Lecture 8: Oncology Flashcards
1
Q
Differentiation
A
- process by which normal cells undergo physical and structural changes during development to form different body tissues
- when a tumor has completely lost identity with the parent tissue, it is considered to be undifferentiated (anaplastic)
- the less differentiated a tumor becomes, the more it metastasizes and the prognosis declines
2
Q
Dysplasia
A
-adult cell that varies from its normal size, shape, or organization
3
Q
Metaplasia
A
- adult cell changes from one type to another (early dysplasia)
- reversible and benign
4
Q
Hyperplasia
A
-increase in number of cells in tissues
5
Q
Tumors
A
- aka neoplasms
- abnormal growths of new tissue that serve no useful purpose and may harm host organism by competing for vital blood supply and nutrients
- primary tumor arises from cells that are normally local
- secondary tumor arises from cell that have metastasized from another part in the body
- carcinoma in situ: pre-invasive epithelial tumors of glandular or squamous cell origin; not broken through basement membranes of squamous cells and occur in cervix, skin, oral cavity, esophagus, bronchus, and breast
6
Q
Classifications of a Neoplasm
A
- cell type, tissue of origin, degree of differentiation, anatomic site, or whether it is benign or malignant
- a benign growth is considered harmless and does not spread or invade other tissues; can become large enough to distend, compress, or obstruct normal tissues and to impairing normal body functions
- tumors are classified by cell type and named according to tissue from which they came: 5 major classifications-epithelial, connective and muscle, nerve, lymphoid, hematopoietic
- from epithelial tissue=carcinoma
- from glandular tissue-adenocarcinoma
- from connective tissue and muscle=sarcoma
- from brain or spinal cord tissue=gliomas but are named for cell involved and are often benign
- from lymphoid tissues=lymphoma
- from pigment cells=melanomas
- from plasma cells=myelomas
- from hematopoietic tissues=leukemias, multiple myeloma, myelodysplasia, and myeloproliferative syndromes
7
Q
Staging and Grading
A
- staging is process of describing extent of disease at time of diagnosis from 0-IV
- TNM classification scheme: most often used for solid tumors
- primary tumor (T) rated from 0-4
- regional lymph nodes (N) involvement ranked 0-4
- metastasis (M) is rated 0 if there is none and 1 if present
- numbers are used with each component to denote extent of involvement
- grading classifies degree of malignancy and differentiation of malignant cells…
- low grade closely resemble normal cells (tend to remain localized, may not be an issue, tends to take a while to be found
- high grade are poorly differentiated cells, highly metastasized
8
Q
Incidence
A
- steady downward trends have been attributed to improved vigilance among Americans who are benefiting from early screening and advances in Rx, as well as smoking less, improving diets, and exercising more
- most commonly diagnosed cancers: lung, breast, and colorectal
- most prevalent in world is breast cancer
- lung cancer accounts for most deaths worldwide
- cancer is second leading cause of death in US
- overall incidence has declined in last decade by 1.1% annually with 1.4% decline in death rates
9
Q
Etiology
A
- causative agents subdivided: endogenous (genetic) and exogenous (environmental or external)
- most cancers develop as result of multiple environmental, viral and genetic agents working together
- cancers showing a familial pattern are prostate, breast, ovarian, and colon cancers
- 50% of all cancers caused by one or more of nearly 500 different cancer causing agents…
- etiologic agents capable of initiating malignant transformation of cell are called carcinogens
- chemical agents and physical agents may cause cancer after close and prolonged contact
- some drugs are carcinogenic
- hormones have been linked to tumor development and growth
- excessive alcohol consumption
10
Q
Risk Factors
A
- advancing age
- lifestyle
- alcohol consumption
- sexual and reproductive behaviors
- hormonal exposure for women
- geographic location and environmental variables
- ethnicity
- precancerous lesions
- stress
11
Q
Advancing Age (over 50)
A
- one of most significant risk factors
- median age for all cancer is 70
- telomeres are c’somal structures located at ends of chromosomes: in normal cells telomere shortens each time a cell divides, cell dies when telomere becomes so short it can no longer divide, telomerase keeps normally dividing cell healthy by rebuilding telomeres and shuts down when cells are mature but in cancer cells it keeps rebuilding; telomerase is active in up to 85% of all human cancers
- people 65 and older have risk of cancer development much greater than younger persons
12
Q
Lifestyle
A
- tobacco use is carcinogenic: most important cause of cancer, lung cancer is now leading cancer-causing death in both genders, cigarette smoking is related to nearly 90% of all lung cancers
- diet and nutrition: healthy diet is thought to detoxify carcinogens; intake of cured, pickled, smoked, salted, and preserved food has been conclusively linked to stomach cancer; intake of fresh fruits and vegetables and fiber has been shown to reduce cancer risks
13
Q
Alcohol Consumption
A
- linked to increased rates of cancer of mouth, pharynx, larynx, esophagus, and liver
- it can also increase circulating levels of estrogens
14
Q
Sexual and Reproductive Behaviors
A
- linked to risk of developing various cancers
- cervical cancer related to age of first sexual intercourse, number, and type of STD and number of sexual partners
- pregnancy and childbearing seem to be protective against cancers of endometrium, ovary, and breast
- prolonged lactation may also have significant impact in reduction of breast cancer risk
15
Q
Hormonal Exposure for Women
A
-prolonged use of estrogen hormone replacement therapy for relief of menopause has been linked with increased rates of breast cancer
16
Q
Geographic Location and Environmental Variables
A
- colon cancer more prevalent in urban than rural areas but in rural areas skin cancer is more common
- people living in rural areas are less likely to use preventive screening services or to exercise regularly
- availability of specialty care is also contributing factor for rural areas
17
Q
Ethnicity
A
- incidence and mortality from cancer is 10% higher in African Americans compared to caucasians
- attributed to preventable risk factors, such as absence of early screening, delayed diagnosis, smoking and diet
- black american men have world’s highest rate of prostate cancer
18
Q
Precancerous Lesions
A
- precancerous and some benign tumors may undergo transformation later into cancerous lesions and tumors
- common ones are pigmented moles, polyps of colon and stomach