5.3.3 Risk factors
The majority of cancers can be attributed to the
particular environment in which an individual is living and his/her lifestyle.
Here below we have the major risk factors for the cancer sites included in the
Stomach cancer: It has been estimated that most cases of this cancer
are preventable by appropriate diets and associated factors. Non-starchy
vegetables, allium vegetables, and fruits protect against stomach cancer; salt
and also salt-preserved foods are the causes of this cancer. There is strong
evidence that infection with a certain bacteria, Helicobacter pylori, is
associated to an increased risk of stomach cancer (WCRF, 2007).
Colorectal cancer: the evidence that physical
activity protects against colorectal cancer is convincing, although
the evidence is stronger for colon than for rectum. The evidence that red meat,
processed meat, substantial consumption of alcoholic drinks (in men), body
fatness and abdominal fatness, and the factors that lead to greater adult
attained height, or its consequences, are causes of colorectal cancer is
convincing. Substantial consumption of alcoholic drinks is probably a cause of
this cancer in women. Foods containing dietary fibre, and garlic, milk, and
calcium probably protect against this cancer (WCRF, 2007). Cancer control
priority should be given to the promotion of those health determinants related
to colorectal cancer aetiology, such as a healthy diet and physical
Lung cancer: smoking is a primary cause of lung cancer, although
pollution and exposure to certain gases/chemicals may also be influential.
Geographic patterns of lung cancer incidence and mortality are influenced by
past exposure to tobacco smoking, and the geographic pattern in women reflects
the rather different historical patterns of smoking compared to men (Parkin et
al, 2005). Although male lung cancer incidence is decreasing in all European
macro-areas, lung cancer remains the first cancer diagnosed in men in Eastern and
Southern Europe and the second in Western and Northern Europe. Therefore,
awareness of tobacco as a risk factor promoting lung cancer is increasing, but
the war against tobacco has not been won yet. To achieve this goal we need to
make additional efforts For instance specific actions addressed to women and
young people are needed.
Breast cancer: Breast cancer is hormone related, and the factors
that modify the risk of this cancer when diagnosed pre-menopausally and when
diagnosed (much more commonly) post-menopausally are not the same. Risk factors
for breast cancer in women include the events of reproductive life and
lifestyle factors ( e.g. unbalanced diet and alcohol) that modify endogenous
levels of sex hormones (Key et al, 2002). Physical activity
probably protects against breast cancer in post-menopause, and there is limited
evidence suggesting that it protects against this cancer diagnosed in
pre-menopause. The evidence that alcoholic drinks are a cause of breast cancer
at all ages is convincing. The evidence that the factors that lead to greater
adult attained height, or its consequences, are a cause of postmenopausal
breast cancer is convincing, and these are probably also a cause of breast
cancer diagnosed in premenopause (WCRF, 2007).
Cervical cancer: the main risk factor is the infection by some forms
of genital human papilloma virus or HPV (Stewart and Kleihues, 2003). Genital
HPV is usually spread by sexual contact. Abnormal cells, derived from HPV
infection, take many years to progress into cervical cancer, and once detected
early by screening via PAP-smear test, these cells can be easily removed so
they do not develop into cervical cancer.
Prostate cancer: age is the strongest risk factor for prostate cancer:
development of this malignancy is a multi-step process associated with a long
natural history. Other certain risk factors are a diet rich of fat and family
history, while possible risk factors are linked to androgens and race (Stewart
and Kleihues, 2003).