Ahmet Demirkaya

WWOX gene may contribute to progression of non-small-cell lung cancer (NSCLC)

Lung cancer is the most common cause of cancer-related death worldwide and, like many other cancers, is affected by different genetic, epigenetic, and environmental factors. The WW domain-containing oxidoreductase (WWOX) gene is a tumor-suppressor gene located on chromosome 16q23.3–24.1, and it has been shown that it loses its function due to alterations in genetic and epigenetic mechanisms. The aim of this study is to investigate the relationship between lung cancer and WWOX gene. Tumor tissue samples, corresponding normal tissues, and blood samples obtained from 50 lung cancer patients were involved in the study. We analyzed methylation profile by methylation-specific PCR and mutations and polymorphisms by DNA sequencing. Methylation analysis showed that promoter hypermethylation was present in 38 of 50 (76%) patients. In addition, promoter region of WWOX gene of younger patients was more frequently methylated than older patients. Using DNA sequencing, we found four genetic alterations in WWOX gene. Two of them were germline mutations (Exon 4 and 7), and two of them were polymorphic (Exon 6 and 8). We found a new mutation in exon 7 (Arg-254→Cys) which has not been described previously. The changes in the short-chain dehydrogenase domain of the protein caused by the genetic alterations may affect the function of the gene. We conclude that hypermethylation of WWOX gene promoter region and mutations in the gene might be related to lung carcinogenesis.

Reconstruction with a patient-specific titanium implant after a wide anterior chest wall resection

The reconstruction of full-thickness chest wall defects is a challenging problem for thoracic surgeons, particularly after a wide resection of the chest wall that includes the sternum. The location and the size of the defect play a major role when selecting the method of reconstruction, while acceptable cosmetic and functional results remain the primary goal. Improvements in preoperative imaging techniques and reconstruction materials have an important role when planning and performing a wide chest wall resection with a low morbidity rate. In this report, we describe the reconstruction of a wide anterior chest wall defect with a patient-specific custom-made titanium implant. An infected mammary tumour recurrence in a 62-year old female, located at the anterior chest wall including the sternum, was resected, followed by a large custom-made titanium implant. Latissimus dorsi flap and split-thickness graft were also used for covering the implant successfully. A titanium custom-made chest wall implant could be a viable alternative for patients who had large chest wall tumours.

Association of epidermal growth factor receptor and K-Ras mutations with smoking history in non-small cell lung cancer patients

Lung cancer, a major health problem affecting the epithelial lining of the lower respiratory tract, is considered to be one of the deadliest types of cancer in males and females and it is well-known that smoking is the chief cause of lung cancer. In addition to smoking and environmental factors, genetic susceptibility may also contribute to the development of lung cancer. Previous studies have shown that certain non-small cell lung cancer (NSCLC) patients harbor gain-of-function mutations in the epidermal growth factor receptor gene (EGFR). Phosphorylated EGFR triggers the activation of intracellular signal transduction pathways, including the RAS-MAPK, PI3K-Akt and STAT pathways. However, K-Ras gene point mutations in codons 12, 13 or 61 cause the inactivation of GTPase activity which results in overstimulation of cellular growth and gives rise to neoplastic development. Our aim was to investigate the presence and association of EGFR and K-Ras mutations in 50 primary NSCLC patients with a smoking history by using real-time PCR and sequencing. EGFR mutations were detected in four patients (8%). Two of these mutations were L858R mutations and the remaining two were deletion mutations spanning between codons 746 and 750. The L858R mutation was significantly associated with smoking status (P=0.003). K-Ras codon 12 and 61 mutations were also observed in four patients. However, no association was observed between K-Ras mutations and the tumor staging, gender, histology and smoking status of the patients.

Unusual cause of dysphagia: inflammatory pseudotumor of the lung.

Inflammatory pseudotumor (IPT) is a rare disease that usually occurs in the lung. Patients with IPT are usually asymptomatic, with a solitary pulmonary nodule or mass detected on routine chest roentgenogram. IPT can behave as a malignant tumor both clinically and radiologically. Cough, fever, dyspnea, and hemoptysis are the usual presenting symptoms. This report describes the case of a 37-year-old man with a 4-month course of dysphagia secondary to lower esophageal invasion by the posterior mediastinal extension of a lung IPT.

