Cancer Biology

• Detection and diagnosis of cancer

  Cancer cells form abnormal tissues called malignant tumours which exhibit abnormal tissue growth and invade nearby tissues
• Classification of cancers: cancer can develop in any tissue of the body and have many different forms in each tissue (>100 types)
• Cancers develop in stages over a long period of time
• Common risks and causes of cancers

  • Carcinogens
• As men age, the likelihood of cancer increases
• There's no improvement in treating pancreatic cancer
• Edwin Smith Papyrus


  1600 BC
• Cancer


  The transition from a normal cell to an abnormal cell is driven by genetic changes that occur in normal cells
• Cancer cells form abnormal tissues called malignant tumours which exhibit abnormal tissue growth and invade nearby tissues
• Benign tumours are NOT cancer; they exhibit abnormal tissue growth but CANNOT invade nearby tissue
• Loss of control over replication

  Nearby tissue is invaded
• Chest X-ray is used for detecting lung cancer
• Digital Mammography is a front-line mode of detection
• Microscopic examination of biopsy or surgical specimen tissue

  Tissue is isolated from a patient, histology slides are prepared, pathologist reviews the slides and prepares pathology report
• Biopsy or surgical tissue staining allows the pathologist to see the cells
• Benign, pre-malignant, and irregular patterns of cells are indicative of cancer
• Tissue types

  • Epithelial
  • Connective
  • Hematopoietic
  • Neuroectodermal
  • Non-epithelial
• Cancer types

  • Carcinomas
  • Sarcomas
  • Leukemias
  • Lymphomas
  • Myelomas
• Epithelial cancer types

  • Squamous Carcinomas
  • Adenocarcinomas
• Connective tissue cancer types

  • Leiomyosarcoma
• Neuroectodermal cancer types

  • Gliomas
  • Glioblastomas
  • Neuroblastomas
  • Schwannomas
  • Medulloblastomas
• Non-epithelial cancer types

  • Acute Lymphocytic Leukemia
  • Erythroleukemia
  • Melanomas
  • Teratomas
• Astrocytes are associated with Glioblastoma multiforme which cannot be surgically removed due to its variety of morphologies in the brain
• Melanomas are derived from melanocytes, highly metastatic, and easily spread as they become cancers
• Teratomas arise from germ cell precursors and can turn into any new cell of the body, typically forming in the ovaries, testicles, or tailbone of children
• Cancer develops from normal tissues, arises from many specialized cell types, develops progressively, and is monoclonal in origin
• Tumour


  • Considered the most bizarre known due to their primitive nature
  • May switch on differentiation
• Cancer develops from normal tissues
• Cancer arises from many specialized cell types
• Cancers develop progressively
• Cancers are monoclonal growths
• Cells don't become cancerous until they begin invading tissue
• It's beneficial to have polyps removed
• Genetic changes are at the root cause of Cancer
• Accumulation of rare events can cause cancer
• Etiology


  Study of disease causes
• Cancers seem to result from exposure to multiple risk factors that occur over time
• Risk factors for cancer

  • Behaviours
  • Chemical agents in the environment
  • Family history of cancer
• Families that have a predisposition to cancer may have predisposing genes or mutations in genes
• Epidemiological approach


  Looks at populations and determines risk factors and exposure related to cancers