Pulmonary Metastasectomy in Colorectal Cancer: A Population-Based Retrospective Cohort Study Using the Korean National Health Insurance Database.

PURPOSE: The study aimed to investigate the current status and prognostic factors for overall survival in patients who had undergone pulmonary metastasectomy for colorectal cancer. MATERIALS AND METHODS: The data of 2,573 patients who had undergone pulmonary metastasectomy after surgery for colorectal cancer between January 2009 and December 2014 were extracted from the Korean National Health Insurance Service claims database. Patient-, colorectal cancer-, pulmonary metastasis-, and hospital-related factors were analyzed using the Kaplan-Meier method, log-rank test, and Cox proportional hazards analysis to identify prognostic factors for overall survival after pulmonary metastasectomy. RESULTS: The mean age of the patients was 60.9±10.5 years; 66.2% and 79.1% of the participants were male and had distally located colorectal cancer, respectively. Wedge resection (71.7%) was the most frequent extent of pulmonary resection; 21.8% of the patients underwent repeated pulmonary metastasectomies; 73% of pulmonary metastasectomy cases were performed in tertiary hospitals; 53.9% of patients were treated in Seoul area; 82% of patients received chemotherapy in conjunction with pulmonary metastasectomy. The median survival duration was 51.8 months. The 3- and 5-year overall survival rates were 67.7% and 39.4%, respectively. In multivariate analysis, female sex, distally located colorectal cancer, pulmonary metastasectomy-only treatment, and high hospital volume (> 10 pulmonary metastasectomy cases/yr) were positive prognostic factors for survival. CONCLUSION: Pulmonary metastasectomy seemed to provide long-term survival of patients with colorectal cancer. The female sex, presence of distally located colorectal cancer, and performance of pulmonary metastasectomy in high-volume centers were positive prognostic factors for survival.

Value of 18F-FDG PET/CT for Predicting the World Health Organization Malignant Grade of Thymic Epithelial Tumors: Focused in Volume-Dependent Parameters.

PURPOSE: We investigated whether preoperative parameters of 18F-FDG PET/CT were correlated with the World Health Organization (WHO) classification and/or Masaoka staging of thymic epithelial tumors. PATIENTS AND METHODS: We reviewed 61 patients retrospectively who were diagnosed with thymic epithelial tumors after surgical resection and PET/CT. A volume of interest was drawn on the primary lesion, using an SUV cutoff of 2.5, and metabolic indices such as SUVmax, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured. RESULTS: There were 24 male patients (38.7%), and the mean (SD) age was 50.23 (12.54) years. The mean (SD) tumor size was 6.11 (3.41) cm. There were 22 low-risk thymomas (36.9%) (A, AB, B1), 32 high-risk thymomas (51.6%), and 7 thymic carcinomas (11.5%). The Masaoka stage was I in 15 (24.6%), II in 30 (49.2%), III in 11 (18.0%), and IV in 5 patients (8.2%). Mean (SD) SUVmax was 3.43 (1.01) in low-risk thymomas, 4.42 (1.70) in high-risk thymomas, and 8.23 (2.61) in thymic carcinoma; the differences were significant (P < 0.001). Mean (SD) MTV and TLG were 90.74 (114.56) and 229.36 (300.56) in low-risk thymomas, 80.82 (112.49) and 233.93 (340.91) in high-risk thymomas, and 90.63 (90.74) and 390.94 (437.62), respectively, in thymic carcinomas. MTV and TLG showed no correlation with the WHO classification. On receiver operating characteristic curve analysis, the cutoff value for discriminating thymomas and thymic carcinomas was 5.05. SUVmax and TLG were correlated with Masaoka stage. CONCLUSIONS: Although volume-dependent parameters were not correlated with the WHO classification, a significant relationship was observed between SUVmax and WHO classification and Masaoka stage.

Single-Port Video-Assisted Thoracic Surgery for Secondary Spontaneous Pneumothorax: Preliminary Results.