Minimally invasive repair of pectus excavatum (MIRPE) in adults: is it a proper choice?

Introduction The Nuss procedure is suitable for prepubertal and early pubertal patients but can also be used in adult patients. Aim To determine whether the minimally invasive technique (MIRPE) can also be performed successfully in adults. Material and methods Between July 2006 and January 2016, 836 patients (744 male, 92 female) underwent correction of pectus excavatum with the MIRPE technique at our institution. The mean age was 16.8 years (2–45 years). There were 236 adult patients (28.2%) (> 18 years) – 20 female, 216 male. The mean age among the adult patients was 23.2 years (18–45 years). The recorded data included length of hospital stay, postoperative complications, number of bars used, duration of the surgical procedure and signs of pneumothorax on the postoperative chest X-ray. Results The MIRPE was performed in 236 adult patients. The average operative time was 44.4 min (25–90 min). The median postoperative stay was 4.92 ±2.81 days (3–21 days) in adults and 4.64 ±1.58 (2–13) in younger patients. The difference was not statistically significant (p = 0.637). Two or more bars were used in 36 (15.8%) adult patients and in 44 (7.5%) younger patients. The difference was not statistically significant either (p = 0.068). Regarding the overall complications, complication rates among the adult patients and younger patients were 26.2% and 11.8% respectively. The difference was statistically significant (p = 0.007). Conclusions MIRPE is a feasible procedure that produces good long-term results in the treatment of pectus excavatum in adults.

A prospective randomized trial comparing homologous and autologous fibrin sealants for the control of alveolar air leak

Background Postoperative air leak is a common complication seen after pulmonary resection. It is a significant reason of morbidity and also leads to greater hospital cost owing to prolonged length of stay. The purpose of this study is to compare homologous sealant with autologous one to prevent air leak following pulmonary resection. Methods A total of 57 patients aged between 20 and 79 (mean age: 54.36) who underwent pulmonary resection other than pneumonectomy (lobar or sublobar resections) were analyzed. There were 47 males (83%) and 10 females (17%). Patients who intraoperatively had air leaks were randomized to receive homologous (Tisseel; n=28) or autologous (Vivostat; n=29) fibrin sealant. Differences among groups in terms of air leak, prolonged air leak, hospital stay, amount of air leak were analyzed. Results Indications for surgery were primary lung cancer in 42 patients (71.9%), secondary malignancy in 5 patients (8.8%), and benign disease in 10 patients (17.5%). Lobectomy was performed in 40 patients (70.2%), whereas 17 patients (29.8%) had wedge resection. Thirteen (46.4%) patients developed complications in patients receiving homologous sealant while 11 (38.0%) patients had complication in autologous sealant group (P=0.711). Median duration of air leak was 3 days in two groups. Time to intercostal drain removal was 3.39 and 3.38 days in homologous and autologous sealant group respectively (P=0.978). Mean hospital stay was 5.5 days in patients receiving homologous sealant whereas it was 5.0 days in patients who had autologous agent (P=0.140). There were no significant differences between groups in terms of measured maximum air leak (P=0.823) and mean air leak (P=0.186). There was no significant difference in the incidence of complications between two groups (P=0.711). Conclusions Autologous and heterologous fibrin sealants are safe and acts similarly in terms of air leak and hospital stay in patients who had resectional surgery.

CHD5 is a potential tumor suppressor in non small cell lung cancer (NSCLC)

Lung cancer is one of the deadliest types of cancers and genetic and epigenetic alterations play major roles in its development. Chromodomain (CHD) protein family acts in chromatin organization, regulation of transcription and also genomic stability and cancer prevention. Although CHD5, a member of this family was shown to contribute to major cellular events and functions as a tumor suppressor gene in various types of cancer, it is not clear whether CHD5 plays a role in lung carcinogenesis. The aim of this study was to investigate the possible role of CHD5 in progression of non-small cell lung cancer (NSCLC). Expression levels of CHD5 gene in 59 tumor and corresponding non-cancerous lung tissue samples were analyzed by qRT-PCR and the methylation status of the promoter region was investigated by methylation specific PCR (MS-PCR). The Akt phosphorylation levels were investigated by Western Blot (WB). CHD5 was down-regulated in 17 (39.5%) and up-regulated in 24 (55.8%) of tumor specimens. Even though the promoter of CHD5 was hypermethylated in 8 patients, it was not found associated with CHD5 gene expression (p=0.08). Akt phosphorylation was increased in 14 (53.8%) and decreased in 12 (46.2%) of the samples but no significant association was found between p-Akt phosphorylation and CHD5 expression (p=0.67). We suggest that CHD5 may act as a tumor suppressor gene in NSCLC.

