Prediction of postoperative final degree and recurrence of pectus excavatum using machine learning algorithms.

Background: Chest wall re-depression after bar removal (BR) in pectus excavatum (PE) is insufficiently investigated. However, it is not easy to investigate chest wall re-depression due to its multifactorial characteristics. Herein, we investigated chest wall re-depression after BR using machine learning algorithms. To the best of my knowledge, this is the first study of chest wall re-depression after BR using machine learning algorithms. Methods: We retrospectively reviewed 199 consecutive subjects who underwent both minimally invasive repair of pectus excavatum (MIRPE) and BR at a single hospital from March 2012 to June 2020. We investigated attributes of chest wall re-depression and risk factors for recurrence after BR, predicted final degree and recurrence of PE after BR, and suggested the optimal age at the time of MIRPE based on recurrence. Data for the chest wall re-depression were analyzed to discover differences according to age group [<10 years (early repair group; EG) vs. ≥10 years (late repair group; LG)]. Results: We observed no significant difference between the Haller index and radiographical pectus index (RPI) (P=0.431) and a significant correlation between Haller index and RPI (P<0.001). RPI significantly increased for the first 6 months after BR in both age groups (both P<0.001) and was maintained at 1 year after BR. RPI value of the LG were significantly higher than those of the EG for the entire period after MIRPE (P=0.041). Recurrence of PE in the LG was significantly more frequent than in the EG (P<0.001). RPI values before and after MIRPE and age group were identified as independent risk factors for recurrence after BR (P<0.001, P=0.007, and P=0.001, respectively). The linear regression model outperformed for final RPI with performance scores of mean squared error 0.198, root mean squared error 0.445, mean absolute error 0.336, and R2 0.415. In addition, the logistic regression model outperformed for predicting recurrence with performance scores of 0.865 the area under the curve, 0.884 accuracy, 0.859 F1, 0.865 precision, and 0.884 recall. Conclusions: The present study shows that machine learning algorithms can provide good estimates for postoperative results in PE. An approach integrating machine learning models and readily available clinical data can be used to create other models in the thoracic surgery field.

Pleural Carcinoembryonic Antigen and Maximum Standardized Uptake Value as Predictive Indicators of Visceral Pleural Invasion in Clinical T1N0M0 Lung Adenocarcinoma.

Background: Visceral pleural invasion (VPI) is a poor prognostic factor that contributes to the upstaging of early lung cancers. However, the preoperative assessment of VPI presents challenges. This study was conducted to examine intraoperative pleural carcinoembryonic antigen (pCEA) level and maximum standardized uptake value (SUVmax) as predictive markers of VPI in patients with clinical T1N0M0 lung adenocarcinoma. Methods: A retrospective review was conducted of the medical records of 613 patients who underwent intraoperative pCEA sampling and lung resection for non-small cell lung cancer. Of these, 390 individuals with clinical stage I adenocarcinoma and tumors ≤30 mm were included. Based on computed tomography findings, these patients were divided into pleural contact (n=186) and non-pleural contact (n=204) groups. A receiver operating characteristic (ROC) curve was constructed to analyze the association between pCEA and SUVmax in relation to VPI. Additionally, logistic regression analysis was performed to evaluate risk factors for VPI in each group. Results: ROC curve analysis revealed that pCEA level greater than 2.565 ng/mL (area under the curve [AUC]=0.751) and SUVmax above 4.25 (AUC=0.801) were highly predictive of VPI in patients exhibiting pleural contact. Based on multivariable analysis, pCEA (odds ratio [OR], 3.00; 95% confidence interval [CI], 1.14-7.87; p=0.026) and SUVmax (OR, 5.25; 95% CI, 1.90-14.50; p=0.001) were significant risk factors for VPI in the pleural contact group. Conclusion: In patients with clinical stage I lung adenocarcinoma exhibiting pleural contact, pCEA and SUVmax are potential predictive indicators of VPI. These markers may be helpful in planning for lung cancer surgery.

Imaging features and clinical significance of atypical pleural plaques mimicking bone tumors: a retrospective case series.

