Chapter 20 - Neoplasms and Cancer

Identify the mechanisms of action of antineoplastic medications

Antimitotics, antimetabolites, alkylating agents, and some antibiotics interfere with protein synthesis and DNA replication at different points in the tumor cell cycle, therefore decreasing growth of the tumor

severe tissue wasting

cachexia

cancer-causing agent

carcinogen

sarcoma

malignant tumors of connective tissue

Malignant tumors

Cells: Varied in size and shape with large nuclei Many undifferentiated Mitosis increased and atypical nuclei present Growth: Rapid growth Cells lack adhesion, infiltrate adjacent tissue No capsule Spread: Invade nearby tissues and may metastasize to distance sites through blood and lymph vessels Systemic effects: Often present General prognosis: Destroy local tissue function if untreated Many metastasize to vital organs, causing death if not treated

Cartilage Malignant Tumor

Chondrosarcoma

Three specific pathophysiologic changes that occur in the formation of malignant tumors

normal organization, growth inhibition, cell-to cell communications—all absent (Alternate answers: cell membranes, surface antigens are altered)

Pancreas Malignant Tumor

Adenocarcinoma

Pancreas Benign Tumor

Adenoma

What is a biologic response modifier? How are these agents useful in the treatment of some types of cancer?

Biologic response modifiers are agents that augment the natural immune response to improve immune surveillance and removal of abnormal cells.

Benign tumors

Cells: Similar in appearance to normal cells Differentiated Mitosis normal Growth: Relatively slow Cells adhere in one mass No invasion of tissue Usually encapsulated Spread: Remain localized Systemic effects: Rare—except in CNS General prognosis: Life-threatening in certain locations (e.g., brain)

Cartilage Benign Tumor

Chondroma

Skin Benign Tumor

Epithelioma

The three potential goals of gene therapy in the treatment of cancer

Gene therapy treatment is designed to replace mutated genes with healthy ones, inactivate mutated genes, and introduce new genes.

Liver Malignant Tumor

Hepatocarcinoma

Liver Benign Tumor

Hepatoma

Fat Malignant Tumor

Liposarcoma

Describe how malignant cells spread from the original tumor to distant sites in the body. What is this called?

Malignant tumor cells lack cohesiveness and easily separate from the growing tumor mass; if invasive and eroding blood or lymphatic vessels, tumor cells can enter the circulation and reach distant sites. This is called metastasis.

Explain why individuals who have incompetent immune systems are at a higher risk for developing malignancies.

Malignant tumors often have altered "nonself" antigens on their surface, which, if detected early, may invoke an immune response that prevents the growth and spread of the tumor. If the immune system is compromised or deficient (e.g., in individuals with AIDS), then transformed cells go undetected until sufficient growth has occurred to establish the tumor.

Bone Benign Tumor

Osteoma

Bone Malignant Tumor

Osteosarcoma

Identify adverse effects that commonly occur during both radiotherapy and chemotherapy, and explain why they happen.

Radiation and chemotherapy are most effective against reproducing cells, both normal and malignant because of their effects on DNA replication. Therefore, normal cells that are dividing regularly are at the greatest risk (e.g., skin, GI tract mucosa, bone marrow, and gonads). Adverse effects include bone marrow depression (resulting in anemia, infections, bleeding, etc.), nausea and vomiting, and hair loss.

Explain how radiotherapy is effective in treating some types of cancer

Radiation causes mutations in the tumor cell DNA, preventing mitosis and tumor growth and causing immediate cell death; it also damages blood vessels, cutting off tumor blood supply

Identify the four conventional treatment measures employed in the treatment of cancer. Why are they often used in combination rather than singly?

Radiation, surgery, and chemotherapy are often used in combination to completely eradicate local tumor and treat and/or prevent metastases. Biologic modifiers and hormones may be used to limit the growth of specific tumors.

neoplasm

a tumor, a cellular growth that is no longer responding to normal body controls

Paraneoplastic syndrome

additional problems associated with certain tumors (e.g., bronchogenic carcinoma cells producing ACTH, causing manifestations of Cushing syndrome)

failure of cells to develop specialized features

anaplasia

What is the most common form of skin cancer?

basal cell carcinoma

transformation of normal cells into cancer cells

carcinogenesis

malignant tumor arising in epithelial tissue

carcinoma

A promoter in relation to carcinogenesis

cause additional changes in DNA, resulting in less differentiation and greater rate of mitosis.

Initiating factor in relation to carcinogenesis

cause the first irreversible cellular changes in the process of carcinogenesis.

