Current relevance of hypoxia in head and neck cancer

Abstract

Head and Neck cancer (HNC) is a complex mix of cancers and one of the more common cancers with a relatively poor prognosis. One of the factors that may assist us in predicting survival and allow us to adjust our treatment strategies is the presence of tumor hypoxia. In this overview we aim to evaluate the current evidence and potential clinical relevance of tumor hypoxia in head and neck cancer according to an extensive search of current literature.An abundance of evidence and often contradictory evidence is found in the literature. Even the contradictory evidence and comparisons are difficult to judge as criteria and methodologies differ greatly, furthermore few prospective observational studies exist for verification of the pre-clinical studies. Despite these discrepancies there is clear evidence of associations between prognosis and poor tumor oxygenation biomarkers such as HIF-1α, GLUT-1 and lactate, though these associations are not exclusive. The use of genetic markers is expanding and will probably lead to significantly more and complex evidence. The lack of oxygenation in head and neck tumors is of paramount importance for the prediction of treatment outcomes and prognosis. Despite the wide array of conflicting evidence, the drive towards non-invasive prediction of tumor hypoxia should continue.

Hypoxia modulates CCR7 expression in head and neck cancers

“…and is associated with resistance to radiotherapy, reduced therapeutic response, and a poorer clinical outcome. [53,54] The role of hypoxia in head and neck tumours is undoubtedly complex and acts through multiple pathways. However, understanding the mechanisms by which hypoxia can promote the tumour progression, provides opportunities to combat its negative impact on the disease.…”

Tumor Macroenvironment: An Update

“…Although rare, they are well characterized and studied because of the direct relevance to the clinic [16]. In addition to the paraneoplastic syndromes, it appears appropriate to mention here that the recent literature on tumor and homeostasis has confirmed the importance of understanding the whole complex of disturbance in cancer patients -the tumor macroenvironment -for better management and treatment [17][18][19][20][21][22].…”

Srednji volumen trombocita kod karcinoma grkljana – uloga u određivanju stadija karcinoma

“…Kronična upala prati sve stadije karcinoma grkljana te je upravo ona važan uzrok hipoksije tumorskog tkiva. Hipoksiju tumora označava smanjenje parcijalnog tlaka kisika (pO 2 ) u tkivu tumora u odnosu na okolno zdravo tkivo 18 . Rezultat smanjene obskrbe kisikom je stvaranje novih krvinih žila.…”

“…Osim VEGF-a kod karcinoma grkljana opisana je i uloga ostalih biomarkera, poput EGFR-a (engl. epidermal growth factor receptor), eritropoetina (EPO) i EPOR-a (eritropoetin receptor) 18,20 . EGFR je transmembranski protein koji ima ključnu ulogu u regulaciji staničnog ciklusa.…”