasion revealed a clear division into favorable and unfavorable prognostic subgroups. CONCLUSIONS: Consideration of the vascular invasion status in addition to the predominant subtype could provide a more accurate assessment of malignant aggressiveness and prognosis of patients with early-stage lung adenocarcinoma.

[Anomalous Systemic Arterialization of a Normal Basal Lung Segment with Aneurysm of the Aberrant Artery].

A 40-year-old woman was noted to have clubbing of the nails during an outpatient service for smoking cessation. Chest computed tomography showed an aneurysm of an aberrant artery running from the descending aorta to the left lower lobe. Hence, we diagnosed anomalous systemic arterialization of the lung. The proximal part of the aberrant artery measured 13 mm in diameter;moreover, it had developed an aneurysm(17 mm in diameter) in the lung parenchyma. The aberrant artery was ligated with a covering material (absorbable felt) and cut via a small access thoracotomy by a cardiovascular surgeon;subsequently, left lower lobectomy was performed. Pathological examination revealed significant atherosclerosis in the aberrant artery, demonstrating its severe fragility. To apply appropriate safety procedures and approaches are recommended when treating an aberrant artery to the lung, especially in the presence of an aneurysm.

[Tracheal Resection and Primary Anastomosis for Adenoid Cystic Carcinoma Using an Extracorporeal Membrane Oxygenation].

We report a case of tracheal resection and primary anastomosis for adenoid cystic carcinoma using an extracorporeal membrane oxygenation (ECMO). A 45-year-old female was referred to our hospital because of a tracheal tumor that occupied most of the tracheal lumen. In case of airway obstruction by the tracheal tumor during anesthesia and operation, we decided to use ECMO before induction of general anesthesia. Under secure respiratory control using ECMO, tracheal resection and primary anastomosis was performed. Since histopathological examination revealed microscopically positive results at the surgical margin, postoperative adjuvant radiation therapy( 60 Gy/30 Fr) was conducted. Although a tracheal tumor is a relatively rare neoplasm, careful planning and a treatment strategy are necessary with special emphasis on the location and size of tumor. In this case, ECMO made a substantial contribution to secure respiratory control during surgery.

Comparison of Postoperative Pain after Different Thoracic Surgery Approaches as Measured by Electrical Stimulation.

BACKGROUND: Postoperative pain is commonly evaluated using the numerous rating scale (NRS), visual analogue scale, or pain scale; however, these assessments are easily affected by various subjective factors. We measured the degree of postoperative chest pain among different thoracic surgery approaches using NRS and electrical stimulation measurements. METHODS: Seventy patients who underwent lobectomy or segmentectomy were enrolled. Concomitant with NRS, pain scores were quantitatively measured on postoperative day 2 using an electrical neurostimulator to compare the degree of pain among three different surgical approaches: pure video-assisted thoracic surgery (VATS), hybrid VATS, and conventional thoracotomy. The risk factors associated with postoperative pain were also analyzed. RESULTS: Thirty patients underwent lung resection with pure VATS, while 30 had hybrid VATS, and 10 had conventional thoracotomy. Among the three surgical approaches, analyzing the pain score indicated statistically significant differences (pure, 159.50 ± 26.22; hybrid, 269.36 ± 30.49; thoracotomy, 589.40 ± 141.11; p = 0.003); however, NRS did not obtain a statistically significant difference between the three approaches (pure, 4.26 ± 0.27; hybrid, 4.96 ± 0.30; thoracotomy, 5.50 ± 0.68; p = 0.105). A multivariate analysis showed that the surgical approach was an independent risk factor for postoperative pain as determined by the pain score (pure vs. hybrid, p = 0.076; pure vs. thoracotomy, p < 0.001). CONCLUSION: For lung surgery, the differences in surgical approach were an independent risk factor for postoperative pain. In the early postoperative period, pure VATS was shown to be the least painful of the three surgical approaches.

[Assessment of Feasibility of Early Ambulation and Food-intake on the Operative Day after Lung Resection].

To decrease the risk of morbidity, we have started an early ambulation and food-intake program conducted on the same day as pulmonary resection. This protocol was developed with consideration of the characteristics of lung surgery and conducted through an interdisciplinary team-approach. The assessment of feasibility and clinical effectiveness of this protocol was evaluated in 64 consecutive patients. No apparent adverse effect relating to this protocol was recorded. Fifty-five of 64 patients( 80%) were able to accomplish ambulation to the up-right standing position. Thirty-four of 64 patients( 53%) were able to consume more than half the amount of their hospital supper. No patients, including 5 patients who had had a past-history of postoperative delirium after their previous surgery, developed postoperative delirium after conducting this protocol. This protocol, which consisted of extraordinary early ambulation and food-intake on the operative day, was done safely and is expected to have some benefit as a postoperative management protocol for lung surgery.

