Onc lec 1

What is cancer?

What is cancer?

disease of unregulated cell growth, division, and differentiation

What does angiogenesis mean?

formation of new blood supply

What are some mechanisms that cancer is spread?

rapid growth, dec cellular adhesion, inc motility, angiogenesis

What does carcinoma affect?

epithelial tissue

What does adenocarcinoma affect?

glandular epithelial tissue

what does sarcoma affect?

connective tissue

What does glioma affect?

CNS glial cells

What does neuroblastoma affect?

neurons (and Brenna’s brother apparently)

what does lymphoma affect?

lymphocytes

What is knudson hypothesis?

cancer is the result of accumulated mutations to a cell’s DNA (takes multiple “hits” to DNA for malignancy to develop, not just one)

What is carcinogenesis?

development of cancer depends on accumulation of genetic modifications (activation of proto-oncogenes or inhibition of tumor suppressor genes)

What are proto-oncogenes?

genes that stimulate cell proliferation

What are tumor suppressor genes?

genes that keep proliferation in tact

What is the most common cancer in men?

prostate

What is the most common cancer in women?

breast

What are the 2nd and 3rd most common cancers in both sexes?

lung and colorectal

How did the incidence disparity b/t males and female change from the early 90s?

it significantly narrowed

What combined strategy contributed to the decrease in death rate and increased 5 year survival rate?

prevention (reduction in smoking), early detection, improved treatment

There have been notable improvements in survival for most cancer types due to ____

earlier detection and/or advances in tx

What is the 2nd most common cause of death in the US? (heart disease is 1st)

cancer

What is the leading cause of death for both sexes?

lung cancer

What is the second cause of death in women?

breast cancer

What is the 2nd cause of death in men?

prostate cancer

What is the 3rd cause of death in both sexes?

colon and rectal cancer

What is the most common, preventable cause of cancer?

tobacco

carcinogen pathophysiology

exposure to carcinogens —> covalent bonds form b/t carcinogens and DNA —> accumulation of permanent mutations in critical genes

What type of radiation has deep penetrating power and breaks DNA?

ionizing radiation

What type of radiation has little penetrating power and damages pyrimidines, interfering w/ replication?

nonionizing radiation

What is ionizing radiation used for?

used to sterilize drugs, vaccines, and some f foods including fruits. spinach, lettuce, and meat

What is nonionizing radiation used for?

used to sterilize air, water, and solid surfaces

What are examples of ionizing radiation?

gamma rays, xrays, cathode rays

What are examples of non ionizing radiation?

UV rays

What happens when tumor suppressor genes are deleted or mutated?

growth proceeds unchecked

What activates oncogenes resulting uncontrolled cellular proliferation?

a mutational change in the gene

what are homologs of normal cellular genes that participate in cell growth pathways and cell cycle regulation?

oncogenes (humans normally carry some, but they are usually kept in check)

What are examples of viral oncogenes?

EBV- burkitt and hodgkin lymphoma

HPV- cervical, head, and neck cancers

Hep B- hepatocellular carcinoma

How do viral oncogenes cause cancer?

some viruses carry an oncogene and incorporate it into human DNA when the virus infects the cell and sometimes turns on a human oncogene

(all oncogenic viruses have ability to stimulate unlimited cell growth)

What are the most important ways for nonsmokers to reduce cancer risk?

maintain healthy weight, regular physical activity, and healthy diet

How many drinks of alcohol per day would substantially increase risk for cancer?

2

What is the most commonly used system for staging at the initial diagnosis?

T- tumor location, size, level of invasion

N- presence or absence of nodal metastases

M- presence or absence of metastases

What determines the treatment and outcomes of cancer?

staging

What is clinical staging?

based on physical examination, imaging tests, and biopsies of affected areas

What is pathologic staging?

can only be determined from individual pt’s who have had surgery to remove a tumor or explore the results of both clinical staging with surgical results

What is the staging system for Hodgkins and non-hodgkins lymphoma?

Ann Arbor

What is the staging system for multiple myeloma?

international staging system (ISS)

What staging is used for prostate cancer?

Gleason score grades aggressiveness of cancer cells (2-10)

add scores from 2 areas w/ the most cancer cells

What are many solid tumors graded on?

proliferative indices

what is molecular testing useful for?

determining both prognosis and treatment

What are paraneoplastic effects of a tumor?

remote effects that are not related to the direct invasion, obstruction or metastasis

sx usually due to aberrant hormonal or metabolic effects

How are paraneoplastic syndromes divided?

by the system they affect (endocrine, hematologic, neurologic, neuromuscular, mucocutaneous)

What are paraneoplastic endocrine syndromes?

the tumor tissue itself secretes the hormone that produces the syndrome (ectopic hormone production)

believed to result from activation of oncogenes in the tumor that are usually suppressed in normal tissue

What are ectopic hormones?

pro-hormones of higher molecular weight than those secreted by normal, differentiated endocrine cell

What are paraneoplastic neurologic syndromes?

immunologic response is directed against shared antigens that are ectopically expressed by the tumor, but otherwise predominantly expressed by the nervous system

antibodies detected in serum and CSF fluid in most pts

Why are paraneoplastic syndromes clinically important?

may provide early clues to the presence of some cancers or the metabolic or toxic effects of the syndrome may create a more urgent situation than the cancer itself (once the tumor resolves, the syndrome resolves as well)