Right Lower Sleeve Lobectomy: Detailed Technique and Perioperative Patient Management.

PURPOSE: This report reviews our experience with right lower sleeve lobectomy and describes our technique and approach to perioperative patient management. METHODS: We retrospectively reviewed 11 patients who underwent right lower sleeve lobectomy for lung cancer. Surgical techniques and perioperative management were also investigated. RESULTS: Bronchoplasty was performed using 4-0 absorbable monofilament sutures. The deepest portion was anastomosed using continuous sutures; interrupted sutures were used for the more superficial portions. The truncus intermedius and right middle lobe bronchus should be anastomosed in a natural position. Anastomosis patency was confirmed using intraoperative bronchoscopy. Separation of the right upper and middle lobes and pericardiotomy at the inferior edge of the superior pulmonary vein are useful for mobilizing the right middle lobe. Death during hospitalization and treatment-related death did not occur. One patient developed pneumonia, and another developed a bronchopleural fistula. CONCLUSION: We reported our technique of right lower sleeve lobectomy and our approach to perioperative patient management. Sharing knowledge is essential to completing this rare surgery.

[Factors and Mechanisms of Pleural Dissemination in Surgically Treated Cases of Lung Metastasis Originated from Pancreatic Cancer].

Pancreatic cancer with distant metastasis typically results in a poor prognosis, but patients with only pulmonary metastasis are reported to have a relatively good prognosis. In this study, we investigated the clinicopathological data and prognosis of 15 patients who underwent surgery for lung metastasis of pancreatic cancer at our hospital between April 2010 and December 2021. The median disease-free interval after pancreatic cancer treatment was 24.5 (9.6-71.8) months. Ten of the 15 patients underwent successful radical resection, while the remaining 5 had pleural dissemination and underwent non-radical resection. The median follow-up duration was 13.5 months, with the median survival time for radical resection and non-radical resection cases being 49.5 months and 31.2 months, respectively. This indicates significantly worse prognosis for non-radical resection cases( p=0.010). Furthermore, the median CA19-9 levels before lung resection were 22 U/ml for radical resection and 2,181 U/ml for non-radical resection cases, significantly higher in the latter (p=0.049). Immunostaining of resected specimens revealed that MMP-2 was positive in 11 of 15 cases, particularly in 4 of 5 cases with pleural dissemination. CA19-9 levels before lung resection may be a predictive factor for pleural dissemination, and MMP-2 may play a role in the mechanism of pleural dissemination.

Elevation of the Neutrophil-to-Lymphocyte Ratio Is a Significant Postoperative Poor Prognostic Factor in Patients With Clinical T3-4 Centrally Located Primary Lung Cancer.

BACKGROUND/AIM: In centrally located non-small cell lung cancer (CLNSCLC) surgery, large tumors and extension to neighboring structures prevent the attainment of adequate surgical fields and make operations more difficult, and some patients have extremely poor outcomes. This study aimed to identify novel postoperative prognostic factors in patients with advanced CLNSCLC. PATIENTS AND METHODS: CLNSCLC was defined as a tumor requiring pneumonectomy or sleeve lobectomy for complete removal. We retrospectively investigated the clinical courses of 35 patients with cT3-4 CLNSCLC. RESULTS: This study included 21 patients with cT3 and 14 with cT4 lung cancer. Nine patients underwent pneumonectomy and 26 underwent sleeve lobectomy. Univariate analysis revealed that a high neutrophil-to-lymphocyte ratio (NLR, p=0.005) and carcinoembryonic antigen (CEA) positivity (p=0.028) were significant poor prognostic factors. Only high NLR (p=0.020) was a significant independent predictor in multivariate analysis. Nine of 16 patients with high NLR (56%) experienced disease recurrence, whereas 6 of 19 patients without high NLR (32%) had recurrent disease. CONCLUSION: High NLR and CEA positivity were significant poor prognostic factors in patients with cT3-4 CLNSCLC, and only high NLR was an independent predictor. Our findings may be helpful in selecting optimal treatments for advanced CLNSCLC.

Surgical Outcomes After Pulmonary Resection With Typical or Atypical Bronchoplasty in Patients With Primary Lung Cancer.

