Module 17 Flashcards
Uncontrolled proliferation of cells.
Cells of this type are often referred to as _________.
cancer
neoplastic
What are the 5 characteristics of cancer cells?
Persistent, uncontrollable cell proliferation Invasive Metastatic Immortal Angiogenesis
The ability of cancer cells to travel to different sites in the body and invade to form new tumours.
Metastatic
Cancer cells develop their own blood vessels to supply nutrients.
Angiogenesis
What are the three main treatment modalities for cancer?
Surgery
Radiation
Chemotherapy
Describe chemotherapy.
Drugs target rapidly dividing cells.
Describe radiation.
High energy radiation causes DNA damage to both cancerous, and non-cancerous cells.
Describe the stages of the cell cycle.
G1 - the cell prepares to duplicate its DNA S - synthesis of DNA G2 - the cell prepares for mitosis M - mitosis G0 - resting, cells do not replicate
Describe how toxicity to normal cells is an obstacle in chemotherapy.
Neoplastic cells are very similar to normal cells.
Cells with very high growth fractions are often affected by the toxic compounds.
What are some examples of cells with high growth fractions?
Bone marrow, GI epithelium, hair follicles, germinal epithelium of the testes (giving rise to sperm
Cure of cancer requires ____% cell kill.
100
Describe the kinetics of cell death with chemotherapy.
1st order
A constant percentage of cancerous cells are killed at a given dose
What are the three most prevalent cancers in Men in Ontario?
Women?
Men
- prostate, lung, colon and rectum
Women
- breast, lung, colon and rectum
Describe the screening protocols (Canadian) for breast cancer.
Clinical breast examination every 2 years starting at age 40, for women.
High risk patients are screened more often and screening may begin before age 40.
Describe the screening protocols (Canadian) for cervical cancer.
Sexually active women should have a Pap smear every 1-3 years.
Describe a Pap smear.
A speculum is insertred into the vagina, exposing the cervix.
A curette is then inserted into the endocervix.
Cells are scraped from the cervix and examined under a microscope to check for disease.
Describe the screening protocols (Canadian) for colorectal cancer/
Men and women (not high risk) should have a fecal occult blood test every two years.
Colonoscopy may also be eperformed evert 5 years in high risk patients
Describe the screening protocols (Canadian) for prostate cancer/
Men over 50 should have the Digital Rectal Exam and/or PSA blood test.
Describe the screening protocols (Canadian) for skin cancer.
(What do we look for?)
Self-checks should be performed regularly.
in particular, look for changes to birthmarks and/or moles, any new skin growths, and sores that don’t heal properly/
Describe the screening protocols (Canadian) for testicular cancer.
Males over the age of 15 should regularly perform the testicular self-examination
Why do ______ tumours respond poorly to chemotherapy?
Solid tumours
Respond poorly to chemotherapy as they have a large fraction of cells in the G0, resting, state. Thus, since chemotherapeutic agents target actively replicating cells, these are largely ineffective.
What are some ways in which cancer cells develop resistance to drugs?
Decreased drug uptake increased drug efflux Decreased drug acgivatoin Reduced target sensibitiy/increased cellular repair (mostly DNA) Decreased apoptosis
This pump can cause MDR.
P-gp
Describe intermittent chemotherapy.
The intent is to administer chemotherapeutic drugs intermittently, allowing normal cells to recover.
This only works if normal cells grow faster than cancerous cells