Cancer A class of non-infectious diseases occurring when cell cycle control mechanisms fail. Prefix:...
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Transcript of Cancer A class of non-infectious diseases occurring when cell cycle control mechanisms fail. Prefix:...
CancerA class of non-infectious diseases occurring when cell cycle control
mechanisms fail. Prefix: Onco
• Nonspecialized: they do not carry out the functions of the tissues where they form. As a result the tissue loses its functioning power.
• Have abnormal nuclei, usually enlarged with mutated chromosomes displaying extra copies.
• Divide non stop and have the ability to form multiple layers, resulting in tumor formation. Do not undergo apoptosis and have mechanisms to resist immune system attack.
• May undergo metastasis (spreading out).
• May cause angiogenesis (formation of new blood vessels).
Characteristics of cancer cells.
• Have a much shorter cell cycle and enter mitosis more often.
Healthy cells and tissues are starved of nutrients and/or physical squashed by the growth of the tumor cells.
Death due to loss of organ function.
• Multiple mutations are generally needed for full-fledged cancer; thus the incidence increases with age.
• At the DNA level, a cancerous cell is usually characterized by at least one active oncogene and the mutation of several tumor-suppressor genes.
Cancer and Aging
• Carcinoma: Begins in the skin or in organ tissue. Makes up 80% of all cancers.
Types of Cancer
• Lymphoma: Cancer of the lymphatic system.
• Melanoma: Cancer of the melanocytes (skin cells responsible for skin color).
• Leukemia: Cancer of blood-forming tissue in the bone marrow).
• Sarcoma: Cancer that starts connective tissue (fat, bone, muscle, cartilage..).
Pancreatic Cancer (Carcinoma)• Probably the deadliest type of cancer due to its high mortality rate and low
survival rate (1-year survival rate = 25%, 5-year survival rate = 6%, survival past the 5-year mark is extremely rare).
• “Silent killer” because early pancreatic cancer has no symptoms and tends to go undiagnosed until too late. Late cancer symptoms include abdominal pain, loss of appetite, nausea & vomiting, weight loss...
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Most common treatments: Lumpectomy & Mastectomy-Lumpectomy: surgical removal of cancerous lump.-Mastectomy: surgical removal of breast.
• Surgery: If diagnosed early; requires preventive medicine. Examples: mastectomy, hysterectomy...)
Treatment
• Chemotherapy: Drugs designed to arrest cell division or target fast-dividing cells. Many side-effects.
• Radiotherapy: Controlled doses of radiation designed to destroy cancerous tissue. Only possible for superficial cancers.
• Specialized treatments: Such as bone transplants for leukemia.