Cancer Epidemiology Flashcards
in what environments are cancer rates elevated?
cities farming locations near hazardous waste sites downwind of industrial and radiation activities near contaminated water wells areas of high pesticide use toxic work exposures waste incinerators other sources of pollution
What are cancers that have increased substantially in the United States?
melanoma non-Hodgkin lymphoma testicular brain thyroid
what is epigenetics?
-a change in the EXPRESSION of the gene or phenotype that is heritable but does not involve DNA mutation
Epigenetic changes collaborate with genetic changes and environmental-lifestyle factors to cause the development of…
CANCER
What are the three major types of epigenetic processes?
- Methylation (the addition of a methyl group [CH3] to the cytosine ring); aberrant methylation can lead to silencing of tumor-suppressor genes
- Histone modifications can result in gene silencing
- Micro-ribonucleic acids (miRNAs) are small RNA molecules that can target gene expression post-transcriptionally; they act like a volume control lever to modulate the production of defined proteins in cells
epigenetic processes can be modified by…
lifestyle (diet and environment), pharmacologic interventions, or both
What is transgenerational inheritance?
the heritable transmission to future generations of environmentally-caused phenotypes
Epigenetic alterations can be inherited when it involves what kind of cells?
Germline cells!!
When it involves somatic cells, it will not promote transgenerational phenotypes…but germline cells can lead to transgenerational effects, independent of continued environmental exposure
Biologically active food components can modify what directly?
DNA methylation
What is one of the best examples of early life events and future cancer…
the chemical exposure to diethylstilbestrol (DES), a synthetic estrogen
- DES interfered with the development of the reproductive system in the fetus
- DES-associated increase in cancer of the female genital tract is elevated throughout a woman’s reproductive years
- for every 1000 DES-exposed women ages 45-49 it is estimated that 4 will be diagnosed with breast cancer
What is the developmental basis of health and disease concept?
-the focus of disease prevention and intervention needs to include the decades before onset…in utero and neonatal periods
Tobacco use is associated primarily with what types of cancer?
squamous and small cell adenocarcinomas
nonsmokers who live with smokers are at greatest risk for…what? why?
lung cancer as well as numerous noncancerous conditions
-secondhand smoke also called environmental tobacco smoke (ETS); is a combination of the burning end of the cigarette smoke and the smoke exhaled by the smoker’s mouth
What are xenobiotics?
“foreign life” that includes toxic, mutagenic, and carcinogenic chemicals
What are dietary sources of carcinogenic subsances?
- compounds produced in the cooking of fat, meat, or protein
- naturally occuring carcinogens associated with plant food substances, such as alkaloids or mold byproducts
MEAT PROTEIN- greatest levels are found in well-down charboiled beef
