Circulating endothelial cells (CECs) as well as bone-marrow-derived endothelial precursor cells (EPC) play an important role in neovascularisation and tumour growth. To study the impact of neoadjuvant chemotherapy on the amounts of CEC and their precursor cells, mature CEC and their progenitors were quantified by flow cytometry in peripheral blood of breast cancer patients during anthracycline and/or taxane based neoadjuvant chemotherapy and subsequent surgery in comparison to age-matched healthy controls. Cell numbers were tested for correlation with serum levels of angiopoietin-2, erythropoietin, endostatin, endoglin, VEGF and sVCAM-1 as well as clinical and pathological features of breast cancer disease. Circulating endothelial cells were significantly elevated in breast cancer patients and decreased during chemotherapy, whereas EPC (CD34 þ /VEGFR-2 þ ) as well as their progenitor cell population CD133 þ /CD34 þ and the population of CD34 þ stem cells increased. Concomitantly with the increase of progenitor cells an increase of VEGF, erythropoietin and angiopoietin-2 was observed. These data suggest that chemotherapy can only reduce the amounts of mature CEC, probably reflecting detached cells from tumour vessels, whereas the EPC and their progenitors are mobilised by chemotherapy. Since this mobilisation of EPC may contribute to tumour neovascularisation an early antiangiogenic therapy in combination with chemotherapy could be beneficial for the success of cancer therapy.

The superior vena cava syndrome (SVCS) comprises various symptoms due to occlusion of the SVC, which can be easily obstructed by pathological conditions (eg, lung cancer, due to the low internal venous pressure within rigid structures of the thorax [trachea, right bronchus, aorta]). The resulting increased venous pressure in the upper body may cause edema of the head, neck, and upper extremities, often associated with cyanosis, plethora, and distended subcutaneous vessels. Despite the often striking clinical presentation, SVCS itself is usually not a life-threatening condition. Currently, randomized controlled trials on many clinically important aspects of SVCS are lacking. This review gives an interdisciplinary overview of the pathophysiology, etiology, clinical manifestations, diagnosis, and treatment of malignant SVCS.