Were you aware of all the ACS recommendations for the early detection of cancer prior to reading this chapter? If you were not, which recommendations were new to you? Will you follow these recommendations? Why or why not? If you were aware of all the ACS recommendations, do you follow those recommendations for your sex and age group? W hy or why not?
Chapter 13
Cancer
What Is Cancer?
• Cancer refers to many diseases.
• Characterized by abnormal growth, division, and
differentiation
• Cancer cells metastasize, form masses called
malignant tumors, and do not stop growing and
dividing at appropriate times.
How Cancers Develop and Spread
• Cancer develops only in cells with damaged genes
(mutations).
• Mutations can be inherited or caused by exposure
to low-dose radiation, drugs, or toxic chemicals.
• Infection with certain viruses can cause mutations.
How Cancers Develop and Spread:
Genes and Cancer Development
• Oncogenes—“on” switches that speed cell growth
• Tumor-suppressor genes—“off” switches that slow cell
growth
• Benign tumors are surrounded by a fibrous capsule and
do not spread or invade surrounding tissues.
How Cancers Develop and Spread:
Metastasis
• Cancer cells have the ability to spread, or
metastasize.
• Cells that metastasize are called malignant
• Cancer cells can enter the bloodstream or
lymphatic system and travel to other parts of the
body and form new tumors.
How Cancers Develop and Spread:
Metastasis
• Cancers are named according to the type of tissue from
which they develop.
– Carcinomas arise from epithelial tissue.
– Sarcomas arise from connective or muscle tissue.
– Leukemias are cancers of the blood and related cells.
– Lymphomas are cancers of the lymphatic system.
– Cancers of the nervous system have various names.
How Cancers Develop and Spread
Cancer Detection and Staging
• American Cancer Society (ACS) recommends
screening for early detection, particularly for high-risk
people or people with symptoms.
– Visual examination
– Self-examination
– Clinical (physician) examination
– Laboratory testing
– Scans (MRI, CAT)
Cancer Detection and Staging
• Cancer staging describes the extent of growth and
metastasis of cancer.
• TNM system of staging:
– T describes the original tumor
– N describes if cancer has reached lymph nodes
– M describes if cancer has metastasized
• The overall stages are I, II, III, and IV.
Cancer Treatment: Surgery,
Radiation, and Chemotherapy
• Surgery removes localized cancers.
– Most cancer cures are accomplished by surgery.
• Radiation kills localized cancers
– Used alone or with surgery.
• Chemotherapy inhibits cancer cell reproduction or
destroys metastasized cancer cells.
– Used most often when cancer has spread
Cancer Treatment: Laser and
Photodynamic Therapy
• Lasers are high intensity lights that can be focused with
great precision.
• Remove superficial cancers as well as those in interior
body locations
• Chemical called photosensitizer reacts with special
light, killing tumor cells.
• Tumor cells become targets for treatment because they
absorb photosensitizer better than healthy cells.
Cancer Treatment: Targeted
Therapies
• Drugs or other substances that block the growth and
spread of cancer
• Small-molecule drugs
– Do a specific job, such as blocking certain enzymes
or growth factor receptors, modifying the function
of proteins that regulate cancer cell functions, and
stopping cancerous tumors from developing new
blood vessels
Cancer Treatment: Targeted
Therapies—Immunotherapy
• Biomodulation—(biological response modification)
manipulation of the immune system to rid the body of
its cancer
• Key to the working of the immune system is its ability
to recognize an intruder as foreign.
Cancer Treatment: Bone Marrow and
Peripheral Blood Stem Cell Transplants
• Patients receive stem cell transplants in a process that
is like receiving a blood donation.
• Used in two ways
– To resupply the bone marrow when it has been
destroyed by chemotherapy or radiation
– To supply healthy stem cells to a person who has
cancer of the blood-forming tissue, such as leukemia
Prevalent Cancers in the United States:
Risk Factors
Unmodifiable
• Heredity
Modifiable
• Cigarette smoking
• Advanced age
• Dietary patterns
• Sex
• Physical activity
• Weight management
Prevalent Cancers in the United States:
Caused by or Related to Tobacco
• Lung cancer is the leading cause of cancer deaths.
