Chapter 6 Main Ideas
Describe staging as it relates to cancer
Staging - process of describing the extent of disease at the time of diagnosis; rate of growth, and prognosis; aids in treatment planning and compare results of different treatments
Stage 0: premalignant, preinvasive (carcinoma in situ)
Stage 1: early stage, local cancer
Stage 2: increase risk of spread because of tumor size
Stage 3: local cancer has spread but not to distant regions
Stage 4: cancer has spread to distant sites
TNM System - most often used in solid tumors; anatomic extent of the primary tumor, involvement of regional lymph nodes, distant metastases
Tumor (T): primary tumor 0-4
Regional lymph nodes (N): lymph node involvement 0-4
Metastasis (M): 0 = no metastasis; 1 = metastasis
When a neoplasia originates in a single cell by acquired genetic change
investigations of tumors confirmed that tumor cells are characterized by chromosomal abnormalities - both numeric and structural
Google def: proposes cancer and aging are caused by mutations in somatic/body cells
Somatic mutation theory
This type of cancer treatment will block process of tumor growth by cutting off tumor blood supply rather than on destruction of the tumor itself.
Antiangiogenic therapy
Mechanisms of metastasis
Rapidly growing tumors - millions of tumor cells are shed into vascular system; most that enter bloodstream are eliminated; small % initiate metastatic colonies; via veins - arteries are harder to break through
Metastatic cascade - complicated series of tumor-host interactions in a metastatic colony
Tumor angiogenesis - tumor starts to move by local invasion, blood vessels from preexisting vessels grow into the solid tumor
Ability of tumor to grow - ability to gain access to adequate blood supply (sometimes hormones)
A cell described as:
Differentiation is altered or lost
Cells may not be recognizable compared to parent cells
The less differentiated a tumor becomes- the faster
the metastasis and worse prognosis
Malignant cells
A Preinvasive, premalignant epithelial tumor of
glandular r squamous cell origin. has not broken through basement membranes.
Carcinoma in situ
These are considered risk factors for getting cancer
Age
Over 50
Longer exposure to carcinogens
Effects of age on immune system and host defense
Cancers in older population seem to be biologically different from younger population
Poor prognosis could be related to resistance to chemotherapy
Lifestyle
Tobacco - carcinogenic, most important cause of cancer
Diet/Nutrition - poor diet blunts immune systems natural defenses; healthy diet inhibits carcinogenesis process; lean body mass important during active cancer treatment
Alcohol - increased circulating levels of estrogens; alcohol acts with tobacco smoke synergistically - solvent for smoke, increases absorption of carcinogens
Geographic location - rural areas less likely to use preventative screening, exercise regularly, special care availability; occupational exposure to chemicals, fibers, air pollution
Stress - strong link
Chronic physical or emotional - hormonal changes, facilitate growth and proliferation of cancer
Psychological - immune down-regulation
Distress and depression - poorer repair of DNA; alterations in programmed cell death
Physical inactivity, obesity, type 2 DM, IBD (inflammatory bowel disease), sexual/reproductive behaviors, exposure to viruses, hormonal exposure, ethnicity, precancerous lesions, heredity
Process by which normal cells undergo physical and structural changes as they develop to form different tissues of the body (muscle cells, nerve cells, skin cells, etc)
Differentiation
Also called neoplasms; abnormal growth of new tissue that serves no useful purpose and may harm the host organism by competing for vital blood supply and nutrients
Tumor
Describe grading as it relates to cancer
Grading - numerical score or scale; different grading for different types of tumors; staging is more predictive than grading
-lower grade = cells more closely resemble normal cells; remains local
-higher grade = poorly differentiated cells; metastasize early
The process by which a normal cell undergoes malignant transformation
Carcinogenesis
This type of cancer treatment will destroy dividing cancer cells by destroying hydrogen bonds between DNA strands within the cancer cells while damaging resting normal cells as little as possible
Radiation therapy (XRT)
What are the Clinical manifestations of metastasis
Usually occurs within 3-5 years of initial diagnosis
Low-grade lesions can reappear up to 20 years later
Most common in areas rich in nutrition
Hepatic system - filters blood from GI system
Skeletal system - bone microenvironment provides fertile ground for tumor growth
CNS (brain/spinal cord)
Lymphatic system
Spread to adjacent structures and penetrate body cavities
Direct extension
This cancer treatment is immune-based therapy; modifies the relationship between the tumor and host - strengthens the hosts biological response to tumor cells
Biotherapy
Name the five major classifications of body tissue and identify what a typical tumor would be referred to as from each type.
Epithelium:
Cancer in any of these tissues are called carcinoma
Tumors from granular tissues are adenocarcinomas
Connective tissue:
Cancers in these tissues are called sarcomas
Nerve tissue:
Named for the tissue they arise from (ex: tumors from astrocytes would be called astrocytomas)
Cancers in these tissues are called neuromas
Lymphoid tissue: Called lymphoma
Hematopoietic: includes leukemias, multiple myeloma (cancerous plasma cells accumulate in the bone marrow) , myelodysplasia
Endogenous = ?
Exogenous = ?
Genetic
Environment
This type of cancer treatment are chemical agents used to destroy cancer cells by affecting DNA synthesis or function in the growth phase
Chemotherapy
What's the difference between a primary tumor and a secondary tumor?
Primary tumor - arises from cells that are normally local
Secondary tumor - arise from cells that have metastasized from another part of the body
A classification of neoplasms; cancerous; potential to grow uncontrollably; invasive (into other tissues or organs); capable of metastasizing to other parts of the body through bloodstream or lymphatic system
Malignant
Increasing in the number of cells in tissue, resulting in increased tissue mass; tumor formation and abnormal process (can be normal in wound healing and bone callus)
Hyperplasia
When a cells break away from the primary tumor and travel through the body (blood/lymph), get trapped in capillaries of organs, infiltrate the organ and grow into new tumor deposits;
Metastasis
A process by which unspecialized cells, like stem cells, develop into specific cell types with distinct functions (muscle cells, nerve cells, skin cells)
Differentiation
These cells differentiate properly and follow controlled growth patterns.
These cells lose the ability to differentiate properly.
Normal cells
Cancer cells
A classification of neoplasms; harmless as does not spread or invade other tissue; can become large enough to distend, compress, or obstruct normal tissues and impair function
Benign
A general category that indicates a disorganization of cells in which an adult cell varies from its normal size, shape, or organization
Dysplasia
The first level of dysplasia; reversible and benign but abnormal change in which one adult cell changed from one type to another
Metaplasia
A loss of cellular differentiation-
the most advanced form of metaplasia-
characteristic of malignant cells ONLY
Anaplasia