Treatment for cancer may be curative, palliative, or prophylactic.

curative: used if tumor is small and localized; palliative: in advanced cancer, intended to reduce the manifestations and complications related to the cancer; prophylactic: used to prevent metastasis

degree of differentiation of malignant cells

grading

anaplasia

growth of undifferentiated cells of varying size and shape

Malignant tumors also have generalized systemic effects. Outline the factors that contribute to the development of the following systemic manifestations: i. weight loss and cachexia: ii. anemia: iii. systemic infections: iv. bleeding:

i. anorexia, fatigue, pain, stress, nutrient trapping, altered metabolism, and cachectic factors produced by macrophages ii. anorexia, decreased appetite and food intake, chronic bleeding, and bone marrow depression iii. host resistance decline; tissue breakdown and diminished immune system function; immobility iv. local invasion/erosion of blood vessels by tumor; bone marrow depression, and hypoproteinemia

Explain how the following diagnostic tools can assist in the detection and diagnosis of cancer: i. blood tests: ii. tumor markers: iii. x-ray, ultrasound, magnetic resonance imaging (MRI), and computed tomography (CT or CAT scan): iv. biopsy and histologic and cytologic examinations:

i. indicator of effects of chemotherapy and radiation; hemoglobin and erythrocyte counts may be low—often a general sign of cancer ii. tests of blood and body fluids for tissue enzymes or hormones associated with particular cancers (e.g., carcinoembryonic antigen [CEA], human chorionic gonadotropin [hCG], prostate-specific antigen [PSA] tests) iii. signs of abnormal growth or changes in organs and tissues iv. histopathologic confirmation of diagnosis of malignancy

A tumor is a space-occupying mass that produces predictable local effects as it enlarges. Describe the consequences that could result from the following effects: i. compression of blood vessels: ii. compression or obstruction of a tube or duct: iii. compression of nerves: iv. erosion of blood vessels and other structures: v. invasion and replacement of normal tissue:

i. ischemia, necrosis, and areas of inflammation around the tumor; potential for infection ii. blockage of secretion or normal flow of air (bronchi), food (GI tract), blood, or lymph depending on location iii. pain and loss of function iv. hemorrhage, inflammation, necrosis v. loss of normal tissue function

Identify eight risk factors for developing cancer, and include at least one example of each.

i. viruses: hepatitis virus (hepatic cancer) ii. radiation: (skin cancer) iii. chemical exposure: (lung cancer) iv. chronic irritation or inflammation: ulcerative colitis (breast cancer) v. increasing age: (many cancers are more common in older individuals) vi. diet: high-fat diet (colon cancer) vii. hormones: estrogen (endometrial cancer) viii. genetics: chromosomal abnormalities (leukemia)

confined to the site of origin (hyphenated)

in-situ

invasion

infiltration

Grading of neoplasms

is a reflection of the degree of differentiation or undifferentiation (degree of malignancy) of the tumor cells.

Staging of neoplasms

is the classification of tumors that reflects the extent of disease, that is, size of primary tumor, extent of lymph node spread, and metastasis (as in breast cancer).

Fat Benign Tumor

lipoma

carcinoma

malignant tumors of epithelial tissue

Skin Malignant Tumor

melanoma

spread of cancer to a distant site

metastasis

agents capable of causing alterations in DNA

mutagens

the study of cancer

oncology

malignant tumor arising from connective tissue

sarcoma

spread of cancer via body secretions

seeding

Other types of drugs that may be used in the treatment of cancer, including the rationale for each.

sex hormones when the tumor growth is dependent on, or accelerated by, such hormones; hormone blocking agents, often effective in reducing tumors and preventing recurrences; angiogenesis inhibitor to prevent enhanced blood supply to tumors by preventing endothelial cell growth; analgesics for pain management; narcotics as pain intensity increases

conversion of normal cells to cancerous cells

transformation

benign

tumor of differentiated cells that reproduce at higher than normal rate but do not spread

malignant

tumor of undifferentiated, nonfunctional cells that reproduce rapidly, infiltrate surrounding areas, and may spread by metastases to other organs and tissues

Identify the warning signs of cancer

unusual bleeding or discharge anywhere in the body; change in bowel or bladder habits (e.g., prolonged diarrhea or discomfort); a change in a wart or mole (i.e., color, size, or shape); a sore that does not heal (on the skin or in the mouth, anywhere); unexplained weight loss; anemia or low hemoglobin, and persistent fatigue; persistent cough or hoarseness without reason; a solid lump, often painless, in the breast or testes or anywhere on the body