Transcript International & National Patterns of Cancer Rates

World Burden
of Cancer
Epi 242 Cancer Epidemiology
Binh Goldstein, Ph.D.
October 7, 2009
Measures of Cancer Frequency:
Incidence
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number of new cases occurring
can be expressed as an absolute number
of cases per year or as a rate per 100,000
persons per year.
incidence rate provides approximation to
average risk of developing a cancer and is
necessary to compare risk of disease
between populations
reduction in incidence is the appropriate
statistics to use when considering impact
of primary prevention strategies
Measures of Cancer Frequency:
Mortality
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number of deaths occurring
mortality rate is the number of deaths
per 100,000 persons per year
mortality rates measure average risk
of dying from a specific cancer
number of deaths is one measure of
outcome or impact of cancer
Fatality, (1-survival), is probability that
an individual with cancer will die from
it and is generally assumed to be most
severe sequelae of disease
Measures of Cancer Frequency:
Prevalence
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NO agreed definition of “prevalence” of cancer
number of persons in a defined population alive at
a given time who have had cancer diagnosed at
some time in past
partial prevalence limits number of patients to
those diagnosed during fixed time in past and is
more useful prevalence measure of cancer burden
prevalence for cases diagnosed within 1, 3, 5
years are likely to be of relevance to different
stages of cancer therapy: initial treatment (1
year), clinical follow-up (3 years) and cure (5
years)
patients still alive 5 years after diagnosis are
considered “cured” since their death rates are
similar to general population (some exceptions,
like breast cancer)
Other Measurements: Survival
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survival time defined as time that elapsed
between diagnosis and death
most basic measure of patients’ survival is
the observed survival
5-year observed survival is percentage of
patients alive after 5 years of follow-up
from date of diagnosis
Other Measurements: Relative
Survival
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deaths from other competing causes will
lower the observed survival rates and
preclude comparison between groups
where probability of death in the general
population vary
relative survival rate can be calculated to
avoid this problem
relative survival rate is observed survival
rate in a patient group divided by expected
survival of a comparable group in the
general population with respect to age,
sex, and calendar period of investigation
Measures of Cancer Frequency
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How are the different measures
related?
• M = I x F, where F is fatality
• M ≈ I(1-S), where S is 5-year survival
• P = I x D, where D is duration
• F = (1-S)
Other Measurements of Burden
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PYLLs (Potential Years of Life Lost)
QALYs (Quality Adjusted Life Years)
DALYs (Disability Adjusted Life
Years)
Global Cancer Statistics
Incidence by sex and cancer site, World 2002
Source: Table 1: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108
Mortality by sex and cancer site, World 2002
Source: Table 1: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108
Estimated Age-adjusted Survival (%)
Source: Table 2: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108
Incidence and prevalent cases,
World 2002
Source: Figure 3: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108
The Major Cancers
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Lung (ICD-10 C33 and C34)
Breast (female, C50)
Colon/rectum (C18-C20)
Stomach (C16)
Prostate (C61)
Liver (C22)
Cervix uteri (C53)
Esophagus (C15)
Age Standardized Incidence Rates
US
Site
More developed
countries
Less developed
countries
Males
Females
Males
Females
Males
Females
61.9
36.1
54.9
17.0
25.9
9.4
─
101.1
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67.8
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23.8
44.6
33.1
40.0
26.6
10.2
7.7
Stomach
7.2
3.3
22.3*
10.0*
21.5
10.4
Liver
5.5
2.0
8.5
3.0
18.4
7.1
124.8
─
56.2
─
9.4
─
─
7.7
─
10.3
─
19.1
5.9
1.3
6.8
1.3
13.7
6.5
Lung
Breast
Colon/Rectum
Prostate
Cervix
Esophagus
World Age Standardized
Incidence and Mortality Rates
Incidence
Lung
Breast
Colon/Rectum
Stomach
Liver
Prostate
Cervix
Esophagus
Males
35.5
─
20.1
22.0
15.7
25.3
─
11.5
Mortality
Females Males Females
12.1
31.2
10.3
─
37.5
13.2
14.6
10.2
7.6
10.3
5.8
─
16.2
4.7
16.3
14.9
8.2
─
9.6
7.9
5.7
─
9.0
3.9
Lung cancer
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1.35 million new cases and 1.18 million
deaths worldwide estimated in 2002
50% new cases occurred in more
developed countries (previously 69%)
more common in males (2.9 male:female
ratio)
patterns of lung cancer occurrence
determined largely by past exposure to
tobacco smoking
Age-standardized incidence rates for
lung cancer
Source: Figure 5: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108
Lung cancer
incidence trends
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in countries where
smoking was first
established (UK, US,
Australia, etc.),
rates declining
among men
in most other
countries, rates
rising
rates in women
generally increasing
since tobacco habit
is fairly recent,
except in countries
where their smoking
prevalence is
declining
Lung cancer
mortality trends
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similar to incidence
trends
Breast cancer
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1.15 million new cases and 410,000
deaths worldwide estimated in 2002
most common cancer in women
Over half of new cases occurred in more
developed countries
stage of disease at diagnosis is most
important prognostic factor
most prevalent cancer in world because of
its good prognoses
risk increases with age but slows at about
50 years because of menopause and lower
estrogen levels
Age-standardized incidence and
mortality rates for breast cancer
Source: Figure 6: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108
Breast cancer
incidence trends
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generally increasing
at all ages
Breast cancer
mortality trends
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may be declining
in recent years
(like in US,
Canada, and some
European
countries) due to
screening and
detection of early
stage cancers and
more effective
treatment
Colorectal cancer
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About 1 million new cases and 529,000
deaths worldwide estimated in 2002
3rd most common cause of cancer in world
but 2nd most common in developed
countries.