BACKGROUND/AIM: Atypical bronchoplasty is essential for complete tumor removal and preservation of peripheral lung tissue. This study compared surgical outcomes after atypical or typical bronchoplasty in patients who underwent pulmonary sleeve resection with bronchoplasty. PATIENTS AND METHODS: Typical bronchoplasty was defined as that after one-lobe sleeve resection; atypical bronchoplasty was defined as that after sleeve bilobectomy or sleeve removal of one lobe plus segments. Double-barreled bronchoplasty was also included in the atypical group. Surgical outcomes were retrospectively investigated according to type of bronchoplasty. RESULTS: Fifty-one patients underwent typical bronchoplasty and 20 atypical bronchoplasty. Recurrence was seen in 17 out of 51 (33%) patients after typical bronchoplasty and 10 out of 20 patients (50%) after atypical bronchoplasty. The recurrence-free survival rate was significantly poorer in the atypical bronchoplasty group (p=0.038). However, patients in the atypical bronchoplasty group were able to receive anticancer treatment for tumor recurrence, and there was no significant difference in overall survival rates between the groups. CONCLUSION: Preservation of pulmonary function by atypical bronchoplasty might contribute to tolerability of anticancer treatment for tumor recurrence. Pulmonary resection with atypical bronchoplasty is reliably beneficial for overall survival.

GLUT1 and PKM2 may be useful prognostic predictors in patients with non­small cell lung cancer following curative R0 resection.

Lung cancer has a poor prognosis despite recent progresses being made regarding its treatment. In addition, there is a paucity of reliable and independent prognostic predictors for non-small cell lung cancer (NSCLC) following curative resection. Glycolysis is associated with the malignancy and proliferation of cancer cells. Glucose transporter 1 (GLUT1) promotes glucose uptake, whereas pyruvate kinase M2 (PKM2) promotes anaerobic glycolysis. The present study aimed to evaluate the relationship between the expression of GLUT1 and PKM2 and the clinicopathological features of patients with NSCLC, and to identify a reliable prognostic factor for NSCLC following curative resection. Patients with NSCLC who underwent curative surgery were retrospectively enrolled to the present study. GLUT1 and PKM2 expression was assessed using immunohistochemistry. Subsequently, the association between the clinicopathological features of patients with NSCLC and the expression of GLUT1 and PKM2 was assessed. Of the 445 patients with NSCLC included in the present study, 65 (15%) were positive for both GLUT1 and PKM2 expression (G+/P+ group). GLUT1 and PKM2 positivity was significantly associated with sex, absence of adenocarcinoma, lymphatic invasion and pleural invasion. Furthermore, patients with NSCLC in the G+/P+ group presented significantly poorer survival rates than those expressing other markers. G+/P+ expression was significantly associated with poor disease-free survival. In conclusion, the findings of the present study indicated that the combination of GLUT1 and PKM2 may be considered a reliable prognostic factor for patients with NSCLC following curative resection, especially in patients with stage I NSCLC.

Restrictive Ventilatory Impairment as a Poor Prognostic Factor in Patients Who Undergo Surgical Resection for Metachronous Second Primary Lung Cancer.

PURPOSE: To evaluate the prognostic impact of restrictive ventilatory impairment in patients who undergo pulmonary resection of metachronous second primary lung cancer. METHODS: The clinical characteristics and surgical outcomes of 70 patients with metachronous second primary lung cancer were analyzed. RESULTS: The surgical procedures consisted of wedge resection in 40 patients, segmentectomy in 17, lobectomy in 12, and completion pneumonectomy in one. Patients who underwent ipsilateral pulmonary resection developed more perioperative complications (p = 0.0339). Three-year and 5-year overall survival rates were 78.2% and 69.2%, respectively. In univariate analysis, sex, restrictive ventilatory impairment, and histology of second primary lung cancer were significantly poor prognostic factors (all p <0.05). Multivariate analysis identified restrictive ventilatory impairment to be an independent predictor of a poor prognosis (p = 0.0193). In the 22 patients who died, the cause of death was lung cancer in 11 and other diseases, including pneumonia and respiratory failure, in 11. Death from another disease was significantly more common in patients with restrictive ventilatory impairment (p = 0.0216). CONCLUSION: Restrictive ventilatory impairment was an independent predictor of a poor prognosis in patients with a second primary lung cancer. Restrictive ventilatory impairment as a result of repeated thoracic surgery may increase the likelihood of death from another disease.