BACKGROUND: The aim of this study was to evaluate the feasibility of single-port video-assisted thoracic surgery (VATS) in the treatment of secondary spontaneous pneumothorax (SSP). METHODS: Twenty-four patients who were scheduled to undergo single-port VATS for SSP were studied. The medical records of the patients were retrospectively reviewed. The mean follow-up duration was 26.1±19.8 months. In order to evaluate the feasibility of single-port VATS for SSP, the postoperative results of single-port VATS (n=15) in patients with emphysema were compared with those of emphysematous patients who underwent three-port VATS (n=15) during the study period. RESULTS: Single-port VATS was feasible in 19 of 24 patients (79.2%), while an additional port was needed in five patients. In the single-port VATS patients, the median operation time, duration of chest tube drainage, and hospital stay were 84.0 minutes, one day, and two days, respectively. Postoperative complications included prolonged chest tube drainage for more than five days (n=1), wound infection (n=1), and vocal fold palsy (n=1). No recurrence of pneumothorax was observed during the follow-up period. The median operation time, duration of chest tube drainage, and hospital stay of the emphysematous patients who underwent single-port VATS were shorter than those who underwent three-port VATS group (p<0.05 for all parameters). CONCLUSION: Single-port VATS proved to be a feasible procedure in the treatment of patients with secondary spontaneous pneumothorax.

Effects of Alveolar Recruitment and Positive End-Expiratory Pressure on Oxygenation during One-Lung Ventilation in the Supine Position.

PURPOSE: Hypoxemia during one-lung ventilation (OLV) remains a serious problem, particularly in the supine position. We investigated the effects of alveolar recruitment (AR) and positive end-expiratory pressure (PEEP) on oxygenation during OLV in the supine position. MATERIALS AND METHODS: Ninety-nine patients were randomly allocated to one of the following three groups: a control group (ventilation with a tidal volume of 8 mL/kg), a PEEP group (the same ventilatory pattern with a PEEP of 8 cm H2O), or an AR group (an AR maneuver immediately before OLV followed by a PEEP of 8 cm H2O). The tidal volume was reduced to 6 mL/kg during OLV in all groups. Blood gas analyses, respiratory variables, and hemodynamic variables were recorded 15 min into TLV (TLV(baseline)), 15 and 30 min after OLV (OLV15 and OLV30), and 10 min after re-establishing TLV (TLV(end)). RESULTS: Ultimately, 92 patients were analyzed. In the AR group, the arterial oxygen tension was higher at TLV(end), and the physiologic dead space was lower at OLV15 and TLV(end) than in the control group. The mean airway pressure and dynamic lung compliance were higher in the PEEP and AR groups than in the control group at OLV15, OLV30, and TLV(end). No significant differences in hemodynamic variables were found among the three groups throughout the study period. CONCLUSION: Recruitment of both lungs with subsequent PEEP before OLV improved arterial oxygenation and ventilatory efficiency during video-assisted thoracic surgery requiring OLV in the supine position.

Recurrence Risk-Scoring Model for Stage I Adenocarcinoma of the Lung.

PURPOSE: The aim of this retrospective, multicenter study was to develop a recurrence risk-scoring model in patients with curatively resected stage I lung adenocarcinoma (ADC). METHODS: Clinicopathologic and outcome data for a development cohort of 1,700 patients with pathologic stage I ADC from four institutions resected between January 2000 and December 2009 were evaluated. A phantom study was performed for correction of inter-institutional differences in positron emission tomography-standardized uptake value (PET-SUV). A nomogram for recurrence prediction was developed using Cox proportional hazards regression. This model was validated in a cohort of 460 patients in two other hospitals. The recurrence rate was 21.0 % for the development cohort and 22.1 % for the validation cohort. RESULTS: In multivariable analysis, three independent predictors for recurrence were identified: pathologic tumor size (hazard ratio [HR] 1.03, 95 % CI 1.017-1.048; p < 0.001), corrected PET-SUV (HR 1.08, 95 % CI 1.051-1.105; p < 0.001), and lymphovascular invasion (HR 1.65, 95 % CI 1.17-2.33; p = 0.004). The nomogram was made based on these factors and a calculated risk score was accorded to each patient. Kaplan-Meier analysis of the development cohort showed a 5-year recurrence-free survival (RFS) of 83 % (95 % CI 0.80-0.86) in low-risk patients and 59 % (95 % CI 0.54-0.66) in high-risk patients with the highest 30 percentile scores. The concordance index was 0.632 by external validation. CONCLUSIONS: This recurrence risk-scoring model can be used to predict the RFS for pathologic stage I ADC patients using the above three easily measurable factors. High-risk patients need close follow-up and can be candidates for adjuvant chemotherapy.

