Obesity increases the risk of several gynecological cancers. It is a major risk factor for endometrial cancer, increasing risk by 2.6-5.8 times depending on the degree of obesity. Postmenopausal obesity also increases breast cancer risk by fueling estrogen production, and is associated with 10% of postmenopausal breast cancer cases. Evidence also links obesity to a modest increase in ovarian cancer, especially premenopausally and for certain histologic subtypes. Globally, obesity is the third leading cause of cancer and is associated with around 500,000 new cancer cases annually, making it an important preventable risk factor.
3. Prevalence of Obesity
https://www.google.com.eg/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwje_93djLvSAhVHRhQKHUJSCfQQjRwIBw&url=https%3A%2F%2Fscconner.wordpress.com%2F2012%2F05%2F09%2Fegypt-independent-
urbanization-marriage-poverty-and-shame-the-many-faces-of-obesity-in-egyptian-women-by-nadine-ibrahim%2F&bvm=bv.148747831,d.ZGg&psig=AFQjCNGvknhsipEWVJ-uiCNVib5Ff7nZXg&ust=1488656052705848
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4. Incidence of Gynecologic Cancers in Egypt
0
5
10
15
20
25
Breast
Cancer
Cervical
Cancer
Ovarian
Cancer
Uterine
Cancer
Percent
Source: GLOBOCAN 2000.
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6. Convincing
1. Endometrial cancer
2. Postmenopausal breast
cancer
3. Colorectal cancer
4. Renal cell carcinoma
5. Esophageal
adenocarcinoma
6. Pancreatic cancer
7. Liver cancer
Probable
1. Ovarian cancer
2. Gallbladder
cancer
3. Gastric cardia
cancer
World Cancer Research Fund, 2016
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8. Promotion of cancer in obese patients.
1. Endogenous sex hormones
2. Insulin resistance/hyperinsulinaemia,
3. Adipokines, cytokines
4. Chronic inflammation
(Benedetto et al, 2015)
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9. 1. ENDOMETRIAL CANCER
The 6th most common cancer in women worldwide
The most common gynecologic malignancy in the developed
world.
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10. Obesity
Significantly increases the incidence of endometrial
cancer
(Modesitt , van Nagell , 2005)
Mild obesity
2.6-fold increase
Moderate obesity
4.7-fold increase
Central obesity
Twofold increase
Early-life obesity
moderately increased risk of endometrial cancer
later in life.
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11. OR of endometrial cancer in obese women
0.4
0.8 0.7
2.1
4.1
20-25 25-29.9 30-34.9 35-39.9 >40
BMI, kgm2
×1.9
×5.8
E. Ilenko, N. Artymuk, 2007
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12. Endometrial Caner in Egypt
0
5
10
15
20
25
30
35
Overall ≥75 Years ≥60-74 Years ≥50-59 Years
Incidence/100,000 Women
Ibrahim AS et al. 2014
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16. 2. BREAST CANCER
The most common cancer among women
25.2 % of incident female cancer cases
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17. Obesity
relationship and breast cancer risk is complex
differs by
1. tumor characteristics
2. menopausal status
3. exogenous hormone use.
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18. Obesity
has opposing effects on breast cancer risk,
depending on the window of exposure
Premenopausal women, obesity, in childhood or
during adult life:
decreased risk of both hormone receptor-
positive and hormone receptor-negative
disease.
{reduced exposure to endogenous
progesterone because of
obesity-induced ovarian hyperandrogenism}
(Benedetto et al, 2015)
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19. Postmenopausal
increases risk of
hormone receptor-positive disease
{oestrogen receptor (ER)-progesterone receptor (PR)-positive}
limited to women not using HRT
support the hypothesis that estrogens may be
the crucial link
After menopause
adipose tissue is the major source of estrogens
obesity is associated with higher estrogen
concentrations, which
have tumor-promoting activities.
may explain the higher breast cancer risk.
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20. Weight gain in postmenopausal
increases risk of postmenopausal disease
limited to
women not using HRT
hormone receptor-positive disease.
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21. Mechanisms linking adiposity and breast cancer
{insulin resistance: increased levels of circulating
insulin: reduced hepatic synthesis of SHBG
increased peripheral aromatisation of
androgens: increased levels of estrogens
(Key et al, 2003)}ABOUBAKR ELNASHAR
22. Obesity
10 % of all postmenopausal breast cancer cases
worldwide
14 % of cases in North America and Europe, can
be attributed to obesity
[Arnold et al, 2015].
highlight the relevance of
maintaining a healthy weight
minimizing weight gain, as a strategy for
modulating breast cancer risk.
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23. Obesity
poorer breast cancer-specific survival
irrespective of
menopausal status or
hormone receptor status of the tumor.
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24. 3. OVARIAN CANCER
The 7th most common cancer among women
Incidence rates
highest in developed regions
lower in less developed regions
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25. Data are less convincing
43 studies
3,491,943 participants
limited, inconsistent evidence of a positive
association between obesity and ovarian cancer
risk.
(Foong, Bolton;2017, SR)
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26. Obesity:
Modestly increase of premenopausal ovarian
cancer which are less likely to be of high-grade serous histology
(Modesitt , van Nagell , 2005)
Each 5-unit higher BMI: 7 % higher risk of ovarian
cancer
[Clendenen et al, 2011].
Risk of certain histologic subtypes
low-grade serous
invasive mucinous tumors.
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27. Obesity
not a strong risk factor for ovarian cancer,
particularly compared to reproductive and
hormonal factors
{1. ovarian cancer is a heterogeneous disease
2. association with obesity may differ according to
type of tumor}
[Clendenen et al, 2011].
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29. 4. CERVICAL CANCER
data are less convincing
A modest positive association between BMI and
cervical cancer
{impact on glandular cancers or decreased screening
compliance}.
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30. OBESITY AS AN AVOIDABLE CAUSE OF CANCER
(Attributable Risks)
Endometrial, post-menopausal breast, and colon
cancers
2/3 of cancers attributable to obesity.
Obesity
an established risk factor for increased incidence
of several adult cancers.
Worldwide
3rd commonest attributable risk factor for
cancer (after smoking and infection)
Western populations
2nd biggest preventable cause of cancer after
smoking.
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31. Population Attributable Fraction: PAF
Excess cancers attributable to obesity in populations
Avoidable cases and the opportunity for
prevention.
Worldwide attributed to obesity
3.6 % or
half a million new cancer cases in adults
Higher in women compared with men
(5.4 % vs. 1.9 %).
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32. Estimated numbers and PAFs of cancer cases
associated with high BMI
(Andrew et al, 2016)
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33. Estimated PAFs by major risk factors for cancer at a
global level and for the UK
(Andrew et al, 2016)
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34. You can get this lecture and 424
lecture from:
1.My scientific page on Face book:
Aboubakr Elnashar Lectures.
https://www.facebook.com/groups/2277
44884091351/
2.Slide share web site
3. elnashar53@hotmail.com
4.My clinic: Althwara st, Mansura, Egypt
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