Epidemiology of cancer

DR SUHAS.K.R

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Epidemiology is the study of the distribution and determinants of

health-related states or events in specified populations and the

application of this study to control health problems

The oldest known description of human cancer is found in Egyptian

papyri written between 3000-1500 BC.

Two of them, known as the "Edwin Smith" and "George Ebers"

papyri, contain details of conditions that are consistent with

modern descriptions of cancer.

Introduction

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Cancer EpidemiologyHistorical Perspective

1713 Bernardino Ramazzini, an Italian doctor - the virtual

absence of cervical cancer and relatively high incidence of breast

cancer in nuns

1775 - British surgeon, Percival Pott - probably the first description of

occupational carcinogenesis in the form of scrotum cancer among

chimney sweeps.

1950 - Lung cancer study conducted by Doll and Hill -

linked tobacco smoking to an increased mortality of lung cancer in

over 40,000 medical professionals in the United Kingdom3

Cancer EpidemiologyHistorical Perspective

Tobacco and Lung Cancer

Asbestos and Lung Cancer

Leather Industry and Nasal Cancer

Dyes and Bladder Cancer

Ionizing Radiation and Many Cancers

DES and Vaginal Adenocarcinoma

EBV and Burkitt’s Lymphoma

HPV and Cervical Cancer

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Aims of Cancer Epidemiology

Uncover new etiologic leads

study of the distribution of cancer

quantify the risk associated with different exposures and

host factors

Promote insights into the mechanisms of carcinogenesis

Assess efficacy of preventive measures

Investigate predictors of survival

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The Surveillance, Epidemiology, and End Results (SEER)

Program of the National Cancer Institute (NCI) - an

authoritative source of information on new cancer cases and

cancer survival in the United States.

Case ascertainment for SEER began in 1973

The World Health Organization's International Agency for

Research on Cancer and the International Association of Cancer

Registries publishes Cancer Incidence in Five Continents6

Cancer EpidemiologySources

US SEER Registry System

IARC International Registries

State/Hospital Registries

Etiologic Clues

“Alert” Clinician

Experimental Studies

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Study designs

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Methods of Cancer Epidemiology

Descriptive Studies

Incidence, mortality, survival

Time Trends

Geographic Patterns

Patterns by Age, Gender, SES,

Ethnicity

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a global perspective on cancer is critical

The huge international variation in the occurrence of many types of cancer

worldwide burden of cancer is no longer confined predominantly to the industrialized, wealthy countries

The impact of migration on cancer rates

Global Cancer Incidence (Surveillance, Epidemiology, and End Results Database)

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Incidence and Mortality Rates

quantify the number of newly diagnosed cancer cases or

deaths, respectively, in a specified population over a defined time

period

Prevalence

the rate at which new cancer cases are diagnosed in a

specified population and time interval, measures the number or

percentage of people in the population who are living after a

diagnosis of cancer.

Data Sources and Measurements

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In addition to the effects of age, the overall risk of developing

or dying from cancers is affected by gender, socioeconomic

status, race/ethnicity and geographic location

Sex

The incidence rates of most cancers that affect both men

and women are higher in men than women

few exceptions breast, thyroid, and gallbladder

Overall Cancer Risk

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Socioeconomic Status

Race and Ethnicity

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Cancers that are strongly related to infectious etiologies, for

example, stomach, liver, and uterine cervix are, in general,

decreasing globally

Rapid increase in the occurrence of malignancies that were

historically common only in wealthy countries, but that now

are increasing in middle- and low-resource countries - include

cancers of the lung, breast, prostate, and colon/rectum.

Temporal Trends

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Indian scenario-ICMR DATA

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A comparison of inter registry rates showed that among males, lung

cancer was the leading site in Bhopal, Delhi and Mumbai while it was the

second leading site in Chennai and Bangalore.

Cancer of the stomach was the leading site in Chennai and Bangalore,

whereas, it occupied different positions in other registries.

In Barshi, cancer of oesophagus occupied the leading site.

Tongue and mouth - the leading site of cancer in Ahmedabad registry.

Comparison

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In females, breast cancer was the leading site of cancer in all

registries except Barshi

This was followed by cancer cervix as the second leading site of

cancer.