Prognostic factors for cases with no extracranial metastasis in whom brain metastasis is detected after resection of non-small cell lung cancer.

OBJECTIVES: This study aimed to determine prognostic factors associated with postrecurrence survival in cases with postoperative brain metastasis but with no extracranial metastasis in non-small cell lung cancer (NSCLC). MATERIAL AND METHODS: Between 1992 and 2012, a total of 2832 patients underwent surgical resection for NSCLC. Among those, 86 patients had postoperative brain metastasis as the initial recurrence. Those patients were retrospectively reviewed. RESULTS: The median follow-up time after the initial lung resection was 24.0 months (range, 2.0-126.0 months). The median overall survival after initial lung cancer resection was 25.0 months and the median overall postrecurrence survival was 11 months. An initial lesion of adenocarcinoma (hazard ratio, 0.548; 95% confidence interval, 0.318 to 0.946; p=0.031), non-pneumonectomy, and a disease-free interval longer than 10.0 months (hazard ratio, 0.565; 95% confidence interval, 0.321-0.995; p=0.048) from the initial lung resection to the diagnosis of brain metastasis positively related to a good postrecurrence survival. Solitary brain metastasis and a size of less than 3 cm for the largest brain lesion were also positive factors for postrecurrence survival. Systemic chemotherapy for brain metastasis (hazard ratio, 0.356; 95% confidence interval, 0.189-0.670; p=0.001) and local treatment of surgery and/or stereotactic radiosurgery (SRS) for brain lesions (hazard ratio, 0.321; 95% confidence interval, 0.138-0.747; p=0.008) were positive factors for better postrecurrence survival. CONCLUSION: In patients with brain metastasis after resection for NSCLC with no extracranial metastasis, adenocarcinoma histologic type, longer disease-free interval, systemic chemotherapy for brain metastasis and local treatment of surgery and/or SRS for brain metastasis are independent positive prognostic factors for postrecurrence survival.

Predictive factors for myasthenic crisis after videoscopic thymectomy in patients with myasthenia gravis.

INTRODUCTION: Predictive factors for myasthenic crisis after transsternal thymectomy have been reported, but little is known about myasthenic crisis after videoscopic thymectomy (MCAVT). METHODS: We investigated 146 myasthenia gravis patients who underwent videoscopic thymectomy. RESULTS: Patients with MCAVT had a lower forced vital capacity (FVC) (2.1 vs. 3.0 L, P < 0.001) than those without. Low-frequency repetitive nerve stimulation showed decremental responses of the orbicularis oculi (47.1% vs. 18.1%, P = 0.001) and nasalis muscles (54.1% vs. 21.4%, P < 0.001), which were more pronounced in patients with MCAVT than those without. According to multivariate analysis, FVC (OR 0.144, 95% confidence interval [CI], 0.044-0.479, P = 0.002) and decremental response of orbicularis oculi (odds ratio, 1.029; 95% CI, 1.001-1.058, P = 0.044) were independently associated with MCAVT. CONCLUSIONS: FVC and decremental response of orbicularis oculi were associated with MCAVT.

Autophagy activity in pulmonary metastatic tumor tissues from colorectal cancer: a pilot study.

