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Chapter 12 Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 1 Ahead: What Is Cancer? The Causes of Cancer Common Cancers Detecting and Treating Cancer Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 2 Cancer: abnormal, uncontrolled multiplication of cells, which, if left untreated, can ultimately cause death Cancer is responsible for 1 out of every 4 deaths in the U.S. each year, and it is the second leading cause of death after heart disease Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 3 Tumor: a mass of tissue that serves no physiological purpose; also called a neoplasm Benign tumor: a tumor that is not cancerous Malignant tumor: a tumor that is cancerous and capable of spreading Lymphatic system: a system of vessels that returns proteins, lipids, and other substances from fluid in the tissues to the circulatory system Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 4 Cancer begins when a malignant cell divides without regard for normal control mechanisms Produces a mass of abnormal cells Eventually detected A few cancers, like leukemia, do not produce a mass Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 5 Metastasis: spread of cancer cells from one part of the body to another Occurs because cancer cells do not stick to each other as strongly as normal cells do and therefore may not remain at the original site To control the cancer, every cancerous cell must be removed Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6 Genetic factors Environmental factors Lifestyle factors Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 7 DNA basics Chromosomes: threadlike bodies in a cell nucleus that contain molecules of DNA; most human cells contain 23 pairs of chromosomes DNA: deoxyribonucleic acid, a chemical substance that carries genetic information Gene: a section of a chromosome that contains the instructions for making a particular protein; the basic unit of heredity Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 8 DNA mutations and cancer Mutation is any change in the makeup of a gene ▪ Some mutations are inherited ▪ Others are caused by environmental agents Oncogene: a gene involved in the transformation of a normal cell into a cancer cell Cancer promoters Some substances accelerate the growth of cells, which means less time for a cell to repair DNA damage caused by other factors Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 9 Smoking is responsible for up to 90% of lung cancers and for about 29% of all cancer deaths Responsible for nearly one in five American deaths each year Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 10 Jump to long image description Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 11 Dietary fat and meat Diets high in fats and meat may contribute to colon, prostate, and stomach cancer Omega-6 polyunsaturated fats are associated with a higher risk of certain cancers Alcohol Associated with several cancers Alcohol and tobacco interact as risk factors for oral cancer Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 12 Foods cooked at high temperatures High levels of acrylamide, a probable human carcinogen, found in starch-based foods that are fried or baked at high temperatures ▪ Acrylamide is also found in tobacco Fiber Experts recommend a high-fiber diet for its overall positive effect on health Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. © Anastasia traveller / Alamy RF 13 Fruits and vegetables Researchers have identified mechanisms by which food components may act against cancer Carotenoid: yellow-to-red plant pigments that can be converted to vitamin A by the liver ▪ Many act as antioxidants or have other anti-cancer effects Phytochemical: naturally occurring substance found in plant foods that may help prevent chronic diseases such as cancer and heart disease Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 14 Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Jump to long image description 15 FOOD PHYTOCHEMICAL POTENTIAL ANTICANCER EFFECTS Chili peppers (Note: Hotter peppers contain more capsaicin.) Capsaicin Neutralizes effect of nitrosamines; may block carcinogens in cigarette smoke from acting on cells Oranges, lemons, limes, onions, apples, berries, eggplant Flavonoids Act as antioxidants; block access of carcinogens to cells; suppress malignant changes in cells; prevent cancer cells from multiplying Citrus fruits, cherries Monoterpenes Help detoxify carcinogens; inhibit spread of cancer cells Cruciferous vegetables (broccoli, cabbage, bok choy, cauliflower, kale, brussels sprouts, collards) Isothiocyanates Boost production of cancer-fighting enzymes; suppress growth; block effects of estrogen on cell growth Garlic, onions, leeks, shallots, chives Allyl sulfides Increase levels of enzymes that break down potential carcinogens; boost activity of cancer-fighting immune cells Grapes, red wine, peanuts Resveratrol Act