Environmental Cancer (23) Flashcards
Definition of environment to cancer scientists:
everything outside the body that enters and interacts with it
Researchers have estimated that as many as _____ cases of cancer are linked to some type of environmental factor, including use–or abuse–of tobacco, alcohol, and food, as well as exposures to radiation, viruses, and substances in the air, water, and soil.
2/3
Almost _____ of all cancer deaths could be prevented by eliminating the use of tobacco products, for example, and making better dietary choices could prevent many more premature deaths from this disease
1/3
exposure to asbestos is linked to which type of cancer?
lung
exposure to benzidine is linked to which type of cancer?
bladder
exposure to carcinogens from tobacco use is linked to which types of cancer?
lung, bladder, mouth, lip, throat, voice box, esophagus
“_____ loads the gun… and _____ pulls the trigger.” – Francis Collins
Genetics, the environment
Inheritance explains no more than _____% of new cancer cases.
5
Factors that may change your cancer risk:
Inheritance, having a stronger/weaker immune system, variations in detoxifying enzymes or repair genes, differences in hormone levels
True/False, faulty gene repair activities can pass from generation to generation.
True.
Can detox proteins be hyperactive or slow?
Yes.
The individual chance that someone will develop cancer in response to a particular, single environmental exposure depends on how ______ and how ____ that person was exposed. It also depends on the person’s:
- exposures to certain _____ (including diet, hormones)
- _______
- ____ and _____
long, often
environmental factors
genetic makeup
age and gender
6 official nasties:
arsenic, lead, beryllium, nickel, cadmium, chromium
Every two years, the Federal Government’s National Toxicology Program publishes a report on ______ that are linked to cancer (http://ntp.niehs.nih.gov/). The recent report included ____ substances, some known to be linked, others strongly suspected of having an association.
environmental exposures
246
cigarette, cigar, and pipe smoking have been linked to more than a dozen types of cancer, including these five:
lung, mouth, bladder, colon, kidney
chewing tobacco and snuff increase the risk of…
oral cancer
second-hand smoke increases the risk of…
lung cancer
exposure to cancer-causing substances in tobacco products account for about ___% of cancer deaths in the United States
30
_____ is the single most common cause of cancer
smoking
the cancer risks of smoking and drinking have what type of relationship?
synergistic
heavy drinkers have an increased risk of cancers to the ______
mouth, throat, voice box, liver, esophagus, some evidence of breast
drinkers who smoke may have an even higher risk of some _______ and ______ cancers
oral and throat
Being overweight is linked to which types of cancer?
breast, endometrial, kidney, colon, esophagus
Not being physically active increases the risk of which types of cancers?
colorectal, breast
Together, obesity and physical activity are linked to about ___% of the cases of colon, endometrial, kidney, and esophageal cancers, as well as ___% of breast cancers in older women.
30, 30
What types of foods probably increase the risk of stomach and colorectal cancers?
red meat, preserved meats, salt-preserved meats, salt
Viruses (4) that are risk factors for cancer (and which types):
human papillomavirus (HPV) (cervical, anal), Hepatitis B and C (liver), Epstein-Barr (lymphoma), human herpesvirus 8 (Kaposi’s sarcoma)
Bacteria that can be cause for cancer:
Helicobacter pylori- stomach
UV radiation can lead to which types of cancer?
melanoma, other forms of skin cancer
True or false, exposure during childhood is a particularly important factor that increases skin cancer risk.
True
Sources of ionizing radiation:
cosmic rays, radon, fallout from atomic bombs or above-ground nuclear testing, screening or diagnostic X-rays
Radon is linked to which type of cancer?
lung cancer
Japanese atomic bomb survivors had increased rates of cancers of the:
breast, thyroid, lung, stomach, and other organs
True or false, getting an X-ray to diagnose a disease or condition increases your personal cancer risk
false; only your baby if you’re pregnant
Those who receive radiation to treat conditions of the head or neck have increased risks of which types of cancers?
thyroid, tumors of the head and neck
Which two hormones, when given to women to treat the symptoms of menopause, have been linked to an increased risk of breast cancer?
estrogen and progesterone
Estrogen alone increases the risk of which type of cancer, which the combination with progesterone then decreases?
endometrial
Women who take oral contraceptives, which contain both estrogen and progestin, may have increases in early-onset _____ cancers and ____ cancer, but have substantially reduced risks of ____ and ____ cancers.
breast, liver
endometrial, ovarian
The synthetic hormone ____ is used in breast cancer therapies to prevent recurrence of disease or to prevent onset in women at high risk for this cancer, but it may increase the risk of _____ cancer, strokes, and blood clots.
tamoxifen, endometrial
_____ is another synthetic hormone that was prescribed to pregnant women in the 1940s, 1950s, and 1960s. Its use was discontinued after scientists discovered that women taking it had an increased risk of breast cancer, and that girls born to women taking it had an increased risk of rare types of vaginal and cervical cancer. Most physical or structural differences associated with exposure are found in the reproductive tract, including a “hood” or collar on the cervix and a T-shaped uterus.
DES (diethylstilbestrol)
The strongest evidence linking a solvent to cancer involves _____, which is also found in cigarette smoke and gasoline. It increases the risk of ______.
If you must work with solvents, work outside or make sure the area is _____.
benzene, leukemia, well-ventilated
Asbestos is linked to increased risks of ______ cancer and ______.
lung cancer and mesothelioma (a rare cancer of the lining of the lung and abdominal cavity)
Workers in which industries may still be exposed to asbestos?
construction, electrical work, carpentry
What can be stored in fat, for which losing weight can release?
dioxins
Dioxins are byproducts of which processes?
paper bleaching, smelting, and waste incineration
which compounds come from the burning of carbon-based material?
polycyclic aromatic hydrocarbons (PAHs)
PAHs have been linked to increased risks of which cancer types?
lung, skin, urinary
Lead poisoning potentially leads to which types of cancers?
Kidney, brain
Lead is present in which materials?
cotton dyes, metal coating, drier in paints, varnishes and pigment inks, certain plastics, specialty glass
What carcinogen is used in the plastic industry and has been associated with lung cancer and angiosarcomas of the liver and brain?
vinyl chloride
What carcinogen is used in the production of dyes for paper, textiles, and leather?
benzidine
Aflotixins are produced by ____ and increase the risk of ____ cancer.
certain types of fungi that grow on grains and peanuts, liver
Three types of studies that can help to identify cancer-causing substances, and the fourth type?
human studies, animal studies, laboratory studies,
structure-activity relationships
The type of study that is the way to decide with the most certainty whether a substance causes cancer.
Human studies.
How does a human study work?
By following groups of people over time to see whether certain exposures lead to cancer, and comparing a group of people with cancer to another without.
Animal studies: mice and rats are used why?
relatively short lifespan, bodily response to cancer-causing chemicals is similar to a human response
Which type of study is often done to see whether or not animal studies are needed?
laboratory studies of human cells
Risk assessment involves which three factors?
potency, type of exposure, dose response
Types of cancer to screen for and type of test:
- colon/rectum: fecal occult blood test, sigmoidoscopy, colonoscopy
- breast: mammogram
- cervix: Pap smear
Over a lifetime, a person’s __________ persistently interacts with many _______ such as diet, smoking, alcohol use, hormone levels, or exposures to certain viruses and cancer-linked chemicals (called carcinogens).
internal genetic makeup
external factors