• Signs and symptoms
– Chronic cough, excess sputum, wheezing, chest
pain, and lung infection
• Diagnosis
– Chest X-rays, MRI and CT scans; analyses of the
types of cells in the sputum; and fiber optic
examination of the bronchial passageways
Prevalent Cancers in the United States:
Caused by or Related to Tobacco
• Risk factors and prevention
– The number of cigarettes smoked/day
– The number of years a person smokes
– How deeply he or she inhales
– Smoking high-tar or unfiltered cigarettes
– Quitting smoking reduces the risk of developing
lung cancer; after 10 years it will be about half that
of a person who continued to smoke.
Prevalent Cancers in the United States:
Caused by or Related to Tobacco
• Risk factors and prevention
– High consumption of alcoholic beverages and
obesity
– Passive smoking is associated with a 20% to 30%
increase in lung cancer risk.
– Asbestos particle inhalation
– Radon gas exposure appears to multiply the
carcinogenic effects of tobacco smoke.
Prevalent Cancers in the United States:
Caused by or Related to Tobacco
• Physicians treat lung cancer with surgery, radiation,
and chemotherapy.
Prevalent Cancers in the United States:
Caused by or Related to Tobacco
• Cancers of the larynx, oral cavity, and esophagus
– Caused by tobacco and alcohol use as well as HPV
– Hoarse voice, difficulty swallowing, and a sore
throat may indicate larynx cancer.
– Recurrent heartburn may indicate esophageal cancer.
– Oral cancer tumors are easy to detect because they
are visible; they metastasize quickly.
Prevalent Cancers in the United States:
Caused by or Related to Tobacco
• Cancers of the kidney and bladder
– Come in contact with inhaled carcinogens after the
substances enter the bloodstream
– Blood in the urine is a sign of kidney or bladder
cancer; frequent, urgent, or difficult urination are
also signs of bladder cancer.
– Men who are over 50 years old and are heavy
smokers have a high risk of these cancers.
Prevalent Cancers in the United States:
Caused by or Related to Tobacco
• Cancers of the pancreas
– “Silent” cancer because early symptoms (nausea,
vomiting, weakness and discomfort in the abdomen)
are vague
– Obesity, high-fat diet, physical inactivity, and
diabetes are other risk factors for the disease.
– Only 6% of people who have pancreatic cancer
survive beyond 5 years.
Prevalent Cancers in the United States:
Caused by or Related to Tobacco
• Acute myeloid leukemia
– Affects blood-producing cells in bone marrow
– Fewer white blood cells are produced, particularly
the ones that combat bacterial infections.
– Exposure to benzene and ionizing radiation
increases the risk of AML.
– Benzene and substances that emit ionizing radiation
are in cigarette smoke.
Prevalent Cancers in the United States:
Related to Diet
• Each year, poor diet
and lack of physical
activity (including
obesity) account for
about one-third of
cancer deaths in the
United States.
Prevalent Cancers in the United States:
Related to Diet
• Cancer of the stomach
–Incidence of and death rate from stomach cancer has
declined dramatically over the past 75 years.
–“Silent” in early stages; symptoms may be attributed
to minor intestinal upsets.
–Risk increases with age.
–Diets high in salt-cured, nitrate-cured, or smoked
foods, consuming alcohol, and cigarette smoking also
are risk factors.
Prevalent Cancers in the United States:
Related to Diet
• Cancer of the colon and rectum
– Colorectal cancer is the third most deadly cancer in
the United States.
– Signs and symptoms depend on location of the
tumor.
– Abdominal pain, change in bowel habits, and blood
in the stools are important signs.
