Oral cancer occurs most frequently on the lips or tongue, but can also manifest on the lining of the cheeks, the floor of the mouth, the gums or on the palate. In most cases the so-called squamous cell carcinoma occurs, and these tend to expand rapidly. Substances such as tobacco or excessive consumption of alcohol are factors associated with the majority of cases of oral cancer. Other factors that cause oral cancer are chronic irritation, human papillomavirus (HPV) infection, and ingestion of medication that weakens the immune system, and poor oral and dental hygiene. Men older than 40 are those mainly affected by this pathology. The treatment consists of the surgical removal of the tumour for small growths and removal together with the application of radiotherapy or chemotherapy for larger tumours.