EXAM 2 (cancer)
Carcinomas
(the most common) which arise from the epithelial (outside) layers of cells. Important epithelial layers include the skin, the epithelium of glandular organs (breast, uterus, prostate), and cells lining the respiratory, gastrointestinal, and urinary tract
Cancer Causes
- May originate from viral causes
Alcohol has a synergistic effect, what does that mean?
2 + 2 = 5, 6 or 7 More than the sum of it's parts
Mutation
A change in the genetic material, the DNA, within a living cell. DNA, the main constituent of a cell's chromosomes, provides the coded instructions for the cell's activities. Many mutations are harmful, giving rise to cancers, birth defects, and hereditary diseases.
Oncogene
A gene that codes for proteins that control cellular growth and development
What is a tumor?
A group of cells that have grown spontaneous new tissue that has no physiological purpose
Gene
A portion of DNA that codes for, or provides the blueprint for, production of a single protein. The hereditary material in chromosomes includes thousands of genes coding for all the proteins needed by a cell
What is a benign tumor?
A tumor made up of cells similar to the surrounding normal cells and are enclosed in a membrane that prevents them from penetrating other tissues. It is considered dangerous from its physical presence interfering with normal functions such as blood flow in the brain. A benign tumor is non-cancerous
p53 gene
A tumor suppressor gene that can prevent inappropriate cell division.
Types of skin cancers (Basal cell carcinoma, Squamous cell carcinoma, Melanoma)
Basal cell carcinoma is the most common. Found in areas exposed to the sun as a small, shiny, pink, fleshy bump that grows slowly and persists beyond the time a pimple or inflammation would resolve. Not generally painful, although it may crust and bleed. Squamous cell carcinoma is the second most common. It is generally found on ears, face, lips, and mouth. It is a persistent, sharply outlined, red, scaly, plate like patch, an open sore, or a hard, rough bump. Melanoma is the third most common and most dangerous. It spreads rapidly, can occur anywhere on the body, and most commonly is seen on the back, chest, abdomen, and lower legs. It starts at the site of a preexisting mole, which may enlarge, change color, or develop an irregular surface or border; it may itch, burn, or bleed easily.
How is a malignant tumor is different form a benign tumor?
Both types of tumors have cells characterized by uncontrolled growth. Malignant tumors are capable of invading surrounding tissue
What is the most common type of cancer?
Carcinoma Leukemia Sarcomas
Possible signs of cancer (CAUTION)
Change in bowel or bladder habits A sore that does not heal Unusual bleeding or discharge Thickening or lump in breasts or elsewhere Indigestion or difficulty in swallowing Obvious change in a wart or mole Nagging cough or hoarseness
Colon and rectal cancers (Diagnosis)
Colon and rectal cancers are the second most prevalent, and have been linked to diet and genetic susceptibility. Up to one-third of the population may be genetically prone to this cancer. Prevention includes a high fiber diet, especially insoluble fiber. Colon cancer is rare before age 40. Removing polyps before a cancer ever develops can eliminate development of colon tumors. Early signs include bleeding from the rectum and a change in bowel habits. Diagnosis is by routine rectal exams, recommended once per year after 40. Survival rate is 55% overall, 85% if the tumor is localized, and 40% if it has spread.
Five year survival rate
Considered a cure. Only 13% are alive 5 years after diagnosis (Lung Cancer). Highest death rate is among men
Oral cancers
Easy to detect and difficulty to treat. Smokeless tobacco is associated with cancer of the mouth, larynx, throat and esophagus. Alcohol and tobacco interact as carcinogens.
Exposure Stage of Cancer Development
Introduced to a carcinogen such as sunlight (radiant energy), tobacco smoke, pollution
Risk factors for breast cancer
Living in an industrialized country Genetic factors,Diet, Hormonal Factors,Moderate Alcohol Consumption Not a factor.... Trauma to the breast, 8 out of 10 lumps found are benign, Survival rate is 75% for all stages of tumors and almost 90% for small localized tumors More women die annually from heart disease
What is the most common form of carcinoma cancer?
Lung cancer is the most common form of carcinoma cancer
Breast cancer
Most commonly found in women over 50, but does occur in younger women. Survival rate is 75% for all stages of tumors, and almost 90% for small-localized tumors. Disease of civilization, breast cancer is far more prevalent in industrialized Western countries than in less developed countries. Genetics, as well as dietary and hormonal risk factors predispose individuals to breast cancer. Obesity, early first menstruation, late menopause, late first motherhood, and not breast feeding all may be related to estrogen as a cancer promoter. Estrogen has been shown to slow down osteoporosis and protect against cardiovascular disease, but is also linked with endometrial (uterine) cancer and may or may not be linked to breast cancers. Hormone Replacement Therapy is usually prescribed for postmenopausal symptoms instead of just estrogen replacement therapy.
smokeless tobacco and the cancers it is associated with.
Mouth, larynx, throat, & esophagus cancers
Skin Cancer
Prevention includes protection from sunlight by using sunscreens and protective clothing, and avoiding harsh sunlight, especially at midday. Detection is by regular examination of the skin, and follow ups by a physician. Early diagnosis is critical. Family history is important. Treatment is surgical removal, often done in a physician's office using local anesthesia. Survival rates, even for melanoma are 95% for five years and 90% for ten years; late treatment is the main reason for fatality.
Mammogram
Recommended annually for all women over age 40 Very small tumors may be missed Recommended as part of a personal program for early detection
Is cancer genetic?