Usefulness of pyruvate dehydrogenase-E1α expression to determine SUVmax cut-off value of [18F]FDG-PET for predicting lymph node metastasis in lung cancer.

A more accurate cut-off value of maximum standardized uptake value (SUVmax) in [18F]fluorodeoxyglucose positron emission tomography/computed tomography ([18F]FDG-PET/CT) is necessary to improve preoperative nodal staging in patients with lung cancer. Overall, 223 patients with lung cancer who had undergone [18F]FDG-PET/CT within 2 months before surgery were enrolled. The expression of glucose transporter-1, pyruvate kinase-M2, pyruvate dehydrogenase-E1α (PDH-E1α), and carbonic anhydrase-9 was evaluated by immunohistochemistry. Clinicopathological background was retrospectively investigated. According to PDH-E1α expression in primary lesion, a significant difference (p = 0.021) in SUVmax of metastatic lymph nodes (3.0 with PDH-positive vs 4.5 with PDH-negative) was found, but not of other enzymes. When the cut-off value of SUVmax was set to 2.5, the sensitivity and specificity were 0.529 and 0.562, respectively, and the positive and negative predictive values were 0.505 and 0.586, respectively. However, when the cut-off value of SUVmax was set according to PDH-E1α expression (2.7 with PDH-positive and 3.2 with PDH-negative), the sensitivity and specificity were 0.441 and 0.868, respectively, and the positive and negative predictive values were 0.738 and 0.648, respectively. The SUVmax cut-off value for metastatic lymph nodes depends on PDH-E1α expression in primary lung cancer. The new SUVmax cut-off value according to PDH-E1α expression showed higher specificity for [18F]FDG-PET in the diagnosis of lymph node metastasis.

Detailed Surgical Techniques and Short-term Clinical Outcomes of Sleeve Lobectomy for Locally Advanced Right Lower Lobe Lung Cancer.

BACKGROUND/AIM: The surgical techniques of pulmonary resection with bronchoplasty for right lower lobe lung cancer are not well investigated. This study aimed to provide a detailed description of the pulmonary resection with bronchoplasty technique, including the appropriate patient selection process, in right lower lobe lung cancer patients. PATIENTS AND METHODS: The clinical courses of 17 right lower lobe lung cancer patients who had undergone pulmonary resection with bronchoplasty were retrospectively investigated. RESULTS: Of the 17 patients, 9 had right lower sleeve lobectomy, 5 had right middle and lower sleeve lobectomy, and 3 had right lower sleeve lobectomy with double-barreled bronchoplasty. The median follow-up period was 26 months. There were no treatment-related deaths. Distant organ recurrence was observed in 5 patients and local recurrence was identified in 3. One patient had pneumonia and another had prolonged air leak. Two patients, each of whom had either lower sleeve lobectomy or lower sleeve lobectomy with double-barreled bronchoplasty, developed bronchopleural fistula, and both patients were treated with additional surgery. CONCLUSION: Pulmonary resection with bronchoplasty should be performed only in oncologically and anatomically select patients. Our findings can be used as a guide to select the optimal treatments for this subgroup of patients.

Impact of Central Airway Infiltration Type in Primary Lung Cancer Patients Treated With Sleeve Lobectomy.

BACKGROUND/AIM: There are two types of lung cancer cell infiltration into the central airway. One is when a centrally located lung cancer directly infiltrates the central airway and the other is when cancer cells in the metastatic hilar lymph node infiltrate the central airway. We aimed to identify the impact of central airway infiltration type on the clinical features of patients undergoing sleeve lobectomy. PATIENTS AND METHODS: The clinical courses of 58 primary lung cancer patients who underwent sleeve lobectomy between January 2010 and December 2020 were investigated. RESULTS: Primary tumors directly infiltrated into the central airway in 42 patients, whereas 16 patients had infiltration of cancer cells from the metastatic hilar lymph node. Primary tumor infiltration was a poor prognostic factor according to both univariate (p=0.016) and multivariate analyses (p=0.042). Operation times (p=0.240) and incidences of adverse events (p=0.926) were not associated with the type of central airway infiltration. CONCLUSION: The type of airway infiltration was an independent poor prognostic factor after sleeve lobectomy in primary lung cancer patients. Our findings may guide the selection of optimal treatments for this patient population.

