Transcript Breast Cancer Research in the Developing World

Breast Cancer Research in the
Developing World
Dr. Steven Narod
Canada Research Chair in Breast Cancer
Boston – November 2009
Annual numbers of breast cancers

Top 10 countries

China
224,000

USA
195,000
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India
113,000
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Germany
53,000
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Russia
52,000
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Italy
38,000
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Brazil
38,000
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France
38,000
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United Kingdom
36,000
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Indonesia
28,000
Breast Cancer Cases by Continent
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Asia
South America
Africa
Central America
508
82
69
18
(677)
North America
Europe
Australia
213
324
11
(548)
By Stage of Development
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Developing
739
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Developed
486
(IMF)
Why do research in developing
world?
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Major cause of death in those countries
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Most breast cancers occur in developing world
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Rates may be increasing
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Populations aging
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Better understanding of variation in patterns, etiology
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Might lead to understanding in North America
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Different stage at presentation
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Might be specific etiology for other ethnic groups
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Planning of services
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Milestones
Examples
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Advanced cancers:

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Different than North America
From stage 4 to death
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Metastastic oophorectomy/tamoxifen
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New drugs
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(Raises ethical issues)
Questions about Etiology
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Recessive genes
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Different diets
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Different environmental exposures
Towards a Standard Set of
Descriptors
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Population or hospital-based
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Private or Public
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Prevalent or incident cases
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One year of diagnosis, several year of
diagnosis
Variables to Collect
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Age of diagnosis
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Means of detection patient, physician, mammography
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Size
Nodes examined
Nodes positive
Locally advanced
Clinical Stage Grouping (early, locally advanced, metastatic)
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ER
PR
HER2
Grade
Variables to Collect, cont….
o
o
o
o
Treatment
Radiotherapy (y/n)
Chemotherapy
Regimen
o
o
o
o
o
o
o
o
o
o
o
Hormonal therapy
Oophorectomy
Age of oophorectomy
Tamoxifen
Aromatase inhibitors
Menopausal status at diagnosis
Age of menopause
o Date of last follow-up
o Date of Death
o Cause of Death
Surgery
Mastectomy
Lumpectomy
Bilateral mastectomy
Questions to address

Are people getting appropriate
treatment?
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Is stage at presentation improving?
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Is treatment effective?
Western model applied to
developing countries
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Promotes two-tiered system
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May not be best approach for
population

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Access and affordability
All populations may not respond the
same
Possible recessive basis for breast
cancer
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Test of recessive disease, parents related
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Test in children of consanguinous parents
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Homozygosity mapping
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Countries with high rates of consanguinity:
Pakistan
Bangladesh
Yemen
Saudi Arabia
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Risk Factors May Differ
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Vietnam: 300 cases and 300 hospital
controls
No effect of family history
 No effect of parity
 Very low frequency of BRCA1 and
BRCA2
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Different risk factors?
Hypothesis
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There are no common risk factors for
breast cancer.