World Burden of Cancer Epi 242 Cancer Epidemiology Binh Goldstein, Ph.D. October 7, 2009

World Burden World Burden of Cancerof Cancer

Epi 242 Cancer EpidemiologyEpi 242 Cancer Epidemiology

Binh Goldstein, Ph.D.Binh Goldstein, Ph.D.

October 7, 2009October 7, 2009

Measures of Cancer Frequency: Measures of Cancer Frequency: IncidenceIncidence

number of new cases occurringnumber of new cases occurring can be expressed as an absolute number can be expressed as an absolute number

of cases per year or as a rate per 100,000 of cases per year or as a rate per 100,000 persons per year.persons per year.

incidence rate provides approximation to incidence rate provides approximation to average risk of developing a cancer and is average risk of developing a cancer and is necessary to compare risk of disease necessary to compare risk of disease between populations between populations

reduction in incidence is the appropriate reduction in incidence is the appropriate statistics to use when considering impact statistics to use when considering impact of primary prevention strategiesof primary prevention strategies

Measures of Cancer Frequency: Measures of Cancer Frequency: MortalityMortality

number of deaths occurringnumber of deaths occurring mortality rate is the number of deaths mortality rate is the number of deaths

per 100,000 persons per yearper 100,000 persons per year mortality rates measure average risk of mortality rates measure average risk of

dying from a specific cancerdying from a specific cancer number of deaths is one measure of number of deaths is one measure of

outcome or impact of canceroutcome or impact of cancer Fatality, (1-survival), is probability that Fatality, (1-survival), is probability that

an individual with cancer will die from an individual with cancer will die from it and is generally assumed to be most it and is generally assumed to be most severe sequelae of diseasesevere sequelae of disease

Measures of Cancer Frequency: Measures of Cancer Frequency: PrevalencePrevalence

NO agreed definition of “prevalence” of cancer NO agreed definition of “prevalence” of cancer number of persons in a defined population alive at number of persons in a defined population alive at

a given time who have had cancer diagnosed at a given time who have had cancer diagnosed at some time in pastsome time in past

partial prevalence limits number of patients to partial prevalence limits number of patients to those diagnosed during fixed time in past and is those diagnosed during fixed time in past and is more useful prevalence measure of cancer burdenmore useful prevalence measure of cancer burden

prevalence for cases diagnosed within 1, 3, 5 prevalence for cases diagnosed within 1, 3, 5 years are likely to be of relevance to different years are likely to be of relevance to different stages of cancer therapy: initial treatment (1 stages of cancer therapy: initial treatment (1 year), clinical follow-up (3 years) and cure (5 year), clinical follow-up (3 years) and cure (5 years)years)

patients still alive 5 years after diagnosis are patients still alive 5 years after diagnosis are considered “cured” since their death rates are considered “cured” since their death rates are similar to general population (some exceptions, similar to general population (some exceptions, like breast cancer)like breast cancer)

Other Measurements: SurvivalOther Measurements: Survival

survival time defined as time that elapsed survival time defined as time that elapsed between diagnosis and deathbetween diagnosis and death

most basic measure of patients’ survival is most basic measure of patients’ survival is the observed survivalthe observed survival

5-year observed survival is percentage of 5-year observed survival is percentage of patients alive after 5 years of follow-up patients alive after 5 years of follow-up from date of diagnosisfrom date of diagnosis

Other Measurements: Relative Other Measurements: Relative SurvivalSurvival

deaths from other competing causes will deaths from other competing causes will lower the observed survival rates and lower the observed survival rates and preclude comparison between groups preclude comparison between groups where probability of death in the general where probability of death in the general population varypopulation vary

relative survival rate can be calculated to relative survival rate can be calculated to avoid this problemavoid this problem

relative survival rate is observed survival relative survival rate is observed survival rate in a patient group divided by expected rate in a patient group divided by expected survival of a comparable group in the survival of a comparable group in the general population with respect to age, general population with respect to age, sex, and calendar period of investigationsex, and calendar period of investigation

Measures of Cancer FrequencyMeasures of Cancer Frequency

How are the different measures How are the different measures related?related?

