[Development of thoracic surgery over the next 20 years]

Thoracic surgery is one of the self-contained surgical disciplines with an above average large potential over the next 20 years. An increase in mortality due to pulmonary diseases is to be expected worldwide. Bronchial carcinoma is the most common diagnosis in thoracic surgery patients and will remain a relevant topic for health politics for many years. However, the adequate treatment of these patients demands a high degree of interdisciplinary cooperation. In the future thoracic surgery will therefore be carried out in centres with an organ-dependent and interdisciplinary structure. From a surgical technical perspective minimally invasive operation strategies will become established for standard interventions, which are indispensible components of the repertoire for thoracic surgery. Thoracic surgery is traditionally a clinically oriented discipline with low academic superstructure and a high backlog demand in nearly all areas of research. It offers a large field of activity for the next scientifically interested generation with excellent chances to become established and succeed in this discipline with a very promising future.

Expression and mutational status of PDGFR in thymic tumours

BACKGROUND

There is an ongoing search for new therapeutic targets in invasive non-resectable thymic tumours because of the low response rates in current chemotherapeutic treatment modalities. In this study, the possibility that platelet-derived growth factor receptor A (PDGFRA) and/ or PDGFRB may represent potential therapeutic targets in epithelial tumours of the thymus was investigated.

PATIENTS AND METHODS

Tissue samples were obtained by thymectomy from 36 different patients with epithelial tumours of the thymus (26 thymomas types A, AB, B1-3 and 10 thymic carcinomas). Normal thymi from three young children were used as controls. The PDGFRA and PDGFRB protein expressions as well as the mutational statuses of exons 12, 14 and 18 of the PDGFRA gene were analyzed.

RESULTS

All the subtypes of thymomas and the thymic carcinomas showed staining for PDGFRA, but no mutations in the known mutational hotspots were identified. Only about one third of the tumours stained for PDGFRB. PDGFRA and PDGFRB protein staining were slightly positively correlated.

CONCLUSION

PDGFRA may represent a potential therapeutic target in thymic tumours.

Identification of immunohistochemical prognostic markers for survival after resection of pulmonary metastases from colorectal carcinoma

BACKGROUND

Although aggressive resection of pulmonary metastases prolongs the survival of patients with metastatic colorectal cancer, there is a need for predictive pathologic parameters to understand the key molecular events of metastatic progression. The aim of this study was to verify immunohistochemical markers in addition to established clinical parameters after surgery.

METHODS

From our subset of patients undergoing resection of pulmonary metastases from metastatic colorectal carcinoma, we analyzed 39 patients (23 men and 16 women) between 2003 and 2007. Only patients who met the criteria for a potentially curative operation were included. All patients were analyzed with regard to age and sex, primary tumor location, stage of the primary tumor, history of hepatic metastases, number of pulmonary metastases, pre-thoracotomy carcinoembryonic (CEA) serum antigen level, and the presence of thoracic lymph node metastasis. Furthermore, we immunohistochemically investigated the expression of vascular endothelial growth factor (VEGF)-D, FBJ murine osteosarcoma viral oncogene homolog B (FOS-B), and melanoma antigen (MAGE)-A in the surgical specimens of pulmonary metastatic lesions.

RESULTS

The overall 3-year survival was 50.6 %. A significantly longer survival was observed with multivariate analysis in patients with a pre-thoracotomy serum carcinoembryonic antigen level of no more than 4.2 ng/mL ( P = 0.001), and Dukes stage A or B primary tumor ( P = 0.001). A significantly longer recurrence-free survival was observed with multivariate analysis in patients without thoracic lymph node involvement compared to patients with pulmonary and/or mediastinal lymph node metastases ( P = 0.006). The stage of the primary tumor remained significant ( P = 0.029), and FOS-B expression in tumor cells showed a trend towards favorable recurrence-free survival after pulmonary metastasectomy ( P = 0.059). No statistically significant difference was found in the overall survival rate or recurrence-free survival rate of patients with expression of VEGF-D or MAGE-A antigen in pulmonary metastatic tumor cells.

CONCLUSIONS

Our results suggest that in addition to clinically prognostic factors, FOS-B expression has a debatable impact on patient survival. We conclude that the evaluation of molecular and clinical prognostic parameters at the time of pulmonary metastasectomy offers a greater understanding of the metastatic process and provides important information for patient selection.

[Current surgical management of pulmonary metastases]

Surgical resection has been the first choice for the treatment of isolated pulmonary metastases secondary to extrapulmonary malignancies. Despite recent advances, systemic chemotherapy for metastatic disease without the use of surgery is considered to be merely palliative, as there are rarely long-term survivors. Criteria for resection and prognostic parameters help facilitate patient selection. In addition to the established parameters the most significant factors in selecting patients for operation include the number of pulmonary metastases, disease-free interval, serum tumour marker level, and the question of mediastinal and hilar lymph node metastases. Complete surgical resection is critical to achieving long-term survival and is best accomplished via open thoracotomy accompanied by a systematic mediastinal and hilar lymph node dissection. The recent development of video-assisted thoracoscopic surgery (VATS) and advances in thoracic imaging technique has made the VATS approach more amenable for resection of small pulmonary nodules. However, the oncological radicality of VATS is questionable for pulmonary metastasectomy, thus the VATS approach is mostly limited to diagnostic purposes and in highly selected groups of patients with limited, peripherally located lesions. These operations should be performed preferably within a prospective study setting. All results together demonstrate that resection and re-resection of pulmonary metastases can be beneficial in patients, carefully selected by a multidisciplinary tumour board of thoracic surgeons and medical oncologists.

Guidelines of the European Respiratory Society and the European Society of Thoracic Surgeons for the management of malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a rare tumour but with increasing incidence and a poor prognosis. In 2008, the European Respiratory Society/European Society of Thoracic Surgeons Task Force brought together experts to propose practical and up-to-dated guidelines on the management of MPM. To obtain an earlier and reliable diagnosis of MPM, the experts recommend performing thoracoscopy, except in cases of pre-operative contraindication or pleural symphysis. The standard staining procedures are insufficient in approximately 10% of cases. Therefore, we propose using specific immunohistochemistry markers on pleural biopsies. In the absence of a uniform, robust and validated staging system, we advice use of the most recent TNM based classification, and propose a three step pre-treatment assessment. Patient's performance status and histological subtype are currently the only prognostic factors of clinical importance in the management of MPM. Other potential parameters should be recorded at baseline and reported in clinical trials. MPM exhibits a high resistance to chemotherapy and only a few patients are candidates for radical surgery. New therapies and strategies have been reviewed. Because of limited data on the best combination treatment, we emphasise that patients who are considered candidates for a multimodal approach should be included in a prospective trial at a specialised centre.

The individuality of tumor-stroma interaction in non-small cell lung cancer: Insights from functional and molecular analyses

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Background: Tumor-stroma interaction plays a significant role for malignant growth. Results from prostate and breast cancer rodent models show cancerogenic properties of tumor-associated and genetically altered stromal cells (SC) when combined with initiated or normal epithelium (Olumi et al., Cancer Res 1999, Kuperwasser et al., PNAS 2004). However, data on the mechanisms and sequels of tumor-stroma interaction in lung cancer are scanty. Methods: Here, we analyzed the functional and molecular sequels of cross-talk between the non-small cell lung cancer (NSCLC) cell lines A549, H23, and H1703 and primary stromal cells (SC) derived from matched normal lung tissue and tumors of newly diagnosed NSCLC patients. Tumor cells were kept in a non-contact co-culture system with SC and analyzed for alterations in proliferation, colony formation, migration, adhesion, invasion, chemosensitivity and gene expression by Affymetrix HG U133 Plus 2.0 arrays. Results: Exposure to SC altered cellular functions and gene expression profiles related to tumor growth, metastasis and response to therapy. Each cell line showed individual alterations that were hierarchically governed by the (1) type of tumor cell, (2) the SC donor and his histology (3) and the local origin of the SC (normal lung tissue vs. tumor-associated). Conclusions: This in vitro model demonstrates an individual pattern of tumor-stroma interaction in NSCLC that is determined by both, the properties of the tumor cells and those of the stromal environment. Thus, biomarker programs in NSCLC should also consider the stromal compartment.

No significant financial relationships to disclose.

[Pleural drainage]

A chest tube is used to drain the contents of the pleural space to reconstitute the physiologic pressures within the pleural space and to allow the lungs to fully expand. Indications for chest tube placement include pneumothorax, hemothorax, pleural effusion, pleural empyema, and major thoracic surgery. The most appropriate site for chest tube placement is the 4th or 5th intercostal space in the mid- or anterior- axillary line. Attention to technique in placing the chest tube is vital to avoid complications from the procedure. Applying the step-by-step technique presented, placement of a chest tube is a quick and safe procedure. Complications - frequently occurring when the tube is inserted with a steel trocar - include hemothorax, dislocation, lung lacerations, and injury to organs in the thoracic or abdominal cavity.

Incidence and treatment modalities of tracheobronchial injuries in Germany

This study presents the first systematic data collection on incidence and therapeutic management of both iatrogenic and non-iatrogenic tracheal lacerations in Germany. In this survey (n=231 questionnaires) based on the geographical coverage of the country, the representation of all levels of service, and the inclusion of specialized thoracic departments as well as non-specialized surgical departments, a representative conspectus on the management of tracheal injuries in Germany was developed. A total number of 1033 tracheal injuries were reported; n=429 of non-iatrogenic origin (blunt trauma: n=276, penetrating wounds: n=94, bullet wounds: n=16, other etiology: n=43) and n=604 of iatrogenic origin (endotracheal intubations/mechanical ventilation: n=372, dilative tracheotomy: n=181, endoscopic interventions: n=51). In institutions of high level of service there was a trend towards higher rates of surgical repair as opposed to conservative management. On the basis of these data the estimated risk of tracheal lacerations, due to single lumen intubation was 1:75,000 (0.000013%); the risk of clinically significant tracheal lacerations due to dilative tracheostomy 1:575 (0.002%) and lacerations requiring surgical treatment 1:975 (0.001%). Data of this survey state that specialized thoracic surgeons to a high proportion are involved in the management of both iatrogenic and non-iatrogenic tracheal injuries.

Recurrent pleural effusion: who benefits from a tunneled pleural catheter?

Recurrent malignant pleural effusion (MPE) is a common concomitant phenomenon of malignant disease, which can worsen the patient's quality of life and lead to significant morbidity. Tunneled indwelling pleural catheters (TIPC) offer new modalities in patients with recurrent MPE and impaired dilatability of the lung. We report on our experience with 100 consecutive patients suffering from recurrent benign (n = 12) and malignant pleural effusion (n = 88) who were treated with TIPC. The catheter was placed during a VATS procedure or under local anesthesia in an open technique. The median residence time of the TIPC was 70 days; spontaneous pleurodesis was achieved in 29 patients. The rate of complications was low: pleura empyema (n = 4), accidental dislodgement (n = 2), malfunction of the drainage (n = 3). In conclusion, TIPC is a useful method for the palliative treatment of patients with recurrent malignant or nonmalignant pleural effusions and 3 groups of patients seem to benefit most: a) patients with the intraoperative finding of a trapped lung in diagnostic VATS procedure; b) patients after a history of repeated pleuracenteses or previously failed attempts at pleurodesis; c) patients in a reduced condition with a limited lifespan due to underlying disease.

[Plastic surgical reconstruction of extensive thoracic wall defects after oncologic resection]

In defect reconstruction following radical oncologic resection of malignant chest wall tumors, adequate soft-tissue reconstruction must be achieved along with function, stability, integrity, and aesthetics of the chest wall. The purpose of this retrospective analysis was to evaluate the oncoplastic concept following radical resection of malignant chest wall infiltration with an interdisciplinary approach. Between 1999 and 2005, 36 consecutive patients (nine males, 27 females, mean age 55 years, range 20-78) were treated with resection for malignant tumors of the chest wall. Indications were locally recurrent breast carcinoma (patient n=22), thymoma (n=1), and desmoid tumor (n=1). Primary lesions of the chest wall were spinalioma (n=1), sarcoma (n=7), and non-small-cell lung cancer (n=2). There were distant metastases of colon and cervical cancer in one patient each. Soft-tissue reconstruction was carried out using primary closure (n=1), external oblique flap (n=1), pectoralis major myocutaneous flap (n=3), latissimus dorsi myocutaneous flap (n=18), vertical or transversal rectus abdominis myocutaneous flap (n=9), free tensor fascia lata- flap (n=6), trapezius flap (n=1), serratus flap (n=1), and one filet flap. In 15 reconstructive procedures microvascular techniques were used. An average of 3.4 ribs were resected. Stability of the chest wall was obtained with synthetic meshes. The latissimus dorsi flap is considered the flap of choice in chest wall reconstruction. However, alternatives such as pectoralis major flap, VRAM/TRAM flap, free TFL flap, and serratus flap must also be considered. Low mortality and morbidity rates allow tumor resection and chest wall reconstruction even in a palliative setting.

