global health challenges social analysis 76: lecture 14

Harvard University Initiative for Global Health

Global Health ChallengesSocial Analysis 76: Lecture 14


WHO Election Update

• Of 11 candidates, 5 have made it to the short-list:


Burden and Trends of Cancers

Progress in Treating Cancers

Specific Cancers

Burden of Cardiovascular Diseases

Intervention Options

CVD Challenges


Traditionally, cancers have been characterized by the Traditionally, cancers have been characterized by the body organ system where they first appear. body organ system where they first appear.

Cancers affecting the lung, for example, may have Cancers affecting the lung, for example, may have different etiologies and appearances. different etiologies and appearances.

As genetic information accumulates, it is clear that the As genetic information accumulates, it is clear that the molecular pathway that is disrupted may be different molecular pathway that is disrupted may be different for cancers that appear to be the same. for cancers that appear to be the same.

At the same time cancers in different sites may share At the same time cancers in different sites may share the same molecular or genetic origin. the same molecular or genetic origin.

Cancers


Two sources of information about the distribution of Two sources of information about the distribution of cancers in the population: population-based cancer cancers in the population: population-based cancer registries and vital registration systems. registries and vital registration systems.

Interpretation of trends and patterns of cancers is Interpretation of trends and patterns of cancers is confounded by differences in the ascertainment rate confounded by differences in the ascertainment rate over time in cancers, incomplete follow-up in some over time in cancers, incomplete follow-up in some developing country sites and changes in developing country sites and changes in classification schemes.classification schemes.

How Do We Know About Cancers?


7.1 Million Global Cancer Deaths 2002

Liver9%

Pancreas3% Lung

17%

Other neoplasms12%

Leukaemia4%

Lymphomas/MM

5%

Mouth and oropharynx

4%

Oesophagus 6%

Breast cancer7%

Melanoma/Skin1%

Bladder 2%

Prostate 4%

Ovary 2%

Corpus uteri 1% Cervix

3%

Colon/rectum 9%

Stomach 12%


Cancer risk is substantially determined by Cancer risk is substantially determined by environmental exposures, diet and genetic environmental exposures, diet and genetic susceptibility. Much of the heterogeneity in cancer susceptibility. Much of the heterogeneity in cancer risk across communities is not understood. risk across communities is not understood.

On average, however, developing countries have On average, however, developing countries have higher risks of cancers of the stomach, liver, cervix, higher risks of cancers of the stomach, liver, cervix, mouth, and esophagus and probably prostate. mouth, and esophagus and probably prostate.

On average, developed countries have higher risks of On average, developed countries have higher risks of lung and colon/rectum cancers.lung and colon/rectum cancers.

Tobacco consumption explains the enormous rise of Tobacco consumption explains the enormous rise of lung cancer, and a component of mouth oro-lung cancer, and a component of mouth oro-pharynx.pharynx.

Cancers and the Epidemiological Transition




Specific Cancers



CVD Challenges


Cancer literature uses two measures to analyze the Cancer literature uses two measures to analyze the impact of cancer diagnosis and treatment: 5-year impact of cancer diagnosis and treatment: 5-year absolute and relative survival.absolute and relative survival.

Absolute survival is the percentage of individuals Absolute survival is the percentage of individuals diagnosed with a cancer alive after 5 years. diagnosed with a cancer alive after 5 years.

Relative survival is the percentage of individuals Relative survival is the percentage of individuals diagnosed with cancer alive after 5 years divided by diagnosed with cancer alive after 5 years divided by the percentage of the age-sex matched general the percentage of the age-sex matched general population alive after 5 years. population alive after 5 years.

5-Year Relative and Absolute Survival


5-Year Relative survival rates (%), Whites, 1950-2000Source data: NCI, SEER Cancer Statistics Rev.

