Factors that increase the chance of developing cancer are
referred to as cancer risk factors. These factors can alter
the genetic or epigenetic information in our cells, which
may directly lead to cancer development or increase an
individual’s chance of developing cancer later in life. Many
of the factors that increase a person’s risk of developing
cancer, such as smoking, are also associated with worse
outcomes after a cancer diagnosis (see Modifying Behaviors
to Improve Outcomes, p. 88).
Decades of basic, epidemiologic, and clinical research
have led to the identification of numerous cancer risk
factors (see Figure 4, p. 26). As a result of this work, we
know that more than half of all global cancer cases are
attributable to preventable causes, including tobacco
use, poor diet, physical inactivity, and obesity ( 20, 31).
In addition, vaccination against infection with the
human papillomavirus (HPV) and decreasing exposure
to ultraviolet (UV) radiation from the sun and indoor
tanning devices can further reduce the burden of certain
types of cancer ( 31). Ongoing research may uncover
additional cancer risk factors; one area of intensive research
investigation is understanding how early life experiences
may contribute to cancer development in adulthood ( 32).
Many cancer risk factors are also risk factors for other
chronic diseases, such as cardiovascular disease,
respiratory diseases, and diabetes. Therefore, reducing
or eliminating exposure to these factors through behavior
modification or public education and policy initiative
implementation has the potential to reduce the burden
of both cancer and other diseases.
In the United States, many of the greatest reductions
in cancer morbidity and mortality have been achieved
through the implementation of effective public education
and policy initiatives. For example, such initiatives drove
down cigarette smoking rates among U.S. adults by greater
that twofold from 1965 to 2015 ( 34). However, even
today, every three out of 10 cancer deaths are caused by
cigarette smoking, and lung cancer is still the leading
cause of cancer-related deaths for both men and women
( 35). Thus, it is imperative that we identify strategies to
enhance the dissemination and implementation of our
current knowledge of cancer prevention. We also need
to develop, disseminate, and implement more effective
evidence-based practices that reduce risky behaviors in
all population groups.
ELIMINATE TOBACCO USE
Tobacco use is the leading preventable cause of cancer and
cancer-related deaths. This is because use of tobacco, or
exposure to secondhand smoke, exposes people to many
harmful chemicals, including more than 60 different
chemicals called carcinogens that can cause cancer by
damaging DNA, increasing the chances that it will acquire
a mutation ( 35).
• More than half of global cancer cases
are a result of preventable causes.
• Not using tobacco is the single best
way a person can prevent cancer
• About 20 percent of U.S. cancer diagnoses
are related to people being overweight
or obese, being physically inactive,
and/or consuming a poor diet.
• Many cases of skin cancer could be
prevented by protecting the skin from
ultraviolet radiation from the sun
and indoor tanning devices.
• The number of U.S. cancer cases
attributable to human papillomavirus
(HPV) infection is rising, but most U.S.
adolescents have not received the full HPV
• There are disparities in the burden
of cancer attributable to preventable
causes among certain segments
of the U.S. population.
In this section you will learn: