Chapter 20: Cancer
What are the phases of cancer?
1. a single cell undergoes gene mutation(s) 2. tumor formation leads to more mutations 3. cancer in situ has formed 4. tumor cells invade neighboring tissues
What are the typical steps in the progression of cancer from a single mutation to a metastatic tumor?
1. single cell acquires a mutation for repeated cell division 2. another mutation allows single cell to start a tumor 3. one cell within the tumor acquires another mutation 4. tumor cells invade underlying tissues 5. metastatic tumors appear at distant site(s)
What tumor suppressor genes are associated with the development of breast cancer?
BRCA2 and BRCA1
What are potential symptoms of nehroblastoma?
a low grade fever blood in the urine, and a decrease in appetite
What is a "gain-of-function" mutation?
a mutation that coverts a proto-oncogene into an oncogene because it results in the overexpression of a growth factor
Which gene is associated with retinoblastoma?
a tumor-suppressor gene
What is a sarcoma?
a type of cancer that arises in a bone
What are common cellular abnormalities exhibited by cancer cells?
abnormal chromosome number, gene amplification, defective chromosomes
What is a mutagen?
an agent that causes mutations
What is apoptosis?
another term for programmed cell death
What medications help lessen the side effects of radiation and chemotherapy?
antemetic drugs, antidepressants, antianxiety medications
What does ABCDE self examination stand for?
asymmetry, border, color, diameter, elevated
Why should any female who chooses to receive the HPV vaccine should still have regular Pap tests?
because the HPV vaccine won't protect against any infection that occurred prior to vaccination and is not effective against all types of the virus
Why do cancer patients who are receiving chemotherapy also receive red bone marrow transplants?
because the none marrow has large numbers of dividing cells and is at risk because of the drugs used
Why are some tumors classified as benign?
because their cells resemble normal cells and they are surrounded by a capsule of connective tissue
Why are drugs like endostatin being developed as anti-cancer agents?
because they break up capillary networks around tumors
Which cancer is microsatellite DNA repeated linked to?
bladder cancer
What are tumor marker tests?
blood tests that are specific for antigens released from tumors, or antibodies produced in response to tumors
Which cancer is BRCA1 linked to?
breast cancer
What are leukemias?
cancers of the blood
What is combination chemotherapy treatment ?
cancers such as Hodgkin disease can be cures with the use of several different drugs in this treatment
What is the function of a tumor suppressor?
codes for proteins that inhibit the cell cycle and promote apoptosis
What is the function of a proto-oncogene?
codes for proteins that promotes the cell cycle and prevent apoptosis
What do most chemotherapeutic drugs do?
destroy cells by damaging existing DNA or inheriting with DNA synthesis
What are common chromosomal abnormalities seen in cancer cells?
duplication, gene amplification, deletion
What is the second leading cause of cancer in the United States?
exposure to radon gas
If a physician runs a fecal occult blood test on a patient and it is positive, the patient still might not have colon cancer. If not, then this was what type of test result?
false positive
What are cancer preventative behaviors?
getting tested for cancer and eating a diet rich in fiber, fruits, and vegetables
Which cancer is the human T-cell lymphotropic virus linked to?
hairy cell leukemia
What do Ras proteins promote?
in general, mitosis
Which cancer is surgery alone can be a sufficient cancer therapy?
in situ cancer
Which cancer is the hepatitis B virus linked to?
liver cancer
What types of tumors have abnormal cells and are able to invade surrounding tissues?
malignant
Which cancer is p16 linked to?
melanoma cancer
What is passive immunity?
monoclonal antibodies can be designed to bind to and destroy cancer cells
What happens if DNA is exposed to an x-ray, a type of ionizing radiation?
mutations can result
Which cancer is the Epstein-Barr virus linked to?
nasopharyngeal cancer
What is contact inhibition?
normal cells stop diving when they come into contact with other cells
What are tumor suppressor genes that inhibit the cell cycle or promote apoptosis?
p53 and Bax
What are cyclins?
proteins that direct the cell through the cell cycle
What genes code for proteins that promote cell division and the cell cycle?
proto-oncogenes
What are the 3 procedures recommended for breast cancer screening?
regular mammography, annual physical exam, and monthly breast self examination
What are characteristics of breast and testicular self-examination?
testicular self-examination should be done once a month and breast self-examination should be done once a month
What is carcinogenesis?
the development of cancer
What is metastasis?
the development of new tumors far away from the primary tumor
What is a telomerase?
the enzyme that can add telomere sequences to the ends of the chromosomes
What is angiogenesis?
the formation of new blood vessels
What is cellular differentiation?
the process by which cells acquire their specific structure and function that cancer cells lack
What is a tumor?
the result of cancerous cells growing in multiple layers to form a mass of undifferentiated tissue
What is oncology?
the study of cancer
Where are telomeres located?
the tips of chromosomes and shorten with each cell division
Where do cells from malignant tumors typically spread?
throughout the body by invading blood and lymphatic vessels
What is the most common cancer of the human endocrine system?
thyroid cancer
Which cancer is RET linked to?
thyroid cancer
Which tissues are more likely to become cancerous?
tissues with cells that divide frequently
What is magnetic resonance imaging (MRI) used for?
tumors in tissues surrounded by bone
What is cancer situ (in place)?
when a malignant tumor remains in its place of origin and has not spread beyond the basement membrane of the tissue
What is an oncogene?
when a mutation causes a proto-oncogene to become a cancer-causing gene
What are loss of function mutations?
when tumor suppressor genes mutate their products no longer inhibit the cell cycle nor promote apoptosis
What would affect a cancer patient's prognosis?
whether a tumor has invaded surrounding tissues and whether the tumor metastasized to distant body parts
True or False: Cancer cells undergo apoptosis as regularly as normal cells
False
Which cancer is the human immunodeficiency virus linked to?
Kaposi's sarcoma
True or False: A benign tumor can be fatal
True
What are types of caner therapy radiations?
X-rays, gamma rays, protons, and neutrons
What is a growth factor?
a chemical signal that activates a cell-signaling pathway, resulting in cell division
What is a carcinogen?
a chemical that causes cancer by being mutagenic
What is recommended to help prevent cancer?
a diet high in fruits, vegetables, and whole grains with moderate to vigorous activity for about 30-45 minutes a day, 5 days a week
Which cancer is the human papillomavirus linked to?
cervical cancer
What is ultrasound used for?
tumors of soft tissues, such as stomach, pancreas, uterus, etc.
What is the major defining feature of cancer?
uncontrolled cell growth