Elevation of Neutrophil-to-Lymphocyte Ratio Is a Significant Poor Prognostic Factor in Completely Resected Centrally Located Lung Squamous Cell Carcinoma.

BACKGROUND/AIM: The neutrophil-to-lymphocyte ratio (NLR) plays key roles in cancer growth. This study aimed to identify novel prognostic factors in patients who underwent complete resection of centrally located lung squamous cell carcinoma. PATIENTS AND METHODS: We retrospectively investigated the clinical courses of 45 patients who underwent sleeve lobectomy or pneumonectomy for centrally located squamous cell carcinoma. RESULTS: High NLR (p<0.001) and pathological T3/4 (p=0.008) were significant poor prognostic factors according to univariate analysis. Patients with pathological N2 had poor prognosis; however, there was no significant difference (p=0.095). Among these factors, only high NLR (p=0.003) was an independent poor prognostic factor according to multivariate analysis. Of the 23 patients with high NLR, 11 (49%) had recurrence, whereas in the 22 patients without high NLR, only two (9%) had recurrence. CONCLUSION: High NLR is an independent poor prognostic factor in centrally located lung squamous cell carcinoma. Our findings may guide the selection of optimal treatments for this subgroup of patients.

Lung cancer surgery after COVID-19 infection in a patient with severe interstitial pneumonia and restrictive ventilatory impairment.

BACKGROUND: The spread of COVID-19 infection increased the number of patients who underwent pulmonary resection for lung cancer after COVID-19 infection. It is unclear how previous infection with COVID-19 affects perioperative complications and acute exacerbation of interstitial pneumonia after surgery in patients with interstitial pneumonia. CASE PRESENTATION: An 80-year-old man was referred to our hospital because of a tumor in his left lung. Chest computed tomography showed a 28-mm nodule in the lower lobe of the left lung and usual interstitial pneumonia in bilateral lungs. Bronchoscopic examination was performed, which diagnosed squamous cell carcinoma. Pulmonary function testing revealed restrictive ventilatory impairment, and we planned to perform basal segmentectomy of the left lung. However, before the planned surgery, the patient contracted symptomatic COVID-19. Chest computed tomography revealed ground-glass opacities owing to COVID-19. The patient was admitted for surgery 7 weeks after COVID-19 infection. Preoperatively, pulmonary function testing was repeated, which revealed decreased % vital capacity (%VC) and % diffusing capacity for carbon monoxide (%DLco). The 6-min walk test indicated a distance of 500 m, and the percutaneous oxygen saturation at the end of the test was 94%. Basal segmentectomy of the left lung was performed by video-assisted thoracoscopic surgery. The patient's postoperative course was favorable, and he was discharged without the need for oxygen inhalational therapy 12 days after the surgery. Pathological examination of the resected specimen revealed usual interstitial pneumonia in the non-cancerous areas of the lung. Additionally, the infiltration of immature fibroblasts in the alveoli and perivascular infiltration of inflammatory cells were observed, which were consistent with fibrotic change after inflammation owing to COVID-19. Three months after the surgery, the patient was alive without recurrence or acute exacerbation of the interstitial pneumonia. Pulmonary function testing 6 weeks after surgery revealed decreased %VC and %DLco. Testing 12 weeks after surgery revealed persistently decreased %VC and improved %DLco (Table 1). Table 1 Pulmonary function test results before and after COVID-19 infection and 6 and 12 weeks after surgery VC (ml) %VC (%) %DLco (%) Before COVID-19 infection 2070 71.9 74.9 7 weeks after COVID-19 infection 1700 59.6 51.9 6 weeks after surgery 1500 52.6 53.1 12 weeks after surgery 1510 53.0 61.7 %VC % vital capacity, %DLco % diffusing capacity for carbon monoxide CONCLUSION: We successfully performed basal segmentectomy of the left lung for lung cancer 7 weeks after COVID-19 infection in a patient with severe interstitial pneumonia and restrictive ventilatory impairment.