Tumor distance from the mediastinum predicts N2 upstaging in clinical stage I lower-lobe non-small cell lung cancer.

OBJECTIVE: Pulmonary lymphatic drainage of the lower lobe into the mediastinal lymph nodes includes not only the pathway via the hilar lymph nodes but also the pathway directly into the mediastinum via the pulmonary ligament. This study aimed to determine the association between the distance from the mediastinum to the tumor and the frequency of occult mediastinal nodal metastasis (OMNM) in patients with clinical stage I lower-lobe non-small cell lung cancer (NSCLC). METHODS: Between April 2007 and March 2022, data of patients who underwent anatomical pulmonary resection and mediastinal lymph node dissection for clinical stage I radiological pure-solid lower-lobe NSCLC were retrospectively reviewed. In computed tomography axial sections, the ratio of the distance from the inner edge of the lung to the inner margin of the tumor within the lung width of the affected lung was defined as the inner margin ratio. Patients were divided into 2 groups based on whether the inner margin ratio was ≤0.50 (inner-type) or >0.50 (outer-type), and the association between inner margin ratio status and clinicopathological findings was assessed. RESULTS: In total, 200 patients were enrolled in the study. OMNM frequency was 8.5%. More inner-type than outer-type patients had OMNM (13.2% vs 3.2%; P = .012) and skip N2 metastasis (7.5% vs 1.1%; P = .038). Multivariable analysis revealed that the inner margin ratio was the only independent preoperative predictor of OMNM (odds ratio, 4.72; 95% CI, 1.31-17.07; P = .018). CONCLUSIONS: Tumor distance from the mediastinum was the most important preoperative predictor of OMNM in patients with lower-lobe NSCLC.

Omitting Lymph Node Dissection for Small Ground-Glass Opacity-Dominant Tumors.

BACKGROUND: The purpose of this study was to determine the optimal extent of lymph node dissection required in patients with small (≤3 cm) radiologically ground-glass opacity-dominant, peripheral, non-small cell lung cancer tumors. METHODS: The study analyzed the clinicopathologic findings and surgical outcomes of 988 patients with radiologic, ground-glass opacity-dominant non-small cell lung cancer without lymph node involvement who underwent complete resection of the primary tumor between 2010 and 2020. Patients were followed up for 54.5 months (median). Kaplan-Meier curves and the log-rank test were used in statistical analyses of the prognosis. RESULTS: Median age, whole tumor size, solid tumor size, and maximum standardized uptake values were 68 years, 1.7 cm, 0.4 cm, and 0.9, respectively. Sixty percent of the cohort was female (n = 590). Wedge resection, segmentectomy, and lobectomy were performed in 206, 372, and 410 patients, respectively. A total of 982 of 988 (99%) tumors were adenocarcinomas. One patient had hilar lymph node involvement; however, no mediastinal lymph node metastasis or hilar or mediastinal lymph node recurrence was detected. The 5-year overall survival rate was 96.5% (95% CI, 94.8%-97.7%). Excellent survival outcomes were achieved regardless of procedure (wedge resection, 94.7% [95% CI, 89.1%-97.5%]; segmentectomy, 96.9% [95% CI, 93.7%-98.5%]; and lobectomy, 97.1% [95% CI, 94.4%-98.5%]). CONCLUSIONS: Omitting lymph node dissection may be acceptable with curative intent for small tumors with radiologic ground-glass opacity dominance. Appropriate surgical procedures such as wedge resection, segmentectomy, or lobectomy can provide satisfactory outcomes in patients with indolent tumors if surgical margins are secured.

Sublobar Resection in Early Non-Small Cell Lung Cancer With Epidermal Growth Factor Receptor Mutant.

