Causes and Prevention: Overview
Despite all the attention given to cancer genes in the press, less than 10% of
all cancers are inherited.
Cancer cases that are not inherited, 90%
Cancer cases that are inherited, 10%
Many other people would like to blame cancer on synthetic chemicals – but
pollution, food additives, and industrial wastes account for less than 5% of
cancers in the U.S. So what is really behind cancer?
Cancer cases caused by synthetic chemicals, 5%.
Cancer cases that are inherited, 10%
A world map can give surprising clues about cancer causes, as well as prevention.
Although cancer affects people of all nationalities, epidemiologists look for
cancer “hot spots” – regions with high cancer rates. Then they
attempt to find environmental, dietary, cultural, or lifestyle factors that are
common to the regions where cancers are most frequent.
Cancer Epidemiology
Examine the worldwide distribution of cancer types.
Where is lung cancer most prevalent?
What do the
hot spots have in common?
Click here to
find out.
Environment?
Diet?
Culture?
Lung Cancer: The incidence of lung cancer is directly related to smoking.
The highest rates are found in developed countries, where people can afford
the
luxury of
a cigarette habit. Lung cancer cases rose in men following WWII, but have fallen
in recent years. Unfortunately, smoking - and lung cancer - are on
the rise in women. Lung cancer is the leading cause of cancer deaths in the
United States, but deaths would drop 85% if no one smoked.
Where is liver cancer most prevalent?
What do the
hot spots have in common? Click here
to
find out.
Environment?
Diet?
Culture?
Liver Cancer: The incidence of liver cancer is correlated with infection by
the Hepatitus B virus, and also to aflatoxin - a powerful mutagen released
by mold on
peanuts and other foodstuffs. High rates of liver cancer roughly coincide with
areas of hepatitis infection and where foodstuffs are improperly stored under
damp conditions.
Where is stomach cancer most prevalent?
What do
the hot spots have in common? Click here
to
find out.
Environment?
Diet?
Culture?
Stomach Cancer: Stomach cancer appears to be strongly influenced by diet. The
high rates found in Asia are puzzling, but thought to be related to pickled
and
smoked foods prevalent in the diet.
Where is skin cancer most prevalent?
What do the
hot spots have in common? Click here
to
find out.
Environment?
Diet?
Culture?
Skin Cancer: Most skin cancers are caused by sunlight exposure. Pigments in
dark or tanned skin absorb some of the ultraviolet light that is responsible
for
the
DNA mutations behind skin cancers. High rates of deadly melanomas are found
mainly in the middle latitudes, where large populations of fair-skinned Caucasian
people
live. The highest rates are found in dry, sunny climates, where people can
spend a lot of time outdoors.
Where is breast cancer most prevalent?
What do
the hot spots have in common? Click here
to
find out.
Environment?
Diet?
Culture?
Breast Cancer: Many people suspect environmental causes are at the root of
breast cancer "hot spots." However, a woman's lifetime exposure to
estrogen is probably the best predictor of cancer risk. This is roughly measured
as
the length of time between the onset of menstruation and childbirth. Breast
cancer
rates are highest in affluent areas, where good nutrition decreases the average
age at which girls reach puberty and where working women are most likely to
postpone childbirth. A high fat diet also seems to contribute to breast cancer.
Where is cervix cancer most prevalent?
What do
the hot spots have in common? Click here
to
find out.
Environment?
Diet?
Culture?
Cervix Cancer: The incidence of cervix cancer is related to genital wart infection.
It is one of the most preventable cancers, since precancerous cells can be
detected by a PAP smear. Thus, areas of high incidence correlate with high
levels of sexually
transmitted diseases and poor routine health care for women.
Where is colon/rectum cancer most prevalent?
What
do the hot spots have in common? Click here
to
find out.
Environment?
Diet?
Culture?
Colon/Rectum Cancers: Colon/Rectum cancersare associated with the high-fat, low-fiber
diets found in affluent nations. However, colonoscopy can detect most polyps
before
they progress to tumors. So colon cancer rates are dropping – about 2%
per year in the U.S. – as colonoscopy becomes a routine part of health
care in developed countries.