Large Tumor Size and High Neutrophil-to-lymphocyte Ratio Predicts Poor Prognosis After Pneumonectomy or Sleeve Lobectomy in Patients With Non-small-cell Lung Cancer.

BACKGROUND/AIM: The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are useful biomarkers in non-small cell lung cancer (NSCLC). The aim of this study was to identify novel prognostic factors after pneumonectomy or sleeve lobectomy. PATIENTS AND METHODS: The clinical courses of 68 patients with NSCLC who underwent pneumonectomy or sleeve lobectomy were retrospectively investigated. RESULTS: High NLR (p=0.002) and PLR (p=0.006), and large tumor (>40 mm) (p=0.024) were indicative of poor prognosis in univariate analysis. High NLR (p=0.021) and large tumor (>40 mm) (p=0.017) remained independent factors indicating poor prognosis in multivariate analysis. Eighteen patients with both high NLR and large tumor (>40 mm) had significantly poorer prognoses than the remaining patients, 10 of them having recurrences within a short time after surgery. CONCLUSION: A high NLR and large tumor size indicate a poor prognosis after pneumonectomy or sleeve lobectomy. Our findings may be helpful in selecting optimal treatments for this subgroup of patients.

Lymph Node Metastasis Location and Postoperative Adjuvant Chemotherapy in Patients With pN1 Stage IIB Non-small Cell Lung Cancer.

BACKGROUND/AIM: The benefit of adjuvant chemotherapy for patients with pN1 non-small cell lung cancer (NSCLC) according to the location of lymph node (LN) metastases remains unclear. In this study, we examined the location of LN metastasis and prognosis to identify the significance of adjuvant chemotherapy. PATIENTS AND METHODS: Thirty-five patients with pathological T1a-2bN1M0 NSCLC who underwent curative resection between 2010 and 2016 were enrolled in the study. We defined patients with LN metastasis extending in stations 10-12 as the hilar group (n=22), and only in stations 13-14 as the intralobar group (n=13). RESULTS: There was a significant difference in the overall survival (OS) (p=0.042) and disease-free survival (DFS) rates (p=0.021) between the intralobar and hilar groups. In the intralobar group, there were no significant differences in the OS and DFS rates according to adjuvant chemotherapy. However, patients without adjuvant chemotherapy had a poorer OS (p<0.001) and DFS rates (p<0.001) in the hilar group. CONCLUSION: Prognosis significantly differed according to adjuvant chemotherapy in the hilar group.

Surgical Techniques of Y-Sleeve Lobectomy in Patients With Primary Lung Cancer.

BACKGROUND/AIM: The directions of distal and proximal airway stumps were different in Y-sleeve lobectomy. This difference might make Y-sleeve lobectomy a difficult procedure. In this article, we present our surgical techniques and analyse short-term outcomes of Y-sleeve lobectomy. PATIENTS AND METHODS: Right middle and lower, left lower, and left lower and lingular segment sleeve lobectomies are categorized in Y-sleeve lobectomy. We retrospectively investigated the clinical courses of 17 patients who underwent Y-sleeve lobectomy from January 2017 to December 2020. RESULTS: No treatment-related deaths occurred. One patient developed a bronchopleural fistula. Four patients developed pneumonia and were cured by repeated bronchoscopies and antibiotic therapy. Three patients had retention of pleural effusion, and two had prolonged air leakage. One patient had empyema after prolonged air leakage and was cured by thoracic drainage and antibiotic therapy. CONCLUSION: A major complication was observed only in one patient. Y-sleeve lobectomy is a reliable surgical method to avoid pneumonectomy.

Peripheral pulmonary mucous gland adenoma with a cavity mimicking lung cancer.

A 71-year-old woman presented to our hospital because of a 10 mm nodule with a cavity in right lower lobe on chest computed tomography. Fluorodeoxyglucose-positron emission tomography showed slight accumulation in the nodule (maximum standard uptake value 2.08). Her serum carcinoembryonic antigen concentration was 5.4 ng/mL. Wedge resection of the tumor was performed for diagnostic and treatment purposes. Findings on intraoperative pathological examination of a frozen section were suspicious for adenocarcinoma. We, therefore, performed a right lower lobectomy and mediastinal lymph node dissection. Postoperative histological examination revealed a mucous gland adenoma. The patient's postoperative course was favorable and she was discharged 7 days after surgery. Four months later, the serum carcinoembryonic antigen concentration had decreased to 3.1 ng/mL. Pulmonary mucous gland adenomas are rarely located peripherally. These benign tumors should be considered, even in the presence of high serum carcinoembryonic antigen concentrations or increased fluorodeoxyglucose uptake on fluorodeoxyglucose-positron emission tomography.

