Long-term heavy drinking increases the risk of
developing certain forms of cancer, especially cancer of the esophagus,
mouth, throat, and voice box. Women are at slightly increased risk of
developing breast cancer if they drink two or more drinks per day.
Drinking may also increase the risk for developing cancer of the colon and
rectum. (Source: excerpt from Alcohol What You Don't Know Can Harm You: NIAAA)
A
number of factors that increase a person's chance of
developing cancer have been identified. Many types of cancer
are related to the use of tobacco, what people eat and drink,
exposure to ultraviolet
(UV) radiation from the sun, and, to a lesser extent,
exposure to cancer-causing agents (carcinogens )
in the environment and the workplace. Some people are more
sensitive than others to factors that can cause cancer.
Still, most people who get cancer have none of the known
risk factors. And most people who do have risk factors do not
get the disease.
Some cancer risk factors can be avoided. Others, such as
inherited factors, are unavoidable, but it may be helpful to
be aware of them. People can help protect themselves by
avoiding known risk factors whenever possible. They can also
talk with their doctor about regular checkups and about
whether cancer screening tests could be of benefit.
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Tobacco. Smoking tobacco, using smokeless tobacco,
and being regularly exposed to environmental tobacco smoke
are responsible for one-third of all cancer deaths in the
United States each year. Tobacco use is the most preventable
cause of death in this country.
Smoking accounts for more than 85 percent of all lung
cancer deaths. For smokers, the risk of getting lung cancer
increases with the amount of tobacco smoked each day, the
number of years they have smoked, the type of tobacco
product, and how deeply they inhale. Overall, for those who
smoke one pack a day, the chance of getting lung cancer is
about 10 times greater than for nonsmokers. Cigarette
smokers are also more likely than nonsmokers to develop
several other types of cancer, including oral cancer and
cancers of the larynx, esophagus, pancreas, bladder, kidney,
and cervix. Smoking may also increase the likelihood of
developing cancers of the stomach, liver, prostate, colon,
and rectum. The risk of cancer begins to decrease soon after
a smoker quits, and the risk continues to decline gradually
each year after quitting.
People who smoke cigars or pipes have a risk for cancers
of the oral cavity that is similar to the risk for people
who smoke cigarettes. Cigar smokers also have an increased
chance of developing cancers of the lung, larynx, esophagus,
and pancreas.
The use of smokeless tobacco (chewing tobacco and snuff)
causes cancer of the mouth and throat. Precancerous
conditions, tissue changes that may lead to cancer, often
begin to go away after a person stops using smokeless
tobacco.
Studies suggest that exposure to environmental tobacco
smoke, also called secondhand smoke, increases the risk of
lung cancer for nonsmokers.
People who use tobacco in any form and need help quitting
may want to talk with their doctor, dentist, or other health
professional, or join a smoking cessation group sponsored by
a local hospital or voluntary organization. Information
about finding such groups or programs is available from the
Cancer Information
Service (CIS) at 1-800-4-CANCER. CIS information
specialists can send printed materials, and also can give
suggestions about quitting that are tailored to a caller's
needs.
-
Diet. Researchers are exploring how dietary
factors play a role in the development of cancer. Some
evidence suggests a link between a high-fat diet and certain
cancers, such as cancers of the colon, uterus, and prostate.
Being seriously overweight may be linked to breast cancer
among older women and to cancers of the prostate, pancreas,
uterus, colon, and ovary. On the other hand, some studies
suggest that foods containing fiber and certain nutrients
may help protect against some types of cancer.
People may be able to reduce their cancer risk by making
healthy food choices. A well-balanced diet includes generous
amounts of foods that are high in fiber, vitamins, and
minerals, and low in fat. This includes eating lots of
fruits and vegetables and more whole-grain breads and
cereals every day, fewer eggs, and not as much high-fat
meat, high-fat dairy products (such as whole milk, butter,
and most cheeses), salad dressing, margarine, and cooking
oil.
Most scientists think that making healthy food choices is
more beneficial than taking vitamin and mineral
supplements.
-
Ultraviolet
(UV) radiation . UV radiation from the sun causes
premature aging of the skin and skin damage that can lead to
skin cancer. (Two types of ultraviolet radiation -- UVA and
UVB -- are explained in the Dictionary.) Artificial sources
of UV radiation, such as sunlamps and tanning booths, also
can cause skin damage and probably an increased risk of skin
cancer.
To help reduce the risk of skin cancer caused by UV
radiation, it is best to reduce exposure to the midday sun
(from 10 a.m. to 3 p.m.). Another simple rule is to avoid
the sun when your shadow is shorter than you are.
Wearing a broad-brimmed hat, UV-absorbing sunglasses,
long pants, and long sleeves offers protection. Many doctors
believe that in addition to avoiding the sun and wearing
protective clothing, wearing a sunscreen
(especially one that reflects, absorbs, and/or scatters both
types of ultraviolet radiation) may help prevent some forms
of skin cancer. Sunscreens are rated in strength according
to a sun
protection factor (SPF). The higher the SPF, the
more sunburn protection is provided. Sunscreens with an SPF
of 12 through 29 are adequate for most people, but
sunscreens are not a substitute for avoiding the sun and
wearing protective clothing.