Prevalent Cancers in the United States:
Related to Diet
• Cancer of the colon and rectum: risk factors
– Advanced age
– Heredity; personal or family history
– Physical inactivity and obesity
– Diets high in fat and/or red meat; inadequate intake
of fruits and vegetables
– Smoking cigarettes
– Having more than one alcoholic drink per day
Prevalent Cancers in the United States:
Related to Diet
• Cancer of the colon and rectum: prevention
– Low-dose aspirin
– Regular exercise
– Diet with adequate fruits, vegetables, and whole
grains
– Eating less red meat and more fish
– Eating less saturated fat
Prevalent Cancers in the United States:
Related to Hormone Function
• Breast cancer
– Breast cancer is the second leading cancer cause of
death for women in the United States.
Prevalent Cancers in the United States:
Related to Hormone Function
Breast cancer risk factors Signs and symptoms
• Changes in the breast
• Family history: firstdegree relative
tissue
• Tenderness of the nipple
• Early menarche or late
menopause (younger than or nipple discharge
age 12)
• Swelling or distortion of
the breast.
• Not bearing children
• High-fat diet and obesity
Prevalent Cancers in the United States:
Related to Hormone Function
Breast cancer detection
• Breast selfexaminations
• Clinical breast exams
• Mammography
Treatment
• Lumpectomy
• Radiation
• Mastectomy
• Chemotherapy
• Hormonal
Prevalent Cancers in the United States:
Related to Hormone Function
• Endometrial cancer
– The endometrium is the lining of the uterus.
– Endometrial cancer is most common in
postmenopausal women.
– Primary symptom is abnormal uterine bleeding.
– Pap tests for cervical cancer do not reveal
endometrial cancer; endometrial biopsy is needed.
Prevalent Cancers in the United States:
Related to Hormone Function
• Endometrial cancer
– Primary risk factor is high cumulative exposure to
estrogen.
– Using combination oral contraceptives reduces risk.
– Treatments include total hysterectomy, radiation,
hormones and/or chemotherapy.
Prevalent Cancers in the United States:
Related to Viral Infection
• Cervical cancer
• Incidence has declined dramatically since 1960 due
to Pap test screening.
• Most women have no signs or symptoms when
diagnosed with the disease.
• Most often develops in women 20 to 40 years of age
• Treatments include surgery, radiation, laser
treatment, and cryotherapy.
Prevalent Cancers in the United States:
Related to Viral Infection
• Cervical cancer
– Human papillomavirus (HPV) and cervical cancer
• Causes genital warts
• Risk of infection increases with an increased
number of sexual partners and/or nonmonogamous partners.
• Women who became sexually active before age
17 have higher risk.
Prevalent Cancers in the United States:
Related to Viral Infection
• Cervical cancer
– Long-term use of oral contraceptives is associated
with an increased risk of cervical cancer.
– The vaccine, Gardasil, prevents infection with four
types of HPV.
– ACS recommends that all women have annual Pap
tests starting 3 years after first vaginal intercourse
but no later than age 21.
Prevalent Cancers in the United States:
Related to Viral Infection
• Cervical cancer: treatment
– Surgery
– Electrocoagulation
– Cryotherapy
– Carbon dioxide laser surgery
Prevalent Cancers in the United States:
Related to Ultraviolet Radiation
• Three types of UV radiation: UVA, UVB, and UVC
• All types are harmful and have potential to cause skin
cancer.
• UVA is associated with sunburn, skin cancer
formation, and premature aging effects.
• Artificial UV sources may also generate UVC rays.
• UVC is potent cancer-causing radiation.
Prevalent Cancers in the United States:
Related to Ultraviolet Radiation
• Basal cell carcinoma
– May look like moles or pimples with pearl-like
borders
– May crust, scale, and bleed
– Treatment
• Removed by surgery and cryotherapy
Prevalent Cancers in the United States:
Related to Ultraviolet Radiation
• Squamous cell carcinoma
– Flat, red, scaling lesions; may be slightly elevated
– Develops in people with darker skin from chemical
exposure, X-rays, burns, and chronic skin ulcers
– Treatment
• Removed by surgery and cryotherapy
Prevalent Cancers in the United States:
Related to Ultraviolet Radiation
• Malignant melanoma
– Most frequent cancer in women aged 25 to 29 and
second most frequent cancer in women aged 30 to
34
– People with fair skin have higher risk than those
with dark skin.
