Download Behavioral Objectives

CHAPTER 22
CANCER
BEHAVIORAL OBJECTIVES
1. Describe five characteristics of cancer cells. [22.1, p.444, Table 22.1]
2. Explain how the patient’s prognosis is determined by the stage of cancer, and list the three stages of
progression. [22.1, p.444, Fig. 22.2]
3. Understand that the cell cycle is normally closely regulated. [22.2, p. 446]
4. Name two types of genes whose mutation is necessary to the development of cancer. [22.2, p.446-447, Fig.
22.3]
5. Explain how the regulatory network malfunctions when a proto-oncogene becomes an oncogene. [22.2, p.446447, Fig. 22.3]
6. Explain the role of apoptosis in cancer development. [22.2, p.448, Fig. 22.4]
7. Understand the role heredity plays in cancer development. [22.3, p. 448]
8. Define “carcinogen” and list several types. [22.3, pp.448-449. Fig. 22.5]
9. Give examples of routine screening tests, tumor marker tests, and proposed oncogene tests to diagnose cancer.
[22.4, pp. 450-452]
10. Motivate students to develop the habit of periodic self-examination for cancer. [22.4, p.451, Fig. 22A-C]
11. Describe three current, standard approaches to treating cancer. [22.4, pp.452-453, Fig. 22.7]
12. Describe possible ways to treat cancer in the future. [22.4, pp. 454-455]
13. Identify and discuss seven ways (including dietary guidelines) people can minimize their risk of developing
cancer. [22.4, p.456, Health Focus]
14. Understand and use the bold-faced and italicized terms included in this chapter. [Understanding Key Terms,
p.458]
EXTENDED LECTURE OUTLINE
22.1 Cancer Cells
Carcinogenesis takes many years because it requires many mutations that occur over time. It may be many years
before the person is aware they have developed a tumor.
Characteristics of Cancer Cells
Cancer Cells Lack Differentiation
Cancer cells are not specialized and lack differentiation. Unlike normal cells, they can undergo a limitless
number of cell divisions.
Cancer Cells Have Abnormal Nuclei
Nuclei of cancer cells are enlarged and can have abnormal numbers of chromosomes. Gene amplification is
more common in cancer cells. Cancer cells do not undergo apoptosis.
Cancer Cells Form Tumors
Normal cells exhibit contact inhibition, but cancer cells do not have this restraint. Instead, they produce an
abnormal mass, or tumor. Benign tumors do not spread.
Cancer Cells Induce Angiogenesis
Angiogenesis is needed to help cancerous tumors continue to grow. Cancer cells release growth factors that
promote this.
Cancer Cells Metastasize
Cancer cells tend to be motile and produce enzymes that allow them to dissolve basement membranes and
invade surrounding tissues.
Prognosis depends on whether the tumor has spread to surrounding tissues, whether there is lymph node
involvement, and whether distant tumors have begun.
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Mader VRL CD-ROM
Image 0427l.jpg (Fig. 22.1)
Image 0428al.jpg (Fig. 22.2)
Image 0428bl.jpg (Fig. 22.2)
Transparencies
324 (Fig. 22.2)
22.2 Origin of Cancer
Mutations in four classes of genes can lead to cancer.
Regulation of the Cell Cycle
A stimulatory and an inhibitory pathway extends from the plasma membrane to the nucleus. Plasma membrane
receptors can receive growth stimulatory factors and growth inhibitory factors. Cytoplasmic proteins can therefore
be turned on or off and in turn either stimulate or inhibit certain genes in the nucleus.
Oncogenes
Proto-oncogenes are normal genes that stimulate the cell cycle to occur. Mutations can cause protooncogenes to become oncogenes which promote the cell cycle even when no stimulatory signal has been
received at the plasma membrane.
Tumor-Suppressor Genes
Tumor-suppressor genes ordinarily suppress the cell cycle and when they mutate they stop suppressing the
cell cycle and it can occur nonstop.
