cancer

• carcinogens

  things that causes cancer such as ionising radiation
• tumour

  masses of cells formed when cells grow and divide uncontrollably
• benign tumour

  masses of cells that stay in one part of the body- they dont invade tissues around them or spread to other parts of the body benign tumours are not cancers
• malignant tumour

  masses of cells that can invade tissues around them and spread to other parts of the body malignant tumours are cancers
• cells can break off from malignant tumour and enter the bloodstream spreading them around the body - these cells can form secondary tumours
• risk factors for cancer

  • obesity
  • smoking
  • exposure to UV rays
• there are also genetic risk factors for some cancers for example breast or ovarian cancer