L3.4.1: Types According to Location

• Localized

  ● Stays in a particular area

  ● Doesn’t spread

  ● During early stages of cancer

  ● Often easier to treat and managed

  ● Usually for benign tumors (not cancerous at all)

  ● I.e., benign cyst (easily removable)
• Metastasis or Direct Extension

  ● Creeping mechanism caused by invasion

  ● Portal is through the bloodstream which makes it easier to perform their function.
• TWO MECHANISMS

  • Invasion
  • Metastasis
• INVASION

  Direct migration & penetration by cancer cells into neighboring tissues

  ● Leads to

  ○ Tissue destruction

  ○ Loss of organ function

  ○ Spread to adjacent structures

  ○ Metastasis
• METASTASIS

  Ability of cancer cells to penetrate into lymphatic & blood vessels, circulate through the bloodstream, & then invade normal tissues elsewhere in the body
• Steps

  1. Cancer cells invade surrounding tissues and vessels

  2. Cancer cells are transported by the circulatory system to distant sites

  3. Cancer cells reinvade and grow at new locations.