Jae Hyun Jeon

Early clinical outcomes of robot-assisted surgery for anterior mediastinal mass: its superiority over a conventional sternotomy approach evaluated by propensity score matching

OBJECTIVES We performed this study to assess early clinical outcomes of robot-assisted surgery for anterior mediastinal mass by comparing results of the robot group with those of the sternotomy group after propensity score matching. METHODS Between 2008 and 2012, 145 patients underwent resection of anterior mediastinal mass. Robot-assisted surgery was performed in 37 patients, and conventional surgery by sternotomy in 108 patients. Propensity score matching was done between two groups with variables of age, sex, size of the mass, myasthenia gravis, resection of other organ and pathological diagnosis. Thirty-four patients from the robot group and 34 from the open group were matched, fitting the model. The clinical outcomes of matched groups were compared. RESULTS In the robot group, mediastinal cyst consisted of 47.1% (16 of 34), thymoma 32.4% (11 of 34), thymic carcinoma 8.8% (3 of 34), thymic hyperplasia 8.8% (3 of 34) and liposarcoma 2.9% (1 of 34). The mean duration of follow-up was 1.11 ± 0.21 and 1.85 ± 0.19 years for the robot and open groups, respectively. There were no mortality or recurrence in both groups during the follow-up. There were no significant differences in operation time, postoperative white blood cell and C-reactive protein increase, maximum visual analogue scale score for pain as well as postoperative intensive care unit care between the two groups. The robot group revealed a lesser number of drains (1.09 ± 0.1 vs 1.41 ± 0.1) and 24-h tube drainage (189.4 ± 20.5 vs 397.6 ± 52.6 ml), lower haemoglobin loss (0.54 ± 0.4 vs 1.35 ± 0.1 g/dl) and haematocrit decrease (1.92 ± 0.5 vs 3.85 ± 0.4%), shorter chest tube days (1.53 ± 0.2 vs 3.06 ± 0.2) and length of hospital stay (2.65 ± 0.2 vs 5.53 ± 0.8) after operation, which were all statistically significant. Although statistically insignificant, there were no postoperative complications in the robot group, but there were 5 (14.7%) in the open group (P = 0.063). CONCLUSIONS In carefully selected patients with relatively smaller sized masses, robot-assisted surgery resulted in excellent early clinical outcomes with lesser tube drainage, lower blood loss, shorter tube days and length of hospital stay without any postoperative complications, compared with the matched open group. Further investigation for long-term clinical outcomes and oncological outcomes is required for a robotic approach. Particularly, long-term follow-up for the local recurrence rate according to the pathological diagnoses is required.

Video-assisted thoracoscopic lobectomy in non-small-cell lung cancer patients with chronic obstructive pulmonary disease is associated with lower pulmonary complications than open lobectomy: a propensity score-matched analysis

OBJECTIVES Non-small-cell lung cancer (NSCLC) patients with chronic obstructive pulmonary disease (COPD) are at an increased risk of pulmonary complications after pulmonary resection. This study aimed to identify whether video-assisted thoracoscopic (VATS) lobectomy can reduce postoperative pulmonary complications compared with lobectomy by thoracotomy in NSCLC patients with COPD. METHODS Among a total of 1502 NSCLC patients who underwent lobectomy from April 2005 to June 2012 at the Seoul National University Hospital, 446 (29.7%) were diagnosed with COPD based on the spirometric criteria of the Global Initiative for COPD. Among the 446 patients, 283 presented with stage I NSCLC and were selected for this study. The study patients were divided into two groups: patients undergoing VATS (n = 160) lobectomy and patients undergoing thoracotomy (n = 123) lobectomy. A propensity analysis that incorporated preoperative variables, such as age, sex, Charlson comorbidity index, extent of smoking, preoperative pulmonary function, size of the mass, histological type of the tumour and additional lung resection, was performed, and postoperative outcomes were compared. RESULTS Matching based on propensity scores produced 91 patients in each group for the analysis of postoperative outcomes. There were only three operative mortalities in the thoracotomy group, and all of these patients died of postoperative pneumonia. The overall incidence of postoperative complications was 32.9% (30 of 91) and 22.0% (20 of 91) in the thoracotomy group and in the VATS group, respectively (P = 0.14). Compared with lobectomy by thoracotomy, VATS lobectomy was associated with a lower incidence of pulmonary complications (1.1 vs 12.1%; P < 0.01), shorter operation time (165 vs 201 min; P < 0.01) and shorter length of stay (6.0 vs 9.0 days; P = 0.04). CONCLUSIONS VATS lobectomy is associated with a lower incidence of pulmonary complications compared with lobectomy by thoracotomy in stage I NSCLC patients with COPD. VATS lobectomy may be the preferred strategy for appropriately selected NSCLC patients with COPD.