Ovarian cancer occupies the third leading site in Delhi, Mumbai,

Chennai, Bhopal and Ahmedabad registry while it was placed

fourth and fifth in Bangalore and Barshi respectively.

Comparison

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Ten Leading Sites of Cancer - Delhi

Males

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Ten Leading Sites of Cancer -Delhi

females

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Number(#) & Proportion(%) of specific sites of cancer among all

Tobacco Related Cancers (TRC)

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Number(#) & Proportion(%) of specific sites of cancer among all

Tobacco Related Cancers (TRC)

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Worldwide, lung cancer - the most common cancer in terms of both

newly diagnosed cases and deaths

The highest rates are among men in eastern Europe, North America,

and the rest of Europe, whereas the lowest rates are observed in Africa,

excluding South Africa

Lung Cancer

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Lung cancer - more strongly associated with cigarette smoking

than any other cancer site. Globally, an estimated 85% of lung

cancers in men and 47% in women

Cigarette smoking is estimated to have killed 100 million

people in the 20th century, and is projected to kill one billion

people in the 21st century, unless smoking patterns change

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trends

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The joinpoint trend in SEER cancer incidence with associated APC(%) for cancer of the lung and bronchus

between 1975-2010, All Races

Male and Female Male Female

Trend Period Trend Period Trend Period

2.5* 1975-1982 1.4* 1975-1982 5.6* 1975-1982

1.0* 1982-1991 -0.4 1982-1991 3.4* 1982-1991

-0.7* 1991-2007 -1.8* 1991-2010 0.5* 1991-2007

-2.6* 2007-2010

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http://seer.cancer.gov/statfacts/html/lungb.html









Based on rates from 2008-2010, as 1 in 15 men and women will

be diagnosed with cancer of the lung and bronchus during their lifetime.

Lifetime Risk

Stage Distribution and 5-year Relative Survival by Stage at Diagnosis for

2003-2009, All Races, Both Sexes

Stage at DiagnosisStage

Distribution (%)

5-year

Relative Survival (%)

Localized (confined to primary

site)15 53.5

Regional (spread to regional

lymphnodes)22 26.1

Distant (cancer has metastasized) 57 3.9

Unknown (unstaged) 6 7.833

Among women, breast cancer is the most frequently diagnosed

cancer and the leading cause of cancer death worldwide

Female Breast Cancer

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Factors that contribute to the striking international variation -

historical differences in reproductive factors (age at menarche,

menopause, and first live birth and number of children), use of

hormone-replacement therapy, obesity after menopause,

alcohol intake, and screening practices.

Based on rates from 2008-2010, 1 in 8 women will be diagnosed

with cancer of the breast during their lifetime

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The joinpoint trend in SEER cancer incidence with

associated APC(%) for cancer of the breast between

1975-2010, All Races

Female

Trend Period

-0.5 1975-1980

4.0* 1980-1987

-0.2 1987-1994

1.8* 1994-1999

-2.3* 1999-2004

0.1 2004-2010

The joinpoint trend in US cancer mortality with

associated APC(%) for cancer of the breast


Female

Trend Period

0.4* 1975-1990

-1.8* 1990-1995

-3.2* 1995-1998

-1.9* 1998-2010

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http://seer.cancer.gov/statfacts/html/breast.html







Cancers of the colon and rectum (colorectal cancer) are the

fourth most common cancer diagnosed in men and the third most common in women

Colon and Rectum Cancer

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The joinpoint trend in SEER cancer incidence with associated APC(%) for cancer of the colon and rectum




0.8* 1975-1985 1.1* 1975-1985 0.3 1975-1985

-1.8* 1985-1995 -1.2* 1985-1991 -1.9* 1985-1995

1.5 1995-1998 -3.2* 1991-1995 1.8 1995-1998

-2.3* 1998-2008 2.0 1995-1998 -2.0* 1998-2008

-5.1* 2008-2010 -2.8* 1998-2008 -5.1* 2008-2010

-4.8* 2008-2010

Based on rates from 2008-2010, 1 in 21 men and women will be diagnosed with cancer of the colon and rectum

during their lifetime.

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http://seer.cancer.gov/statfacts/html/colorect.html















Distribution (%)

5-year



site)40 90.3


lymphnodes)36 70.4



1 in 21 men and women will be diagnosed with cancer of the colon and rectum during their lifetime.

