This document discusses breast cancer epidemiology and risk factors. It begins by describing the normal structure of the breast and types of breast cancer. The most common type is invasive ductal carcinoma. Risk factors include being a woman and aging, as well as factors like family history, early menstruation, late pregnancy/childbirth, and not breastfeeding. Environmental factors like chemicals that mimic estrogen may also increase risk. While some risk factors cannot be changed, maintaining a healthy lifestyle and limiting chemical exposure may help lower breast cancer risk.

1. Breast Cancer
Epidemiology & Factors
Influencing The Risk factors

2. *Normal Breast
To understand breast cancer, it helps to have some basic
knowledge about the normal structure of the breast :

3. The female breast is made up mainly of lobules
(milk-producing glands), ducts (tiny tubes that
carry the milk from the lobules to the nipple),
and stroma (fatty tissue and connective tissue
surrounding the ducts and lobules, blood
vessels, and lymphatic vessels).

4. *Breast cancer
Breast cancer is a type of cancer originating
from breast tissue, most commonly from the inner
lining of milk ducts or the lobules that supply the
ducts with milk.

5. The first noticeable symptom of breast cancer is
typically a lump that feels different from the
rest of the breast tissue.
More than 80% of breast cancer cases are
discovered when the woman feels a lump. The
earliest breast cancers are detected by
a mammogram. Lumps found in lymph nodes
located in the armpits can also indicate breast
cancer.

6. *Types of breast cancers
There are several types of breast cancer,
but some of them are quite rare. In some
cases a single breast tumor can be a
combination of these

7. -Ductal carcinoma in situ :
Ductal carcinoma in situ . DCIS is the most common type of
non-invasive breast cancer. DCIS means that the cancer cells
are inside the ducts but have not spread through the walls of
the ducts into the surrounding breast tissue.

8. Invasive (or infiltrating) ductal carcinoma :
This is the most common type of breast cancer. (IDC)
starts in a milk duct of the breast, breaks through the
wall of the duct, and grows into the fatty tissue of the
breast.

9. -Invasive (or infiltrating) lobular carcinoma
Invasive lobular carcinoma (ILC) starts in the milk-producing
glands (lobules). Like IDC,it can spread
(metastasize) to other parts of the body.

10. Less common types of breast cancer :
-Inflammatory breast cancer:
This uncommon type of invasive breast cancer
accounts for about 1% to 3% of all breast cancers.
Usually there is no single lump or tumor. Instead,
inflammatory breast cancer (IBC) makes the skin on
the breast look red and feel warm.

11. type -Paget disease of the nipple:
This of breast cancer starts in the breast ducts
and spreads to the skin of the nipple and then
to the areola, the dark circle around the
nipple. It is rare, accounting for only about
1% of all cases of breast cancer.

12. Epidemiology of Breast Cancer :
Breast cancer is the second most prevalent cancer in
the world and the most common cancer among women.
Breast cancer still persists as an international health
burden despite advances in its early diagnosis,
treatment and also increased knowledge of its
established risk factors. Although North American and
Northern European countries have the highest rates of
breast cancer incidence, the incidence of this disease is
increasing in developing countries. Asia, the largest
continent in the world.

13. Numerous epidemiological studies on risk factors
of breast cancer have produced evidence on
international variations. Many studies in the
literature have reported that breast cancer is
related to the reproductive life of women; such as
early menarche, late menopause, nulliparity, late
age at first birth, diet, physical exercise and
hormone usage

14. The American Cancer Society's most recent
estimates for breast cancer in the United States
are for 2012:
•About 226,870 new cases of invasive breast
cancer will be diagnosed in women.
•About 63,300 new cases of carcinoma in situ
(CIS) will be diagnosed (CIS is noninvasive and
is the earliest form of breast cancer).
About 39,510 women will die

15. The chance that breast cancer will be
responsible for a woman's death is about 1 in
36 (about 3%). Death rates from breast cancer
have been declining since about 1990, with
larger decreases in women younger than 50.
These decreases are believed to be the result of
earlier detection through screening and
increased awareness, as well as improved
treatment

16. RISK FACTORS OF THE BREAST
CANCER
RISK FACTORS YOU CAN NOT CHANGE
FACTORS WITH CONTROVERSIAL,OR UNPROVEN
EFFECT
LIFE-STYLE RELATED RISK FACTORS
ENVIROMENTAL FACTORS

17. Risk factors you can not
change
Gender
Aging
Genetic risk factor
Family history of breast cancer
Personal history of breast cancer
Certain benign breast conditions
Menstural periods

18. Gender
• Simply being a woman , is the main risk factor
for developing breast cancer.

19. Aging
The older the women is , the more likely she is to
get breast cancer.
• Why does age increase the risk of breast cancer?

20. Genetic risk factor
About 5% to 10% of breast cancer cases are thought
to be hereditary.
• Inherited gene that may cause breast cancer
include:BRCA1,BRCA2,tp53.