Breast femaleMelanoma of skin

Testis

Prostate

Hodgkin lymphoma

Childhood CA(0-14yrs)Urinary bladder

Leukemia

Myeloma

Non-Hodgkin lymphoma

All sites

Kidney & renal pelvis

Colon & rectum

RectumColon

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60 70 80 90 100

1950-1954

1995

-200

0


Survival of Cancer Patients in EuropeSource data: EUROCARE-2 Study

0

20

40

60

80

100

120

Fiv

e-y

ear

rela

tive s

urv

ival (

%)


Dramatic increase in understanding of cancer biology Dramatic increase in understanding of cancer biology and genetics over the last 20 years.and genetics over the last 20 years.

Targeted therapy – imatinib (Gleevec) induces nearly Targeted therapy – imatinib (Gleevec) induces nearly complete and sustained remission in patients with complete and sustained remission in patients with early stage chronic myeloid leukemia.early stage chronic myeloid leukemia.

Lots of promise for new generation treatments but they Lots of promise for new generation treatments but they may be many years away. may be many years away.

New Directions in Cancer Treatment




Specific Cancers



CVD Challenges


High incidence and mortality in East Asia.High incidence and mortality in East Asia.

Major decline in stomach cancer incidence and Major decline in stomach cancer incidence and mortality in Western countries over the last 50 mortality in Western countries over the last 50 years.years.

Many theories that refrigeration of food and the Many theories that refrigeration of food and the declining use of some preservatives have been declining use of some preservatives have been important drivers. important drivers.

H.Pylori infection is accepted as a risk for stomach H.Pylori infection is accepted as a risk for stomach cancer and may account for 40% of stomach cancer and may account for 40% of stomach cancers worldwide.cancers worldwide.

Stomach Cancer


High incidence and mortality in Africa, East Asia.High incidence and mortality in Africa, East Asia.

Major risk factor is chronic infection with Hepatitis B Major risk factor is chronic infection with Hepatitis B and Hepatitis C viruses.and Hepatitis C viruses.

85% of cases in developing countries are attributable to 85% of cases in developing countries are attributable to these infections.these infections.

Hepatitis B vaccination is effective and has been Hepatitis B vaccination is effective and has been recommended as a childhood vaccination to be recommended as a childhood vaccination to be included in the expanded programme of included in the expanded programme of immunization. immunization.

GAVI reports 41.6 million children immunized through GAVI reports 41.6 million children immunized through their programmes.their programmes.

Liver Cancer

Harvard University Initiative for Global HealthSource: WHO/UNICEF joint reporting form, 2002data from 192 WHO member states

HepB vaccine not introduced (51 countries or 27%) (in 5 countries HepB administered for adolescence)

HepB3 < 80% (30 countries or 15% )

HepB vaccine introduced but no coverage data reported (40 countries or 21%)

HepB3 > 80% (71 countries or 37%)

(141 countries introduced)

Countries having introduced HepB vaccineand reported HepB3 coverage, 2002

Slide Date: December 03


Lung cancer is the most common cancer and the Lung cancer is the most common cancer and the largest cause of cancer mortality. largest cause of cancer mortality.

Nearly all variation in lung cancer incidence can be Nearly all variation in lung cancer incidence can be attributed to tobacco smoking. In fact, Peto and attributed to tobacco smoking. In fact, Peto and Lopez have used the observed lung cancer death Lopez have used the observed lung cancer death rate as a biological index of cumulative tobacco rate as a biological index of cumulative tobacco consumption in a population. consumption in a population.

The main strategy for tackling lung cancer is to reduce The main strategy for tackling lung cancer is to reduce tobacco consumption which we will discuss in detail tobacco consumption which we will discuss in detail in the lecture on tobacco. in the lecture on tobacco.

Lung Cancer


Most common incident cancer in women. Most common incident cancer in women.

Incidence is recorded as higher and increasing in high Incidence is recorded as higher and increasing in high income countries. income countries.

Reproductive factors and family history are important Reproductive factors and family history are important risks. risks.

5-year survival has improved from 60% to 89% in the 5-year survival has improved from 60% to 89% in the last 50 years in the United States for white last 50 years in the United States for white populations. populations.

