Cancer

• What is cancer caused by?

  • In mitosis, one cell is copied into two cells 
  • Cell division by mitosis occurs all over the body, especially during growth and during repair , for example after an injury 
  • Mitosis is tightly controlled - genes in the nucleus tell cells when to divide and stop dividing 
  • But, sometimes changes take place in these genes, and  that leads to uncontrolled cell division - this causes cancer 
  • This forms masses of cells called tumours

  
• Cancer is a non-communicable disease
• What are the two main types of tumour

  • Benign tumours
  • Malignant tumours
• What are benign tumours?

  • Benign tumours are growths of abnormal cells which found in one area 
  • They are usually contained within a membrane 
  • Benign tumours do not spread to other parts of the body - They stay in the one place

  
• What are malignant tumours?

  • Malignant tumours are growths of abnormal cells that invade neighbouring tissues  
  • Malignant tumour cells are classed as a cancer 
  • Malignant tumour cells move to the bloodstream, and once they are there, they spread to different parts of the body where they form new tumours - these are called secondary tumours

  
• Cancers can be linked to genetics

  • Some cancers are genetic 
  • This is due to the fact that genes can be inherited from our parents , and they can make us more susceptible to certain types of cancer 
  • Examples of cancers caused by genetic risk factors are : Certain types of breast cancer , prostate cancer , and cancer of the large intestine

  
• Cancers can be linked to lifestyle

  • Some cancers are caused due to a person’s lifestyle 
  • Lung cancer is linked to smoking 
  • Skin cancer is linked to exposure to ultraviolet light (e.g. sunbathing)
  • Mouth and throat cancer are linked to drinking alcohol 
  • Obesity and common viruses are also linked to cancers

  
• How does radon cause cancer

  • Radon is a radioactive gas which increases your risk of developing lung cancer 
  • This is because radon releases ionising radiation which damages the DNA in our cells  
  • This can cause our cells to undergo uncontrolled cell division , leading to cancer