Chapter 11 Cancer Risk Management Chapter Outline Cancer Development Incidence of Cancer Common...

Chapter 11Cancer Risk Management

ChapterOutline

CancerDevelopment

Incidence of Cancer

CommonSites ofCancer

AssessingYourRisks

Guidelines forPreventing

Cancer

WarningSignals of

Cancer

RecommendedCheck Ups

Hoeger & Hoeger. All slides © Wadsworth Publishing.

Key termsCancer: Group of diseases characterized by uncontrolled growth and spread of abnormal cells

Benign: Noncancerous

Malignant: Cancerous

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



Key termsDeoxyribonucleic acid (DNA): Genetic substance of which genes are made; molecule that contains cell’s genetic code

Ribonucleic acid (RNA): Genetic material that guides the formation of cell proteins

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



Key termsOncogenes: Genes that initiate cell division

Suppressor genes: Genes that deactivate the process of cell division

Angiogenesis: Formation of blood capillaries

Metastasis: The movement of cells from one part of the body to another

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



Cancer developmentMore than 100 types of cancer can develop in the body

The process of cancer begins with an alteration in DNA

Within DNA are oncogenes and tumor suppressor genes, which normally work together to repair and replace cells

Defects in these genes ultimately allow the cell to grow into a tumor; defects are caused by

External factors such as radiation, chemicals, and viruses

Internal factors such as immune conditions, hormones, and genetic mutations

Cancer starts with the abnormal growth of one cell, which then can multiply into billions of cancerous cells

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



Cancer developmentA critical turning point in the development of cancer is when a tumor reaches about one million cells

At this stage, it is referred to as carcinoma in situ

An undetected tumor may go for months or years without any significant growth

While encapsulated, it does not pose a serious threat to human health

To grow, tumors require more oxygen and nutrients

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



Cancer developmentIn time, a few cancer cells start producing chemicals that enhance angiogenesis (capillary or blood vessel formation into the tumor)

Angiogenesis is the precursor of metastasis

Through the new blood vessels formed by angiogenesis:

Cancerous cells break away from a malignant tumor

Migrate to other parts of the body

Can cause new cancers

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



Figure 11.4

How cancer starts and spreads


Cancer developmentOnce cancer cells metastasize, treatment becomes more difficult

Therapy can kill most cancer cells, but a few cells might become resistant to treatment

Treatment-resistant cells can grow into a new tumor that will not respond to the same treatment

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



Cancer statisticsCancer is the second leading cause of death in the U.S.

About 23% of all yearly deaths are caused by cancer

Aproximately 1 in 2 men and 1 in 3 women in the U.S. will develop cancer

More than 550,000 Americans die from cancer each year

More than 1.3 million new cases are diagnosed each year

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



Figure 11.5

Death rates for major cancer sites

© American Cancer Society


CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer


Critical thinkingHave you ever had or do you now have any family members with cancer?

Can you identify lifestyle or environmental factors as possible contributors to the disease?

If not, are you concerned about your genetic predisposition, and are you making lifestyle changes to decrease your risk?


Cancer-causing factorsAs much as 80% of all human cancer is related to lifestyle or environmental factors

Diet

Obesity

Tobacco use

Sedentary lifestyle

Excessive use of alcohol

Exposure to occupational hazards

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



Figure 11.7Cancer-causing factors

SOURCE: Harvard Center for Cancer Prevention. Causes of Human Cancer, HarvardReport on Cancer Prevention, 1 (1996).


Guidelines forpreventing cancer

Get proper nutrition

Abstain from tobacco

Avoid excessive sun exposure

Monitor estrogen, radiation exposure, and potential occupational hazards

Engage in physical activity

Maintain recommended body weight

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Incidence of Cancer


AssessingYourRisks


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Dietary guidelinesPredominately a vegetarian diet (high in fiber and low in fat)

Should include a variety of fruits and vegetables, in particular cruciferous vegetables

The use of tea, soy products, calcium, and omega-3 fats is encouraged

Adequate fiber intake is recommended (25 to 38 gr/day)

Protein intake should be kept within the recommended guidelines

Alcohol, if used at all, should be consumed in moderation (1 to 2 servings per day)

Grilling of meats at high temperatures is discouraged

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



Dietary guidelinesConsume ample amounts of fruits and vegetables which are high in antioxidants and phytochemicals

Antioxidants seem toAbsorb free radicals before they can cause damageInterrupt the sequence of reactions once damage has begun