PURPOSE: Autophagy has been reported to be involved in treatment failure in tumor. We aimed to evaluate autophagy activity in tumor tissue and compare them between the recurrence and non-recurrence groups. MATERIALS AND METHODS: We analyzed expressions of autophagy-related proteins in tumor tissues which were obtained from pulmonary metastases of colorectal cancer patients by Western blot. We also analyzed autophagosomes by transmission electron microscopy. RESULTS: Tumor tissues from recurrence group showed increased levels of LC3B-II, decreased levels of p62/SQSTM1, and also a marked accumulation of autophagosomes compared with tissues from non-recurrence group. CONCLUSION: The present study suggests that autophagy may be associated with treatment failure of metastatic colorectal cancer.

Recurrence after thymoma resection according to the extent of the resection.

BACKGROUND: Complete resection of the thymus is considered appropriate for a thymoma resection because any remaining thymic tissue can lead to local recurrence. However, there are few studies concerning the extent of thymus resection. Therefore, we conducted a retrospective study to investigate whether recurrence following thymoma resection correlated to the extent of resection. METHODS: Between 1986 and 2011, a total of 491 patients underwent resection of thymic epithelial tumors with curative intent. Of those, we excluded patients with an undetermined World Health Organization (WHO) histologic type, patients with type C thymoma, and patients who underwent incomplete resection (n = 21). The remaining 342 patients were reviewed retrospectively and compared recurrence according to the extent of resection. RESULTS: Extended thymectomy was performed in 239 patients (69.9%) and limited thymectomy was performed 103 patients (30.1%). In the extended thymectomy group, 29 recurrences occurred, and in the limited thymectomy group, 10 recurrences occurred.Comparing rates of freedom from recurrence between two groups, there was no significant statistical difference in total recurrence (p = 0.472) or local recurrence (p = 0.798). After matching patients by stage and tumor size, there was no significant difference in freedom from recurrence between the two groups (p = 0.162). Additionally, after adjusting for histologic type and MG, there was also no significant difference (p = 0.125) between groups. CONCLUSIONS: No difference in the rate of recurrence was observed in patients following limited thymectomy compared with extended thymectomy.

Identification of somatic mutations in EGFR/KRAS/ALK-negative lung adenocarcinoma in never-smokers.

BACKGROUND: Lung adenocarcinoma is a highly heterogeneous disease with various etiologies, prognoses, and responses to therapy. Although genome-scale characterization of lung adenocarcinoma has been performed, a comprehensive somatic mutation analysis of EGFR/KRAS/ALK-negative lung adenocarcinoma in never-smokers has not been conducted. METHODS: We analyzed whole exome sequencing data from 16 EGFR/KRAS/ALK-negative lung adenocarcinomas and additional 54 tumors in two expansion cohort sets. Candidate loci were validated by target capture and Sanger sequencing. Gene set analysis was performed using Ingenuity Pathway Analysis. RESULTS: We identified 27 genes potentially implicated in the pathogenesis of lung adenocarcinoma. These included targetable genes involved in PI3K/mTOR signaling (TSC1, PIK3CA, AKT2) and receptor tyrosine kinase signaling (ERBB4) and genes not previously highlighted in lung adenocarcinomas, such as SETD2 and PBRM1 (chromatin remodeling), CHEK2 and CDC27 (cell cycle), CUL3 and SOD2 (oxidative stress), and CSMD3 and TFG (immune response). In the expansion cohort (N = 70), TP53 was the most frequently altered gene (11%), followed by SETD2 (6%), CSMD3 (6%), ERBB2 (6%), and CDH10 (4%). In pathway analysis, the majority of altered genes were involved in cell cycle/DNA repair (P <0.001) and cAMP-dependent protein kinase signaling (P <0.001). CONCLUSIONS: The genomic makeup of EGFR/KRAS/ALK-negative lung adenocarcinomas in never-smokers is remarkably diverse. Genes involved in cell cycle regulation/DNA repair are implicated in tumorigenesis and represent potential therapeutic targets.