Importance of lymph node dissection in thymic carcinoma.

BACKGROUND Lymph node dissection plays important role in oncologic surgery. We investigated outcomes of lymph node dissection in thymic carcinoma. METHODS We retrospectively reviewed 37 patients, who underwent complete resection for thymic carcinoma. Patients were divided into four groups: no node dissection (Nx), 8; pathologic N0 by limited dissection (N0a), 13; pathologic N0 by extensive dissection (N0b), 10; and node metastasis (N1), 6. Outcomes of lymph node dissection were investigated. Disease-free survival (DFS) and freedom from recurrence of the four groups were compared. RESULTS A total of 349 lymph nodes were dissected in 29 patients. Metastasis was confirmed in 19 nodes in 6 patients, with tumor invading adjacent organs. Anterior mediastinal lymph node metastasis was confirmed in 4 patients. Intrathoracic lymph node metastasis was confirmed in 3 patients at the right paratracheal lymph nodes. Recurrences were diagnosed in 11 patients (Nx, 2; N0a, 4; N0b, 1; N1, 4). The 5-year overall survival rate was 65.5%, DFS was 60.9%, and freedom from recurrence was 68.2%. DFS rates of the N0b subgroup were significantly better than in the N1 subgroup (90% vs 33.3%). DFS rates of the Nx and N0a subgroups were similar (75% vs 48.7%, p=0.98), and the prognoses of both groups were intermediate between the N0b and N1 groups. Analyses of freedom from recurrence proved identical results. CONCLUSIONS Extensive lymph node dissection, meaning dissection of more than 10 lymph nodes, is required to predict prognosis accurately. Anterior mediastinal and right paratracheal lymph nodes should be dissected in thymic carcinoma.

Prognostic and predictive role of epidermal growth factor receptor mutation in recurrent pulmonary adenocarcinoma after curative resection

OBJECTIVES Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) treatment prolongs the progression-free survival of patients with advanced non-small-cell lung cancer harbouring EGFR mutations. This study aimed to evaluate the prognostic factors influencing survival after recurrence, and the effectiveness of EGFR-TKIs in patients with recurrent pulmonary adenocarcinoma after curative resection. METHODS EGFR mutations were prospectively evaluated in 594 patients who underwent curative surgical resection for pulmonary adenocarcinoma. Among them, 138 patients who had postoperative recurrent disease were enrolled in the study. Potential prognostic factors for post-recurrence survival (PRS) were evaluated, and predictive factors of responsiveness to EGFR-TKIs were also analysed. RESULTS Among the 138 patients who had postoperative recurrent disease, EGFR mutations were identified in 73 (52.9%) patients. In multivariable analysis, never-smoking status [hazard ratio (HR), 0.522; P = 0.012], adjuvant radiotherapy (HR, 1.995; P = 0.016), disease-free interval of less than 1 year from initial resection to recurrence (HR, 2.382; P = 0.001), surgical treatment for recurrence (HR, 0.346; P = 0.002) and EGFR mutation (HR, 0.552; P = 0.013) were independent prognostic factors for PRS. Among patients treated with EGFR-TKI, EGFR mutation status was the only predictor of response to EGFR-TKI (P < 0.001), and patients with EGFR mutation showed better PRS (3- and 5-year survival rates after recurrence, 68.8 and 41.1%, respectively) than those without EGFR mutations (3- and 5-year survival rates after recurrence, 39.1 and 15.7%, respectively; P = 0.017). CONCLUSIONS Our study demonstrated that EGFR mutation is an independent prognostic factor for PRS. Considering that EGFR mutations were the only independent predictors for response to EGFR-TKIs, selecting patients for EGFR-TKI therapy according to EGFR mutation status may lead to a better prognosis in patients with recurrent pulmonary adenocarcinoma.

