Head and throat squamous cell carcinomas (HNSCCs) are the sixth most common malignancy in the world. areas seems to play a protumoral role by secreting VEGF and stimulating the neoangiogenesis. 1 Epidemiology Treatment and Prognosis Head and neck squamous cell carcinomas (HNSCCs) remain a significant cause of morbidity worldwide with approximately 650 0 new cases diagnosed each year [1 2 HNSCCs constitute a collection of diseases that although united by location and histology can become very different types of tumors that differ in pathogenesis biology sublocation and treatment and that can affect quality of life including survival [1 2 HNSCC patients associated with low clinical stages (stages I and II) have similar survival rates with a SB 743921 5-12 months survival between 70% and 90% independent of the sublocation [3]. In contrast HNSCC patients with advanced clinical stages (stages III and IV) display completely different survival rates depending on the histological type of the tumor and its sublocation [3 4 The treatment of HNSCC patients with advanced stages of disease combines surgery radiation oncology medical oncology medical imaging and clinical pathology [1-4]. This type of collaborative medical approach was initiated as early as 1970 when Fletcher and Evers reported the first convincing evidence of the benefits of combining radiotherapy with surgery [5]. With this SB 743921 context cisplatin was investigated in the treatment of HNSCC in the early 1970s and from your late SB 743921 1970s to the early 1990s promising results were obtained with the use of various mixtures of postoperative chemotherapy with radiotherapy in randomized [6] and nonrandomized studies [7]. In the early SB 743921 2000s the Radiation Therapy Oncology Group [4] and the Western Organization for Study and Treatment of Malignancy (EORTC) [8] carried out two randomized studies to test the relative effectiveness of concurrent postoperative cisplatin administration and radiotherapy in the treatment of HNSCC. These two studies shown that local control of the disease was significantly higher in the combined therapy group than in the group that received radiotherapy only [4 8 Regrettably these combined treatments were frequently associated with adverse side effects. Although significant progress has been observed after combined treatments a number of statements currently remain valid concerning HNSCCs: (i) almost two-thirds of HNSCC individuals possess advanced forms (phases III and IV) of the disease at analysis (ii) 50% of the individuals pass away of HNSCC within the two years following initial analysis and (iii) every year 5 of the individuals develop additional main tumors. Therefore novel approaches seem to be required to provide SB 743921 head and neck oncologists with a more effective armamentarium against this demanding disease [9 10 2 Immune System and Cancers In the 1950s Burnet and Thomas proposed the concept of immune surveillance of malignancy. This physiological function would have the ability to identify tumor cells as irregular cells and to ruin them before they develop into dangerous detectable tumors [11]. Tumor growth invasion and metastasis are important aspects of the tumor immune escape. The different mechanisms that are developed by tumor cells are a defect of manifestation of antigens within the tumor cell surface; a loss or a reduction of the manifestation of MHC (major histocompatibility complex) class 1 molecules a loss of manifestation of costimulatory molecules the production of immunosuppressive molecules such as transforming growth element (TGF)-production [46] and (v) evidence of pronounced apoptotic features in a considerable proportion of TILs [38 47 Moreover immune cell dysfunction in HNSCC individuals appears to lengthen much beyond the tumor PRKACG microenvironment because both practical defects and massive lymphocyte death have also been observed in the peripheral blood circulation of individuals with advanced HNSCC [48]. In addition HNSCC cells that create proinflammatory cytokines autonomously are endowed with an advantage regarding success and development [49]. HNSCC cells also generate high levels of TGF-subunits from the proteolytic delta and MB1 inducible proteasome convert immature DCs into tolerogenic DCs that may stimulate antigen-specific T-cell tolerance via many mechanisms.