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Chapter 20 NEOPLASMS AND CANCER •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •1 Introduction: Terminology Differentiation Each cell types differentiates and carries out particular functions. The structure reflects the function of the tissue. Mitosis Part of the cell cycle Requires genetic control—DNA and RNA Mutation If DNA in parent cell is altered and passed on, offspring cells will carry the mutation Apoptosis Programmed cell death Controlled by genetic elements •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •2 Neoplasms Neoplasm or tumor Cellular growth that no longer responds to normal genetic controls Cell continues to reproduce, without need for them to reproduce Deprives other cells of nutrition Neoplasms may consist of atypical or immature cells. Characteristics of each tumor depend on: Type of cell from which the tumor arises Unique structure and growth pattern •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •3 Nomenclature Benign tumors have tissue name plus the suffix oma (e.g., adenoma) Malignant tumors (cancers) have the tissue name plus the suffix -carcinoma (e.g., adenocarcinoma) Tumors of connective tissue are usually termed sarcomas and are often malignant. Several malignant tumors have unique names: Hodgkin’s disease Wilms’ tumor Leukemia •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •4 Tumor Nomenclature •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •5 Benign and Malignant Tumors Benign tumors Usually differentiated cells that reproduce at a higher rate than normal Encapsulated Tissue damage This is a result of compression of adjacent structures. It can be life-threatening in the brain. Malignant tumors Undifferentiated, nonfunctional cells Rapid reproduction—abnormal mitotic figures Infiltrate or spread into surrounding tissue Spread to distant sites •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •6 Characteristics of Benign and Malignant Tumors •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •7 Characteristics of Benign and Malignant Tumors (Cont’d) •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •8 Malignant Tumors: Cancer Lack control of mitosis and do not undergo apoptosis No normal organization or differentiation No contact inhibition Abnormal cell membranes Altered surface antigens Do not adhere to each other Often break loose from mass Invade other tissues and may spread to distant sites •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •9 Malignant Tumors: Cancer (Cont’d) Mass compresses blood vessels. Tumor cells may secrete enzymes or hormones. Break down of proteins and cells Systemic effects, such as altered calcium levels Inflammation and loss of normal cells Leads to necrosis and inflammation around tumor Lead to progressive reduction in organ integrity and function Angiogenesis Some tumor cells secrete growth factors. Stimulate the development of new capillaries in the tumor •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •10 Warning Signs of Cancer •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •11 Local Effects of Tumors Pain May be absent until very late stages Occurs when tumor is well advanced Severity depends on the type of tumor Obstruction Occurs wen tumor compresses a duct or passageway Blood supply or lymphatic flow may be restricted Digestive tract Airflow in bronchi Tissue necrosis and ulceration May lead to bleeding or infection around the tumor •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •12 Obstruction by Tumors •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •13 Systemic Effects of Malignant Tumors Weight loss and cachexia Anorexia, fatigue, pain, stress Increased demands on the body from tumor cells Anemia Caused by blood loss at tumor site Nutritional deficits may reduce hemoglobin synthesis. Severe fatigue Caused by inflammatory changes, cachexia, anemia Stress of treatment schedule Psychological factors •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •14 Systemic Effects of Malignant Tumors (Cont’d) Effusions Infections Occur frequently as resistance declines Bleeding Inflammation causes fluid buildup in body cavities. Tumor cells may erode the blood vessels. Paraneoplastic syndrome Associated with certain tumor types Tumor cells release substances that affect neurological function and may have hormonal effects. •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •15 Diagnostic Tests Routine screening Essential for early detection Following treatment to detect any further tumors Self-examination Early detection if done consistently Breast, testicular, and skin examinations are important. Blood tests Measure blood cell levels during treatment May detect tumor markers (e.g., PSA test) •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •16 Diagnostic Tests (Cont’d) Radiographic, ultrasound, MRI, CT Methods of visualizing changes in tissues or organs Cytological tests require biopsy or cell sample Histological and cytological examinations to determine degree of differentiation and tumor type May be tested for growth promoter sensitivities, (e.g., estrogen-dependent tumors) Most dependable confirmation of malignancy •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •17 Spread of Malignant Tumors Invasion Local spread Tumor cells grow into adjacent tissues Example: Uterine carcinoma invades the vagina. Metastasis Spread to distant sites Via blood or lymph or other body fluids Example: Carcinoma of the colon spreads to the liver. •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •18 Invasive Carcinoma of the Cervix •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •19 Metastatic Breast Cancer •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •20 Ovarian Cancer Spread Through Pelvic and Peritoneal Cavity Fluids •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •21 Staging Cancer Essential to standardize comparative studies of treatments and outcomes Used to estimate prognosis Most common system used is the TMN system: Size of primary tumor (T) Involvement of regional lymph nodes (N) Spread (metastasis) of tumor (M) •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •22 Carcinogenesis Process whereby normal cells are transformed into cancer cells Process varies greatly with respect to time Cancer is thought to be a multifactorial disease because of : Environmental effects Change in gene expression (heredity) Infection in some cases (e.g., cervical and hepatic cancers) Some cancers have well-established risk factors. •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •23 Stages in Carcinogenesis Initiating factors Procarcinogens cause the first irreversible change in cellular DNA. Do not create an active neoplasm Exposure