Screening with mammography is believed to have Screening with mammography is believed to have contributed to improved 5-year survival by detecting contributed to improved 5-year survival by detecting cancers at an earlier stage. cancers at an earlier stage.

Breast Cancer


Cervical cancer is highest in poor developing countries.Cervical cancer is highest in poor developing countries.

HPV (selected high risk serotypes) are the main risk HPV (selected high risk serotypes) are the main risk factor for cervical cancer.factor for cervical cancer.

Most young women who are sexually active are Most young women who are sexually active are infected with HPV.infected with HPV.

Cervical cancer incidence and mortality have declined Cervical cancer incidence and mortality have declined substantially over the last 40 years in high-income substantially over the last 40 years in high-income countries. This decline in part is attributable to countries. This decline in part is attributable to cervical cancer screening programs. cervical cancer screening programs.

HPV vaccines have demonstrated efficacy in large-HPV vaccines have demonstrated efficacy in large-scale trials.scale trials.

Cervical Cancer


% of women 18-69 who had a pelvic exam during the 3 years before the survey and a PAP test during the same exam

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

90.0%

100.0%

BG

DE

TH

MM

RLK

AN

PL

LAO

MW

IM

RT

GH

AIN

DS

WZ

ZM

BP

AK

KE

NM

LIM

AR

TC

DB

FA

ZW

EC

IVC

OM

PH

LT

UN

GE

OV

NM

SE

NN

AM

MU

SA

RE

CH

NM

YS

ZA

FIR

LG

TM

BIH

NLD

GR

CE

CU

CO

GP

RY

ES

PP

RT

ME

XU

RY

DO

MIS

RS

VK

HU

NE

ST

HR

VIT

AD

NK

SW

ER

US

AU

SB

EL

BR

AU

KR

FIN

SV

NLV

AK

AZ

NO

RD

EU

CZ

EA

UT

FR

ALU

X


War on Cancer – National Cancer Institute, War on Cancer – National Cancer Institute, International Agency for Research on Cancer (Lyon, International Agency for Research on Cancer (Lyon, part of WHO)part of WHO)

Tobacco control efforts – Framework Convention on Tobacco control efforts – Framework Convention on Tobacco ControlTobacco Control

Cervical and breast cancer screening included in Cervical and breast cancer screening included in discussions of the Cairo Reproductive Health discussions of the Cairo Reproductive Health agendaagenda

Hepatitis B vaccination included in GAVIHepatitis B vaccination included in GAVI

No other treatment initiatives No other treatment initiatives

Global Cancer Response




Specific Cancers



CVD Challenges


Causes of 16.7 Million Global Cardiovascular Deaths, 2002

Rheumatic 2%

Ischaemic 44%

Cerebrovascular 33%

Inflammatory 2%

Other 14%

Hypertensive5%


Ischemic heart disease occurs when the muscle of the Ischemic heart disease occurs when the muscle of the heart does not receive sufficient oxygen due to total heart does not receive sufficient oxygen due to total or partial occlusion of the arteries supplying blood to or partial occlusion of the arteries supplying blood to the heart. the heart.

Lack of oxygen is relative to oxygen consumption so Lack of oxygen is relative to oxygen consumption so that symptoms of ischemic heart disease often that symptoms of ischemic heart disease often occur when an individual exerts themselves. The occur when an individual exerts themselves. The classic symptom is chest pain, angina pectoris. classic symptom is chest pain, angina pectoris.

A myocardial infarction often called MI, a heart attack, A myocardial infarction often called MI, a heart attack, occurs when an area of the heart muscle is occurs when an area of the heart muscle is destroyed by acute lack of oxygen due to a total destroyed by acute lack of oxygen due to a total occlusion. occlusion.

Ischemic Heart Disease


Stroke occurs when an area of the brain receives Stroke occurs when an area of the brain receives insufficient oxygen and the cells die. insufficient oxygen and the cells die.