as antioxidants; suppress tumor growth Green, oolong, and black teas (Note: Drinking burning hot tea may increase cancer risk.) Polyphenols Increase antioxidant activity; prevent cancer cells from multiplying; help speed excretion of carcinogens from the body Orange, deep yellow, red, pink, and dark green vegetables; some fruits Carotenoids Act as antioxidants; reduce levels of cancer-promoting enzymes; inhibit spread of cancer cells Soy foods, whole grains, flax seeds, nuts Phytoestrogens Block effects of estrogen on cell growth; lower blood levels of estrogen Whole grains, legumes Phytic acid Bind iron, which may prevent it from creating cell-damaging free radicals Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 16 The ACS recommends maintaining a healthy weight throughout life by balancing caloric intake with physical activity The ACS also recommends achieving and maintaining a healthy weight if you are currently overweight or obese Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. © Peathegee Inc./Getty Images RF 17 Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 18 Ingested chemicals Some food additives are potentially dangerous, including the nitrates and nitrites found in processed meats Environmental and industrial pollution Less than 2% of cancer deaths are caused by general environmental pollution Exposure to carcinogenic materials in the workplace is a more serious problem Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 19 Radiation All sources of radiation are potentially carcinogenic Successful efforts have been made to reduce radiation needed for necessary medical X-rays Microbes About 15–20% of the world’s cancers are caused by microbes ▪ HPV ▪ Epstein-Barr virus Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 20 Jump to long image description Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 21 Lung cancer Colon and rectal cancer Breast cancer Prostate cancer Cancers of the female reproductive tract Skin cancer Head and neck cancers Testicular cancer Other cancers Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 22 Lung cancer is the most common cause of cancer death in the U.S. Responsible for about 158,000 deaths a year When combined with other carcinogens, risk for smokers can increase 10 times or more ▪ Carcinogen: any substance that causes cancer Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. © McGraw-Hill Companies, Inc./Gary He, photographer 23 Symptoms include persistent cough, chest pain, or recurring bronchitis Most often treated with a combination of surgery, radiation, and chemotherapy Chemotherapy: the treatment of cancer with chemicals that destroy cancerous cells Only 15% of lung cancer patients are alive 5 years after diagnosis Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 24 90% of cases are diagnosed in people age 50 and older Many cancers arise from preexisting polyps Many cases of colon cancers may be due to inherited gene mutations Protective lifestyles can affect colon cancer risk, including good nutrition, physical activity, and not smoking Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 25 Symptoms include changes in bowel habits and bleeding from the rectum Tests can detect small amounts of blood in the stool Rectal exams can detect some tumors, as can a colonoscopy Exams should be performed yearly after age 50 Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 26 Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 27 Breast cancer is the most common cancer in women and is second to lung cancer in the number of cancer deaths among women © Dan Steinberg / AP Images Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 28 Risk factors Strong genetic factor Other risk factors: ▪ ▪ ▪ ▪ ▪ ▪ Early first menstruation, or late-onset menopause Having no children or having a first child after age 30 Hormone replacement therapy Being obese Using alcohol Smoking Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 29 Risk factors The female hormone estrogen may be a common element in some risk factors ▪ Estrogen promotes cell growth in responsive tissues, so increased estrogen exposure may raise the risk of breast cancer ▪ Fat cells produce estrogen, and estrogen levels are higher in obese women ▪ Alcohol increases estrogen in the blood Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 30 Prevention Eat a low-fat, vegetable-rich diet Exercise regularly Limit alcohol intake Maintain a healthy body weight Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 31 Detection Mammogram: low-dose X-ray of the breasts; used for early detection of breast cancer Clinical breast exam Breast self-exams Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 32 Detection Biopsy: removal and examination of small piece of body tissue for purpose of diagnosis Ultrasonography: an imaging method in which inaudible high-pitched sound (ultrasound) is bounced off body structures to create an image on a