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Cancer. Normal cells have regulation that keeps their rates of cell division in check. Normal cells generally remain in one location Cancer is unregulated growth of a cell population. Characteristics of Benign Tumors and Cancers. Table 18.1. Terms. Hyperplasia – increased formation
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Cancer • Normal cells have regulation that keeps their rates of cell division in check. • Normal cells generally remain in one location • Cancer is unregulated growth of a cell population Bio 130 Human Biology
Characteristics of Benign Tumors and Cancers Bio 130 Human Biology Table 18.1
Terms • Hyperplasia – increased formation • Tumor – new growth • Benign tumors- have defined characteristics • Dysplasia- cells change form • Cancer- at least some cells loose organization. Bio 130 Human Biology
Tumors • Benign: • Remain in one location • Single, well-defined mass • May be surrounded by connective tissue • Cancerous: • Abnormal cell structure, may appear undifferentiated • May spread • Edge of tumor not clearly defined Bio 130 Human Biology
Malignant Tumor Development Bio 130 Human Biology Figure 18.2
How cancers develop • Is genetic in character • Proto-oncogenes • Oncogenes • Tumor suppressor genes • p53 Bio 130 Human Biology
How Cancer Develops • Mutated or damaged genes • Proto-oncogenes: normal regulatory genes • Oncogenes: mutated or damaged proto-oncogenes • Tumor suppressor genes: regulatory genes repress cell growth, division, differentiation, adhesion • May be turned off, damaged, or mutated in cancers • Mutator genes: genes of DNA repair, when they are damages the cell is more likely to make a mistake. Bio 130 Human Biology
Indicated cause of cancer • Carcinogens • Inherited susceptibility • Viruses and bacteria • Starts with a single cell that is no longer under normal control Bio 130 Human Biology
Cancer Characteristics • loss of contact inhibition • Cancer cells do not self-destruct when their DNA is damaged • Cancer cells divide indefinitely • Cancer cells attract a blood supply • Cancer cells do not adhere to neighboring cells Bio 130 Human Biology
The immune system plays an important role • If your immune system recognizes a cell as being cancerous then it will be destroyed Bio 130 Human Biology
Progredssion of cancer requires multiple genetic changes in regulatory genes. Bio 130 Human Biology
Tumor Imagine X rays Positron emis temography Magnetic resonance imaging Genetic testing Enzyme markers PET and MRI focus on metabolic differences Ethaical problems withgenetic testing? Large scale testing. Testing for Cancer Bio 130 Human Biology
Cancer Treatments • Conventional treatments: surgery, radiation, and chemotherapy • Delivery mechanisms: coated metal beads, light-sensitive drugs • Immunotherapy: promotes the immune response • Starving cancers: inhibits angiogenesis • Molecular treatments: target oncogenes Bio 130 Human Biology
Surgery Radiation Chemotherapy Immunotherapy Inhibiting angiogenesis Treatment of cancer Bio 130 Human Biology
Surgery, Radiation, and Chemotherapy Are Conventional Ways to Treat Cancer • Surgery is used to remove tumors • Radiation therapy is used to kill localized cancer cells • Chemotherapy is used to kill cancer cells throughout the body • Immunotherapy boosts the immune responses against cancer cells • Inhibition of blood vessel formation may slow the spread of cancer cells • Gene therapy may someday help fight cancer in several ways Bio 130 Human Biology
Skin Breast Prostate Lung Colon rectum Some common cancers Bio 130 Human Biology
Ten Most Common Cancers Bio 130 Human Biology Table 18.3
Prevention • Best way to beat cancer is to not get it. Bio 130 Human Biology
Most Cancers Are Preventable • Know family history • Get regular medical screenings • Learn self-examination techniques • Avoid direct sunlight 10 a.m. to 4 p.m., avoid sunlamps and tanning salons • Watch diet and weight • Don’t smoke • Drink in moderation, if at all • Be informed Bio 130 Human Biology