Vascular thoracic outlet syndrome developed after minimally invasive repair of pectus excavatum.

The Nuss procedure is a minimally invasive surgical repair technique for pectus excavatum with fewer delayed complications compared to open procedures. We report the case of a 22-year-old man with deep pectus excavatum who developed vascular thoracic outlet syndrome after the Nuss procedure. Further evaluation demonstrated that the first rib was causing severe obstruction of the right subclavian artery. The patient showed clinical features of subclavian artery compression. A first rib resection, division of the anterior scalene muscle and fibrous bands provided complete relief of the complaints. The forced structural and spatial changes produced by the elevation of the depressed upper chest might have caused this complication. Vascular thoracic outlet syndrome should be kept in mind as a possible complication in patients who have undergone minimally invasive repair of pectus excavatum, and this complication can be treated by first rib resection.

Comparative study of video-assisted thoracoscopic surgery versus open thymectomy for thymoma and myasthenia gravis

Introduction Thymectomy is the preferred standard treatment in younger non-thymoma patients with myasthenia gravis as well as in patients with early stage thymoma. Total thymectomy by median sternotomy has been the surgical approach since resection of the thymus with video-assisted thoracoscopic surgery (VATS). Aim To compare the clinical outcomes of VATS thymectomy with conventional open thymectomy for neoplastic and non-neoplastic thymic diseases. Material and methods Forty patients underwent thymectomy between October 2012 and January 2016. Fifteen patients were male and 25 patients were female. The mean age was 40.3 ±17.7 years. Seventeen (55%) patients underwent VATS thymectomy and 23 (45%) patients underwent an open procedure. We retrospectively reviewed the data of the patients and compared these two techniques. Results The mean tumor size was 5.17 ±3.2 cm in the thymoma group (VATS 2.5 ±2.4 cm vs. open access 4.7 ±3.7 cm). None of the patients experienced a myasthenic crisis. Conversion to thoracotomy was required in 1 patient in the VATS group due to bleeding from the right internal mammary artery; therefore, the conversion rate was 2.5% among all the patients. No mortality occurred in either group. No significant difference was found in the perioperative blood loss, operative time or pain visual analogue scale scores. On the other hand, regarding postoperative drainage, duration of chest tube drainage and length of hospital stay, VATS thymectomy yielded better results and the differences were significant. Conclusions Video-assisted thoracoscopic surgery thymectomy can be performed for both neoplastic and non-neoplastic thymic diseases with minimal morbidity and mortality.

Uniportal versus multiport video-assisted thoracoscopic surgery for anatomical lung resections: a glance at a dilemma

Introduction As the number of operations performed by videothoracoscopy is increasing, there is also a tendency to decrease the number of port incisions. Apart from the reduced number of surgical incisions, there are a few reports and systematic reviews that demonstrate some potential advantages of the uniportal video-assisted thoracoscopic surgery, but the impact of the reduced incisions in the clinical setting still remains uncertain. Aim To compare uniportal video-assisted thoracoscopic surgery to multiport video-assisted thoracoscopic surgery for anatomical lung resections in patients with malignant and benign lung diseases. Material and methods From August 2010 to April 2016, a total of 102 patients with malignant and benign lung diseases underwent videothoracoscopic lobar and sublobar lung resections in our department. Comorbidities, tumor stage, tumor localization, mortality, operative time, pain visual analogue scale, length of hospital stay, perioperative blood loss, duration and amount of postoperative drainage and air leak, number of harvested lymph nodes and complication rates were analyzed. Results No significant difference was found in the duration of chest tube drainage, pain visual analogue scale score, length of hospital stay, perioperative blood loss, amount of postoperative drainage, number of harvested lymph nodes or complication rate. There was no surgical mortality in either of the two groups. However, operative time was shorter (189 min vs. 256 min, p < 0.005) in the multiport group than in the uniportal group. Conclusions Compared with the uniportal approach, the multiport approach is associated with a significantly shorter operative time in our study.