to promoters Includes hormones and environmental chemicals Cause further changes in DNA Less differentiation and increased rate of mitosis and/or lack of apoptosis Dysplasia or anaplasia may be evident. Process leads to tumor development •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •24 Multistage Carcinogenesis •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •25 Risk Factors Genetic factors Viruses Oncogenes that regulate all growth Oncoviruses alter host cell’s DNA. Radiation Ultraviolet rays X-rays and gamma rays Radioactive isotopes Risk is increased with higher cumulative dosage. •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •26 Risk Factors (Cont’d) Chemicals (check health and safety information) Organic solvents Asbestos Heavy metals Formaldehyde Chemotherapy agents Biological factors Chronic irritation and inflammation Age Diet Hormones •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •27 Risk Reduction Limit UV exposure from sun or tanning booths. Regular medical and dental examinations Self-examination Diet Increased fiber content Reduced fats Five to ten servings of fresh fruits and vegetable daily. These foods contain antioxidants, which reduce changes in DNA. •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •28 Immunity and Cancer Risk Cell-mediated immunity recognizes some tumor cells and destroys them. Immunization for cervical cancer and hepatitis is recommended to reduce cancer risk from infection. •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •29 Treatment Depends on specific cancer Surgery, chemotherapy, immunotherapy, radiation Combination of the above •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •30 Effects of Treatment on Solid Tumor •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •31 Surgery Removal of tumor and surrounding tissue May be done with laparoscope and several small incisions Minimizes tissue damage Improves recovery time Removal of adequate surrounding tissue may result in changes in function. Radiofrequency ablation (RFA) - an alternative surgery for various tumors •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •32 Radiation Therapy May be used alone or combined with other therapies Causes mutations or alterations in target DNA Most effective in rapidly dividing cells Some types of cancers are radioresistant. May be used as an adjuvant therapy prior to surgery to shrink tumor •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •33 Radiation Therapy (Cont’d) Methods of administration External sources—cobalt machine Radiation for a short time to specific site in the body Requires multiple treatments Internal Insertion of radioactive material at the tumor site Treat specific cancers (e.g., cervical or oral tumors). Instill radioisotope in a solution into a body cavity. Monitor to ensure that there is no leakage Radioisotopes may be given by injection for specific tumors. •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •34 Adverse Effects of Radiation Bone marrow depression Decreased leukocytes—increase risk of infection Decreased erythrocytes—fatigue, tissue breakdown Decreased platelets—excessive bleeding Epithelial cell damage Infertility Damage to blood vessels and skin, hair loss Caused by abdominal radiation Nonspecific fatigue and lethargy Can lead to mental depression •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •35 Chemotherapy Antineoplastic drugs Can be used alone or in combination with surgery or radiation Usually combination of two to four drugs Given at periodic intervals Classifications include: Antimitotics Antimetabolites Alkylating agents Antibiotics Drugs interfere with protein synthesis and/or DNA replication. •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •36 Cell Cycle and Chemotherapy •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •37 Adverse Effects of Chemotherapy Bone marrow depression Limiting factor with chemotherapy Blood test taken before each treatment Nadir is point of lowest cell count—different points in cycle Nausea May occur prior to, during, or shortly after treatment Antiemetic drugs helpful for decreasing nausea •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •38 Adverse Effects of Chemotherapy (cont’d.) Epithelial cell damage Occurs easily Hair loss Breakdown of skin and mucosa Damage to specific areas With some antineoplastic drugs Fibrosis in the lungs Damage to myocardial cells Kidney damage •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •39 Other Drugs Blocking agents Biological response modifiers (BRMs) Augment the natural immune response Angiogenesis inhibitors Act to block receptors for growth promoters on cancer cells Inhibit the stimulus for growth of blood vessels Analgesics Prescribed to alleviate pain May be used in high dosages •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •40 Nutrition Patients with advanced cancer are often malnourished. Contributing factors Change in taste sensation Anorexia Vomiting and/or diarrhea from treatments Sore mouth or loss of teeth Pain and fatigue Malabsorption caused by inflammation in the digestive tract •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •41 Complementary Therapies May include Massage Meditation Counseling Exercise Therapeutic touch Research-based evidence has not been published for: Raw food macrobiotic diet Use of insulin and glucose with chemotherapy Health care workers need to be aware of these different types of therapies to advise patients. •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •42 Prognosis Cancer-free state generally defined as 5-year survival without recurrence Some cancers such as childhood leukemias can be considered cured after a 10-year, cancer-free period. Remission—no clinical signs of cancer Client may experience several remissions Life expectancy and death rates for specific cancers vary. •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •43 Examples of Malignant Tumors Skin cancer Visible, easily diagnosed and treated Excellent prognosis, with exception of malignant melanoma Ovarian cancer Poor prognosis because of hidden nature of cancer High mortality rates Brain tumors Both benign or malignant tumors are life-threatening because of compression of brain tissue. Primary tumor usually fatal; thus, no metastasis •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •44 Basal Cell Carcinoma •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •45 Brain Tumors in Various Locations •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •46 Cancer Incidence Most common in men Prostate cancer Lung cancer Colorectal cancer Most common in women Breast cancer Lung cancer Colorectal cancer •Copyright © 2014, 2011, 2006 by Saunders, an imprint of Elsevier, Inc. •47