-
Alcohol. Heavy drinkers have an increased risk of
cancers of the mouth, throat, esophagus, larynx, and liver.
(People who smoke cigarettes and drink heavily have an
especially high risk of getting these cancers.) Some studies
suggest that even moderate drinking may slightly increase
the risk of breast cancer.
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Ionizing radiation. Cells may be damaged by
ionizing radiation from x-ray
procedures, radioactive
substances, rays that enter the Earth's atmosphere from
outer space, and other sources. In very high doses, ionizing
radiation may cause cancer and other diseases. Studies of
survivors of the atomic bomb in Japan show that ionizing
radiation increases the risk of developing leukemia and
cancers of the breast, thyroid, lung, stomach, and other
organs.
Before 1950, x-rays were used to treat noncancerous
conditions (such as an enlarged thymus, enlarged tonsils and
adenoids, ringworm of the scalp, and acne) in children and
young adults. Those who have received radiation therapy to
the head and neck have a higher-than-average risk of
developing thyroid cancer years later. People with a history
of such treatments should report it to their doctor.
Radiation that patients receive as therapy for cancer can
also damage normal cells. Patients may want to talk with
their doctor about the effect of radiation treatment on
their risk of a second cancer. This risk can depend on the
patient's age at the time of treatment as well as on the
part of the body that was treated.
X-rays used for diagnosis expose people to lower levels
of radiation than x-rays used for therapy. The benefits
nearly always outweigh the risks. However, repeated exposure
could be harmful, so it is a good idea for people to talk
with their doctor about the need for each x-ray and to ask
about the use of shields to protect other parts of the
body.
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Chemicals and other substances. Being exposed to
substances such as certain chemicals, metals, or pesticides
can increase the risk of cancer. Asbestos, nickel, cadmium,
uranium, radon, vinyl chloride, benzidene, and benzene are
examples of well-known carcinogens. These may act alone or
along with another carcinogen, such as cigarette smoke, to
increase the risk of cancer. For example, inhaling asbestos
fibers increases the risk of lung diseases, including
cancer, and the cancer risk is especially high for asbestos
workers who smoke. It is important to follow work and safety
rules to avoid or minimize contact with dangerous
materials.
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Hormone
replacement therapy (HRT). Doctors may recommend
HRT, using either estrogen
alone or estrogen in combination with progesterone ,
to control symptoms (such as hot flashes and vaginal
dryness) that may occur during menopause. Studies have shown
that the use of estrogen alone increases the risk of cancer
of the uterus. Therefore, most doctors prescribe HRT that
includes progesterone along with low doses of estrogen.
Progesterone counteracts estrogen's harmful effect on the
uterus by preventing overgrowth of the lining of the uterus;
this overgrowth is associated with taking estrogen alone.
(Estrogen alone may be prescribed for women who have had a
hysterectomy ,
surgery to remove the uterus, and are, therefore, not at
risk for cancer of the uterus.) Other studies show an
increased risk of breast cancer among women who have used
estrogen for a long time; and some research suggests that
the risk might be higher among those who have used estrogen
and progesterone together.
Researchers are still learning about the risks and
benefits of taking HRT. A woman considering HRT should
discuss these issues with her doctor.
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Diethylstilbestrol (DES). DES is a synthetic form
of estrogen that was used between the early 1940s and 1971.
Some women took DES during pregnancy to prevent certain
complications. Their DES-exposed daughters have an increased
chance of developing abnormal cells (dysplasia )
in the cervix and vagina. In addition, a rare type of
vaginal and cervical cancer can occur in DES-exposed
daughters. DES daughters should tell their doctor about
their exposure. They should also have pelvic
exams by a doctor familiar with conditions related to
DES.
Women who took DES during pregnancy may have a slightly
higher risk for developing breast cancer. These women should
tell their doctor about their exposure. At this time, there
does not appear to be an increased risk of breast cancer for
daughters who were exposed to DES before birth. However,
more studies are needed as these daughters enter the age
range when breast cancer is more common.
There is evidence that DES-exposed sons may have
testicular abnormalities, such as undescended or abnormally
small testicles. The possible risk for testicular cancer in
these men is under study.
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Close relatives with certain types of cancer. Some
types of cancer (including melanoma and cancers of the
breast, ovary, prostate, and colon) tend to occur more often
in some families than in the rest of the population. It is
often unclear whether a pattern of cancer in a family is
primarily due to heredity, factors in the family's
environment or lifestyle, or just a matter of chance.
People who have any of the cancer risk factors listed above
should talk with their doctor. The doctor may be able to
suggest ways to reduce the risk and can recommend an
appropriate schedule of checkups. (Source: excerpt from What You Need To Know About Cancer - An Overview: NCI)
Risk factors for Cancer are factors that do not seem
to be a direct cause of the disease,
but seem to be associated in some way.
Having a risk factor for Cancer
makes the chances
of getting a condition higher but does
not always lead to Cancer.
Also, the absence of any risk factors
or having a protective factor does not necessarily
guard you against getting Cancer.
For general information and a list of risk factors,
see the risk center.
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