• M = I x F, where F is fatalityM = I x F, where F is fatality• M ≈ I(1-S), where S is 5-year survivalM ≈ I(1-S), where S is 5-year survival• P = I x D, where D is durationP = I x D, where D is duration• F = (1-S)F = (1-S)

Other Measurements of BurdenOther Measurements of Burden

PYLLs (Potential Years of Life Lost)PYLLs (Potential Years of Life Lost) QALYs (Quality Adjusted Life Years)QALYs (Quality Adjusted Life Years) DALYs (Disability Adjusted Life Years)DALYs (Disability Adjusted Life Years)

Global Cancer StatisticsGlobal Cancer Statistics

Incidence by sex and cancer site, World 2002Incidence 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 2002Mortality 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 (%)Estimated Age-adjusted Survival (%)

Source: Table 2: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108

Incidence and prevalent cases, Incidence and prevalent cases, World 2002World 2002

Source: Figure 3: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108

The Major CancersThe Major Cancers

Lung (ICD-10 C33 and C34)Lung (ICD-10 C33 and C34) Breast (female, C50)Breast (female, C50) Colon/rectum (C18-C20)Colon/rectum (C18-C20) Stomach (C16)Stomach (C16) Prostate (C61)Prostate (C61) Liver (C22)Liver (C22) Cervix uteri (C53)Cervix uteri (C53) Esophagus (C15)Esophagus (C15)

   USUSMore developed More developed

countriescountriesLess developed Less developed

countriescountries

SiteSite MalesMales FemalesFemales MalesMales FemalesFemales MalesMales FemalesFemales

LungLung 61.961.9 36.136.1 54.954.9 17.017.0 25.925.9 9.49.4

BreastBreast ── 101.1101.1 ── 67.867.8 ── 23.823.8

Colon/RectumColon/Rectum 44.644.6 33.133.1 40.040.0 26.626.6 10.210.2 7.77.7

StomachStomach 7.27.2 3.33.3 22.3*22.3* 10.0*10.0* 21.521.5 10.410.4

LiverLiver 5.55.5 2.02.0 8.58.5 3.03.0 18.418.4 7.17.1

ProstateProstate 124.8124.8 ── 56.256.2 ── 9.49.4 ──

CervixCervix ── 7.77.7 ── 10.310.3 ── 19.119.1

EsophagusEsophagus 5.95.9 1.31.3 6.86.8 1.31.3 13.713.7 6.56.5

Age Standardized Incidence RatesAge Standardized Incidence Rates

World Age Standardized World Age Standardized Incidence and Mortality RatesIncidence and Mortality Rates

IncidenceIncidence MortalityMortality

MalesMales FemalesFemales MalesMales FemalesFemales

LungLung 35.535.5 12.112.1 31.231.2 10.310.3

BreastBreast ── 37.537.5 ── 13.213.2

Colon/RectumColon/Rectum 20.120.1 14.614.6 10.210.2 7.67.6

StomachStomach 22.022.0 10.310.3 16.316.3 7.97.9

LiverLiver 15.715.7 5.85.8 14.914.9 5.75.7

ProstateProstate 25.325.3 ── 8.28.2 ──

CervixCervix ── 16.216.2 ── 9.09.0

EsophagusEsophagus 11.511.5 4.74.7 9.69.6 3.93.9

Lung cancerLung cancer

1.35 million new cases and 1.18 million 1.35 million new cases and 1.18 million deaths worldwide estimated in 2002deaths worldwide estimated in 2002

50% new cases occurred in more 50% new cases occurred in more developed countries (previously 69%)developed countries (previously 69%)

more common in males (2.9 male:female more common in males (2.9 male:female ratio)ratio)

patterns of lung cancer occurrence patterns of lung cancer occurrence determined largely by past exposure to determined largely by past exposure to tobacco smoking tobacco smoking

Age-standardized incidence rates for Age-standardized incidence rates for lung cancer lung cancer

Source: Figure 5: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108

Lung cancer Lung cancer incidence trendsincidence trends

in countries where in countries where smoking was first smoking was first established (UK, US, established (UK, US, Australia, etc.), rates Australia, etc.), rates declining among declining among menmen

in most other in most other countries, rates countries, rates risingrising

rates in women rates in women generally increasing generally increasing since tobacco habit since tobacco habit is fairly recent, is fairly recent, except in countries except in countries where their smoking where their smoking prevalence is prevalence is decliningdeclining

Lung cancer Lung cancer mortality trendsmortality trends

similar to incidence similar to incidence trendstrends

Breast cancerBreast cancer 1.15 million new cases and 410,000 1.15 million new cases and 410,000

deaths worldwide estimated in 2002deaths worldwide estimated in 2002 most common cancer in womenmost common cancer in women Over half of new cases occurred in more Over half of new cases occurred in more

developed countriesdeveloped countries stage of disease at diagnosis is most stage of disease at diagnosis is most

important prognostic factor important prognostic factor most prevalent cancer in world because of most prevalent cancer in world because of

its good prognosesits good prognoses risk increases with age but slows at about risk increases with age but slows at about

50 years because of menopause and lower 50 years because of menopause and lower estrogen levelsestrogen levels

Age-standardized incidence and Age-standardized incidence and mortality rates for breast cancermortality rates for breast cancer

