McCance Pathophysiology Ch. 12 - Cancer Biology

Local invasive factors include all except: a. increased cellular adhesion. b. lytic enzymes. c. mechanical pressure. d. cellular multiplication.

A

Telomeres: a. block unlimited cell division. b. activate oncogenes. c. encode repair proteins for damaged DNA. d. lead to increased mutation rates.

A

Which cancers are associated with chronic inflammation? (Select all that apply.) a. Brain b. Colon c. Bone d. Thyroid gland e. Urinary bladder

ANS: B, D, E Some organs appear to be more susceptible to the oncogenic effects of chronic inflammation; for example, the GI tract, prostate, thyroid gland, pancreas, urinary bladder, pleura, and skin. At present, no research supports a link between the remaining options and chronic inflammation.

What are characteristics of benign tumors? a. Benign tumors invade local tissues. b. Benign tumors spread through the lymph nodes. c. Benign tumors cause systemic symptoms. d. Benign tumors include the suffix -oma.

ANS: D Benign tumors are usually encapsulated and well-differentiated. They retain some normal tissue structure and do not invade the capsules surrounding them or spread to regional lymph nodes or distant locations. Benign tumors are generally named according to the tissues from which they arise and include the suffix -oma. Benign tumors do not cause systemic symptoms.

Why are two "hits" required to inactivate tumor-suppressor genes? a. Each allele must be altered, and each person has two copies, or alleles, of each gene, one from each parent. b. The first hit stops tissue growth, and the second hit is needed to cause abnormal tissue growth. c. Tumor-suppressor genes are larger than proto-oncogenes, requiring two hits to affect carcinogenesis. d. The first hit is insufficient to cause enough damage to cause a mutation.

ANS: A A single genetic event can activate an oncogene, acting in a dominant manner in the cell. However, each person has two copies, or alleles, of each gene, one from each parent. Therefore two hits are required to inactivate the two alleles of a tumor-suppressor gene, allowing the process to become active. The remaining options do not describe the reason two hits are required.

Which cancer originates from connective tissue? a. Osteogenic sarcoma b. Basal cell carcinoma c. Multiple myeloma d. Adenocarcinoma

ANS: A Cancers arising from connective tissue usually have the suffix -sarcoma. Carcinomas arise in epithelial tissue. Myeloma arises in the bone marrow.

What is the role of caretaker genes? a. Maintenance of genomic integrity b. Proliferation of cancer cells c. Secretion of growth factors d. Restoration of normal tissue structure

ANS: A Caretaker genes are responsible for the maintenance of genomic integrity. The other options are not roles assumed by caretaker genes.

A healthcare professional is caring for a patient undergoing chemotherapy. What is the skin-related health risk the professional should assess the patient for and be prepared to treat? a. Infection b. Ultraviolet damage c. Pain d. Erythema

ANS: A Decreased renewal rates of the epidermal layers in the skin may lead to skin breakdown and dryness, altering the normal barrier protection against infection. The healthcare professional should assess the patient for infection regularly and be prepared to treat any infection noted. Radiation therapy may cause skin erythema (redness). Pain and ultraviolet damage is not related to chemotherapies.

What is apoptosis? a. Normal mechanism for cells to self-destruct when growth is excessive b. Antigrowth signal activated by the tumor-suppressor gene Rb c. Mutation of cell growth stimulated by the TP53 gene d. Transformation of cells from dysplasia to anaplasia

ANS: A Normal cells have a mechanism that causes them to self-destruct when growth is excessive and cell cycle checkpoints have been ignored. Unchecked proliferation could lead to malignancy.

The professor explains to students that oncogenes are genes that are capable of what? a. Undergoing mutation that directs the synthesis of proteins to accelerate the rate of tissue proliferation b. Directing synthesis of proteins to regulate growth and to provide necessary replacement of tissue c. Encoding proteins that negatively regulate the synthesis of proteins to slow or halt the replacement of tissue d. Undergoing mutation that directs malignant tissue toward blood vessels and lymph nodes for metastasis

ANS: A Oncogenes are independent of normal regulatory mechanisms; thus the cell is driven into a state of unregulated constitutive expression of proliferation signals and uncontrolled cell growth.

What are tumor cell markers? a. Hormones, enzymes, antigens, and antibodies that are produced by cancer cells b. Receptor sites on tumor cells that can be identified and marked c. Cytokines that are produced against cancer cells d. Identification marks that are used in administering radiation therapy

ANS: A Tumor (biologic) markers are substances produced by both benign and malignant cells that are found either in or on the tumor cells or in the blood, spinal fluid, or urine. Tumor markers may include hormones, enzymes, genes, antigens, and antibodies. Tumor markers are not receptor sites, cytokines, or identification marks for radiation.