Two main forms of stroke: hemorrhagic stroke where a Two main forms of stroke: hemorrhagic stroke where a blood vessel in the brain ruptures and thrombotic blood vessel in the brain ruptures and thrombotic stroke where a blood vessel is occluded because of stroke where a blood vessel is occluded because of a blood clot.a blood clot.

For those who survive, stroke causes substantial For those who survive, stroke causes substantial disability. The disability depends on which part of disability. The disability depends on which part of the cortex has been destroyed. Because of the left the cortex has been destroyed. Because of the left and right sides of the cortex, symptoms of stroke and right sides of the cortex, symptoms of stroke often affect one side of the body. often affect one side of the body.

Cerebrovascular Disease or Stroke


Cardiovascular Diseases CPD (0-80), 2002

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

Males Females


IHD vs CVD CPD (0-80), 2002

0.0%5.0%

10.0%15.0%20.0%25.0%30.0%35.0%40.0%45.0%50.0%

0.0% 5.0% 10.0% 15.0% 20.0% 25.0% 30.0%

CVD CPD (0-80)

IHD

CP

D (

0-8

0)

EUR C EUR C MalesMales

WPR B WPR B malesmales

WPR B WPR B femalesfemales

AFR D+E AFR D+E femalesfemales

AMR A AMR A MalesMales




Specific Cancers



CVD Challenges


Three main strategies:Three main strategies:

1)1) Tobacco control. Tobacco control.

2)2) Diet and physical activity modification.Diet and physical activity modification.

3)3) Direct interventions for known major risks: blood Direct interventions for known major risks: blood pressure and cholesterol. pressure and cholesterol.

Are these strategies synergistic or competitive?Are these strategies synergistic or competitive?

Tackling Global CVD


Wide range of dietary components influence CVD risk: Wide range of dietary components influence CVD risk: trans-fatty acids, high sodium, high caloric intake, trans-fatty acids, high sodium, high caloric intake, fruits and vegetables, fish oils, etc. fruits and vegetables, fish oils, etc.

Controversies on the evidence: intervention trials have Controversies on the evidence: intervention trials have shown different effects than the observational shown different effects than the observational studies e.g. anti-oxidants.studies e.g. anti-oxidants.

How effective are we at changing national diets once How effective are we at changing national diets once the optimal diet has been identified?the optimal diet has been identified?

Quest for the Healthy Diet


Interventions Targeting Blood Pressure and Cholesterol

• Stepwise reductions of salt content of processed foods with either legislation or voluntary agreements and food labelling

• Health education through mass-media

• Threshold based treatment eg hypertension >160 mmHg, >140 mmHg etc

• Absolute risk based combination therapy – statin, low dose BP lowering and aspirin

• The Polypill


The polypill aka “The Little Red Heart Pill”

aka“The risk pill”

– Statin, low-dose aspirin & blood pressure drugs

– 65% reduction in heart attack & stroke risk

– Very safe and tolerable– ~$20 a year


Treatments developed over the last 35 years are Treatments developed over the last 35 years are effective in reducing the disability associated with effective in reducing the disability associated with angina pectoris and congestive heart failure. angina pectoris and congestive heart failure. Emergency therapy of MI has also reduced the Emergency therapy of MI has also reduced the case-fatality rate. case-fatality rate.

Main treatment strategies: Main treatment strategies:

1)1) Pharmacological management of angina, CHFPharmacological management of angina, CHF

2)2) Pharmacological management of BP, cholesterol, Pharmacological management of BP, cholesterol, plus aspirin and/or beta-blockersplus aspirin and/or beta-blockers

3)3) Revascularization of the heart muscle using Revascularization of the heart muscle using angioplasty or coronary artery bypass graft angioplasty or coronary artery bypass graft

4)4) Emergency revascularization through thrombolytic Emergency revascularization through thrombolytic agents (clot busters)agents (clot busters)

Treatment of IHD

global health challenges social analysis 76: lecture 14

Documents

time cancers

distribution of cancers

patterns of cancers

different sites

different etiologies

genetic information

trends of cancersprogress

ma neoplasms7106354