good prognoses (40-50% 5-year survival)
makes it the 2nd most prevalent cancer
males and females have similar rates
Age-standardized incidence rates for
colorectal cancer
Source: Figure 7: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108
Colorectal cancer
incidence trends
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increasing trend in
low-risk areas
stabilized or
decreasing trends in
high-risk areas
greatest increases
observed in Asia
(especially Japan)
and Eastern Europe
(possibly from
“westernization” of
lifestyle/diet)
Colorectal cancer
mortality trends
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decreasing trend in
developed countries
may be due to
decreasing in
incidence, improved
treatment, and
improvements in
early detection (from
screening)
Stomach cancer
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934,000 new cases and 700,000 deaths
worldwide estimated in 2002
ranked 4th in number of new cancers but
2nd in most common cause of deaths from
cancer
almost two-thirds of cases occur in
developing countries
more common in males (1.75 male:female
ratio)
however, in younger age groups (<40
years) rates in women are greater than
men
Age-standardized incidence rates for
stomach cancer
Source: Figure 8: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108
Stomach cancer
incidence trends
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general decline in
rates among both
developed and
developing countries
because of improved
food preservation
practices
(refrigerators) and
better nutrition
(higher vegetable
and fruit intake)
Stomach cancer
mortality trends
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generally declining in
both less and more
developed regions
Prostate cancer
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679,000 new cases and 221,000 deaths
worldwide estimated in 2002
2nd most common new cancer and most
prevalent form of cancer among males
75% of cases occur in men aged 65+
prostate-specific antigen assay introduced
in mid to late ‘80s
Age-standardized incidence rates for
prostate cancer
Source: Figure 5: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108
Prostate cancer
incidence trends
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in many developed
countries incidence
increased greatly,
especially among
younger men (<65
yrs)
most dramatic
increases are in
high-risk areas
partly due to
detection of
prevalent latent
cancers using PSA
less developed
countries also
increasing
Prostate cancer
mortality trends
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generally increasing
but not as
dramatically as
incidence
since 1990s, decline
in several developed
countries attributed
to earlier detection
and improved
treatment
Liver cancer
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626,000 new cases and 598,000 deaths
worldwide estimated in 2002
6th most common cancer and 3rd most
common cause of deaths from cancer
82% of cases occur in developing
countries (55% in China)
male:female ratio is about 2.4
Age-standardized incidence rates for
liver cancer
Source: Figure 10: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108
Liver cancer incidence
trends
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difficult to interpret
because of ICD
revisions
• 7th revision includes gall
bladder cancer
• 9th revision includes
category of “unspecified
10 or 20”
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↓ among Chinese
because of ↓ in
prevalence of HBV
↑ in Japan because of
↑ alcohol consumption
and HCV prevalence
↑ in developed
countries possibly
from ↑ HCV infection
(from transfusions
and drug use)
Liver cancer
mortality trends
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similar to incidence
trends
increase in mortality
among developed
countries not
necessarily from
alcohol (since
mortality from liver
cirrhosis is
decreasing)
Cervical cancer
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493,000 new cases and 274,000 deaths
worldwide estimated in 2002
2nd most common new cancer among
women
83% of cases occur in developing
countries
rates are very low in developed countries
generally, incidence rises at age 20-29
and peaks around 45-49 in developed
countries, but usually later in developing
countries
Age-standardized incidence and
mortality rates for cervical cancer
Source: Figure 11: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108
Cervical cancer
incidence trends
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decreases in many
developed countries
because of
screening programs
in developing
countries, trends
vary, but generally,
rates (including
mortality) are
stabilized or
decreasing
Cervical cancer
mortality trends
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decreases in many
developed countries
also because of
diagnoses at earlier
stages and improved
treatment
Esophageal cancer
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462,000 new cases and 386,000 deaths
worldwide estimated in 2002
84% of cases occur in developing countries
generally, more common in males
(male:female ratio over 2), but female
predominance in some areas of
“esophageal cancer belt”
Age-standardized incidence rates for
esophageal cancer
Source: Figure 12: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108
Esophageal cancer
incidence trends
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trends vary from
increasing (Eastern
Europe and US),
stabilized (Southern
Europe), to decreasing
(Finland and China)
Esophageal cancer
mortality trends
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inconsistent trends
like incidence
Resources
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Garcia M, et al. Global Cancer Facts &
Figures 2007, American Cancer Society,
2007.
Ferlay J, et al. GLOBOCAN 2002 Database.
Descriptive Epidemiology Group,
International Agency for Research on
Cancer, 2002.
Parkin DM, et al. Global Cancer Statistics,
2002. CA Cancer J Clin, 2005; 55: 74-108.
Parkin DM, et al. Cancer burden in the
year 2000. The global picture. Eur J
Cancer, 2001; 37 Suppl 8: S4-66.