Matrix metalloproteinase 1 (MMP1) is associated with early-onset lung cancer

Matrix metalloproteinases (MMP) play a key role in the breakdown of extracellular matrix and in inflammatory processes. MMP1 is the most highly expressed interstitial collagenase degrading fibrillar collagens. Overexpression of MMP1 has been shown in tumor tissues and has been suggested to be associated with tumor invasion and metastasis. Nine haplotype tagging and additional two intronic single nucleotide polymorphisms (SNP) of MMP1 were genotyped in a case control sample, consisting of 635 lung cancer cases with onset of disease below 51 years of age and 1,300 age- and sex-matched cancer-free controls. Two regions of linkage disequilibrium (LD) of MMP1 could be observed: a region of low LD comprising the 5' region including the promoter and a region of high LD starting from exon 1 to the end of the gene and including the 3' flanking region. Several SNPs were identified to be individually significantly associated with risk of early-onset lung cancer. The most significant effect was seen for rs1938901 (P = 0.0089), rs193008 (P = 0.0108), and rs996999 (P = 0.0459). For rs996999, significance vanished after correction for multiple testing. For each of these SNPs, the major allele was associated with an increase in risk with an odds ratio between 1.2 and 1.3 (95% confidence interval, 1.0-1.5). The haplotype analysis supported these findings, especially for subgroups with high smoking intensity. In summary, we identified MMP1 to be associated with an increased risk for lung cancer, which was modified by smoking.

An institutional study on thymomas and thymic carcinomas: experience in 77 patients

BACKGROUND

Thymomas and thymic carcinomas are rare tumors of the anterior mediastinum. A WHO classification was introduced in 1999, which has been updated in 2004. Meanwhile, several retrospective studies have been carried out which have shown the prognostic significance of this classification together with Masaoka's staging system and the extent of surgery.

PATIENTS AND METHODS

Between 1983 and 2000, 77 patients (37 male, 40 female) underwent resection of thymomas and thymic carcinomas in our institution. Complete resection was achieved in 57 patients. The median follow-up was 72.6 months.

RESULTS

The overall 5-year survival rate was 71.4 %. The factors "histology" and "extent of resection" had the most important impact on survival. However, even among the patients with complete resection, 12 of them suffered a relapse. Among this patient group, the most important factors for disease-free survival were "tumor stage" and "histology". Patients with an incomplete resection had a 5-year survival rate of only 29 % in spite of adjuvant radiation and/or chemotherapy. Due to the high rate of relapse, the poor survival rate found in incompletely resected patients as well as the failure of classical chemotherapy regimens, especially in type B2 and type B3 thymomas and thymic carcinomas, the search for new chemotherapeutic schemes is mandatory.

CONCLUSION

Our study shows that there are still encouraging therapeutic options for thymomas and thymic carinomas. Type B2, type B3 thymomas and thymic carcinomas have worse outcomes in spite of adjuvant chemo- and radiotherapies. Especially in patients with incomplete surgical resection the outcome remains poor.

Pulmonary epithelioid hemangioendothelioma: report of three cases

Pulmonary epithelioid hemangioendothelioma (PEH) is a rare vascular tumor of low-grade malignancy, the prognosis of which remains unpredictable. Surgical and/or chemotherapeutic options have to be evaluated depending on intrathoracic tumor spread and systemic metastases. Three cases of PEH with both clinical and pathological findings are herein summarized and the relevant current literature discussed.

Establishment, characterization and drug sensitivity testing in primary cultures of human thymoma and thymic carcinoma

Thymomas and thymic carcinomas are peculiar epithelial tumors of the anterior mediastinum. They may show aggressive clinical behavior and are a paradigm for the interaction between the tumor and the immune system. So far, adequate functional studies enabling a better understanding of this malignancy have not been performed, since human thymoma/thymic carcinoma cell lines have not been available. Here, the authors describe the establishment, characterization and functional analyses of epithelial cell lines from a Type B1-thymoma and a poorly differentiated thymic carcinoma. By Fluorescence-activated cell sorting (FACS) analyses, both cell lines were aneuploid. The aneuploid cell fraction of the thymic carcinoma cell line was characterized by a high proliferation index of 55.9%, in contrast to a lower proliferation rate of the aneuploid cell fraction of the thymoma (19.7%). Array-based comparative genomic hybridization (aCGH) and conventional cytogenetic analysis of the thymoma revealed only minor imbalances whereas the thymic carcinoma was characterized by a complex karyotype in the hyperdiploid range that was readily defined with multicolor FISH (mFISH). Application of a selective COX-2 inhibitor reduced cell viability in both cell lines in a dose-dependent manner. In conclusion, these first cell lines of a thymoma and a CD5-positive thymic carcinoma are useful tools for further in vitro studies of cellular, molecular and genetic aspects of the disease and for functional tests to evaluate new therapeutic targets.