Some cancers are linked to genetic susceptibility. Breast and colon
Initiation Stage of Cancer Development
Stage at which a cell's DNA is mutated
True or False - Alcohol and tobacco interact as carcinogens.
TRUE
What is it called when cancer appears in a site other than the primary tumor site?
The cancer has metastasized
Basal Metabolic Rate Theory
The theory of aging that associates fast metabolisms with a shorter life span.
Glycation Theory
The theory of aging that associates the body's inability to pull sugar molecules out of the blood.
Free Radical Theory
The theory of aging that describes a molecule with an unpaired electron in an outer orbit, which when in contact with the cell's DNA may cause mutations to occur
Genetic Error
The theory of aging that describes errors in transcription of DNA being passed along to the next set of cells
Biologic Clock
The theory of aging that suggests that our cells are pre-programmed genetically to divide a specific number of times and then cells lose their ability to repair themselves
Malignant Melanoma
Usually appears at the site of a preexisting mole
Uterine, cervical, and ovarian cancers.
Uterine (endometrial) cancer is more prevalent, but ovarian and cervical cancers are more lethal. Uterine cancer is most common between ages 55-69. Risk factors are history of infertility, obesity, and prolonged estrogen therapy. It is treatable with an 88% five year survival rate. Invasive cervical cancer occurs in younger women and lethal for about 50%. Pap smears have resulted in early detection and dropped the death rate by 70%. Risk factors are smoking and infection with the sexually transmitted herpes virus (risk increases with multiple sex partners). Ovarian cancer the most unusual and most lethal because it is difficult to detect until late in it's course; incidence increases with age; specific risk factors are unknown. Prostate cancer is the most common cancer in men and is the third leading cause of cancer deaths in men. Eighty percent of cases are diagnosed in men over 65 years of age. Early detection by rectal exam is followed by ultrasound and biopsy if the rectal exam detects a lump. Treatment includes surgical removal of the prostate, combined with radiation, hormones, or anti-cancer drugs (chemotheraphy). Survival rates have risen from 48% to 70% over the last 20 years.
CANCER PREVENTION
Vitamins C & E (antioxidants) are thought to intercept and reduce chemical agents that damage DNA (cancer initiators). Stop smoking and avoid second hand smoke. Protect your skin from the sun. Avoid smokeless tobacco. Avoid excessive exposure to radiation, nickel, chromate, asbestos & vinyl chloride (occupational hazards). All radiation is carcinogenic, including x-rays, radioactive substances, and ultraviolet sunrays. Hiroshima survivors have a much higher incidence of leukemia and other cancers. Radon gas, a decomposition product of radium, produces mutations. Sunlight is a surface carcinogen. Control your weight, and exercise regularly. Control your diet; and nitrites added to processed meats to prevent spoilage and preserve color combine to form nitrosamines in the human body, which may lead to cancer development. Diets high in saturated fats contribute to colorectal and breast cancers, probably by requiring digestion in the intestine by bacteria that produce a highly mutagenic class of compounds. Moderate alcohol intake is associated with a 50% increase in the rate of breast cancer. Alcohol most clearly involved in oral cancers, evidenced by a 15 time greater risk of oral cancers in heavy drinkers and smokers.
What is a malignant tumor?
capable of invading surrounding tissue, this type of tumor is cancerous.
What type of cancer is linked to a high fat diet?
colon cancer
Oral cancer
including cancers of the lip, tongue, mouth, and throat, is directly related to cigarette and cigar smoking, excess alcohol consumption, and smokeless tobacco use. Oral cancer is easy to detect and difficult to treat. Treatment is usually surgery and radiation. Five-year survival rates are 32% for throat cancer and 91% for lip cancer. Skin cancers are easily detectable and treatable, although they may cause considerable scarring if they are not treated early. Sun exposure is the primary cause of skin cancer. There is some genetic tendency for skin cancer.
Bladder cancer
is three times more common in men than women. Risk factors include smoking (50%), urban living, and industrial chemicals such as benzene
Testicular cancer
only 1% of male cancers, but most common cancer in ages 29-35. Detectible by self examination. Risk factors include undescended testicles, which can be corrected at childhood.
Colon Cancer often arises from?
polyps
Kaposi's sarcoma
rare and only seen in older adults prior to AIDS. Symptoms are purple or brownish lesions
Lifestyle choices (the big three)
smoking, alcohol, and nutrient intake (food choices).
Progression Stage of Cancer Development
stage at which cells have formed a mass large enough to significantly affect body functions
Promotion Stage of Cancer Development
stage during which cells are stimulated to grow rapidly after DNA alterations have been "locked" into the genetic material of the cells
Pancreatic cancer
the fifth leading cancer killer. Detection is difficult leading to it's deadliness. Smoking is the greatest risk factor.
Lung cancer (Diagnosis, Treatment)
the most common cancer, is difficult to detect at an early stage. Symptoms of lung cancer include a persistent cough, chest pain, and recurring bronchitis. Diagnosis is made by cell examination and chest x-ray or fiber optic bronchoscopy. Only 13% of lung cancer patients are still alive five years after diagnosis. Treatment for lung cancer is usually surgery, as long it has not spread too far throughout the lungs. Oat cell and small cell lung cancer is now being treated with a combination of chemotherapy and radiation, leading to a remission of the disease.
Lymphomas
which are cancers of the lymph nodes
Sarcomas
which arise from connective and fibrous tissue like muscle, bone, cartilage, and the membranes covering muscles and fat
Leukemia
which is cancer of the blood-forming cells (residing primarily in the bone marrow)