Changes in pedicle pericardial fat tissue around the anastomotic site after tracheobronchoplasty.

PURPOSE: Pericardial fat is appropriate tissue to cover the bronchial anastomotic site because its harvesting is minimally invasive. We investigated the changes in pericardial fat tissue around the anastomotic site after pulmonary resection with tracheobronchoplasty. METHODS: The subjects of this study were 43 lung cancer patients who underwent pulmonary resection with tracheobronchoplasty. We measured the maximum cross-sectional area and average computed tomography (CT) values of the pedicle pericardial fat pad around the anastomotic site 1 week and then 6 months after the operation. RESULTS: The average volume of the residual pedicle pericardial fat pad 6 months postoperatively was 61%. A body mass index (BMI) < 21.2 kg/m2 (P = 0.031) and a blood albumin level < 3.4 g/dl (P = 0.005) were significant predictors of pedicle flap shrinkage. Patients with fat tissue shrinkage had significantly elevated CT values 6 months postoperatively (P = 0.029), whereas those without shrinkage maintained low CT values. CONCLUSIONS: Preoperative nutritional conditions, reflected in high BMI and blood albumin levels, correlated with a high residual pedicle pericardial fat pad. Conversely, patients with pedicle flap shrinkage had significantly increased CT values, suggesting that the fat might have taken on another form such as scar tissue.

Artificial pneumothorax suppresses postoperative inflammatory reaction in mediastinal tumor surgery.

OBJECTIVE: The induction of artificial pneumothorax has many intraoperative advantages. However, few reports on the postoperative effects of artificial pneumothorax induction are available. In this study, we investigated the effect of artificial pneumothorax on postoperative clinical course in patients with mediastinal tumors. METHODS: We retrospectively investigated the clinical courses of 89 patients who had undergone mediastinal tumor resection between January 2010 and December 2020. Sixty-five patients had undergone resection with artificial pneumothorax. RESULTS: The tumor location significantly varied across patients. The proportion of patients in whom artificial pneumothorax was induced was higher among those having anterior mediastinal tumors. The number of ports and the total skin incision length were significantly higher in patients without artificial pneumothorax. The C-reactive protein level elevation on postoperative day 2 and pleural effusion at 24 h after surgery were significantly higher in patients without artificial pneumothorax. Furthermore, the albumin level reduction and hospital stay after surgery were significantly lower in patients with artificial pneumothorax. Multiple regression analysis showed that the use of artificial pneumothorax was an independent predictive factor of the C-reactive protein level elevation on postoperative day 2 and pleural effusion at 24 h after surgery. In patients without artificial pneumothorax, the operation time positively correlated with the C-reactive protein level (r = 0.646, P < 0.001). CONCLUSIONS: Artificial pneumothorax suppressed the postoperative inflammatory response, pleural effusion, and albumin reduction, and shortened the hospital stay in patients undergoing mediastinal tumor surgery.

Pyruvate dehydrogenase E1α represents a reliable prognostic predictor for patients with non-small cell lung cancer resected via curative operation.