Source: Figure 6: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108

Breast cancer Breast cancer incidence trendsincidence trends

generally increasing generally increasing at all agesat all ages

Breast cancer Breast cancer mortality trendsmortality trends

may be declining may be declining in recent years in recent years (like in US, (like in US, Canada, and some Canada, and some European European countries) due to countries) due to screening and screening and detection of early detection of early stage cancers and stage cancers and more effective more effective treatmenttreatment

Colorectal cancerColorectal cancer

About 1 million new cases and 529,000 About 1 million new cases and 529,000 deaths worldwide estimated in 2002deaths worldwide estimated in 2002

33rdrd most common cause of cancer in world most common cause of cancer in world but 2but 2ndnd most common in developed most common in developed countries.countries.

good prognoses (40-50% 5-year survival) good prognoses (40-50% 5-year survival) makes it the 2makes it the 2ndnd most prevalent cancer most prevalent cancer

males and females have similar ratesmales and females have similar rates

Age-standardized incidence rates for Age-standardized incidence rates for colorectal cancer colorectal cancer

Source: Figure 7: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108

Colorectal cancer Colorectal cancer incidence trendsincidence trends

increasing trend in increasing trend in low-risk areaslow-risk areas

stabilized or stabilized or decreasing trends in decreasing trends in high-risk areashigh-risk areas

greatest increases greatest increases observed in Asia observed in Asia (especially Japan) (especially Japan) and Eastern Europe and Eastern Europe (possibly from (possibly from “westernization” of “westernization” of lifestyle/diet)lifestyle/diet)

Colorectal cancer Colorectal cancer mortality trendsmortality trends

decreasing trend in decreasing trend in developed countries developed countries may be due to may be due to decreasing in decreasing in incidence, improved incidence, improved treatment, and treatment, and improvements in improvements in early detection (from early detection (from screening)screening)

Stomach cancerStomach cancer

934,000 new cases and 700,000 deaths 934,000 new cases and 700,000 deaths worldwide estimated in 2002worldwide estimated in 2002

ranked 4ranked 4thth in number of new cancers but in number of new cancers but 22ndnd in most common cause of deaths from in most common cause of deaths from cancercancer

almost two-thirds of cases occur in almost two-thirds of cases occur in developing countriesdeveloping countries

more common in males (1.75 male:female more common in males (1.75 male:female ratio)ratio)

however, in younger age groups (<40 however, in younger age groups (<40 years) rates in women are greater than years) rates in women are greater than men men

Age-standardized incidence rates for Age-standardized incidence rates for stomach cancer stomach cancer

Source: Figure 8: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108

Stomach cancer Stomach cancer incidence trendsincidence trends

general decline in general decline in rates among both rates among both developed and developed and developing countries developing countries because of improved because of improved food preservation food preservation practices practices (refrigerators) and (refrigerators) and better nutrition better nutrition (higher vegetable (higher vegetable and fruit intake)and fruit intake)

Stomach cancer Stomach cancer mortality trendsmortality trends

generally declining in generally declining in both less and more both less and more developed regionsdeveloped regions

Prostate cancerProstate cancer

679,000 new cases and 221,000 deaths 679,000 new cases and 221,000 deaths worldwide estimated in 2002worldwide estimated in 2002

22ndnd most common new cancer and most most common new cancer and most prevalent form of cancer among malesprevalent form of cancer among males

75% of cases occur in men aged 65+75% of cases occur in men aged 65+ prostate-specific antigen assay introduced prostate-specific antigen assay introduced

in mid to late ‘80sin mid to late ‘80s

Age-standardized incidence rates for Age-standardized incidence rates for prostate cancer prostate cancer

Source: Figure 5: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108

Prostate cancer Prostate cancer incidence trendsincidence trends

in many developed in many developed countries incidence countries incidence increased greatly, increased greatly, especially among especially among younger men (<65 younger men (<65 yrs)yrs)

most dramatic most dramatic increases are in increases are in high-risk areas high-risk areas partly due to partly due to detection of detection of prevalent latent prevalent latent cancers using PSAcancers using PSA

less developed less developed countries also countries also increasingincreasing

Prostate cancer Prostate cancer mortality trendsmortality trends

generally increasing generally increasing but not as but not as dramatically as dramatically as incidenceincidence

since 1990s, decline since 1990s, decline in several developed in several developed countries attributed countries attributed to earlier detection to earlier detection and improved and improved treatmenttreatment

Liver cancerLiver cancer

626,000 new cases and 598,000 deaths 626,000 new cases and 598,000 deaths worldwide estimated in 2002worldwide estimated in 2002

66thth most common cancer and 3 most common cancer and 3rdrd most most common cause of deaths from cancercommon cause of deaths from cancer