BACKGROUND: Lobectomy is a standard surgical procedure for peripherally located early-stage non-small cell lung cancers (NSCLCs) measuring 2 to 4 cm. However, it is unclear whether sublobar resections, such as wedge resection and segmentectomy, are effective in treating tumors with driver mutations in the epidermal growth factor receptor (EGFR). METHODS: We analyzed the clinicopathologic findings and surgical outcomes of 1395 patients with radiologically solid-dominant NSCLC measuring 2 to 4 cm, without clinical lymph node involvement, who underwent complete resection between 2010 and 2020. The patients, who underwent sublobar resections (n = 231) or lobectomy (n = 1164), were categorized by their EGFR mutation status and the surgical procedures performed. The follow-up was conducted for a median of 45.3 months. RESULTS: The 5-year overall survival (OS) rates after sublobar resections (n = 39) were comparable to those after lobectomy (n = 359) in patients with EGFR mutation-positive tumors (80.5% [95% CI, 51.3%-93.2%] vs 88.8% [95% CI, 84.1%-92.1%], respectively; P = .16). Multivariable Cox regression analysis of OS revealed that the surgical procedure was an independent prognostic predictor in the entire cohort (hazard ratio, 0.6; 95% CI, 0.4-1.0; P = .028), but it was not an independent prognostic predictor in patients with EGFR-mutated tumors (hazard ratio, 0.6; 95% CI, 0.2-1.7; P = .32). CONCLUSIONS: Sublobar resection with a secure surgical margin could be a viable option for appropriately selected patients with peripheral early-stage NSCLC tumors measuring 2 to 4 cm and harboring EGFR mutations, because it provides comparable OS to that of lobectomy.

Postoperative pulmonary function of patients with lung cancer and interstitial lung abnormalities.

OBJECTIVE: We investigated the impact of radiological interstitial lung abnormalities on the postoperative pulmonary functions of patients with non-small cell lung cancer. METHODS: A total of 1191 patients with clinical stage IA non-small cell lung cancer who underwent lung resections and pulmonary function tests ≥ 6 months postoperatively were retrospectively reviewed. Postoperative pulmonary function reduction rates were compared between patients with and without interstitial lung abnormalities and according to the radiological interstitial lung abnormality classifications. Surgical procedures were divided into wedge resection, 1-2 segment resection, and 3-5 segment resection groups. RESULTS: No significant differences in postoperative pulmonary function reduction rates 6 months after wedge resection were observed between the interstitial lung abnormality [n = 202] and non-interstitial lung abnormality groups [n = 989] [vital capacity [VC]: 6.82% vs. 5.00%; forced expiratory volume in 1 s [FEV1]: 7.05% vs. 7.14%]. After anatomical resection, these values were significantly lower in the interstitial lung abnormality group than in the non-interstitial lung abnormality group [VC: 1-2 segments, 12.50% vs. 9.93%; 3-5 segments, 17.42% vs. 14.23%; FEV1: 1-2 segments: 13.36% vs. 10.27%; 3-5 segments: 17.36% vs. 14.39%]. No significant differences in postoperative pulmonary function reduction rates according to the radiological interstitial lung abnormality classifications were observed. CONCLUSIONS: The presence of interstitial lung abnormalities had a minimal effect on postoperative pulmonary functions after wedge resections; however, pulmonary functions significantly worsened after segmentectomy or lobectomy, regardless of the radiological interstitial lung abnormality classification in early-stage non-small cell lung cancer.

Clinical Significance of Preserving Pulmonary Function After Lung Resection in Early-Stage Non-Small-Cell Lung Cancer.

INTRODUCTION: To determine the association between changes in pulmonary function before and after surgery, and the subsequent prognosis, of patients with early-stage non-small-cell lung cancer (NSCLC). METHODS: A total of 485 patients who underwent lobectomy or segmentectomy for NSCLC with whole tumor size ≤2 cm and clinical stage IA at 2 institutions were retrospectively reviewed. The relationship between the postoperative reduction rate in vital capacity (VC), forced vital capacity (FVC), and forced expiratory volume in 1 second (FEV1) and overall survival (OS) was investigated. OS determined the cut-off value of the reduction rate, according to the reduction rate of every 10% in pulmonary function. RESULTS: Multivariable Cox regression analysis showed that a reduction rate in VC at 12 months postoperatively was an independent prognostic factor for OS (hazard ratio, 1.05; 95% confidence interval [CI], 1.02-1.07; P < .001) but those in FVC and FEV1 were not. OS was classified into good and poor with 20% reduction rate in VC. OS and recurrence-free survival (RFS) in a higher than 20% reduction rate in VC were worse than those in ≤20% reduction rate in VC (5 year-OS; 82.0% vs. 93.4%; P = .0004. Five year-RFS; 80.3% vs. 89.8%; P = .0018, respectively). Multivariable logistic analysis showed that lobectomy was a risk factor for the higher than 20% reduction rate in VC (odds ratio, 1.61; 95% CI, 1.01-2.56; P = .045). CONCLUSIONS: Postoperative decrease in VC was significantly associated with the prognosis. Preserving pulmonary function is important for survival of patients with early-stage NSCLC.

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.

Effectiveness of pleurodesis for postoperative air leaks after lung resection.