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The joinpoint trend in SEER cancer incidence with associated APC(%) for cancer of the oral cavity and

pharynx between 1975-2010, All Races



0.7 1975-1981 -0.1 1975-1983 3.4 1975-1979

-1.1* 1981-2003 -1.5* 1983-2001 -0.8* 1979-2010

0.4 2003-2010 0.2 2001-2010

Oral cavity

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http://seer.cancer.gov/statfacts/html/oralcav.html






Distribution (%)

5-year



site)31 82.7


lymphnodes)47 59.2



1 in 92 men and women will be diagnosed with cancer of the oral cavity and pharynx during their lifetime

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Prostate - second most frequently diagnosed cancer and the sixth most common fatal cancer among men worldwide

The joinpoint trend in SEER cancer incidence with

associated APC(%) for cancer of the prostate


Male

Trend Period

2.6* 1975-1988

16.5* 1988-1992

-11.6* 1992-1995

2.4 1995-2000

-2.0* 2000-2010

The joinpoint trend in US cancer mortality with

associated APC(%) for cancer of the prostate


Male

Trend Period

0.9* 1975-1987

3.1* 1987-1991

-0.8 1991-1994

-3.8* 1994-2004

-3.1* 2004-2010

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http://seer.cancer.gov/statfacts/html/prost.html








Stage Distribution and 5-year Relative Survival by Stage at Diagnosis

for

2003-2009, All Races, Males


Distribution (%)

5-year


Localized (confined to

primary site)81 100.0

Regional (spread to

regional lymphnodes)12 100.0

Distant (cancer has

metastasized)4 27.9


1 in 7 men will be diagnosed with cancer of the prostate during their lifetime

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Worldwide incidence of prostate cancer -incidence trends largely by rates of PSA screening

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The joinpoint trend in SEER cancer incidence with associated APC(%) for cancer of the kidney and renal

pelvis between 1975-2010, All Races



2.3* 1975-1994 1.8* 1975-2004 2.7* 1975-1994

-0.6 1994-1997 4.2* 2004-2008 -0.9 1994-1997

3.2* 1997-2008 -3.0 2008-2010 3.4* 1997-2008

-3.4 2008-2010 -6.1 2008-2010

Kidney

The joinpoint trend in US cancer mortality with associated APC(%) for cancer of the kidney and renal pelvis




1.0* 1975-1994 1.1* 1975-1991 1.1* 1975-1994

-0.6* 1994-2010 -0.1 1991-2001 -0.9* 1994-2010

-0.9* 2001-201045

http://seer.cancer.gov/statfacts/html/kidrp.html















Distribution (%)

5-year



site)63 91.7


lymphnodes)17 64.2



1 in 62 men and women will be diagnosed with cancer of the kidney and renal pelvis during their lifetime

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cervix

The joinpoint trend in SEER cancer

incidence with associated APC(%) for

cancer of the cervix uteri between 1975-

2010, All Races

Female

Trend Period

-4.6* 1975-1982

-0.2 1982-1990

-2.5* 1990-2010

The joinpoint trend in US cancer

mortality with associated APC(%) for

cancer of the cervix uteri between 1975-

2010, All Races

Female

Trend Period

-4.3* 1975-1982

-1.6* 1982-1996

-3.7* 1996-2003

-1.1* 2003-2010

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http://seer.cancer.gov/statfacts/html/cervix.html







2003-2009, All Races, Females


Distribution (%)

5-year



site)47 90.9


lymphnodes)36 57.1



1 in 151 women will be diagnosed with cancer of the cervix uteri during their lifetime

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Worldwide incidence

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The burden of cancer worldwide varies across countries according

to differences in risk factors, detection practices, treatment

availability, age structure, and completeness of reporting.

Cancers related to infections account for about 28% of the cases in

developing countries and less than 8% of the cases in developed

countries.

Conclusion

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Cancers in developing countries more often result in death - generally

diagnosed at late stage and the resources for early detection and

treatment limited.

21% of the world population (most of whom are in the more affluent

world) is covered by population-based cancer registries with high-

quality incidence data for only 9% of the world population

expansions of registries in geographic coverage, quality, and scope

will be a necessary step in promoting cancer control programs

worldwide.

Conclusion

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Thank you 52

Epidemiology of cancer

Health & Medicine

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