Impact of cigarette smoking on response to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors in lung adenocarcinoma with activating EGFR mutations.

OBJECTIVES: The aim of this study is to evaluate the predictive impact of cigarette smoking on treatment outcomes of EGFR-tyrosine kinase inhibitors (TKIs) in lung adenocarcinoma patients with activating EGFR mutations. METHODS: We retrospectively analyzed 222 consecutive recurrent or unresectable lung adenocarcinoma patients who harbored activating EGFR mutations (exon 19 deletion or exon 21 L858R) and had received gefitinib or erlotinib. Detailed smoking histories were obtained from all patients according to a standard protocol. RESULTS: Of 222 EGFR-mutated patients, 65.3% were never-smokers, 19.8% were smokers with < 30 pack-years, and 14.9% were smokers with ≥ 30 pack-years smoking dosage. The disease control rate (DCR) and objective response rate (ORR) of smokers with ≥ 30 pack-years were significantly lower than never-smokers and smokers with < 30 pack-years (DCR, 78.8% vs. 93.1%, p = 0.016; ORR, 45.5% vs. 62.4%, p = 0.020). Smokers with ≥ 30 pack-years showed significantly shorter PFS than never-smokers (6.4 vs. 11.8 months, p = 0.001) and smokers with < 30 pack-years (6.4 vs. 11.4 months, p = 0.033), as well as shorter overall survival from the time of metastatic diagnosis than never-smokers (33.6 vs. 46.2 months, p = 0.003). There was no survival difference between smokers with < 30 pack-year and never smokers. In the multivariate analysis adjusted for age, sex, performance status, initial stage, and line of EGFR-TKI, the presence of smoking dosage ≥ 30 pack-years was an independent predictive factor for the disease progression to EGFR-TKIs (hazard ratio, 1.87; 95% confidence interval, 1.15-3.05; p = 0.012). CONCLUSIONS: Cigarette smoking dosage of ≥ 30 pack-years is an independent negative predictive factor of EGFR-TKI treatment outcome in lung adenocarcinoma patients with activating EGFR mutations.

A prospective phase II trial of S-1 and cisplatin-based chemoradiotherapy for locoregionally advanced esophageal cancer.

PURPOSE: S-1 is a novel oral fluoropyrimidine anticancer agent designed to enhance clinical efficacy, reduce gastrointestinal toxicity, and enhance radiotherapy effectiveness. A phase II trial was conducted to evaluate the efficacy and safety of preoperative chemoradiation with S-1 and cisplatin in locoregionally advanced esophageal cancer. METHODS: Eligible patients had stage IIA-IVA esophageal cancer. Patients received two cycles of S-1 (days 1-14 and days 22-35) and cisplatin (days 1 and 22) with concurrent radiotherapy (50.4 Gy total; 1.8 Gy/fraction). Esophagectomy was performed between weeks 12 and 18 as determined by the specialist multidisciplinary team. RESULTS: Sixty patients were enrolled in this study between March 2008 and August 2011, and 59 were eligible. The clinical stage was ≥T3 in 28 patients (47 %) and N1 in 43 patients (72 %), with squamous cell carcinoma histology in 58 patients (97 %). Fifty-four patients (90 %) completed the planned chemoradiation. After chemoradiation, the clinical tumor response rate was 64.4 %. The primary toxicities included neutropenia (24 %) and esophagitis (8.5 %). Three treatment-related deaths were noted. Twenty-five patients (42 %) underwent esophagectomy following chemoradiation, and 15 achieved complete pathologic regression. The estimated overall survival and progression-free survival rates after 2 years were 65 and 48 %, respectively. CONCLUSIONS: Concurrent chemoradiation with S-1 and cisplatin exhibited encouraging results with complete pathologic regression. The survival data were promising compared with the historical data of 5FU/cisplatin and should be confirmed in a randomized phase III trial. Toxicities were significant but clinically manageable.

Clinical and prognostic implications of ALK and ROS1 rearrangements in never-smokers with surgically resected lung adenocarcinoma.