This study aimed to examine the imaging characteristics and clinical implications of atypical pleural lesions that mimic bone tumors and form along the inner margins of consecutive ribs. This retrospective analysis included 45 atypical pleural lesions arising from 13 patients who underwent chest computed tomography (CT) between April 2021 and March 2023. The clinical features, CT findings, and radiologic diagnoses prior to pathologic identification were examined. Pathological findings were reviewed in the surgically resected case. Subgroup analysis was performed based on the presence of concurrent typical pleural plaques. The mean age of the patients was 69.3±8.4 years with a predominance of males (76.9%). The lesions primarily exhibited unilateral involvement (84.6%), being most frequently located in the right mid-level posterior region. Calcification was present in 75.6% of cases, typically seen continuously along the ribs (82.4%). Adjacent rib changes were observed in 28.9% of cases. These lesions were frequently misdiagnosed as osteochondromas or bony spurs (55.6%) by thoracic radiologists. No significant growth was observed during follow-up (n=11, 47±41 months), and the pathological findings were consistent with pleural plaques. Patients with concurrent typical pleural plaques had more atypical pleural lesions without statistical significance (P=0.071) and showed a more even distribution (P=0.039). In conclusion, atypical pleural lesions resembling bone tumors along consecutive ribs represent a distinct subset of pleural plaques. Their unique distribution and morphology should be recognized by radiologists to avoid misinterpretation and unnecessary interventions.

Cancer organoid-based diagnosis reactivity prediction (CODRP) index-based anticancer drug sensitivity test in ALK-rearrangement positive non-small cell lung cancer (NSCLC).

BACKGROUND: Recently, cancer organoid-based drug sensitivity tests have been studied to predict patient responses to anticancer drugs. The area under curve (AUC) or IC50 value of the dose-response curve (DRC) is used to differentiate between sensitive and resistant patient's groups. This study proposes a multi-parameter analysis method (cancer organoid-based diagnosis reactivity prediction, CODRP) that considers the cancer stage and cancer cell growth rate, which represent the severity of cancer patients, in the sensitivity test. METHODS: On the CODRP platform, patient-derived organoids (PDOs) that recapitulate patients with lung cancer were implemented by applying a mechanical dissociation method capable of high yields and proliferation rates. A disposable nozzle-type cell spotter with efficient high-throughput screening (HTS) has also been developed to dispense a very small number of cells due to limited patient cells. A drug sensitivity test was performed using PDO from the patient tissue and the primary cancer characteristics of PDOs were confirmed by pathological comparision with tissue slides. RESULTS: The conventional index of drug sensitivity is the AUC of the DRC. In this study, the CODRP index for drug sensitivity test was proposed through multi-parameter analyses considering cancer cell proliferation rate, the cancer diagnosis stage, and AUC values. We tested PDOs from eight patients with lung cancer to verify the CODRP index. According to the anaplastic lymphoma kinase (ALK) rearrangement status, the conventional AUC index for the three ALK-targeted drugs (crizotinib, alectinib, and brigatinib) did not classify into sensitive and resistant groups. The proposed CODRP index-based drug sensitivity test classified ALK-targeted drug responses according to ALK rearrangement status and was verified to be consistent with the clinical drug treatment response. CONCLUSIONS: Therefore, the PDO-based HTS and CODRP index drug sensitivity tests described in this paper may be useful for predicting and analyzing promising anticancer drug efficacy for patients with lung cancer and can be applied to a precision medicine platform.

Analysis of Factors Affecting Postoperative Opioid Requirement in Pediatric Patients Undergoing Pectus Excavatum Repair with Multimodal Analgesic Management.

Children with pectus excavatum are treated with surgical repair in a procedure known as minimally invasive repair of pectus excavatum (MIRPE). MIRPE causes considerable postoperative pain, resulting in the administration of a substantial dose of opioids. This study aimed to identify perioperative factors that influence the requirement for opioids in children undergoing MIRPE. Retrospective data from children who underwent MIRPE were analyzed. A multimodal analgesic protocol was implemented with a continuous wound infiltration system and administration of non-opioid analgesics. Intravenous opioid analgesics were administered if the pain score was greater than 4. The cumulative opioid use was assessed by calculating the morphine equivalent dose at 6, 24, and 48 h after surgery. Perioperative factors affecting the postoperative opioid use were identified with multiple linear regression analyses. This study included 527 children aged 3-6 years, with a mean age of 3.9 years. Symmetrically depressed chest walls, a lower Haller index, and a lower revised depression index were found to be associated with decreased postoperative opioids. Boys required higher opioid doses than girls. Longer pectus bars (10 inches versus 9 inches) were associated with increased opioid use. Severity indices, gender, and the length of pectus bars influence postoperative opioid requirement in children undergoing MIRPE surgery with multimodal analgesia.

