Pathophysiology (MBS 213) Week 4: Neoplasm PDF

Pathophysiology (1) (MBS 213) week 4: Neoplasm Textbook ;Pathophysiology for the Health Professions, 4th edition, 2011 Chapter 5, P. 95-115  Learning objectives: After studying this chapter ,the student is expected to describe and discuss: Neoplasm: Definition, Nomencl...

Pathophysiology (1) (MBS 213) week 4: Neoplasm Textbook ;Pathophysiology for the Health Professions, 4th edition, 2011 Chapter 5, P. 95-115  Learning objectives: After studying this chapter ,the student is expected to describe and discuss: Neoplasm: Definition, Nomenclature, Types, grading and staging Effects, Diagnostic tests, Methods of spread Carcinogenesis process and risk factors Examples  Benign And Malignant Tumors A neoplasm or tumor is a cellular growth that is no longer responding to normal body controls. The cells continue to reproduce when there is no need for them. This excessive growth deprives other cells of nutrients. Many neoplasms are unable to function as normal tissue cells because they consist of atypical (abnormal) or immature cells. The characteristics of each tumor depend on the specific type of cell from which the tumor arises, resulting in a unique appearance and growth pattern. The expanding mass creates pressure on surrounding structures.  Tumor Nomenclature Tumors are named according to a system. The root word, such as chondro, is the cell of origin, in this case cartilage. Depending on the type of tissue where a tumor is located, the suffix indicates malignant tumors (carcinoma for epithelial tissue, sarcoma for connective tissue). The suffix oma alone indicates a benign tumor, e.g., lipoma. However, a number of neoplastic disorders have acquired unique names that are recognized in medical practice. Examples include Hodgkin disease, Wilms tumor, and leukemia. Oncology is the study of malignant tumors.  Tumors differ greatly depending on their origin. Benign tumors are made of specialized cells that grow faster than normal, are often enclosed, and expand without spreading. They can cause problems by pressing on nearby tissues but are usually not life-threatening unless the pressure is critical (e.g., in the brain). Malignant tumors, on the other hand, are made of unspecialized, disorganized cells that grow rapidly and often have abnormal cell division. These cells can invade surrounding tissues and spread (metastasize) to other parts of the body.  Warning Signs Of Cancer 1. Unusual bleeding or discharge anywhere in the body. 2. Change in bowel or bladder habits (e.g., prolonged diarrhea or discomfort). 3. A change in a wart or mole (i.e., color, size, or shape). 4. A sore that does not heal (on the skin or in the mouth, anywhere). 5. Unexplained weight loss. 6. Anemia or low hemoglobin, and persistent fatigue. 7. Persistent cough or hoarseness without reason. 8. A solid lump, often painless, in the breast or testes or anywhere on the body.  Local Effects of Tumors Pain often emerges in advanced stages of cancer and serves as a warning sign. It varies in severity depending on the tumor type and location. Causes of pain include: - Direct pressure on sensory nerves - Inflammation - Stretching of visceral capsules (e.g., kidney, liver) - Secondary factors like infection, ischemia, and bleeding Obstruction occurs when a tumor compresses or grows within ducts or passageways, affecting: - Airflow in bronchi or nerve conduction -Digestive tract - Blood supply or lymphatic flow (leading to ulceration and edema) Tissue necrosis and ulceration around tumors may lead to infections, especially in areas with opportunistic normal flora, like the oral cavity. Host resistance to infection is often lowered with cancer.  Systemic Effects of Malignant Tumors Weight Loss and Cachexia: Severe tissue wasting due to factors like anorexia, fatigue, pain, stress, and altered metabolism. Anemia: Reduced hemoglobin levels from anorexia, chronic bleeding, and bone marrow depression, leading to fatigue and poor tissue regeneration. Severe Fatigue: Results from inflammatory changes, cachexia, anemia, stress, and psychological factors. Infections: Frequent infections, like pneumonia, occur as host resistance declines and tissue breakdown develops. Bleeding: Tumors can erode blood vessels or cause ulceration, leading to poor clotting and chronic bleeding. Paraneoplastic Syndromes: Tumor-released substances may affect neurologic function, blood clotting, or hormone balance, leading to additional problems like Cushing syndrome.  