OBJECTIVES: The aim of this study is to evaluate the prevalence and prognostic significance of anaplastic lymphoma kinase (ALK) and c-ros oncogene 1 (ROS1) rearrangement in never-smokers with surgically resected lung adenocarcinoma. METHODS: We retrospectively analyzed 162 consecutive never-smokers who underwent curative resection for stage IB to IIIA lung adenocarcinoma at a single institution. We concurrently analyzed mutations in the epidermal growth factor receptor (EGFR) and v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) genes, and investigated ALK rearrangements by fluorescence in situ hybridization assay. ROS1 rearrangement was also determined in all triple (EGFR/KRAS/ALK)-negative tumors. RESULTS: Of 162 never smokers with lung adenocarcinoma, 14 (8.6%) and 5 (3.1%) had ALK and ROS1 rearrangements, respectively. Nineteen of the 74 (25.7%) EGFR and KRAS mutation-negative patients were fusion-positive (ALK or ROS1 fusion). Fusion-positive patients tended to have shorter median disease-free survival (DFS) than fusion-negative patients (28.0 vs. 33.9 months; p=0.128). In multivariate analysis, fusion-positive patients had significantly poorer DFS than fusion-negative patients after adjustment for age, sex, T stage, N stage, and adjuvant chemotherapy use (p=0.022; hazard ratio, 2.11; 95% confidence interval, 1.19-4.30). The first recurrence sites were not significantly different between fusion-positive and fusion-negative patients in this study. CONCLUSION: This study shows significantly poorer DFS of ALK or ROS1 fusion-positive lung adenocarcinoma in never-smokers after curative surgery.

The influence of smoking intensity on the clinicopathologic features and survival of patients with surgically treated non-small cell lung cancer.

BACKGROUND: Smoking is a well-known carcinogen for lung cancer. However, whether smoking affects the biological behavior of lung cancer remains uncertain. This study aimed to investigate the influences of smoking intensity on the clinicopathologic characteristics of and survival in non-small cell lung cancer (NSCLC). METHODS: We retrospectively reviewed 2238 consecutive patients who underwent surgical resection for NSCLC between 1990 and 2010. Smoking intensity was defined as pack-years (PY). The patients were divided into three groups according to the median value of smoking intensity (40 PY): group A (never smokers), group B (smoking intensity less than 40 PY) and group C (smoking intensity more than 40 PY). RESULTS: There were 1629 (72.8%) male patients, and the mean age was 61.71 ± 13.17 years. Adenocarcinoma was reported in 1058 (47.3%) patients. The median follow-up period was 30.7 months (range: 0.0-261.7 months). The 5-year overall survivals for groups A, B and C were 60.1%, 51.6% and 43.2%, respectively (p < 0.001). In subset analysis by histology, the 5-year overall survival was significantly different according to smoking intensity in adenocarcinoma (p < 0.001), but there was no difference in the non-adenocarcinoma. In adenocarcinoma, the incidences of vascular invasion (p = 0.028), pleural invasion (p = 0.013) and poor differentiation (p < 0.001) were higher and tumor sizes (p < 0.001) were greater in group C than others. On multivariate analysis, smoking intensity was an adverse risk factor for overall survival in surgically treated adenocarcinoma patients (hazard ratio = 1.008, p = 0.028). CONCLUSION: Smoking intensity was an adverse prognostic factor after surgical resection of adenocarcinoma. Heavy smoking was correlated with poor pathologic characteristics in adenocarcinoma.

Efficacy of platinum-based adjuvant chemotherapy in T2aN0 stage IB non-small cell lung cancer.