Normally, which cells are considered immortal? (Select all that apply.) a. Germ b. Stem c. Blood d. Epithelial e. Muscle

ANS: A, B Usually, germ cells (those that generate sperm and eggs) and stem cells are the only cells in the body that are immortal. Other cells in the body, such as those found in blood, epithelial tissue, and muscle tissue, are not immortal and can divide only a limited number of times.

A healthcare professional is assessing a patient who has cancer and a hemoglobin of 8.8 mg/dL. What factors should the professional assess the patient for? a. Chronic bleeding b. Malabsorption of iron c. Malnutrition d. Recent blood transfusion e. Current infection

ANS: A, B, C A hemoglobin of 8.8 mg/dL is low, indicating that the patient has anemia. Common causes for cancer patients to become anemic include chronic bleeding, malabsorption of iron, and malnutrition. Recent blood transfusions may have been given to treat anemia, but are not a causative factor. Current infection would not affect the hemoglobin.

What cellular characteristics are affected by anaplasia? (Select all that apply.) a. Size b. Ability to differentiate c. Life expectancy d. Tissue structure e. Shape

ANS: A, B, D, E Anaplasia is defined as the loss of cellular differentiation, irregularities of the size and shape of the nucleus, and loss of normal tissue structure. Life expectancy is not generally included in this term.

Which statements concerning aging and the occurrence of cancer are true? (Select all that apply.) a. Decline in immunologic functions b. Predisposition to nutritional inadequacies c. Unwillingness to access healthcare services d. Reluctance to engage in cancer screenings e. Effects of immobility on the immune system

ANS: A, B, E Many common malignancies occur mostly in older age as a result of immunologic functions declining with age. Older persons are predisposed to nutritional inadequacies, and malnutrition impairs immunocompetence. Far-advanced cancer often results in immobility and general debility that worsens with age. No research supports a correlation between aging and a reluctance to seek healthcare, in general, or cancer screenings, in particular.

What are the most common causes of nosocomial infections among patients with cancer? (Select all that apply.) a. Indwelling medical devices b. Suppressed immune system c. Visitor-introduced microorganisms d. Poor appetite e. Inadequate wound care

ANS: A, C, E Hospital-acquired (nosocomial) infections increase because of indwelling medical devices, inadequate wound care, and the introduction of microorganisms from visitors and other individuals. A suppressed immune system and a poor appetite are possible causes of infections but they are not nosocomial in nature.

What is the role of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in cell metastasis? a. To stimulate growth of nearby tumor cells b. To develop new blood vessels to feed cancer cells c. To prevent cancer cells from escaping apoptosis d. To act as a chemical gradient to guide cells to blood vessels

ANS: B By recruiting new vascular endothelial cells and initiating the proliferation of existing blood vessel cells, the angiogenic factors, such as VEGF and growth factor bFGF, allow small cancers to become large cancers.

By what process do cancer cells multiply in the absence of external growth signals? a. Proto-oncogene b. Autocrine stimulation c. Reliance on caretaker genes d. Pleomorphology

ANS: B Cancer cells must have mutations that enable them to proliferate in the absence of external growth signals. To achieve this, some cancers acquire the ability to secrete growth factors that stimulate their own growth, a process known as autocrine stimulation. A proto-oncogene is a gene that could become an oncogene. Caretaker genes are responsible for genomic integrity. Pleomorphology is the ability of cells to alter their shape or size depending on environmental conditions.

Burkitt lymphomas designate a chromosome that has a piece of chromosome 8 fused to a piece of chromosome 14. This is an example of which mutation of normal genes to oncogenes? a. Point mutation b. Chromosome translocation c. Gene amplification d. Chromosome fusion

ANS: B Chromosome translocations, in which a piece of one chromosome is translocated to another chromosome, can activate oncogenes. One of the best examples is the t(8;14) translocation found in many Burkitt lymphomas; t(8;14) designates a chromosome that has a piece of chromosome 8 fused to a piece of chromosome 14. A point mutation is the alteration of one or a few nucleotide base pairs. Gene amplification is the result of repeated duplication of a region of a chromosome, so that instead of the normal two copies of a gene, tens or even hundreds of copies are present. Chromosome fusion occurs during translocation.

What is the most commonly reported symptom of cancer treatment? a. Nausea b. Fatigue c. Hair loss d. Weight loss

ANS: B Fatigue is the most frequently reported symptom of cancer and cancer treatment. Although patients report the other options, they are not as frequently experienced as fatigue.