monitor Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 33 Treatment Lumps can be scanned by ultrasonography and biopsied to check for malignancy ▪ If a lump is cancerous, several surgical treatments may be used ▪ Chemotherapy or radiation treatment also used Several drugs have been developed for preventing and treating breast cancer If discovered early, patients have about a 98% chance of surviving more than 5 years Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 34 Prostate cancer is the most common cancer in men and the second leading cause of cancer death in men Age is the strongest predictor, with 97% of cases occurring in men over age 50 Prostate-specific antigen (PSA) blood test: diagnostic test for prostate cancer that measures blood levels of PSA Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 35 Treatment is usually removal of the prostate, but radiation may be used Small slow-growing tumors in older men may be treated with watchful waiting 5-year survival rate is now nearly 100% Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 36 Cervical cancer Most cases stem from infection by HPV Pap test: scraping of cells from the cervix for examination to detect cancer ▪ Abnormal cells are removed surgically or by destroying them with an ultra-cold probe or localized laser treatment Two HPV vaccines have been approved by the FDA Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 37 Uterine or endometrial cancer Cancer of the lining of the uterus most often occurs after age 55 Usually detectable by pelvic examination Uterine cancer is treated surgically, as well as by radiation, hormones, and chemotherapy Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 38 Ovarian cancer Ovarian cancer is rare compared with uterine cancer, but it causes more deaths ▪ Often diagnosed late in its development Lowering woman’s lifetime number of ovulation cycles reduces risk ▪ Symptoms: bloating, pelvic or abdominal pain, difficulty eating or feeling full quickly, urinary problems ▪ Treated by surgical removal of ovaries, fallopian tubes, and uterus Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 39 Skin cancer is the most common cancer Linked to exposure to UV radiation from the sun Melanoma: a malignant tumor of the skin that arises from pigmented cells, usually a mole Ultraviolet (UV) radiation: light rays of a specific wavelength, emitted by the sun; most UV rays are blocked by the ozone layer in the upper atmosphere Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 40 Basal cell carcinomas and squamous cell carcinomas are 95% of skin cancers Basal cell carcinoma: cancer of the deepest layers of the skin Squamous cell carcinoma: cancer of the surface layers of the skin Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. © Jose Luis Pelaez/Getty Images 41 Melanoma is the most dangerous skin cancer because it spreads rapidly Usually occurs at site of a mole, which becomes enlarged, mottled, and irregular in surface or borders Melanomas are most common on the back, chest, abdomen, and lower legs © Richard Levine / Alamy Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 42 Jump to long image description Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 43 Cancers of the oral cavity, pharynx, larynx, and nasal cavity Traced to cigarette, cigar, or pipe smoking, the use of spit tobacco, and excessive consumption of alcohol HPV infection linked to cancers of tonsils and tongue Head and neck cancers are twice as common in men and occur most frequently in men over 40 Chemotherapy, radiation, or surgery is used to treat head and neck cancers Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 44 Testicular cancer is the most common cancer among men ages 20 to 35, but it is rare Regular self-examination Tumors treated by surgical removal and, if the tumor has spread, by chemotherapy Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 45 Pancreatic cancer kills 49,000 Americans annually Usually well advanced when detected There is no effective cure available Bladder cancer Men are four times more likely to have it Smoking is a key risk factor Symptoms: blood in the urine, increased frequency of urination Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 46 Kidney cancer usually occurs over 50 Smoking, obesity, and family history are mild risk factors ▪ Symptoms: fatigue, pain in the side, and blood in the urine Brain cancer can arise from most cell types found in the brain Ionizing radiation is a risk factor Some brain tumors are curable Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 47 Leukemia is cancer of the white blood cells Starts in bone marrow but can spread to other organs and the central nervous system Lymphoma is a form of cancer that begins in the lymph nodes May spread to almost any part of the body Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 48 Detecting cancer Self-monitoring ▪ Be aware of risk factors ▪ Report changes to a physician Centers