BACKGROUND: Lung cancer is associated with a high morbidity and mortality rate worldwide; however, no reliable and independent prognostic predictor for non-small cell lung cancer (NSCLC) after curative surgery is available. Glucose metabolism is correlated with cancer cell proliferation. Pyruvate dehydrogenase E1α (PDH-E1α) catalyzes the conversion of pyruvate to acetyl-CoA and promotes aerobic glucose metabolism. In this study, we examined the relationship between PDH-E1α expression and clinicopathological factors associated with NSCLC to identify a reliable prognostic predictor of NSCLC after curative surgery. METHODS: A total of 445 patients with NSCLC who underwent curative resection were enrolled in this study. PDH-E1α expression was evaluated via immunohistochemistry. We analyzed the correlation between PDH-E1α expression and clinicopathological features of the patients. RESULTS: In total, 248 (56%) of the 445 patients with NSCLC were PDH-E1α-positive, and 197 patients were PDH-E1α-negative. PDH-E1α positivity was significantly correlated with the presence of adenocarcinoma (P<0.001) compared to the PDH-E1α-negative group. Patients with NSCLC showing PDH-E1α-negative expression had a significantly poorer overall survival rate (P=0.007) than those showing PDH-E1α-positive expression, especially at stage II. Patients with PDH-E1α negative expression also showed a poorer disease-free survival rate (P=0.02). Multivariate analysis revealed that PDH-E1α negativity (P=0.037) and male sex (P<0.001) were significantly correlated with a poor overall survival. CONCLUSIONS: PDH-E1α may represent a reliable prognostic predictor for NSCLC in patients that have recently undergone curative resection, especially at stage II.

Completion lower lobectomy after basal segmentectomy for pulmonary sclerosing pneumocytoma with lymph node metastasis.

A 20-year-old man was referred to our hospital because of a tumor in his left lung. Chest computed tomography showed a 35-mm nodule in the left lower lung lobe. Bronchoscopic examination and cryobiopsy were performed, which revealed suspicion for sclerosing pneumocytoma. We performed basal segmentectomy, and intraoperative-frozen pathological examination revealed no metastases in the segmental lymph nodes. However, the postoperative pathological diagnosis revealed metastasis in these nodes. We performed additional resection of segment 6 (completion lower lobectomy) and hilar and mediastinal lymph node dissection 2 weeks after the first surgery. The postoperative course was favorable, and the patient was discharged 13 days after the second surgery. Pathological examination of the additional resected specimens revealed lymph node metastases in the interlobar and mediastinal lymph nodes. Pulmonary sclerosing pneumocytoma with lymph node metastasis is extremely rare, and its prognosis is unclear. Recurrence has been reported rarely, and long-term follow-up is required.

Artificial intelligence-supported lung cancer detection by multi-institutional readers with multi-vendor chest radiographs: a retrospective clinical validation study.

BACKGROUND: We investigated the performance improvement of physicians with varying levels of chest radiology experience when using a commercially available artificial intelligence (AI)-based computer-assisted detection (CAD) software to detect lung cancer nodules on chest radiographs from multiple vendors. METHODS: Chest radiographs and their corresponding chest CT were retrospectively collected from one institution between July 2017 and June 2018. Two author radiologists annotated pathologically proven lung cancer nodules on the chest radiographs while referencing CT. Eighteen readers (nine general physicians and nine radiologists) from nine institutions interpreted the chest radiographs. The readers interpreted the radiographs alone and then reinterpreted them referencing the CAD output. Suspected nodules were enclosed with a bounding box. These bounding boxes were judged correct if there was significant overlap with the ground truth, specifically, if the intersection over union was 0.3 or higher. The sensitivity, specificity, accuracy, PPV, and NPV of the readers' assessments were calculated. RESULTS: In total, 312 chest radiographs were collected as a test dataset, including 59 malignant images (59 nodules of lung cancer) and 253 normal images. The model provided a modest boost to the reader's sensitivity, particularly helping general physicians. The performance of general physicians was improved from 0.47 to 0.60 for sensitivity, from 0.96 to 0.97 for specificity, from 0.87 to 0.90 for accuracy, from 0.75 to 0.82 for PPV, and from 0.89 to 0.91 for NPV while the performance of radiologists was improved from 0.51 to 0.60 for sensitivity, from 0.96 to 0.96 for specificity, from 0.87 to 0.90 for accuracy, from 0.76 to 0.80 for PPV, and from 0.89 to 0.91 for NPV. The overall increase in the ratios of sensitivity, specificity, accuracy, PPV, and NPV were 1.22 (1.14-1.30), 1.00 (1.00-1.01), 1.03 (1.02-1.04), 1.07 (1.03-1.11), and 1.02 (1.01-1.03) by using the CAD, respectively. CONCLUSION: The AI-based CAD was able to improve the ability of physicians to detect nodules of lung cancer in chest radiographs. The use of a CAD model can indicate regions physicians may have overlooked during their initial assessment.