82% of cases occur in developing 82% of cases occur in developing countries (55% in China)countries (55% in China)

male:female ratio is about 2.4 male:female ratio is about 2.4

Age-standardized incidence rates for Age-standardized incidence rates for liver cancer liver cancer

Source: Figure 10: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108

Liver cancer incidence Liver cancer incidence trendstrends

difficult to interpret difficult to interpret because of ICD because of ICD revisionsrevisions• 77thth revision includes gall revision includes gall

bladder cancerbladder cancer• 99thth revision includes revision includes

category of “unspecified category of “unspecified 110 0 or 2or 200””

↓ ↓ among Chinese among Chinese because of because of ↓↓ in in prevalence of HBVprevalence of HBV

↑↑ in Japan because of in Japan because of ↑ ↑ alcohol consumption alcohol consumption and HCV prevalenceand HCV prevalence

↑ ↑ in developed in developed countries possibly countries possibly from from ↑ ↑ HCV infection HCV infection (from transfusions and (from transfusions and drug use)drug use)

Liver cancer Liver cancer mortality trendsmortality trends

similar to incidence similar to incidence trendstrends

increase in mortality increase in mortality among developed among developed countries not countries not necessarily from necessarily from alcohol (since alcohol (since mortality from liver mortality from liver cirrhosis is cirrhosis is decreasing)decreasing)

Cervical cancerCervical cancer 493,000 new cases and 274,000 deaths 493,000 new cases and 274,000 deaths

worldwide estimated in 2002worldwide estimated in 2002 22ndnd most common new cancer among most common new cancer among

womenwomen 83% of cases occur in developing 83% of cases occur in developing

countriescountries rates are very low in developed countriesrates are very low in developed countries generally, incidence rises at age 20-29 and generally, incidence rises at age 20-29 and

peaks around 45-49 in developed peaks around 45-49 in developed countries, but usually later in developing countries, but usually later in developing countries countries

Age-standardized incidence and Age-standardized incidence and mortality rates for cervical cancer mortality rates for cervical cancer

Source: Figure 11: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108

Cervical cancer Cervical cancer incidence trendsincidence trends

decreases in many decreases in many developed countries developed countries because of because of screening programsscreening programs

in developing in developing countries, trends countries, trends vary, but generally, vary, but generally, rates (including rates (including mortality) are mortality) are stabilized or stabilized or decreasingdecreasing

Cervical cancer Cervical cancer mortality trendsmortality trends

decreases in many decreases in many developed countries developed countries also because of also because of diagnoses at earlier diagnoses at earlier stages and improved stages and improved treatmenttreatment

Esophageal cancerEsophageal cancer

462,000 new cases and 386,000 deaths 462,000 new cases and 386,000 deaths worldwide estimated in 2002worldwide estimated in 2002

84% of cases occur in developing countries84% of cases occur in developing countries generally, more common in males generally, more common in males

(male:female ratio over 2), but female (male:female ratio over 2), but female predominance in some areas of predominance in some areas of “esophageal cancer belt”“esophageal cancer belt”

Age-standardized incidence rates for Age-standardized incidence rates for esophageal cancer esophageal cancer

Source: Figure 12: Parkin DM, et al. CA Cancer J Clin [2005]; 55: 74-108

Esophageal cancer Esophageal cancer incidence trendsincidence trends

trends vary from trends vary from increasing (Eastern increasing (Eastern Europe and US), Europe and US), stabilized (Southern stabilized (Southern Europe), to decreasing Europe), to decreasing (Finland and China)(Finland and China)

Esophageal cancer Esophageal cancer mortality trendsmortality trends

inconsistent trends inconsistent trends like incidencelike incidence

ResourcesResources Garcia M, et al. Global Cancer Facts & Garcia M, et al. Global Cancer Facts &

Figures 2007, American Cancer Society, Figures 2007, American Cancer Society, 2007.2007.

Ferlay J, et al. GLOBOCAN 2002 Database. Ferlay J, et al. GLOBOCAN 2002 Database. Descriptive Epidemiology Group, Descriptive Epidemiology Group, International Agency for Research on International Agency for Research on Cancer, 2002.Cancer, 2002.

Parkin DM, et al. Global Cancer Statistics, Parkin DM, et al. Global Cancer Statistics, 2002. 2002. CA Cancer J Clin, CA Cancer J Clin, 2005; 55: 74-108.2005; 55: 74-108.

Parkin DM, et al. Cancer burden in the Parkin DM, et al. Cancer burden in the year 2000. The global picture. year 2000. The global picture. Eur J Eur J Cancer, Cancer, 2001; 37 Suppl 8: S4-66. 2001; 37 Suppl 8: S4-66.