CC OS - ORAL CANCERS

• Neoplasms


  An abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of normal tissues and persists in the same excessive manner after cessation of stimuli which evoked the change
• two types of Cancer

  • Benign
  • Malignant
• Cancer


  Any one of a large number of diseases characterized by the development of abnormal cells (mutation) that divide uncontrollably and have the ability to infiltrate (invasion). Cancer often has the ability to spread throughout your body (metastasis)
• Cancer is not one disease, it is a group of more than 100 different and distinctive diseases
• Types of oral cancer


  • Carcinomas (epithelial)
  • Sarcomas (connective)
  • Squamous mostly
  • Some salivary
  • Other malignancies
• Cancer is NOT contagious, it is not transferred directly
• Normal cell


  Cells in our bodies are constantly dividing to make new cells to replace those that are damaged or worn out. This process is controlled by particular genes (Tumor suppressor genes) that make sure the right number and type of new cells are made
• Mutated cell of carcinoma

  If a gene is damaged, cells may start to divide in an uncontrolled way. This may eventually lead to a cancer. The damage to the genes is called a mutation
• It is likely that several mutations occur in the genes before a cell starts to multiply out of control. This series of changes may be brought about by various risk factors
• Proto Oncogenes


  A normal gene that is essential to the regulation of the life cycle of the gene. They may provide signals that lead to cell division
• Tumor Suppressor Genes


  Normal genes that regulate a cell during cell divisions and replication. They may inhibit attachment of growth factors to receptors, inhibit enzymes that signal DNA to replicate, or inhibit DNA transcription
• Oncogenes


  Damaged/mutated proto oncogenes that contribute to cancer development through mutation, gene amplification, or chromosomal rearrangements
• Oral cancer ranks eighth among the most common causes of cancer-related deaths worldwide
• Oral squamous cell carcinoma (OSCC) is a pathological type of oral cancer, accounting for over 90% of oral cancers
• Oral cancer accounts for 48% of all head and neck cancers
• 90% of oral cancers is histologically oral squamous cell carcinoma
• The 5-year survival rate for oral cancer is less than 50%
• Oral cancer is the 8th most common cancer found in Filipinos
• The Philippines ranks #62 among countries with the most incidence of oral cancer
• The death rate for oral cancer in the Philippines is 3.74 per 100,000
• Tobacco


  The most important risk factor to oral squamous cell carcinoma. It causes epigenetic alteration of oral epithelial tissues, inhibits multiple systemic immune functions of the host, and its toxic metabolites can cause oxidative stress on tissues and induce OSCC
• Tobacco contains over 60 different carcinogens and cancer-promoting substances
• Tobacco increases the risk of developing oral cancer 5-9 times more than non-smokers
• The risk may increase to 17 times more if the person is an extreme heavy smoker of 80 sticks or more per day
• Marijuana is considered a risk factor for the rise in oral cancers as well
• Vaping may also be a risk factor to oral cancer due to formaldehyde and diacetyl
• Forms of tobacco use associated with OSCC

  • Cigarette smoking
  • Cigars
  • Pipe smoking
  • Smokeless tobacco
  • Second hand smoke
• Nicotine metabolites that promote cell proliferation

  • 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone
  • Nitrosamines (nitrosamine ketone, N-nitrosonornicotine)
• The influence of smoking in the development of cancer is dose related, depending on the number of cigarettes smoked per day and the number of years of smoking
• Alcohol


  Has a dose-response relationship with oral cancer, with heavy drinkers being at greater risk. The combination of alcohol and tobacco further increases the risk, up to 100 times higher compared to non-drinkers
• Potential role of alcohol in carcinogenesis

  Ethanol is metabolized into acetaldehyde, a known carcinogen and tumor promoter. Alcohol also contains some carcinogenic impurities like polycyclic aromatic compounds and nitrosamines. Alcohol may contribute to making carcinogenic substances more soluble and enhance their penetration into target tissues
• Dietary factors


  Eating food fried in oil may create carcinogenic and mutagenic aldehydes. Low intake of fruits and vegetables has consistently been linked to increased prevalence of oral cancer
• The interview can be a valuable tool in the management of certain conditions like pain, dysfunction, and online consultation
• Antioxidant micronutrients like beta-carotene and vitamin C have protective effects against oral cancers and precancers
• Betel chewing


  Established as an individual cause of oral cancer, and is the leading cause of oral cancer in some Asia Pacific regions. Betel nut (Areca Catechu) is regarded by the IARC as a known human carcinogen, and betel nut chewers often present with premalignant lesions like leukoplakia and submucous fibrosis
• Oral submucous fibrosis (OSMF)


  An oral precancerous condition characterized by inflammation and progressive fibrosis of the submucosal tissues, resulting in marked rigidity and trismus. It has a malignant transformation rate of 7.6%
• Viruses strongly associated with OSCC are HPV and HSV
• Human Papilloma Virus (HPV)


  The most common sexually transmitted infection, with over 200 variants affecting the genitals, mouth and throat. HPV is the primary virus associated with cervical cancers and has also been associated with oral cancers
• Classification of HPV


  • According to natural host (human or bovine)
  • According to clinical prognosis of associated lesion (low risk or high risk)
  • According to IARC (Group 1: HPV 16 and 18 are carcinogenic, Group 2A: HPV 31 and 33 are probably carcinogenic, Group 2B: remaining HPV are possibly carcinogenic)
• Herpes Simplex Virus (HSV)

  Could be a co-carcinogen together with tobacco, as infection with HSV-1 could increase the proportion of animals with pre-malignant lesions and carcinomas