Diagnostic Tests Diagnostic tests play a vital role in early cancer detection and ongoing monitoring post- diagnosis. Routine screenings and self-examinations are particularly crucial for high-risk individuals. A definitive cancer diagnosis requires the direct examination of tumor cells. Key diagnostic methods include: 1. Blood tests: Indicate problems like low blood counts and monitor treatment effects. Some cancers, like leukemia, can be diagnosed through bone marrow tests. 2. Tumor markers: Substances produced by cancer cells, such as CEA (Carcinoembryonic Antigen) for colon cancer or PSA (Prostate-Specific Antigen) for prostate cancer, can help screen, confirm, or monitor cancer, but their presence alone isn’t definitive. 3. Imaging tests: X-rays, ultrasounds, MRIs, and CT scans assess tissue and organ changes. Radioisotopes may be used to track metabolic activity. 4. Cytologic tests: Involve examining cells from biopsies or other samples to confirm malignancy.  Spread of Malignant Tumors There are three basic mechanisms for the spread of cancer: 1. Invasion refers to local spread, in which the tumor cells grow into adjacent tissue and destroy normal cells. 2. Metastasis means spread to distant sites by blood or lymphatic channels. In this case the tumor cells erode into a vein or lymphatic vessel, travel through the body, and eventually lodge in a hospitable environment to reproduce and create one or more secondary tumors. 3. Seeding refers to the spread of cancer cells in body fluids or along membranes, usually in body cavities, the tumor cells break away and travel easily with the movement of fluid and tissue. An example is ovarian cancer, in which the large peritoneal membrane encourages dispersion of the tumor cells throughout the peritoneal cavity Invasion Metastasis Seeding  Staging of Cancer - Staging of cancer is a classification process applied to a specific malignant tumor at the time of diagnosis. - It may be repeated at critical points. The staging system describes the extent of the disease at the time and therefore, provides a basis for treatment and prognosis. Staging systems are based on the: Size of the primary tumor (T) Extent of involvement of regional lymph nodes (N) Spread (invasion or metastasis) of the tumor (M) - Subgroups for each stage have also been established for many types of cancer. - Generally, stage I tumors are small and well localized, easy to treat, and have a good prognosis, whereas stage IV tumors are well advanced, difficult to treat at multiple sites, and have a poorer prognosis.  Stages in Carcinogenesis Carcinogenesis, the transformation of normal cells into cancer cells, occurs through several stages: Initiation: Irreversible DNA changes caused by procarcinogens (genetic or environmental factors) without forming an active tumor. Promotion: Further DNA changes due to promoters (hormones, chemicals), leading to less differentiated cells and increased mitosis, developing into a tumor. Progression: Continuous exposure results in a malignant tumor capable of local invasion. Metastasis: Changes in growth regulation allow cells to detach and spread to distant sites. The process varies in duration, with some tumors developing quickly and others taking decades, impacting treatment decisions. Aggressive tumors metastasize and reproduce rapidly.  Host Defenses Cancer suppressor genes present in the body can inhibit neoplastic growth. The immune system appears to offer protection by reacting to changes in the membranes of some tumor cells, which are seen as “foreign.” The immune response includes both cell-mediated and humoral immunity. Cytotoxic T lymphocytes, natural killer (NK) cells, and macrophages are involved in immune surveillance and the destruction of “foreign” or abnormal cells. Temporary or long-term immunodeficiency has been shown to increase the risk of cancer. For example, human immunodeficiency virus (HIV) infection or acquired immunodeficiency syndrome (AIDS) decreases the number of T lymphocytes. Cancers such as Kaposi’s sarcoma and lymphomas