T1 and T2 Mapping for Characterization of Mediastinal Masses: A Feasibility study.

Purpose: To evaluate the feasibility and usefulness of T1 and T2 mapping in characterization of mediastinal masses. Methods: From August 2019 through December 2021, 47 patients underwent 3.0-T chest MRI with T1 and post-contrast T1 mapping using modified look-locker inversion recovery sequences and T2 mapping using a T2-prepared single-shot shot steady-state free precession technique. Mean native T1, native T2, and post-contrast T1 values were measured by drawing the region of interest in the mediastinal masses, and enhancement index (EI) was calculated using these values. Results: All mapping images were acquired successfully, without significant artifact. There were 25 thymic epithelial tumors (TETs), 3 schwannomas, 6 lymphomas, and 9 thymic cysts, and 4 other cystic tumors. TET, schwannoma, and lymphoma were grouped together as "solid tumor," to be compared with thymic cysts and other tumors ("cystic tumors"). The mean post-contrast T1 mapping (P < .001), native T2 mapping (P < .001), and EI (P < .001) values showed significant difference between these two groups. Among TETs, high risk TETs (thymoma types B2, B3, and thymic carcinoma) showed significantly higher native T2 mapping values (P = .002) than low risk TETs (thymoma types A, B1, and AB). For all measured variables, interrater reliability was good to excellent (intraclass coefficient [ICC]: .869∼.990) and intrarater reliability was excellent (ICC: .911∼.995). Conclusion: The use of T1 and T2 mapping in MRI of mediastinal masses is feasible and may provide additional information in the evaluation of mediastinal masses.

Using Continuous Flow Data to Predict the Course of Air Leaks After Lung Lobectomy.

Background: Assessments of air leaks are usually performed subjectively, precluding the use of air leaks as an evaluation factor. We aimed to identify objective parameters as predictive factors for prolonged air leak (PAL) and air leak cessation (ALC) from air flow data produced by a digital drainage system. Methods: Flow data records of 352 patients who underwent lung lobectomy were reviewed, and flow data at designated intervals (1, 2, and 3 hours postoperatively [POH] and 3 times a day thereafter [06:00, 13:00, 19:00]) were extracted. ALC was defined by flow less than 20 mL/min over 12 hours, and PAL was defined as ALC after 5 days. Cumulative incidence curves were obtained using Kaplan-Meier estimates of time to ALC. Cox regression analysis was performed to determine the effects of variables on the rate of ALC. Results: The incidence of PAL was 18.2% (64/352). Receiver operating characteristic curve analysis showed cut-off values of 180 mL/min for the flow at 3 POH and 73.3 mL/min for the flow on postoperative day 1; the sensitivity and specificity of these values were 88.9% and 82.5%, respectively. The rates of ALC by Kaplan-Meier analysis were 56.8% at 48 POH and 65.6% at 72 POH. Multivariate Cox regression analysis revealed that the flow at 3 POH (≤80 mL/min), operation time (≤220 minutes), and right middle lobectomy independently predicted ALC. Conclusion: Air flow measured by a digital drainage system is a useful predictor of PAL and ALC and may help optimize the hospital course.

The Cross-Bar Technique for Pectus Excavatum Repair: A Key Element for Remodeling of the Entire Chest Wall.