Apoptosis
Apoptotic enzymes can bring about destruction of the cell. These enzymes will ordinarily be activated when a cell is
experiencing run-away cell division. The tumor-suppressor gene p53 is believed to control apoptosis but if this gene
mutates then apoptosis will not occur.
Mader VRL CD-ROM
Image 0429l.jpg (Fig. 22.3)
Image 0430l.jpg (Fig. 22.4)
Life Science Animations VRL 2.0
Transparencies
Principles of Inheritance/Changes in Genetic
Message/Mutations
325 (Fig. 22.3)
326 (Fig. 22.4)
22.3 Causes of Cancer
Cancer is caused by a combination of heredity and environmental factors.
Heredity
Certain cancers, such as breast, lung, and colon cancers, run in families. Some childhood cancers are inherited as a
dominant gene.
Environmental Carcinogens
A mutagen is an agent that enhances the chance of a DNA mutation. A carcinogen is an environmental agent that
can trigger cancer. Carcinogens are frequently mutagenic.
Radiation
Ultraviolet radiation in sunlight and tanning lamps triggers the development of skin cancers. Melanoma is
the spreading form of skin cancer. Radon gas can lead to lung cancer. X rays and nuclear radiation can lead
to cancer.
Organic Chemicals
Tobacco smoke. Tobacco smoke contains numerous carcinogens that can lead to cancers of the lung,
mouth, larynx, bladder, kidney, and pancreas.
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Foods and Hormones. Foods rich in saturated fats and low in fiber are correlated with increased cancer
rates for the colon, rectum, and prostate. Certain food additives may be carcinogenic. Hormone
replacement therapy may contribute to uterine and breast cancers.
Pollutants. Pollutants, industrial chemicals, pesticides, and herbicides are mutagenic and can lead to cancer.
Viruses. Viruses have been linked to liver cancer, cervical cancer, a form of lymphoma, and
nasopharyngeal cancer.
Mader VRL CD-ROM
Image 0431l.jpg (Fig. 22.5)
Dynamic Human 2.0 CD-ROM
Reproductive/Clinical Concepts/Breast Cancer
Life Science Animations VRL 2.0
Principles of Inheritance/Changes in Genetic Message/Causes of
Cancer
22.4 Diagnosis and Treatment
Diagnosis of Cancer
The seven warning signs of cancer spell the word CAUTION (see p. 451).
Routine Screening Tests
Pap smears for cervical cancer are an example of a routine screening test. For breast cancer, routine selfexam, exam by a doctor, and mammography are recommended. Colon cancer screening involves a digital
rectal exam, sigmoidoscopy, a fecal occult blood test, and colonoscopy. Blood tests and urinalysis can
detect leukemia and bladder cancer.
Tumor Marker Tests
Blood tests for tumor antigens/antibodies produced against tumors are called tumor marker tests. They can
be used to detect first-time cancer and cancer relapses.
Genetic Tests
When individuals test positive for the presence of marker genes, such as the ras gene for colon cancer and
the BRCA1 breast cancer oncogene, they should be vigilant for signs of cancer. Microsatellite
abnormalities and the presence of telomerase indicate that cancer is present.
Confirming the Diagnosis
Surgical or needle biopsies, can confirm the presence of cancer. A number of imaging techniques (CAT
scan, MRI, radioactive scans, ultrasound) can confirm a tumor.
Treatment of Cancer
Traditional Therapies
Surgery is sufficient for cancer in situ. Surgery followed by radiation is recommended when cancer cells
may have been left behind.
Radiation. Some cancers (cervix, early prostate, larynx, and Hodgkin’s disease) can be treated successfully
with radiation alone.
Chemotherapy. Chemotherapy is used for metastatic cancers that may have spread throughout the body.
Chemotherapeutic drugs kill cells during cell division.
Bone Marrow Transplants. Bone marrow transplants are used when the patient is to receive high doses of
chemotherapy and radiation in combination. Bone marrow is needed to replace the blood-forming tissues
destroyed by the treatment. In autotransplantation, the patient’s stem cells are harvested, stored temporarily,
and returned to the patient when the treatment is over.