occur frequently in AIDS patients  Treatment Basic treatment measures may involve any (or all) of depending on specific cancer; Surgery (solid tumors) Chemotherapy (hematopoietic cancers such as leukemia because the cancer cells are dispersed in the blood) Radiation Immunotherapy stimulates the patient's immune system to attack the cancer Combination Treatment may be; Curative if the tumor is small and localized, or Palliative if the cancer is advanced, to reduce the manifestations and complications  Prognosis A “cure” for cancer is generally defined as a 5-year survival without recurrence after diagnosis and treatment. In some cases, early diagnosis and treatment limit the extent of the illness in an individual. In other cases, cancer treatment involves a prolonged period of illness with intermittent acute episodes. The death rates for specific cancers vary: For some types of cancer, such as lung cancer, there has been no significant improvement in the outcome even with aggressive treatment. For other cancers, such as certain childhood leukemias and Hodgkin’s lymphoma, effective treatment has been developed, and survival rates are much improved.  Examples Of Malignant Tumors - Skin Cancer Skin Cancer is usually visible and treatable, mostly with surgery, and has a slow progression. Most types, except malignant melanoma, have an excellent prognosis. They often recur, mainly on sun-exposed areas like the head, neck, and back. It's more common in fair-skinned individuals over 40 in southern climates. Reducing sun exposure can help prevent skin cancer. Basal Cell Carcinoma: -Most common form. -Appears as a pearly papule with a central ulcer ("rodent ulcer"). -Lacks pain or itching and grows slowly. -Invades subcutaneous tissues.  Examples Of Malignant Tumors - Ovarian Cancer Ovarian Cancer has a high mortality rate and poor prognosis because it is often hidden and asymptomatic until advanced stages. Location: Tumor hidden in the peritoneal cavity, making early detection difficult. Risk Factors: Hormonal and genetic factors. Symptoms: Vague symptoms appear when the tumor is large and causes pressure on adjacent structures (e.g., bladder, intestine). Tumor Markers: CA125 can help in early diagnosis and treatment monitoring but has limitations. Spread: Tumor spreads easily through lymphatic vessels and seeding in the peritoneal cavity, affecting the liver, uterus, and pelvis.  Examples Of Malignant Tumors - Brain tumors Brain tumors, whether benign or malignant, create pressure within the skull and are serious. Location: Tumors in the brainstem or cerebellum can be fatal due to interference with vital functions like respiration. Removal: Easier if located on the brain surface; difficult and dangerous if deeper. Origin: Can arise from neurons, neuroglial cells, blood vessels, or connective tissue, affecting both children and adults. Symptoms: Early signs include seizures, headaches, drowsiness, vomiting, visual problems, and impaired motor function. Metastasis: Malignant brain tumors typically do not spread outside the CNS, but tumors from other organs can metastasize to the brain.  Malnutrition in Advanced Cancer Patients Patients with advanced cancer often suffer from malnutrition due to: Changes in Taste: Altered taste sensations making food unappealing. Appetite Loss: Anorexia and vomiting reducing food intake. Oral Health: Sore mouth, loss of teeth, and ulcers causing eating discomfort. Pain and Fatigue: Decreasing the desire to eat. Malabsorption: Inflammation in the digestive tract hindering nutrient absorption. Metabolic Changes: Tumor-induced alterations in metabolism. Nutrient Trapping: Tumors consuming nutrients meant for the body. These factors may result from the cancer itself or treatments like chemotherapy and radiation.  Malnutrition in Advanced Cancer Patients Management Strategies: Comfort Measures: Ice and mouth rinses to alleviate mouth ulcers and inflammation. Diet Adjustments: Frequent small meals with favorite, non-irritating foods. Medications: Pain control and antiemetic drugs to stimulate appetite. Nutritional Support: Total parenteral nutrition (TPN) for direct nutrient administration. Addressing these issues can significantly improve the patient's nutritional status and overall well-being. Thank you