for Disease Control and Prevention Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 49 Stages of cancer Physicians need to know the exact size and location of a tumor to treat it effectively Staging ▪ Cancer is categorized in five stages by judging the size or extent, spread, and metastases Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 50 STAGE DESCRIPTION 0 Carcinoma in situ: abnormal cells are present only in the layer of cells in which they developed; not cancer but may become cancer I, II, and III Higher numbers indicate more extensive disease: Larger tumor size and/or spread of the cancer beyond the organ in which it first developed to nearby lymph nodes or to tissues or organs adjacent to the primary tumor IV Cancer that has spread to distant tissues or organs SOURCE: National Cancer Institute. 2015. Cancer staging (http://www.cancer.gov/about- cancer/diagnosis-staging/staging/staging-fact-sheet). Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 51 Treating cancer Surgery ▪ For most cancers, surgery is the most useful treatment Chemotherapy Radiation Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 52 Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 53 CANCER SITE APPROXIMATE PERCENTAGE OF APPROXIMATE PERCENTAGE OF MALE DEATHS ATTRIBUTABLE TO FEMALE DEATHS ATTRIBUTABLE SMOKING TO SMOKING Oropharynx 75% of 5,100 deaths 33% of 2,500 deaths Larynx 80% of 3,000 deaths 75% of 600 deaths Esophagus 70% of 9,700 deaths 55% of 3,000 deaths Stomach 30% of 7,000 deaths 10% of 5,000 deaths Pancreas 20% of 15,000 deaths 20% of 16,000 deaths Lung 90% of 90,000 deaths 70% of 67,000 deaths Bladder 45% of 8,500 deaths 25% of 4,000 deaths Kidney 40% of 7,500 deaths 5% of 4,500 deaths Myeloid leukemia 20% of 4,000 deaths 10% of 3,200 deaths Cervix Not applicable 10% of 3,800 deaths Jump back to slide containing original image Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 54 DO MORE OF: • • • • • • • • • Eat a varied, plant-based diet that is high in fiber-rich foods such as legumes and whole grains. Eat 7–13 servings of fruits and vegetables every day, favoring foods from the following categories: Cruciferous vegetables, Citrus fruits, Berries, Dark green leafy vegetables, and Dark yellow, orange, or red fruits and vegetables. Be physically active. Maintain a healthy weight. Practice safer sex (to avoid HPV infection). Protect your skin from the sun with appropriate clothing and sunscreen. Perform regular self-exams. Obtain recommended screening tests and discuss with your physician any family history of cancer. DO LESS OF: • • • • • • • • • Don’t use tobacco in any form, including Cigarettes, Spit tobacco, Cigars and pipes, Bidis and clove cigarettes. Avoid exposure to environmental tobacco smoke. Limit consumption of fatty meats and other sources of saturated fat. Avoid excessive alcohol consumption. Limit consumption of salt. Don‘t eat charred foods, and limit consumption of cured and smoked meats and meat and fish grilled in a direct flame. Avoid occupational exposure to carcinogens. Limit exposure to UV radiation from sunlight. Avoid tanning lamps or beds. Jump back to slide containing original image Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 55 MEN Cancer Type New Cases Deaths Brain 12,900 8,940 Oral 32,670 6,010 Skin (melanoma) 46,610 9,120 Lung 115,610 86,380 Breast 2,350 440 Stomach 15,540 6,500 Liver 25,510 17,030 Pancreas 24,840 20,710 Colon and rectum 69,090 26,100 Urinary system 96,580 21,110 Prostate 220,800 27,540 Testes 8,430 380 Penis 1,820 310 Myeloma 14,090 6,240 Leukemia 30,900 14,210 Lymphoma 44,950 12,140 Other 16,660 24,480 Total 848,200 312,150 Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. CONTINUED… 56 WOMEN Cancer Type New Cases Deaths Brain 9,950 6,380 Oral 13,110 2,640 Skin (melanoma) 33,490 4,220 Lung 105,590 71,660 Breast 231,840 40,290 Stomach 9,050 4,220 Liver 10,150 7,520 Pancreas 24,120 19,850 Colon and rectum 63,610 23,600 Urinary system 42,130 9,860 Ovary 21,290 14,180 Uterus 54,870 10,170 Cervix 12,900 4,100 Myeloma 12,760 5,000 Leukemia 23,370 10,240 Lymphoma 35,950 8,800 Other 14,850 19,360 Total 810,170 277,280 Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Jump back to slide containing original image 57 Asymmetry: Is one half unlike the other? Border irregularity: Does it have an uneven, scalloped edge rather than a clearly defined border? Color variation: Is the color uniform, or does it vary from one area to another, from tan to brown to black, or from white to red to blue? Diameter larger than 1/4 inch: At its widest point, is the growth as large as, or larger than, a pencil eraser? Evolving: A mole or skin lesion that looks different from the rest or has any change in size, shape, color, elevation, or another trait, or any new symptom such as bleeding, itching, or crusting. Jump back to slide containing original image Copyright © 2017 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 58