INTRODUCTION: The multiple bar approach was developed to cover broader and heavier teenager/adult chest wall deformities. We designed the cross-bar technique to achieve remodeling of the entire chest wall. This study aimed to demonstrate the role of cross-bar and its benefits over the parallel bar. MATERIALS AND METHODS: The cross-bar technique involves placing two bars diagonally and then cross on the target. The primary purposes are to double the lifting forces by making two bars converge on a single target to lift inflexible heavy chest wall depressions or cover lower lateral areas. The results of the cross-bar and parallel bar are compared for the indications, postrepair outcomes, and complications. RESULTS: From 2016 to 2019, 247 patients who underwent multiple bar pectus excavatum (PE) repair were enrolled in the study: 157 with cross-bar and 90 with parallel bar. In the cross-bar group, 33% (51/157) received three bars in XI fashion to cover the upper depression. The cross-bar group was older (18.0 ± 6.1 vs. 15.7 ± 5.0), had higher depression index (1.9 ± 0.7 vs. 1.8 ± 0.3), and was less asymmetric (45% vs. 71%) than those in the parallel bar group. The overall complication rates were not different between the two groups (9.6% vs. 10%, p = 1.0), although the cross-bar group was more rigid and complex. There was no bar displacement or reoperation in both groups. CONCLUSION: The cross-bar technique is as safe and effective as the parallel-bar technique, even though it was selected to correct more complexities. The cross-bar technique could be a method for complex PE deformities for remodeling of the entire chest wall.

Surgical treatment of facial blushing: Patient selection and operative technique (retrospective observational study).

Surgeons are often reluctant to offer further intervention to patients with medically intractable facial blushing. This is mainly because of the relatively high failure rate of blushing resolution and a high incidence of compensatory hyperhidrosis. In this study, we sought to identify the type of blushing that would benefit from surgery and minimize compensatory hyperhidrosis by applying diffuse sympathicotomy (DS). This study was a retrospective review of 62 patients who underwent R2 endoscopic thoracic sympathicotomy (ETS) and preemptive DS for facial blushing. Facial blushing was classified as autonomic-mediated blushing (thermoregulatory, emotional) and vasodilator-mediated blushing (constant) based on the history and precipitating factors for blushing. DS was performed at lower-thoracic levels in the form of limited DS (right R5/7/9/11, left R5/6/8/10) or extended DS (bilateral R5-11). Resolution of blushing (described as "almost disappeared") was achieved in 48% of patients with a median follow-up of 19.6 months. There was a significant difference in resolution among 3 types of blushing (emotional: 55%, thermoregulatory: 28%, constant: 15%, P = .03). Multivariate analysis confirmed thermoregulatory and constant type blushing as a potential independent predictor of blushing resolution. Even though there was no difference between the DS procedures with respect to compensatory hyperhidrosis, intolerable compensatory hyperhidrosis (Hyperhidrosis Disease Severity Scale = 4) occurred in only 11% of patients. DS redistributed sweating area, being predominantly on the chest and mid-back (89%), also seen on the abdomen-waist-groin-buttocks-thighs (63%). Overall, 77% of patients experienced satisfactory results. Emotional blushing proved to be an established indication of ETS where good long-term results can be expected. Expansion of surgical indication to thermoregulatory or constant type blushing needs to be validated in future studies. Additionally, compensatory hyperhidrosis, another hurdle for ETS, can be minimized by preemptive DS, resulting in redistribution and decrease of sweating.

Comparison of early postoperative cytokine changes in patients undergoing intubated and non-intubated thoracic surgery: a randomized controlled trial.

OBJECTIVES: The inflammatory response after surgery is associated with patient prognosis. Patients who undergo thoracic surgery exhibit a profound systemic inflammatory response due to the surgical procedures used and application of one-lung ventilation. The aim of this study was to compare perioperative inflammatory changes in patients after intubated and non-intubated thoracic surgery for primary lung cancer resection. METHODS: This prospective randomized controlled study included forty patients who underwent surgical resection for stage I non-small-cell lung cancer. Blood samples for cytokine analysis were collected just before induction, at 1 and 24 h after surgery. Levels of the pro-inflammatory cytokine and anti-inflammatory cytokines were measured using quantitative sandwich enzyme immunoassay kits. RESULTS: The basal values of cytokines were comparable between 2 groups. Within each group, the postoperative levels of interleukin (IL)-1, IL-6 and tumour necrosis factor-α increased, while those of IL-4 and IL-10 did not change significantly. The levels of IL-6 and tumour necrosis factor-α were significantly lower in group NI at 1 and 24 h postoperatively. Other cytokines did not differ in both groups during postoperative period. The IL-6/IL-10 ratio at 1 h after surgery was lower in non-intubated patients than in intubated patients, but there was no difference at 24 h after surgery. CONCLUSIONS: Non-intubated thoracic surgery may attenuate the early inflammatory cytokine changes following major resection for primary lung cancer compared with intubated conventional surgery. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov registry number NCT04007354.