BACKGROUND: Pleurodesis is often performed for air leaks; however, the ideal materials and timing of the procedure remain controversial. We investigated the efficacy of pleurodesis using different materials and timing. METHODS: We retrospectively reviewed 913 consecutive patients who underwent segmentectomy or lobectomy for non-small cell lung cancer between 2014 and 2021. Pleurodesis efficacy was assessed on the day of chest tube removal. RESULTS: Eighty-six patients (9%) underwent pleurodesis for postoperative air leaks. Pleurodesis was performed on a median of postoperative day (POD) 5. Talc was the most frequently used material (n = 52, 60%), followed by autologous blood patches (n = 20, 23%), OK-432 (n = 12, 14%), and others (n = 2, 2%). No difference existed in the number of days from initial pleurodesis to chest tube removal among the three groups (talc, 3 days; autologous blood patch, 3 days; OK-432, 2 days; P = 0.55). No difference in patient background, except for sex, was observed between patients who underwent pleurodesis within 4 PODs and those who underwent pleurodesis on POD 5 or later. Drainage time was significantly shorter in patients who underwent pleurodesis within 4 PODs (median, 7 vs. 9 days; P = 0.004). CONCLUSIONS: The efficacies of autologous blood patch, talc, and OK-432 would be considered comparable and early postoperative pleurodesis could shorten drainage time. Prospective studies are required.

Feasibility and Comparative Prognosis of Segmentectomy vs. Lobectomy in Centrally Located Small and Solid Dominant cN0 Non-Small Cell Lung Cancer.

OBJECTIVES: This study aimed to determine the feasibility of segmentectomy in patients with central, whole tumor size ≤2 cm and radiologically solid-dominant cN0 non-small cell lung cancer (NSCLC). METHODS: We retrospectively reviewed 1240 patients who underwent lobectomy or segmentectomy for small and radiologically solid-dominant cN0 NSCLC between January 2010 and December 2022. The inclusion criteria encompassed centrally located tumors defined as tumors located in the inner two-thirds of the pulmonary parenchyma. Propensity score matching was applied to balance the baseline characteristics. RESULTS: Among the 299 eligible patients, no significant differences in recurrence-free survival (RFS) and overall survival (OS) were observed between the segmentectomy (n = 121) and lobectomy (n = 178) groups (P = .794 and .577, respectively). After propensity score matching, no significant differences in hilar and mediastinal lymph node upstaging were found among the 93 matched patients (P = 1.00) and locoregional recurrence was comparable between those who underwent segmentectomy (n = 4) and lobectomy (n = 4). RFS and OS did not significantly differ between the two groups (P = .700 and .870, respectively). Propensity score-adjusted multivariable Cox analysis for RFS and OS indicated that segmentectomy was not an independent prognostic factor (RFS: hazard ratio, 0.89; 95% confidence interval, 0.43-1.85; P = .755; OS: hazard ratio, 1.09; 95% confidence interval, 0.38-3.14; P = .860). CONCLUSIONS: Segmentectomy may be a viable treatment option with local control and prognosis comparable to that of lobectomy in appropriately selected patients with central, small (≤2 cm), and radiologically solid-dominant NSCLC.

Application of microwave surgical instrument to lung segmentectomy for small-sized lung cancer.

Objectives: For lung segmentectomy of small lung cancers, we used a microwave surgical instrument for lung parenchymal dissection mainly at the pulmonary hilum, which is difficult to handle with surgical staplers. This technique facilitated the insertion of staples. Methods: In total, 116 patients with cStage 0-1A3 non-small cell lung cancer who underwent lung segmentectomy were included in this study. We compared the perioperative factors of the group in which a microwave surgical instrument was used for dissection procedures, including lung parenchymal dissection at the pulmonary hilum, and peripheral intersegmental dissection was performed with surgical staplers (group M+S: N = 69), with those of the group in which parenchymal dissection was performed mainly with surgical staplers without using the microwave surgical instrument (group S: N = 47). Results: Although more complex segmentectomies were performed in the M+S group (P = .001), the number of staple cartridges (7 staple cartridges vs 8 staple cartridges, P = .005), the surgical times (179 vs 221 minutes, P < .0001), and the blood loss (5 mL vs 30 mL, P = .012) were significantly lower in the M+S group. The duration of chest tube placement was significantly shorter in the M+S group (P = .019), and postoperative complications of grade 2 or greater were significantly lower in the M+S group (P = .049). Conclusions: The effective use of the microwave surgical instrument combined with surgical staplers can simplify pulmonary hilar and intersegmental plane dissections not only for simple segmentectomy but also for complex segmentectomy, leading to favorable intraoperative and postoperative outcomes.