Download Cancer

Chapter 14 Lecture
Cancer
© 2014 Pearson Education, Inc.
Learning Objectives
•
•
•
•
•
•
•
•
Define cancer
Discuss the incidence of cancer in the United States
List the most common types of cancer
Identify factors that influence your risk of developing
cancer
Discuss several types of occupational carcinogens
Outline ways to reduce your risk of skin cancer due to
exposure to ultraviolet light
Discuss the roles of diet and exercise in reducing cancer
risk
Explain how free radicals increase your risk of cancer
© 2014 Pearson Education, Inc.
Cancer
• Second leading cause of U.S. deaths
• A collection of over 100 related diseases characterized
by rapid, uncontrolled cell growth/often forms tumors
• Can occur in almost any tissue/organ
• Two kinds of tumors
– Benign (slower growing, less serious health threats)
– Malignant (fast growing, very serious health threats)
• Biopsy: procedure determining type of cells
• Metastasis: spread of cancer cells through body
• Cancer cells invade other tissues and/or interfere with
organ functions, can lead to organ failure/death
• Key to treatment/survival: early detection
Complete Lab 14.1: Determining Your Cancer Risk
© 2014 Pearson Education, Inc.
Early Cancer Detection: 7 Warning Signs
© 2014 Pearson Education, Inc.
Cancer Growth and Metastasis
© 2014 Pearson Education, Inc.
Cancer Cell Growth
• Controlled by DNA
– DNA damaged by carcinogens
– Uncontrolled cell growth occurs
• Carcinogens include
– Radiation
– Chemicals
– Drugs
– Toxic substances
© 2014 Pearson Education, Inc.
Cancer Cell Formation
© 2014 Pearson Education, Inc.
Types of Cancer
Lung Cancer
• Leading cause of all cancer deaths
• Easiest way to reduce risk: don't smoke
Colon and Rectal Cancer (Colorectal)
• Third leading cause of cancer deaths
• Get regular screenings for polyps after age 50
Breast Cancer
• Most common cancer in women, second
cause of cancer deaths in women
• Get mammograms/perform breast selfexamination
© 2014 Pearson Education, Inc.
Types of Cancer (cont.)
Prostate Cancer
• Second leading cause of cancer deaths in men
• Get regular exams, especially after age 50
Testicular Cancer
• Most common cancer in young men
• Perform routine self-examinations
Skin Cancer
• Most common type of cancer
• Two types: Melanoma and nonmelanoma
• Avoid UV light and tanning beds
• Wear sunscreen SPF 15 or higher
© 2014 Pearson Education, Inc.
Types of Cancer (cont.)
Uterine, Ovarian, and Cervical Cancer
• Uterine: endometrial most common
• Ovarian risk factors
– Age, obesity, longer menstrual history, genetics, infertility, breast
cancer
• Cervical linked: human papillomavirus (HPV)
Other Cancers
• Oral cancer
– Affects lips, mouth, throat, and tongue
– Associated with tobacco and alcohol use
• Leukemia
– Cancer of the blood
• Pancreatic cancer
– Fourth leading cause of cancer deaths
© 2014 Pearson Education, Inc.
U.S. Cancer Death Rates
© 2014 Pearson Education, Inc.
Detecting Skin Cancer
Examine moles monthly using the ABCD rule
• A: Assymetry (one half does not look like the other half)
• B: Border (irregular, notched, or ragged)
• C: Color (differing shades, patches)
• D: Diameter (larger than 6mm, growing)
Not all skin cancers fit ABCD rule
• Check moles/skin lesions regularly for any changes
• Establish a baseline
Other Warning Signs
• A sore that does not heal
• New growth of any kind
• Spread of pigment
• Redness or swelling beyond the border
• Change in sensation on the skin
Complete Lab 14.2: Early Detection
© 2014 Pearson Education, Inc.
Uncontrollable Cancer Risk Factors
Heredity
• Having a close relative with diagnosed cancer
increases risk three-fold
• Learn your family's health history (blood
relatives)
• If hereditary risk exists, start screenings
sooner and get screenings more often
Race
• Blacks have higher overall cancer rates than
whites, death rates have been declining
• Increased awareness and early detection is
critical
© 2014 Pearson Education, Inc.
U.S. Cancer Risk—Racial Diversity
© 2014 Pearson Education, Inc.
Controllable Cancer Risk Factors
Diet
• Most important behavioral factor
• Avoid high-fat, salt-cured, smoked, and nitrite-cured
foods
• Eat foods rich in high-fiber and antioxidants (vitamins
A, E, and C)
Alcohol Use
• Moderate drinking increases risk for some cancers
• Eliminate/limit both frequency and amount
Tobacco Use
• Single largest cause of cancer deaths
• Risk: lifetime exposure to smoke, including secondhand
• Stopping at any time decreases your risk
© 2014 Pearson Education, Inc.
Controllable Cancer Risk Factors (cont.)
Physical Inactivity
• Regular exercise protects against cancer in multiple ways
– strengthens immune system; helps maintain a healthy weight;
positive effects on hormone levels; increases bowel motility
Exposure to Ultraviolet Light
• Common UV sources are sunlight, tanning booths, sunlamps
• Risk: cumulative exposure, not just occasional overexposure
• Limit sun exposure, avoid tanning salons/wear sunscreen daily
Exposure to Viruses
• Can invade cells/damaged DNA = blood, lymphatic, liver,
cervical, nose, pharynx cancer
• To avoid HPV/cervical cancer: abstain from sex, use condoms,
limit number of partners
© 2014 Pearson Education, Inc.
Physical Fitness and Cancer Risk
© 2014 Pearson Education, Inc.
Controllable Cancer Risk Factors (cont.)
Radiation Exposure
• Sources: medical X-rays, computer monitors, electric
blankets, cell phones
• Take precautions/avoid or limit exposure
Occupational Carcinogens
• Sources: industrial chemicals, asbestos, coal tars,
auto paints, herbicides, pesticides
• Follow safety precautions/avoid exposure to industrial
agents
• Contact EPA with questions: chemical exposure/
information
© 2014 Pearson Education, Inc.
Summary
• Cancer is the #2 cause of death in the United
States
• Cancer is the uncontrolled growth and spread of
abnormal cells. Groups of abnormal cells can
form a tumor, which can be classified as benign
or malignant
• Carcinogens are cancer-causing agents. Normal
cells become cancerous when DNA becomes
damaged by carcinogens, resulting in
uncontrolled cell division
• Common sites of cancer include the breasts,
lungs, colon, prostate gland, cervix, testes,
pancreas, and mouth
© 2014 Pearson Education, Inc.
Summary (cont.)
• Heredity and race are non-modifiable risk factors
for cancer
• Modifiable behavioral risk factors for cancer
include exposure to carcinogens (such as
radiation, viruses, tobacco, alcohol, occupational
carcinogens, and ultraviolet light), eating a lowfiber diet, and being physically inactive
• Diet is probably the most important factor in
controlling your risk of cancer
• Exercise has been shown to reduce the risk of
cancer
• Participation in cancer screenings is important
for early detection of cancer
© 2014 Pearson Education, Inc.