What does the student learn about pleomorphic cells? a. Pleomorphic cells are similar in size. b. They have different sizes and shapes. c. They are a result of anaplasia. d. Pleomorphic cells differentiate uniformly.

ANS: B In contrast to normal cells, which are uniform in size and shape, cancer cells are of variable size and shape, known as "pleomorphic."

Which statement supports the hypothesis that intestinal polyps are benign neoplasms and the first stage in the development of colon cancer? a. Cancer cells accumulate slower than noncancer cells. b. An accumulation of mutations in specific genes is required to develop cancer. c. Tumor invasion and metastasis progress more slowly in the gastrointestinal tract. d. Apoptosis is triggered by diverse stimuli, including excessive growth.

ANS: B Multiple genetic mutations are required for the evolution of full-blown cancer. This sequential development of cancer has been well documented in the transformation of benign colon polyps to colon cancer.

What aberrant change causes the abnormal growth in retinoblastoma? a. Proto-oncogenes are changed to oncogenes. b. The tumor-suppressor gene is turned off. c. Genetic amplification causes the growth. d. Chromosomes 9 and 21 are fused.

ANS: B One of the first discovered tumor-suppressor genes, the retinoblastoma (Rb) gene, normally strongly inhibits the cell division cycle. When it is inactivated, the cell division cycle can proceed unchecked. The Rb gene is mutated in childhood retinoblastoma. The remaining options do not describe the abnormal growth in retinoblastoma.

Carcinoma refers to abnormal cell proliferation originating from which tissue origin? a. Blood vessels b. Epithelial cells c. Connective tissue d. Glandular tissue

ANS: B Only cancers arising from epithelial cells are called carcinomas. Connective tissue cancers are called sarcomas. Glandular tissue cancers are named adenocarcinomas. Malignant cancers can invade blood vessels.

A child has been diagnosed with acute lymphoblastic leukemia (ALL). What does the healthcare professional tell the parents about the survival rate at 5 years for this disease? a. 90% b. 70% c. 40% d. 20%

ANS: B The 5-year survival rate for ALL is about 90%.

What is the consequence for cells when the functioning TP53 gene is lost as a result of mutation? a. Cells undergo apoptosis. b. Cells escape apoptosis. c. Cells receive less oxygen. d. Cells adhere more readily.

ANS: B The most common mutations conferring resistance to apoptosis occur in the TP53 gene. The remaining options do not accurately describe the effect when the functioning TP53 gene is lost as a result of mutation.

What is the most common route for distant metastasis? (Select all that apply.) a. Seeding b. Blood c. Lymphatic vessels d. Invasion e. Proliferation

ANS: B, C To transition from local to distant metastasis, the cancer cells must also be able to invade local blood and lymphatic vessels. The remaining options are not directly related to distant metastasis.

How does the ras gene convert from a proto-oncogene to an oncogene? a. Designating a chromosome that has a piece of one chromosome fused to a piece of another chromosome b. Duplicating a small piece of a chromosome, repeatedly making numerous copies c. Altering one or more nucleotide base pairs d. Promoting proliferation of growth signals by impairing tumor-suppressor genes

ANS: C A point mutation is the alteration of one or a few nucleotide base pairs. This type of mutation can have profound effects on the activity of proteins. A point mutation in the ras gene converts it from a regulated proto-oncogene to an unregulated oncogene, an accelerator of cellular proliferation. Fusion, duplications, and proliferation of growth signals are not the cause of a ras gene converting to an oncogene.

In childhood neuroblastoma, the N-myc oncogene undergoes which type of mutation of normal gene to oncogene? a. Point mutation b. Chromosome fusion c. Gene amplification d. Chromosome translocation

ANS: C Amplifications are the result of the duplication of a small piece of a chromosome over and over again; consequently, instead of the normal two copies of a gene, tens or even hundreds of copies are present. The N-myc oncogene is amplified in 25% of childhood neuroblastoma.

Autocrine stimulation is the ability of cancer cells to do what? a. Stimulate angiogenesis to create their own blood supply b. Encourage secretions that turn off normal growth inhibitors c. Secrete growth factors that stimulate their own growth d. Divert nutrients away from normal tissue for their own use

ANS: C Cancer cells must have mutations that enable them to proliferate in the absence of external growth signals. To achieve this, some cancers acquire the ability to secrete growth factors that stimulate their own growth, a process known as autocrine stimulation. The other options describe other activities of cancer cells, but not autocrine stimulation.

