Cancer

• Cell cycle checkpoints


  Regulate the cell cycle and decide whether cells will divide or stop in interphase
• Cell cycle checkpoints


  1. Check for sufficient nutrients

  2. Check if DNA has been replicated

  3. Check for DNA damage
• If a cell does not pass a checkpoint, it will be programmed for cell death (apoptosis)
• Cancer


  A broad group of diseases that result in rapid, uncontrolled cell division
• Cancer cells


  • Ignore signals to stop dividing
  • Accumulate mutations in their DNA
• Carcinogens


  Environmental factors that cause cancer, such as tobacco smoke, radiation, chemicals, viruses
• Tumours


  • Benign: Do not affect surrounding tissues

  Malignant: Interfere with surrounding cells and spread to other parts of the body (metastasis)
• Metastasis


  Cancer cells break away from the primary tumour and establish a secondary tumour elsewhere in the body
• Cancer screening


  Checking for cancer even when there are no symptoms, to increase the chances of early detection
• Cancer screening does not prevent cancer, but increases the chances of early detection
• Reducing risk factors like carcinogens and lifestyle factors can help reduce the risk of cancer
• Cancer diagnostic techniques


  • Endoscopy
  • X-rays
  • Ultrasound
  • CT scan
  • MRI
• The earlier cancer is diagnosed, the better the chances of successful treatment
• Certain cell samples can be obtained easily
• Some cells may need to be removed during surgery
• The goal is to slow down the growth of the tumours or destroy as many cancer cells as possible
• Cancer treatment plans


  1. Surgery

  2. Chemotherapy

  3. Radiation therapy
• Surgery


  Physically removing the cancer
• Tumour needs to be easily accessible
• Chemotherapy


  Treating cancer using drugs
• Chemotherapy


  Slow or stop the cancer cells from dividing and spreading
• Chemotherapy can be injected or taken orally
• The aim of chemotherapy is to shrink a tumour for surgical removal or for radiation
• Common side effects of chemotherapy are hair loss, nausea, and fatigue
• Advantage of chemotherapy is that it can reach tumours that are too small or inaccessible for surgery
• Radiation therapy


  The DNA of daughter cells is damaged by radiation, so cells don't divide