BACKGROUND: Although overall survival for non-small cell lung cancer (NSCLC) has increased, survival rate for pathologically staged T2aN0M0 stage IB NSCLC remains low. Adjuvant chemotherapy is not a standard treatment for stage IB NSCLC. Our purpose was to determine the efficacy of platinum-based adjuvant chemotherapy in stage IB NSCLC. METHODS: We retrospectively reviewed the medical records of 119 stage IB patients who underwent lobectomy and mediastinal lymph node dissection. Among these, 60 patients underwent platinum-based adjuvant chemotherapy (adjuvant group) and 59 did not receive chemotherapy (observation group). RESULTS: Participants had a mean age of 62.12 ± 11.51 years and 73 (61.3%) were male. The median follow-up period was 49.04 months. Mean age was higher in the observation group whereas patients in the adjuvant group had larger tumors, more dissected lymph nodes, and better performance status. The 5-year overall survival was 64.7% in the observation group and 88.2% in the adjuvant group (p = 0.010). The 5-year disease-free survival was 51.3% in the observation group and 74.0% in the adjuvant group (p = 0.011). In multivariate analysis, only platinum-based adjuvant chemotherapy was a risk factor for overall survival [hazard ratio (HR) = 0.428, p = 0.049] and disease-free survival (HR = 0.57, p = 0.043). In subset analysis, patients with a larger tumor (greater than 3.2 cm), moderate to poor differentiation, and good performance status (Eastern Cooperative Oncology Group, 0) benefitted from platinum-based adjuvant chemotherapy. CONCLUSIONS: Platinum-based adjuvant chemotherapy for surgically treated stage IB NSCLC might offer better survival than observation alone. A large-scale randomized clinical trial is needed to validate these findings.

Predictors of recurrence after thymoma resection.

PURPOSE: Recurrence rate is considered a better measure of clinical outcomes after thymoma resection than overall survival due to the indolent behavior of thymomas. This study was designed to determine predictors of recurrence after thymoma resection. MATERIALS AND METHODS: A single-institution, retrospective study was performed, including 305 patients who had undergone thymoma resection between 1986 and 2009. RESULTS: Among 305 patients, recurrence was observed in 41 patients (13.4%). The recurrence rates were 0% (0/19), 6.3% (4/63), 4.2% (2/48), 18.6% (11/59) and 20.7% (24/116) for type A, AB, B1, B2 and B3 tumors, respectively. The recurrence rate according to Masaoka stage was 6.1% (8/132), 11.4% (13/114), 26.8% (11/41) and 50.0% (9/18) for stages I, II, III and IV, respectively. After univariate analysis, completeness of resection (R0 versus R1), World Health Organization (WHO) histologic type (A, AB, B1 versus B2, B3), Masaoka stage, and size of tumor (<8 cm versus ≥8 cm) demonstrated significant differences with freedom from recurrence. Upon multivariate analysis, Masaoka stage was the only independent predictor of recurrence. CONCLUSION: WHO histologic type, Masaoka stage, and size of tumor were associated with recurrence. Particularly, Masaoka stage was the only independent predictor of recurrence after thymoma resection.

Efficacy of polyglycolic acid sheet after thoracoscopic bullectomy for spontaneous pneumothorax.

BACKGROUND: Various procedures have been performed to decrease the incidence of recurrent postoperative pneumothorax after thoracoscopic bullectomy. The purpose of this study was to determine the efficacy of a polyglycolic acid (PGA) sheet and pleural abrasion for prevention of recurrent postoperative pneumothorax. METHODS: From January 2009 to August 2011, 257 patients underwent thoracoscopic bullectomy for primary spontaneous pneumothorax. In group A, 128 patients underwent pleural abrasion. These patients were compared with 129 patients (group B) who underwent a procedure to cover stable lines with an absorbable PGA sheet in addition to pleural abrasion. RESULTS: There was no difference in preoperative demographics, although the age of patients in group A was statistically higher than that of patients in group B (23.67 ± 6.54 versus 21.69 ± 5.65; p = 0.010). In group A, prolonged postoperative air leaks (≥ 3 days) occurred more frequently (7.8% versus 2.3%; p = 0.045). A Kaplan-Meier curve showed that recurrence-free rates were higher in group B (p = 0.047). CONCLUSIONS: Coverage with PGA sheet and pleural abrasion after thoracoscopic bullectomy is effective for preventing prolonged postoperative air leaks and reducing postoperative recurrence rates.