It has been determined that a patient's tumor is in stage 2. How does the healthcare professional describe this finding to the patient? a. Cancer is confined to the organ of origin. b. Cancer has spread to regional structures. c. Cancer is locally invasive. d. Cancer has spread to distant sites.

ANS: C Cancer confined to the organ of origin is stage 1; cancer that is locally invasive is stage 2; cancer that has spread to regional structures, such as the lymph nodes, is stage 3; and cancer that has spread to distant sites, such as a liver cancer spreading to the lung or a prostate cancer spreading to bone, is stage 4.

Carcinoma in situ is characterized by which changes? a. Cells have broken through the local basement membrane. b. Cells have invaded immediate surrounding tissue. c. Cells remain localized in the glandular or squamous cells. d. Cellular and tissue alterations indicate dysplasia.

ANS: C Carcinoma in situ (CIS) refers to preinvasive epithelial malignant tumors of glandular or squamous cell origin. These early stage cancers are localized to the epithelium and have not broken through the local basement membrane or invaded the surrounding tissue. Dysplasia refers to changes in mature cell structure.

Which gastrointestinal tract condition can be an outcome of both chemotherapy and radiation therapy? a. Increased cell turnover b. Constipation c. Stomatitis d. Bloody stool

ANS: C Chemotherapy and radiation therapy may cause a decreased cell turnover, thereby leading to oral ulcers (stomatitis), malabsorption, and diarrhea.

What is the major virus involved in the development of cervical cancer? a. Herpes simplex virus type 6 b. Herpes simplex virus type 2 c. Human papillomavirus d. Human immunodeficiency virus

ANS: C Infection with specific subtypes of human papillomavirus (HPV) causes virtually all cervical cancers. The remaining options are not known to be associated with cervical cancer.

Inherited mutations that predispose to cancer are almost invariably what kind of gene? a. Proto-oncogenes b. Oncogenes c. Tumor-suppressor genes d. Growth-promoting genes

ANS: C Inherited mutations that predispose to cancer are almost invariably in tumor-suppressor genes. At present, no research supports the other options as factors related to how inherited mutations cause cancer.

A healthcare professional is caring for four patients with cancer. Which patient does the professional educate about brachytherapy? a. Lung b. Colon c. Cervical d. Brain

ANS: C Radiation sources, such as small 125I-labeled capsules (also called seeds), can also be temporarily placed into body cavities, a delivery method termed brachytherapy. Brachytherapy is useful in the treatment of cervical, prostate, and head and neck cancers. Brachytherapy is not used in the treatment of the other cancers.

The Papanicolaou (Pap) test is used to screen for which cancer? a. Ovarian b. Uterine c. Cervical d. Vaginal

ANS: C The Pap test, an examination of cervical epithelial scrapings, readily detects early oncogenic human papillomavirus (HPV) infection. The Pap test is not used for screening the other cancer sites listed.

A student studying biology asks the professor to describe how the ras gene is involved in cancer proliferation. What explanation by the professor is best? a. It suppresses the action of the tumor-suppressor genes. b. It changes the way the growth promotion genes work. c. A mutation in this gene allows continuous cell growth. d. It activates a cell surface receptor that allows signaling to the nucleus.

ANS: C Up to one-third of all cancers have an activating mutation in the gene for an intracellular signaling protein called ras. This mutant ras stimulates cell growth even when growth factors are missing. The remaining options do not describe how ras contributes to cancer formation and growth.

What does the health professions student learn about benign tumors? a. The resulting pain is severe. b. Benign tumors are not encapsulated. c. Benign tumors are fast growing. d. The cells are well-differentiated.

ANS: D A benign tumor is well-differentiated with its tissue appearing similar to the tissue from which it arose. The other options are characteristic of a malignant tumor.

Which term is used to describe a cell showing a loss of cellular differentiation? a. Dysplasia b. Hyperplasia c. Metaplasia d. Anaplasia

ANS: D Anaplasia is defined as the loss of cellular differentiation, irregularities of the size and shape of the nucleus, and the loss of normal tissue structure. In clinical specimens, anaplasia is recognized by a loss of organization and a significant increase in nuclear size with evidence of ongoing proliferation. Dysplasia is the presence of an abnormal cell type within a tissue and often is called "precancerous." Hyperplasia is an enlargement of an organ or tissue due to increased production of its cells, also often considered precancerous. Metaplasia is an abnormal change in the characteristics of a tissue.

