© 2011 mcgraw-hill higher education. all rights reserved. cancer chapter twelve

. © 2011 McGraw-Hill Higher Education. All rights reserved.

CancerCancer

Chapter TwelveChapter Twelve


What Is Cancer?• Cancer is the second most common cause of death, after heart

disease• Responsible for 1:4 deaths in the United States

• Cancer is the abnormal, uncontrolled growth of cells

• A tumor (neoplasm) is a mass of tissue that serves no physiological purpose

• A benign tumor is composed of cells that are enclosed, preventing them from spreading to other tissues

• A malignant tumor is cancerous and capable of spreading

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How Cancer Spreads: Metastasis

• Metastasis is the spread of cancer cells from one part of the body to another

• They break away and can pass through:

• Blood vessels

• Lymphatic system

• This form of traveling can result in secondary tumors or metastases

• (a seeding process)

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Figure 12.1 Percentage of all deaths linked to risk factors

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Common Cancers

• Lung Cancer• A carcinogen is any substance that causes

cancer

• Colon and Rectal Cancer

• Breast Cancer

• Prostate Cancer

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Figure 12.2Cancer cases by site and sex

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Lung Cancer

• Lung Cancer is the most common cause of cancer death in the United States

• The chief risk factor is smoking• Accounts for 87% of lung cancer deaths

• It is responsible for about 160,000 deaths per year

• Symptoms do not usually appear until after the disease has advanced to the invasive stage

• Treatment involves a combination of surgery, radiation, and chemotherapy

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Colon and Rectal Cancer

• Also known as colorectal cancer, it is the third leading cancer death cause

• Age and lifestyle are risk factors• Polyps, which are small growths, develop and cause

bleeding from the rectum, which is a strong warning sign • The American Cancer Society (ACS) recommends that

regular screening be started at age 50.• Stool blood test• Colonoscopy

• Surgery is the primary method of treatment

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Breast Cancer

• Breast cancer is the most common cancer in women

• Risk factors include:• Genetic factors• Early-onset menstruation• Having no children or having the first one after age 30• Currently using HRT (hormone replacement therapy)• Obesity• Alcohol consumption

• Prevention involves lifestyle modification

• Detection includes:• Mammograms• Clinical breast exams• Self breast exams

• Treatment is surgery, chemotherapy, or radiation treatment

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Prostate Cancer• Prostate cancer is the most common cancer in men and second to

lung cancer in the number of cancer deaths among men• Risk factors

• Age (strongest predictor)• African American ethnicity• Heredity• Lifestyle factors

• Diet may be an important factor of preventing this cancer

• Detection is by a rectal exam or a prostate-specific antigen (PSA) blood test

• Treatment includes:• Surgical removal• Radiation treatment

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Cancers of the Female Reproductive Tract

• Cervical Cancer• Most cases of cervical cancer stem from HPV (Human

Papillomavirus) infection

• Screenings are usually performed by pap test via a pelvic exam

• If abnormal cells are found, they are surgically removed

• Genital warts are usually transmitted during unprotected sex

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• Uterine or Endometrial Cancer• This is cancer of the lining of the uterus and

mostly occurs after the age of 55• Risk factors similar to those for breast

cancer• Usually detected by pelvic examination• Treatment includes surgery, possibly

combined with radiation and chemotherapy

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• Ovarian Cancer• Considered rare compared with other

reproductive cancers• Risk factors are similar to breast and endometrial

cancer• Ovarian Cancer is treated by surgical removal of

the ovaries, the fallopian tubes, and the uterus

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Skin Cancer• Skin Cancer is the most common type of cancer

when cases of the highly curable forms are included

• Primary risk factor is exposure to ultraviolet (UV) radiation

• UVA = longer wavelength; damages connective tissue, leads to premature aging of the skin, causes skin cancer

• UVB = shorter wavelength; causes sunburn, damages eyes and immune system, causes skin cancer

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Types of Skin Cancer• There are 3 main types of skin cancer, named for the

type of skin cell from where they develop• Basal cell carcinoma develops in the deepest layers

of the skin• Squamous cell carcinoma develops on the surface

layers of the skin• Melanoma is a malignant tumor of the skin that

arises from pigmented cells, usually a mole; is considered the most dangerous form of skin cancer

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Preventing Skin Cancer

• Wear long-sleeved shirts, long pants, hats

• Use a broad-spectrum sunscreen with a high SPF (30+)

• Apply sunscreen 30 minutes before sun exposure, 15–30 minutes after exposure begins, and frequently

• Avoid sun exposure between 10 AM and 4 PM

• Check UV index

• Avoid tanning salons

• Examine your skin on a regular basis

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Figure 12.4 The ABCD test for melanoma

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Oral Cancer

• Oral cancer affects the lip, tongue, mouth, and throat

• It is traced to the use of smokeless tobacco and excessive alcohol use

• Oral cancer is easy to detect but often hard to cure

• Treatment includes:• Surgery• Radiation treatment

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Testicular Cancer

• Testicular Cancer is relatively rare, accounting for only 1% of cancers in men

• More common in white Americans than other ethnic groups• Age 20-35

• Self-exams help with early detection• Treatment includes:

• Surgical removal of tumors• Chemotherapy

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Other Cancers

• Pancreatic cancer• Fourth leading

• Bladder cancer• 3 times more common

in men

• Kidney cancer

• Brain cancer• Leukemia

• Cancer of WBC

• Lymphoma• Hodgkin’s

• Non-Hodgkin’s

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The Causes of Cancer

• The Role of DNA• DNA Basics

• Genetics

• Oncogenes

• Cancer promoters

• Dietary Factors• Fat and meat

• Alcohol

• Fried foods

• Fiber

• Fruits and vegetables

• Inactivity and Obesity• Metabolic syndrome

• Figure 12.5

• Carcinogens in the Environment

• Ingested chemicals

• Environmental and industrial pollutants

• Radiation

• Microbes

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Figure 12.5Body weight and cancer mortality

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Preventing Cancer

• Avoid tobacco

• Control diet and weight

• Exercise

• Protect skin

• Avoid environmental and occupational carcinogens

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CANCERCANCERChapter Twelve

© 2011 mcgraw-hill higher education. all rights reserved. cancer chapter twelve

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