Surgical treatment of compensatory hyperhidrosis: Retrospective observational study.

Compensatory hyperhidrosis is a debilitating postoperative condition occurring in 30% to 90% of patients with primary hyperhidrosis. The most appropriate treatment for compensatory hyperhidrosis remains controversial.Between January 2018 and December 2019, 44 patients with intractable compensatory hyperhidrosis underwent diffuse sympathicotomy (DS). In the early study periods, DS was performed sparsely (limited DS) to avoid possible adverse effects (right R5/7/9/11, left R5/6/8/10). In the late study periods, levels of surgical interruption were further modified to maximize sympatholytic effects (extended DS; bilateral R5/6/7/8/9/10/11). Patients were followed up for symptom resolution. For objective evidence of improved hyperhidrosis, thermographic images were taken for 7 patients.Immediate resolution of compensatory hyperhidrosis was achieved in 81% of patients, as determined at the 1 to 2 week postoperative visit. With a median follow-up of 22.7 months, compensatory hyperhidrosis continued to be resolved in 46% (n = 20). Logistic regression analysis showed that persistent resolution of compensatory hyperhidrosis was independently predicted by extended DS (odds ratio, 25.67, 95% CI, 1.78-1047.6; P = .036). The presence of gender, BMI, isolated compensatory hyperhidrosis, distribution of sweating, prior operation type, reoperation interval, and same-day lumbar sympathectomy failed to gain statistical significance on maintaining persistent resolution of compensatory hyperhidrosis. No patients experienced surgery-related side effects. Thermographic images obtained before/after surgery in 10 patients showed successful denervation and sweat diminishment.This study shows the safeness and effectiveness of DS for treating compensatory hyperhidrosis, representing a new treatment option. Future research should be directed at confirming a promising result of extended DS with further follow-up.

Impact of Sarcopenia on Early Postoperative Complications in Early-Stage Non-Small-Cell Lung Cancer.

BACKGROUND: Risk assessment for pulmonary resection in patients with early-stage non-small-cell lung cancer (NSCLC) is important for minimizing postoperative morbidity. Depletion of skeletal muscle mass is closely associated with impaired nutritional status and limited physical ability. We evaluated the relationship between skeletal muscle depletion and early postoperative complications in patients with early-stage NSCLC. METHODS: Patients who underwent curative lung resection between 2016 and 2018 and who were diagnosed with pathological stage I/II NSCLC were included, and their records were retrospectively analyzed. The psoas volume index (PVI, cm3/m3) was calculated based on computed tomography images from routine preoperative positron emission tomography-computed tomography. Early postoperative complications, defined as those occurring within 90 days of surgery, were compared between the lowest sex-specific quartile for PVI and the remaining quartiles. RESULTS: A strong correlation was found between the volume and the cross-sectional area of the psoas muscle (R2=0.816). The overall rate of complications was 57.6% among patients with a low PVI and 32.8% among those with a normal-to-high PVI. The most common complication was prolonged air leak (low PVI, 16.9%; normal-to-high PVI, 9.6%), followed by pneumonia (low PVI, 13.6%; normal-to-high PVI, 7.9%) and recurrent pleural effusion (low PVI, 11.9%; normal-to-high PVI, 6.8%). The predictors of overall complications were low PVI (odds ratio [OR], 2.18; 95% confidence interval [CI], 1.07-4.09; p=0.03), low hemoglobin level (OR, 0.686; 95% CI, 0.54-0.87; p=0.002), and smoking history (OR, 3.93; 95% CI, 2.03-7.58; p<0.001). CONCLUSION: Low PVI was associated with a higher rate of early postoperative complications in patients with early-stage NSCLC.

Predictors of post-thymectomy long-term neurological remission in thymomatous myasthenia gravis: an analysis from a multi-institutional database.