How do cancer cells use the enzyme telomerase? a. To repair the telomeres to restore somatic cell growth b. As an intracellular signaling chemical to stimulate cell division c. To switch off the telomerase to enable cells to divide indefinitely d. To switch on the telomerase to enable cells to divide indefinitely

ANS: D Cancer cells, when they reach a critical age, somehow activate telomerase to restore and maintain their telomeres and thereby make it possible for cells to divide over and over again.

In a normal, nonmutant state, what is an oncogene referred to as? a. Basal cell b. Target cell c. Caretaker gene d. Proto-oncogene

ANS: D In its normal nonmutant state, an oncogene is referred to as a proto-oncogene. A basal cell is in the innermost surface of epithelial tissue. Target cells are the recipients of mutations or substances. A caretaker gene is responsible for the maintenance of genomic integrity.

A cancer patient has pain at the tumor site and is worried the tumor has metastasized. What does the healthcare provider understand about this patient's complaint? a. Pain is primarily a result of pressure caused by the tumor. b. Pain indicates the metastasis of a cancer. c. Pain is usually the initial symptom of cancer. d. Pain is generally associated with late-stage cancer.

ANS: D Pain is generally associated with the late stages of cancer. Pressure, obstruction, invasion of a structure sensitive to pain, stretching, tissue destruction, and inflammation can cause pain. Pain is not the initial symptom of cancer nor does it indicate that the cancer has metastasized.

What is one function of the tumor cell marker? a. To provide a definitive diagnosis of cancer b. To treat certain types of cancer c. To predict where cancers will develop d. To screen individuals at high risk for cancer

ANS: D Screening and identifying individuals at high risk for cancer are ways tumor markers can be used. The two other uses for these markers are to help diagnosis a specific type of cancer (not give a definitive diagnosis) and to follow the clinical course of a tumor.

Which is not involved in metastasis? a. initial establishment b. interference c. invasion d. dissemination e. proliferation

B

The sequence of carcinogenesis is: a. exposure to carcinogens, selection of subclones, and mutation of genetic molecules. b. ionizing radiation, caretaker gene activity, and point mutations. c. several mutagenic "hits" to DNA, reactivation of telomerase, and development of immortal cells. d. carcinoma in situ, altered genetic molecules, and sequential mutagenic changes.

C

Tumor cell markers: a. are proteases. b. are absolutely diagnostic for cancer. c. can monitor the course of cancer. d. indicate metastasis.

C

Tumor suppressor genes are: a. genes that have the ability to transform a normal cell into a cancerous cell. b. normal genes that regulate growth and development. c. genes that produce proteins that inhibit cellular division. d. Both b and c are correct.

C

Metastasis is: a. an alteration in normal cellular growth. b. growth of benign or malignant neoplastic cells. c. mutational. d. the ability to establish a secondary neoplasm at a new site.

D

Adjuvant chemotherapy: a. produces irreversible tissue alteration. b. is well suited to treat localized disease. c. seeks to shrink tumors. d. is used prior to localized surgery. e. follows surgery to eliminate micrometastases.

E

Carcinoma in situ is: a. preinvasive. b. a glandular or epithelial lesion. c. a teratoma. d. a carcinoma that has broken through the basement membrane. e. Both a and b are correct.

E

In the current theory of carcinogenesis: a. the sequence is initiation-promotion-progression. b. several mutagenic "hits" are required. c. mutations in somatic cells are transmitted to future generations. d. sequential genetic changes occur. e. Both b and d are correct.

E

Known routes of metastasis include: a. continuous extension. b. lymphatic spread. c. bloodstream dissemination. d. Both b and c are correct. e. a, b, and c are correct.

E

Loss of E-cadherin: a. stimulates protease production. b. digests extracellular matrix. c. increases cellular receptiveness to cancer cells. d. transforms a normal cell to a cancerous cell. e. causes cells to detach from their extracellular attachments.

E

The p53 gene: a. enables cells to cope with DNA damage. b. blocks the proliferation of cells that have suffered carcinogenic mutations. c. mutations are the most common genetic lesion in human cancer. d. mutations disable an emergency brake on cell proliferation. e. All of the above are correct.

E

Which characterize(s) cancer cells? a. poorly differentiated b. metastasis c. infiltrative growth mode d. poor cellular cohesiveness e. All of the above are correct.

E - all of the above

Neoplasia; Anaplasia; Autonomy: a. variation in size, shape, and arrangement of cells b. differentiation of dividing cells into cellular types not ordinarily found in a given area c. abnormal, proliferating cells possessing a higher degree of autonomy than normal cells d. increase in absolute number of cells e. lack of cellular differentiation or specialization, primitive cells f. cancer cells' independence from normal cellular controls

Neoplasia: C; Anaplasia: E