cancer

• Cancer


  A family of over 100 distinct diseases that can develop almost anywhere in the body, starting when the orderly process of cell growth is disrupted by genetic changes or mutations
• Tumors


  • Irregular growth of tissue resulting from uncontrolled growth of cells
  • Tumors are either malignant (cancerous) or benign (not cancerous)
  • Malignant tumors can spread to other tissues and organs through the bloodstream or lymphatic system (metastasis)
• Carcinogen


  A chemical or physical agent that has the potential to cause cancer
• Types of cancer


  • Carcinoma
  • Sarcoma
  • Leukemia
  • Lymphoma
  • Myeloma
• Important risk factors for cancer

  • Age
  • Genetics
  • Behaviors (tobacco use, sun exposure, poor diet, lack of exercise, heavy drinking)
  • Viruses or bacteria
  • Exposure to chemicals
  • Radiation
• Direct acting carcinogens


  Chemicals that can cause cancer
• Procarcinogens


  Chemicals that do not cause cancer unless they are changed when they are metabolized
• Cocarcinogens


  Chemicals that do not cause cancer by themselves but can act with another chemical to cause cancer
• IARC classification of carcinogens

  • Group 1 - Carcinogenic (sufficient evidence)
  • Group 2A - Probably carcinogenic (limited evidence in humans, sufficient in animals)
  • Group 2B - Possibly carcinogenic (limited evidence in humans, less than sufficient in animals)
  • Group 3 - Carcinogenicity not classifiable (inadequate evidence in humans and animals)
  • Group 4 - Probably not carcinogenic
• Tools for finding or diagnosing cancer

  • Biopsy
  • Colonoscopy
  • Sigmoidoscopy
  • Ultrasound
• Defenses of the human body


  Protect against all kinds of harmful exposures
• Metabolism


  The process that helps the body use or get rid of something that enters the body more quickly
• Types of carcinogens


  • Chemicals that can cause cancer (direct acting carcinogens)
  • Chemicals that do not cause cancer unless they are changed when they are metabolized (procarcinogens)
  • Chemicals that do not cause cancer by themselves but can act with another chemical to cause cancer (cocarcinogens)
• Viruses or bacteria


  Trigger certain cancers
• Cancer-associated viruses


  • Human papillomavirus (HPV) - causes cervical cancer
  • Hepatitis B and C viruses - can cause liver cancer
  • Epstein-Barr virus - can cause a form of lymphoma
• Bacteria


  • Helicobacter pylori - can cause gastric cancer
• Exposure to chemicals


  May be a risk factor for cancer
• Ionizing radiation


  Has enough energy to damage DNA and cause cancer
• Ionizing radiation


  • Radon
  • X-rays
  • Gamma rays
  • Other forms of high-energy radiation
• Non-ionizing radiation


  Lower-energy forms such as visible light and energy from cell phones have not been found to cause cancer in people
• UV rays


  Can damage the DNA in our skin cells and lead to skin cancer
• Cancer


  The root of the word is traced back to the Greek doctor Hippocrates (460-370 BC), who is considered the "Father of Medicine"
• Carcinos and carcinoma


  Words used by Hippocrates to identify non-ulcer-forming and ulcer-forming tumors
• Carcinos and carcinoma


  In Greek, these phrases refer to a crab, most likely related to the disease because the cancer's finger-like projections brought the shape of a crab to mind
• Cancer


  The Latin word for crab, used by the Roman physician Celsus (28-50 BC)
• Oncos


  The Greek word for swelling, used by the Greek physician Galen (130-200 AD) to describe tumors
• The crab comparison of Hippocrates and Celsus is still used to identify malignant tumors
• The word of Galen is often used as part of the name of oncologists for cancer specialists
• Carcinoma


  Originates in the skin or the tissue that covers the surface of internal organs and glands, can form solid tumors
• Carcinoma


  • prostate cancer
  • breast cancer
  • lung cancer
  • colorectal cancer (colon or the rectum)
• Sarcoma


  Starts in the tissues that support and connect the body, can develop in fat, muscles, nerves, tendons, joints, blood vessels, lymph vessels, cartilage, or bone
• Sarcoma


  • Gastrointestinal stromal tumors (stomach and small intestine)
  • Osteosarcoma (bones)
• Leukemia


  Cancer of the body's blood-forming tissues, including the bone marrow and the lymphatic system
• Leukemia


  • Lymphocytic leukemia (lymphocytes)
  • Myelogenous (my-uh-LOHJ-uh-nus) leukemia (Myeloid cells give rise to red blood cells, white blood cells and platelet-producing cells)
• Lymphoma


  Cancer of the lymphatic system, which is part of the body's germ-fighting network, can affect lymph nodes, spleen, thymus gland, bone marrow, and other organs
• Lymphoma

  • Hodgkin's lymphoma (formerly called Hodgkin's disease)
  • Non-Hodgkin's lymphoma
• Myeloma


  Type of bone marrow cancer, often affects several areas of the body such as the spine, skull, pelvis and ribs
• Myeloma


  • Solitary Plasmacytoma (plasma cells)
  • Extramedullary Plasmacytoma (throat, sinuses, nose and larynx)
• Lymphoma


  Cancer of the lymphatic system, which is part of the body's germ-fighting network
• Components of the lymphatic system

  • Lymph nodes (lymph glands)
  • Spleen
  • Thymus gland
  • Bone marrow