21. Family & Personal history of breast
cancer
• Breast cancer risk is higher among women
whose close blood relative have this disease.
• Less than 15% of women with breast cancer
have a family member with this disease.

22. Certain benign breast conditions
Women diagnosed with certain benign breast
conditions might have an increased risk of
breast cancer.

23. certain benign breast conditions are divided into
3 groups, depending on how they affect this risk:
A)Non-proliferative lesions: These conditions are
not associated with overgrowth of breast tissue.
B)Proliferative lesions without atypia:They
seem to raise a woman's risk of breast cancer
slightly (1½ to 2 times normal).

24. • C)Proliferative lesions with atypia: They have a
stronger effect on breast cancer risk, raising it
3 1/2 to 5 times higher than normal.

25. Menstural periods
• Women who have had more menstrual cycles
because they started menstruating
early(before age 12) and/or went through
menopause later (after age 55) have a slightly
higher risk of breast cancer.

26. Factors with controversial ,or
unproven effect
Diet and vitamin intake
Antiperspirants
Abortion
Fertility drugs
Hair dyes
Trauma to the breast

27. Diet and vitamin intake
Most studies have found that breast cancer is
less common in countries where the typical diet
is low in total fat, low in polyunsaturated fat,
and low in saturated fat.

28. Antiperspirants
• large study of breast cancer causes found no
increase in breast cancer
in women who used underarm antiperspirants
and/or shaved their underarms.

29. Abortion
• Research clearly shows no link between
abortion and breast cancer.

30. Fertility drugs
• Fertility drugs stimulate the ovaries, causing
estrogen levels in the body to increase.
Because high estrogen levels are linked to
breast cancer risk, it has been suggested that
the use of fertility drugs might also increase
risk.

31. Hair dyes

32. Trauma to the breast

33. Life-style related risk factors
Giving birth(pregnancy)
Number of children(number of birth)
Breast feeding
Blood estrogen level
Alcohol
Weight gain and exercise

34. Giving birth(pregnancy)
• women who have had no children or who had
their first child after age 30 have a slightly
higher breast cancer risk.

35. -Why dose age matter?
There are a few possible reasons, One reason relates to
breast cells. During pregnancy, breast cells grow rapidly .

36. Number of children(number of birth)
-In general, the more children a woman has
given birth to, the lower her risk of breast
cancer .

37. Breast feeding
• the longer a woman breast feeds, the greater
the reduction in risk, with a 4.3% decrease in
cancer for every 12 months of breast feeding.

38. Blood estrogen level
• estrogen is produced in a woman’s body (in
the ovaries) and is essential for the
development of the breast.

39. • paradoxically estrogen is also involved in the
development of breast cancer via the
stimulation and proliferation of breast cancer
cells

40. Estrogen in pharmaceutical products
The Pill and HRT

41. *Established risk factors for breast cancer - all of
which increase a woman’s estrogen exposure:
• Starting periods early.
• Late onset of the menopause.
• Not having children or having them later in life.
• Not breastfeeding or breast feeding for only a
short time.
• Use of oral contraceptives.
• Use of hormone replacement therapy.
• Obesity.
• Regular intake of alcohol

42. Alcohol
• Drinking alcohol has consistently been shown
to increase breast cancer risk, in both pre- and
post-menopausal women.

43. Weight gain and exercise
• Being overweight or obese after menopause
increases breast cancer risk.
• Physical activity reduces a woman’s breast
cancer risk, so regular exercise is advisable.

44. Environmental factors
• It is factors in our environment i.e. the world
around us, that are thought to be responsible for at
least some of the unexplained proportion (50%) of
cases .
• Exposure to certain man-made chemicals that can
mimic hormones.
• Our reliance on synthetic chemicals has increased
dramatically over the last 50 years, and they are
an integral part of our everyday 21st century lives,
providing many lifestyle benefits.

45. Some chemicals found in our
environment that have estrogen-disrupting
properties:
Several pesticides : DTT, some pyrethroid
insecticides , methoxychlor..

46. Polychlorinated biphenyls (PCBs)
• Used in capacitors and transformers, and some
building materials.
• Marked under trade name arocol ,
pyranol,clophen.

47. Dioxins
• Are by-products which are not produced
intentionally .
• PLASTICS have been identified as one of the
most common causes of high levels of dioxins.
in the tissues.

48.  Bisphenol A (BPA)
- used in plastics and resins
to make water and food storage containers.

49. Parabens
- preservatives and antioxidants used in toiletries
and cosmetics .

50.  Alkylphenols
-nonyl phenol (NP) and octyl phenol (OP) – from
plastics, paints, inks and detergents, and used
in textile processing.

51. Conclusion
• Breast cancer is a disease of
premenopausal women as a whole, but
it's also affecting younger ages due to
underlying risk factors of life-style
changes and more exposure to man-made
chemicals that has became a
part of our daily life .The most cause of
the cancer may be due to risk factors
of age, family history, estrogen level
and environmental factors.