– Highest risk: people with light blue eyes, very light
hair, and skin that burns easily and freckles rather
than tans
Prevalent Cancers in the United States:
Related to Ultraviolet Radiation
• Malignant melanoma: prevention
– Limit sun exposure.
– Use sunscreens.
– Wear protective clothing when exposed to sunlight.
– Avoid artificial sources of UV light (i.e., tanning
beds).
Prevalent Cancers in the United States:
Related to Ultraviolet Radiation
• Check skin regularly for skin lesions that:
– Are asymmetrical
– Have irregular borders
– Have multiple colors
– Have a diameter greater than pencil eraser
Prevalent Cancers in the United States
• Prostate cancer
• The most prevalent cancer in men
• Signs and symptoms may be nonspecific
–
–
–
–
–
–
Uneven or reduced flow of urine
Incomplete emptying of bladder
Urinating more frequently at night
Pain in the pelvis
Sudden development of impotence
Blood in the urine
Prevalent Cancers in the United States
• Prostate cancer: risk factors
– Location: men living in North America and
northwestern Europe
– Race: African Americans and Jamaicans of African
descent have the highest prostate cancer incidence
rate.
– Advanced age
– Heredity
– Obesity and high-fat diet
Prevalent Cancers in the United States
• Prostate cancer: detection and treatment
– Annual digital rectal exam and PSA blood test are
recommended for men older than 50.
– Prostate cancer is often slow growing; most patients
die of other causes.
– “Watchful waiting” is often treatment of choice,
although recent research challenges this view.
Prevalent Cancers in the United States
• Testicular cancer
– Testicular cancer is rare and highly curable.
– Signs and symptoms
• Painless, swollen testis
• Sensation of heaviness or aching in the testis
• Small lump in one testis
Prevalent Cancers in the United States
• Testicular cancer: risk factors and detection
– Age: strikes primarily teenagers and men between
the ages of 15 and 35
– Failure for testis to descend into scrotal sac by age 6
– Conduct testicular self-exam each month after a
warm bath or shower.
Prevalent Cancers in the United States
• Ovarian cancer
– No signs and symptoms in early stage
– As disease progresses
• Frequent urination or bloating
• Pressure in the abdomen
• Vaginal bleeding in postmenopausal women
• Irregular or heavy menses in premenopausal
women
– Occurs most often after menopause
Prevalent Cancers in the United States
• Ovarian cancer: risk factors
– Advanced age (85% to 90% develop in
postmenopausal women)
– Early menarche or late menopause
– Not bearing children
– Living in a Western country
– Obesity
– Use of oral contraceptives reduces risk
Prevalent Cancers in the United States
• Ovarian cancer: detection and treatment
– No accurate routine screening test for women at
average risk is available.
– Pelvic examination, transvaginal ultrasound, and
blood tests can detect abnormalities.
– Surgery
– Chemotherapy
– Radiation
Reducing Your Risk for Cancer
• Avoid smoking and exposure to secondhand smoke.
• Eat a diet low in fat and red meats and high in fruits
and vegetables daily; avoid eating cured or smoked
meats.
• Exercise most days of the week and maintain a healthy
weight.
• If you are sexually active, use protection and consider
HPV vaccines.
Reducing Your Risk for Cancer
• Use sunblock and cover up in the sun; don’t use
tanning beds.
• Women should consult with their healthcare providers
about risks of using oral contraceptives or hormone
replacement therapy.
• Follow ACS recommendations for cancer screening
tests, including self-examinations and clinical exams.
Cancer Across the Life Span
• In general, cancer risk increases with advancing age.
• Common cancers affecting young adults:
– Melanoma
– Testicular cancer
– Cervical cancer
– Breast cancer
• Only 1% of cancers occur in children.
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