Cancer

• Cancer


  When normal differentiation of cells go wrong
• Tumor

  Abnormal mass of tissue, resulting from uncontrolled division of cells
• Types of Tumours

  • Malignant
  • Benign
• Malignant tumours


  • Cells are able to spread to other parts of body (metastasis)
  • Secondary tumours can develop well away from original tumour
  • Cancerous tumours
• Benign tumours

  • Cells are not able spread to other parts of the body
  • Grow and can press on surrounding tissue
  • Normally have a capsule surrounding them making them easier to remove
  • Non-cancerous tumours
• Causes of cancer

  • Certain environmental factors (carcinogens)
  • Genetic factors
  • Environmental factors
  • Lifestyle factors
  • Infections
  • Hormonal factors
  • Immune system dysfunction
  • Aging
  • Random mutations
• Carcinogen

  Any substance, organism or agent capable of causing a cancer in living tissue
• Carcinogens

  • UV radiation
  • X-rays
  • Ionizing radiation (radium, uranium)
  • Viruses (e.g. HPV)
  • Chemical carcinogens (e.g. alcohol, asbestos, soot, tar, organic solvents in glue & paint, tobacco tar)
• Inherited mutations

  Certain genetic mutations can be passed down from parents to children, increasing the risk of specific cancers (e.g. BRCA1 and BRCA 2 mutations for breast and ovarian cancers)
• Family History

  A family history of cancer can indicate a genetic predisposition to certain types of cancer
• Environmental factors

  • Radiation exposure
  • Chemical exposure
• Lifestyle factors

  • Tobacco use
  • Alcohol consumption
  • Diet
  • Physical inactivity
• Infections

  • Viruses
  • Bacteria and Parasites
• Hormonal factors

  • Hormone replacement therapy
  • Reproductive history
• Immunosuppression


  Conditions or treatments that weaken the immune system (e.g. HIV/AIDS, organ transplant recipients on immunosuppressive drugs) increase the risk of certain cancers such as Kaposi's sarcoma and lymphomas
• Age

  The risk of developing cancer generally increases with age as genetic mutations accumulate over time
• Spontaneous mutations


  Random genetic mutations that occur during cell division can lead to cancer, even without exposure to known risk factors
• Australian Strategies to reduce incidence of cancer

  1. Education

  2. Legislation
• Education

  • Advertising and educational programs to limit exposure to carcinogens
  • Slip! Slop! Slap! to limit UV exposure
• Legislation

  • Laws to control exposure to carcinogens
  • Smoking being banned in many public places
  • Tobacco advertising not permitted
  • Cigarettes must be sold in plain packages/images
  • Standards for manufacture and operation of X-ray machines
  • Banning products containing asbestos
• Other prevention methods

  • Avoid smoking
  • Reduce UV exposure: sunscreen, sunglasses, long-sleeved clothing, shade and hats, stay out of direct sunlight between 10am & 3pm
  • Diet: adequate fibre and low fat, not overweight/obese, limit alcohol
  • Protective clothing when handling chemicals
• Early detection methods

  • Cervical Cancer
  • Breast cancer
  • Bowel Cancer
  • Prostate cancer
• Cervical Cancer detection

  Pap test: cells collected from cervix, smeared on microscope slide and examined
• Breast cancer detection

  Mammogram: X-ray of breasts
• Bowel Cancer detection

  1. Fecal Occult Blood Test (FOBT): at home test for blood in faeces, mail to lab for analysis

  2. Colonoscopy: visual examination of intestine
• Prostate cancer detection

  1. Digital rectal examination (DRE): insert finger into anus to feel surface of prostate

  2. Prostate-specific antigen (PSA): blood test for presence of protein produced by prostate

  3. Biopsy: several small samples of prostate tissue checked for cancer
• Imaging techniques

  • Ultrasound
  • MRI
  • PET scan
• Blood tests

  • Complete blood count
  • Tumour markers
  • Liquid biopsy
• Genetic testing

  BRCA1 and BRCA 2 testing: identifies mutations in these genes that significantly increase the risk of breast and ovarian cancers
• Physical exams and self-exams

  • Skin checks
  • Testicular self-examination
  • Breast self-examination
• Endoscopic procedures

  • Endoscopy can examine the digestive tract for signs of cancer
  • Cystoscopy examines the bladder for signs of bladder cancer