OBJECTIVES: Thymectomy is the treatment of choice for thymomatous myasthenia gravis (MG) for both oncological and neurological aspects. However, only a few studies comprising small numbers of patients have investigated post-thymectomy neurological outcomes. We examined post-thymectomy long-term neurological outcomes and predictors of thymomatous MG using a multi-institutional database. METHODS: In total, 193 patients (47.3 ± 12.0 years; male:female = 90:103) with surgically resected thymomatous MG between 2000 and 2013 were included. Complete stable remission (CSR) and composite neurological remission (CNR), defined as the achievement of CSR and pharmacological remission after thymectomy, were evaluated. Predictors for CSR and CNR were examined by Cox regression analysis. RESULTS: The median duration between MG and thymectomy was 3.1 months. In addition, 161 patients (83.4%) had symptoms less than Myasthenia Gravis Foundation of America clinical classification III. All patients underwent an extended thymectomy; there were no perioperative deaths. The 10-year cumulative probability of CSR and CNR was 36.9% and 69.1%, respectively. Mild preoperative symptoms were a significant predictor for CSR (P = 0.040), and a large tumour was a predictor for CNR (P < 0.001). Patients with a large tumour were associated with early MG onset and no steroid treatment. Surgical methods, thymoma stage and histological subtypes were not associated with long-term neurological remission. CONCLUSIONS: Large tumour size and preoperative mild symptoms were predictors for long-term neurological outcome in thymomatous MG. Considering that patients with early onset of MG and no immunosuppressive treatment tend to have large tumours, early surgical intervention for patients with thymomatous MG having mild symptoms might be beneficial for controlling neurological outcomes.

Atypical Thymic Carcinoid in a Patient with Zollinger-Ellison Syndrome.

Atypical thymic carcinoid is an extremely rare tumor with a poor prognosis. In addition to its known association with multiple endocrine neoplasia type 1, its hallmark characteristics include local invasion and early distant metastasis. In this report, we share our experience treating atypical thymic carcinoid in a patient with Zollinger-Ellison syndrome.

Electromagnetic navigation bronchoscopic dye marking for localization of small subsolid nodules: Retrospective observational study.

Thoracoscopic resection of small subsolid nodules is challenging and requires preoperative localization. We investigated the efficacy, safety, and factors affecting accuracy in localizing pulmonary nodules with electromagnetic navigation bronchoscopy (ENB)-guided dye marking.Patients with small subsolid nodule(s) who underwent thoracoscopic resection after ENB-guided dye marking were retrospectively reviewed. Dye marking was performed at the nearest pleura and the localized nodule(s) was resected thoracoscopically. Efficacy was evaluated by success rates of dye marking and resection of nodules. Navigation accuracy was represented by target distance, which was the closest distance between target and the tip of locatable guide. Factors affecting target distance were evaluated by linear regression analyses.Twenty-nine ENB-guided dye markings were done for 24 nodules in 20 patients. The success rate of the dye marking and nodule localization were 93.1% (27/29) and 95.8% (23/24), respectively. Twenty-three nodules were completely resected thoracoscopically without conversion. There were no ENB-related complications: pneumothorax or bronchopulmonary hemorrhage. Nine targets were in the upper, 14 in the middle, and 6 in the lower zone. Even though navigation time was longer in the upper zone, target distance showed no significant inter-zone difference. Approach angle was the only significant predictor for target distance (0-45°, estimate = -1.24, P = .01; 45-90°, estimate = -1.26, P = .006; reference = ≥90°).Localization with ENB-guided dye marking is effective and safe for thoracoscopic resection of small subsolid nodules. For better performance, a pathway with smaller approach angle (<90°) should be selected to increase the navigation accuracy.

The prognostic effect of the epidermal growth factor receptor gene mutation on recurrence dynamics of lung adenocarcinoma.

OBJECTIVES: The prognostic effects of epidermal growth factor receptor (EGFR) gene mutation on lung adenocarcinoma recurrence have not been well established. The relationship between EGFR gene mutation and recurrence dynamics of lung adenocarcinoma was investigated. METHODS: A total of 527 patients with complete resection for adenocarcinoma were reviewed retrospectively. EGFR gene mutation was analysed by polymerase chain reaction followed by bidirectional direct sequencing in recurred patients. Patients were divided into the EGFR gene mutation group (M) or the wild-type EGFR gene group (W). Recurrence types and disease-free intervals (DFIs) of the 2 groups were compared. DFIs were calculated by the Kaplan-Meier method and compared using the log-rank test and Cox proportional hazard model. RESULTS: EGFR gene sequencing was performed in 115 recurrent adenocarcinoma patients. Sixty-six patients had EGFR mutations and 49 patients had wild-type EGFR. The median DFI of the 2 groups were significantly different (M: 20.3 months, W: 15.1 months, P = 0.012). EGFR gene mutation was the only prognostic factor for DFI [hazard ratio (HR) = 0.639, 95% confidence interval (CI) = 0.428-0.954, P = 0.029]. The proportion of loco-regional recurrences and distant metastases of both groups were similar (P = 0.50). In subgroup analysis, EGFR gene mutation (HR = 0.534, 95% CI = 0.339-0.839, P = 0.007) was a significant prognostic factor for DFI of distant metastases. CONCLUSIONS: Lung adenocarcinoma with EGFR gene mutations had longer DFI than those with wild-type EGFR gene, especially with regard to distant metastasis. EGFR gene mutation was a prognostic factor for lung adenocarcinoma.