Phytochemicals (plant chemicals) seem to prevent cancer by blocking the formation of cancerous tumors and disrupting the process at almost every step of the way

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

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Cancer risks


Abstain from tobacco useThe biggest carcinogenic exposure in the workplace is cigarette smoke

Of all cancers, at least 28% are tied to smoking, and 87% of lung cancers are tied to smoking

Use of smokeless tobacco increases the risk for mouth, larynx, throat, and esophageal cancers

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



Avoiding excessive sunExcessive exposure to ultraviolet radiation (both UVB and UVA rays) contributes to skin cancer

1 in every 6 Americans will develop some type of skin cancer

The most common sites of skin cancer are those areas exposed to the sun most often (face, neck, and back of the hands)

Nearly 90% of the almost 1 million yearly cases of basal cell or squamous cell skin cancers in the U.S. could be prevented by protecting the skin from the sun

Melanoma is the most deadly form of skin cancer, causing 7,700 yearly deaths

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



Avoiding excessive sunTanning of the skin is the body’s natural reaction to permanent damage from too much sun

Even small doses of sunlight add up to a greater risk for skin cancer and premature aging

Avoid sun exposure between 10:00 am and 4:00 pm

Sun lamps and tanning parlors provide mainly ultraviolet A rays (UVA) and have been linked to melanoma

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



Avoiding excessive sunApply sunscreen lotion about 30 minutes before lengthy exposure to the sun

A sun protection factor (SPF) of at least 15 is recommended

When swimming or sweating, reapply waterproof sunscreens often (sunscreens lose strength when diluted)

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer


Critical thinkingWhat significance does a “healthy tan” have in your social life?

Are you a “sun-worshiper,” or are you concerned about skin damage, premature aging, and potential skin cancer in your future?


Monitoring estrogen, radiation exposure, & potential occupational hazards

Use of estrogen therapy has been linked to endometrial cancer in some studies

Exposure to radiation increases the risk for cancer(use the lowest dose possible to keep cancer risk down)

Occupational hazards increase the risk for cancerExamples include asbestos fibers, nickel and uranium dusts, chromium compounds, vinyl chloride, and bischlormethyl ether

Cigarette smoking magnifies the risk from occupational hazards

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



Maintain physical activityAn active lifestyle seems to have a protective effect against cancer

Cancer mortality in active men and women is lower

A daily 30-minute moderate-intensity exercise program lowers the risk for colon cancer and may lower the risk for cancers of the breast and reproductive system

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



Figure 11.9Association between physical fitness and cancer mortality


Warning signals of cancerChange in bowel or bladder habits

Sore that does not heal

Unusual bleeding or discharge

Thickening or lump in breast or elsewhere

Indigestion or difficulty in swallowing

Obvious change in wart or mole

Nagging cough or hoarseness

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



Recommended check upsCancer-related checkup

Every 3 years for people 20–40

Every year for people age 40 and older

Might include examinations for

Cancers of the thyroid, oral cavity, skin, lymph nodes, testes, and ovaries

Some nonmalignant diseases

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



Recommended check upsBreast check up

Women 40 and older should

Have an annual mammogram

Have an annual clinical breast examination (CBE) (conducted close to and before mammogram)

Perform monthly breast self-examination (BSE)

Women 20–39 should

Have a clinical breast examination every 3 years

Perform monthly BSE

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



Recommended check upsColon & rectum check up

Beginning at age 50, men and women at average risk should follow one of the examination schedules below:

Fecal occult blood test (FOBT) every year, or

Flexible sigmoidoscopy every 5 years, or

FOBT every year and flexible sigmoidoscopy every 5 years, or

Double-contrast barium enema every 5 years, or

Colonoscopy every 10 years

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



Recommended check upsProstate checkup

Beginning at age 50, men with life expectancy of at least 10 years should have the choice of having these tests annually

A prostate-specific antigen (PSA) test

A digital rectal exam

Men at high risk should begin testing at age 45

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Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



Recommended check upsUterus check up

Cervix: All sexually active women or women 18 and older should have these tests each year (less frequent after three consecutive tests with normal findings)

Pap test

Pelvic examination

Endometrium: Beginning at age 35, women with or at risk for hereditary non-polyposis colon cancer should be offered an endometrial biopsy annually

CancerDevelopment

Incidence of Cancer


AssessingYourRisks


Cancer

WarningSignals of

Cancer



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