Future Therapies
Cancer Vaccine Therapy. A cancer vaccine that stimulates the body’s immune system to attack cancer cells
has promise but has yet to be highly effective.
Monoclonal Antibody Therapy. The use of monoclonal antibodies designed to combine with receptors on
cancer cells is under investigation.
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p53 Gene Therapy. Retroviruses and adenoviruses are used to carry normal cells into cancerous tissues.
Inhibitory Drug Therapy. Drugs that deactivate the enzymes that allow cancer cells to invade surrounding
tissues may help stop metastasis. Turning off angiogenesis using antiangiogenic drugs confines tumors.
These drugs are currently being tested. Preventing carcinogenesis is now possible in some instances.
Tamoxifen prevents breast cancer.
Complementary Therapy. Due to the insistence of patients, institutions are beginning to make use of such
therapies as homeopathy, biofeedback, acupuncture, and exotic foods.
Mader VRL CD-ROM
Image 0432l.jpg (Fig. 22.6)
Image 0433l.jpg (Fig. 22A)
Image 0434l.jpg (Fig. 22B)
Image 0435l.jpg (Fig. 22C)
Image 0436l.jpg (Fig. 22.7)
Image 0437l.jpg (Fig. 22.8)
Image 0438l.jpg (Fig. 22.9)
Image 0439l.jpg (Fig. 22.10)
Image 0440l.jpg (Fig. 22D)
Image 0441l.jpg (Fig. TA22.1)
Case Studies Online
Got Milk?? Part 1
Got Milk?? Part 2
Got Milk?? Part 3
Transparencies
327 (Figs. 22A, 22B, 22C)
328 (Fig. 22.7)
329 (Fig. 22.8)
330 (Fig. 22.9)
331 (Fig. TA22.1)
SEVENTH EDITION CHANGES
New/Revised Text:
This was chapter 21 in the previous edition. Statistics have been updated.
22.2 Origin of Cancer. Regulation of the Cell Cycle has been reorganized and rewritten for better
understanding of the stimulatory and inhibitory pathways involved in the action of proto-oncogenes and tumorsuppressor genes. Apoptosis has been rewritten and contains new information on caspases and how they work to
bring about apoptosis.
22.4 Diagnosis and Treatment. Future Therapies, which ends the section and the chapter has been updated
and includes new information and a new illustration regarding cancer vaccine therapy and inhibitory drug therapy
(previously called chemoprevention).
The Health Focus and Bioethical Focus readings have been moved to the end of the chapter so text is not
interrupted.
New Bioethical Focus: Tobacco and Alcohol Use
New/Revised Figures:
22.3 Origin of cancer; 22.4 Function of p53; 22.5 Industrial chemicals; 22.7 Treatment of cancer; 22.8
Cancer vaccine
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STUDENT ACTIVITIES
Get the Whole Story
1. Ask students how many have used a tanning booth. Assign students the task of visiting local tanning salons
asking operators to explain the cancer risks that users face in using their tanning booths. Perhaps they will tell
only that their lights have no harmful UV-B radiation. What they neglect to mention is that the UV-A rays
make the skin more sensitive to the UV-B rays that you will get later when you are in the sunshine. How many
operators told the whole story?
Shower Check for Cancer
2. Ask students to read the Health Focus “Shower Check for Cancer”. Have a school nurse or other health
professional demonstrate or explain the correct procedure for a monthly breast or testicle exam. Ask students
how many routinely examine themselves for cancer.
Cancer Prevention
3. Prepare a printed survey, or conduct a show of hands and tally results on the chalkboard, concerning how many
students follow the protective behaviors and the right diet, as shown in the “Prevention of Cancer” Health
Focus. Include the number of students with a history of cancer in their families. Calculate percentages of the
number of students who are exhibiting each protective behavior and of those who are generally following the
dietary guidelines. Discuss why students should alter behavior while they are still young to prevent cancer
development.
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