Ultra-highly sensitive optical gas sensors based on chemomechanical polymer-incorporated fiber interferometer.

We demonstrate a novel optical sensor for use in explosive gas detection, having a simple structure, ultrahigh sensitivity, room-temperature sensing/refreshing operation, and no local power requirements. The sensor relies on a fiber Fabry-Pérot interferometer prepared using poly(4-vinylpyridine), which induces cavity expansion upon absorption of nitrobenzene, thereby shifting the phase matching conditions of the resonating modes. An estimated sensitivity limit as low as 5 ppb was achieved.

Taurolidine: a new alternative agent for the management of the postoperative air leak.

PURPOSE: To evaluate the efficacy of taurolidine instillation on postoperative air leak by clinical study and to investigate the mechanism of action by animal experiments. METHODS: Outcomes of taurolidine instillation in patients with postoperative air leak were retrospectively reviewed. 100 ml of 1% taurolidine solution was instilled through a chest tube in patients with postoperative air leak lasting 4days or more. Success was defined as cessation of air leak within 24 hours with full expansion of lung on chest radiograph and subsequent removal of chest tube within another 24 hours. The effect of taurolidine instillation was estimated by development of adhesion and thickening of the visceral pleura in rabbits. The study group was compared with a control group and a talc poudrage group. RESULTS: Out of 75 patients, the success rate was 66.7%. Out of 96 total attempts, taurolidine instillation was successful in 55%. In animal experiments, pleural adhesion was minimal in the taurolidine and control groups, whereas the talc group showed more adhesions. The taurolidine group showed a moderate visceral pleural thickening. The talc group showed severe visceral pleural thickening, whereas the control group showed mild thickening. CONCLUSION: Taurolidine is an effective alternative agent for the management of air leak. A chemical sclerosing effect is suggested as the mechanism of air leak cessation.

Preoperative serum CYFRA 21-1 level as a prognostic factor in surgically treated adenocarcinoma of lung.

BACKGROUND: High preoperative serum CYFRA 21-1 has been reported as diagnostic marker and poor prognostic factor in non-small cell lung cancer, especially in squamous cell carcinoma. However, the prognostic value in adenocarcinoma of lung has not been reported. This study is performed to investigate the prognostic impact of CYFRA 21-1 in adenocarcinoma of lung. METHODS: We retrospectively reviewed 298 patients who underwent lobectomy or above with complete mediastinal lymph node dissection for adenocarcinoma of lung, between 2004 and 2009. The patients were divided into 2 groups, by receiver operating characteristic (ROC) curve analysis. RESULTS: There were 145 male patients and mean age was 62.2 ± 26.4 years. The median follow-up period was 43.3 months. Mean and median value of CYFRA 21-1 were 2.16 ± 1.97 ng/mL and 1.68 ng/mL (range, 0.37-15.10), respectively. The optimal cut-off value of CYFRA 21-1 for overall survival was 1.95 ng/mL which was determined by ROC curve analysis. One hundred fourteen (38.4%) patients showed high level of CYFRA 21-1. Preoperative serum CYFRA 21-1 was higher in advanced stage (p=0.004). The high CYFRA 21-1 was also correlated with bigger tumor size (p<0.001) and poor differentiation (p=0.008). The 5-year overall survival of low group and high group was 79.1% and 58.4% (p<0.001), respectively. Univariate and multivariate analysis showed that CYFRA 21-1 level was related to the poor prognosis for overall survival (hazard ratio=1.1, p=0.033) in adenocarcinoma of lung. The concordance index for Cox model was also higher in multivariate analysis model with CYFRA 21-1 level than in model without CYFRA 21-1 level (0.722, 95% CI 0.718-0.726 vs. 0.701, 95% CI 0.697-0.705). CONCLUSIONS: High preoperative CYFRA 21-1 may be a determinant for poor prognosis in operated adenocarcinoma of lung.