Erratum: Outcomes of the Multimodal Treatment of Malignant Pleural Mesiothelioma: The Role of Surgery.

[This corrects the article on p. 35 in vol. 51, PMID: 29430427.].

Outcomes of the Multimodal Treatment of Malignant Pleural Mesiothelioma: The Role of Surgery.

BACKGROUND: The treatment of malignant pleural mesothelioma (MPM) is challenging, and multimodal treatment including surgery is recommended; however, the role of surgery is debated. The treatment outcomes of MPM in Korea have not been reported. We analyzed the outcomes of MPM in the context of multimodal treatment, including surgery. METHODS: The records of 29 patients with pathologically proven MPM from April 1998 to July 2015 were retrospectively reviewed. The treatment outcomes of the surgery and non-surgery groups were compared. RESULTS: The overall median survival time was 10.6 months, and the overall 3-year survival rate was 25%. No postoperative 30-day or in-hospital mortality occurred in the surgery group. Postoperative complications included tachyarrhythmia (n=4), pulmonary thromboembolism (n=1), pneumonia (n=1), chylothorax (n=1), and wound complications (n=3). The treatment outcomes between the surgery and non-surgery groups were not significantly different (3-year survival rate: 31.3% vs. 16.7%, respectively; p=0.47). In a subgroup analysis, there was no significant difference in the treatment outcomes between the extrapleural pneumonectomy group and the non-surgery group (3-year survival rate: 45.5% vs. 16.7%, respectively; p=0.23). CONCLUSION: Multimodal treatment incorporating surgery did not show better outcomes than non-surgical treatment. A nationwide multicenter data registry and prospective randomized controlled studies are necessary to optimize the treatment of MPM.

A study of the learning curve for robotic oesophagectomy for oesophageal cancer.

OBJECTIVES: Robot-assisted minimally invasive oesophagectomy (RAMIE) enables radical, meticulous dissection of the oesophagus and lymph nodes. Our goal was to identify the effect of the learning curve for RAMIE when performing radical upper mediastinal dissection in patients with oesophageal cancer. METHODS: We conducted a retrospective review of a prospectively maintained database of patients who underwent RAMIE for oesophageal cancer between May 2008 and July 2016. The gain in proficiency for each postoperative outcome measure was presented using observed-expected cumulative sum (O-E CUSUM) curves. The change points were defined at the maximal distance from the zero axis. RESULTS: A total of 140 patients were included. Squamous cell carcinoma (n = 131, 93.6%) was the dominant type. Thirty-day and 90-day deaths occurred in 1 and 5 patients (0.7% and 3.6%, respectively). The change points of the risk-adjusted O-E CUSUM curves were similar to those of the unadjusted O-E CUSUM curves with the exception of those for thoracic procedure time and vocal cord palsy. The number of harvested lymph nodes increased from 25 to 45 before and after 30 cases. The vocal cord palsy rate decreased from 36% to 17% before and after 60 cases. The total operation time decreased from 496 min to 431 min; the length of the hospital stay decreased from 24 days to 14 days; and the anastomotic leakage rate decreased from 15% to 2% before and after 80 cases. CONCLUSIONS: Our study demonstrated a temporal improvement in postoperative outcomes based on accumulated experience with RAMIE. The risk-adjusted O-E CUSUM curves were similar to the unadjusted O-E CUSUM curves, which represents the significant impact of the effect of a learning period on the postoperative outcomes of RAMIE in patients with oesophageal cancer.