Comparison of thoracoscopic segmentectomy and thoracoscopic lobectomy on the patients with non-small cell lung cancer: a propensity score matching study.

OBJECTIVES Thoracoscopic lobectomy has been widely performed on patients with early-stage lung cancer; meanwhile indications of thoracoscopic segmentectomy have not been clearly defined due to technical difficulties and unclear oncological outcomes. The aim of this study was to compare early and late outcomes between thoracoscopic segmentectomy and thoracoscopic lobectomy. METHODS Between January 2005 and December 2013, 100 thoracoscopic segmentectomies and 1049 thoracoscopic lobectomies were performed on patients with lung cancer in our institute. Preoperative clinical parameters including gender, age, tumour size, pathological stage, histology and forced expiratory volume in 1 s (FEV1) were used for propensity score matching. After propensity score matching, 94 thoracoscopic segmentectomies and 94 lobectomies were selected and compared. RESULTS Thoracoscopic segmentectomies were performed on patients with normal lung function (mean FEV1 = 101.6 ± 24.1%), small-sized tumour (mean diameter 1.7 ± 1.0 cm), early-stage cancer (Stage I 93.7%) and predominant adenocarcinoma (81.9%). The lobectomy group had similar clinical features with the segmentectomy group. Most commonly performed procedures were left upper lobe upper division segmentectomy (19%) and right lower lobe superior segmentectomy (17%). Segmentectomies were performed in all lobes except the right middle lobe. There were no differences between segmentectomy and lobectomy in terms of operation time (166.3 ± 54.7 min vs 181.1 ± 85.2 min, P = 0.47) and hospital stay (6.2 ± 5.2 days vs 7.1 ± 7.1 days, P = 0.31). Incidence of postoperative complications was non-significantly higher in the lobectomy group (17.2 vs 10.6%, P = 0.1), and postoperative mortality rates were also non-significantly higher in the segmentectomy group (1.1 vs 2.1%, P = 0.56). Postoperative FEV1 decrease was non-significantly lower in the segmentectomy group (8.9 ± 10.8 vs 11.0 ± 13.1, P = 0.36). The 3-year overall survival and recurrence-free survival was not different between the two groups (94 and 87% in the segmentectomy group and 96 and 94% in the lobectomy group, P = 0.62 and P = 0.69, respectively). CONCLUSIONS Thoracoscopic segmentectomy could achieve equal short-term surgical results and long-term oncological outcomes compared with thoracoscopic lobectomy.

Natural History of Ground-Glass Nodules Detected on the Chest Computed Tomography Scan After Major Lung Resection

BACKGROUND Detection of ground-glass nodules (GGNs) on computed tomography (CT) is increasing due to advances in CT technology and the findings of the National Lung Screening Trial. Ground-glass nodules are detected on screening chest CTs and CT scans after lung resection surgery. It is important to investigate the natural history of GGNs as it is not yet well known, and a standardized approach to manage them has not been established. METHODS We selected patients who presented with GGNs on chest CT taken after major lung resection. One hundred thirty-nine GGNs were detected in 92 patients and followed up for longer than 1 year. Characteristics of GGN, size, presence of a solid component and multiplicity, and demographic data of patients such as history of smoking and malignant disease were analyzed to identify factors that affected GGN growth. RESULTS During the follow-up period (mean 44.4 months), 23 GGNs showed a significant increase in size. The only predictor for the growth of GGNs was the presence of a solid component (p < 0.001). Pathologic diagnosis was made in 14 patients. Of those, 10 GGNs including 7 primary lung adenocarcinomas were diagnosed as malignant. Three of 4 benign lesions were diagnosed as atypical adenomatous hyperplasia. There were no mortalities directly related to GGNs. CONCLUSIONS In GGNs detected on CT scans of patients who had undergone major lung resection, the presence of a solid component was the only factor that could predict nodule growth. Although the majority of growing GGNs were adenocarcinoma, the clinical course seemed to be indolent.