Mutational load in carotid body tumour

Carotid body tumour (CBT) is the most frequently paraganglioma of head and neck that arises from carotid glomus. Tumour development is closely associated with accumulation of somatic mutations. They could lead to changes in the expression profiles of many genes, including activation of oncogenes and inhibition of tumorsuppressor genes that leads to alterations in various signaling pathways, cell cycle, metabolism, etc. Response to DNA damage occurs as one of the early event in tumorigenesis . It plays a central role in cellular homeostasis and immune response activation, and tumour cells use different mechanisms to escape from immune system. Mutations may create neoantigens that are potential targets for anti-tumor immune response. Melanoma and lung cancer, which are characterized by high mutational load (ML), were demonstrated clinical benefit from immunotherapy. Response to immunecheckpoint blockade therapy has been described in colorectal cancer patients with microsatellite instability (MSI) resulting from defects in mismatch-repair pathways compared to patients with lower mutational load. ML, MSI, as well as neoantigen production were shown as promising markers of sensitivity to immune checkpoint blockade for a few tumors. In this work, we have carried out an accurate estimation of ML in carotid body tumours.