cervical cancer epidemiology of a chronic disease exercise by mary murphy april 2008

Cervical Cancer

Epidemiology of a Chronic Disease Exercise

By Mary Murphy April 2008

What is the clinical problem?• Epidemiological classification:

Cancer/neoplastic disease

• Site: neck of the womb referred to as the Cervix.

• The outer and inner cells of the cervix can become cancerous leading to squamous cell cervical cancer or adeno-carcinoma of the cervix. The former, acccountable for 90-95% cervical cancers.

The transformation zone is the area where cells are most likely to be abnormal and is the site where cervical screens are taken.

Above: diagram female reproductive system

Source: http://www.cancerhelp.org.uk assessed 28/3/08

http://www.cancerhelp.org.uk/

POPULATION AT RISK?

How big is the problem?World: “Cervical cancer accounts for 1 in 10 of all cancers

diagnosed and more than 273,000 deaths in women worldwide every year……In developing countries, cervical cancer is the commonest cancer to affect women, and contributed to 85% of new cases and

deaths worldwide in 2002….”

• Source:http://www.thelancetstudent.com/2007/10/08/reducing-the-burden-of-cervical-cancer-in-the-developing-world/The accessed 14/4/08

UK: About 2,700 women are diagnosed with cervical cancer each year. Overall, 2 out of every 100 cancers diagnosed in women are cervical cancers. But it is the second most common cancer in women under 35 years

old. In 2005 UK had 8 in 100,000. Source:http://www.cancerhelp.org.uk/help/default.asp?page=2755#common accessed 16/4/08

Treatment for Cervical Cancer

• Hysterectomy.

• Radical trachelectomy.

• Radiation.

• Chemotherapy

• Source: http://www.cnn.com/HEALTH/library/DS/00167.html accessed 29/3/08

Risk Factor & Co-factors

Infection with some types of HPV virus• Low socio-economic status• Long-term use of hormonal contraceptives,• high parity, • tobacco smoking, • co-infection with HIV• Other STD infections• Large number of sexual partners• Sexually active before age 18• Early menarche

…….But the real villain

• 99.7% cases caused by Human papillomavirus (HPV). HPV 16 & 18 especially assocated with cervical cancer.

– HPV is a very common virus transmitted through direct transmission person to person, to both men and women

– Up to 75% of people of reproductive age will be infected with HPV at some point in their lives. Majority of women will not get cervical cancer. Cervical cancer is rare while HPV infection is common.

Source: http://www.jotrust.co.uk accessed 28/03/08

Ten most frequent HPV types in women with invasive cervicalcancer in United Kingdom

as compared to Northern Europe and the World

WHO/ICO Information Centre on HPV and Cervical Cancer (HPV Information Centre). Summaryreport on HPV and cervical cancer statistics in United Kingdom. 2007. [6/4/08].

Available at www. who. int/ hpvcentre

Prevalance of Cervical Cancer

Source: http://info.cancerresearchuk.org/cancerstats/types/cervix/incidence/?a=5441#age assessed 30/3/08

Incidence Rates of Invasive Cervical Cancer


Invasive Cervical cancer incidence by age

Source:http://info.cancerresearchuk.org/cancerstats/types/cervix/incidence/?a=5441#age accessed 30/3/2008

Mortality Rates for Cervical Cancer 2005


UK Cervical Cancer Incidence & Mortality

Source: Office for National Stats. Bulletin: 2007/14/HSCIC –Cervical Screening Programme England 2006-07

Cervical cancer mortality trends


0 10 20 30 40 50

Western AsiaAustralia/New Zealand

Eastern AsiaNorthern AmericaNorthern EuropeWestern EuropeSouthern Europe

Northern AfricaEastern Europe

WorldSouth-Eastern AsiaSouth Central Asia

Middle AfricaSouth AmericaWestern Africa

Central AmericaCaribbean

Southern AfricaEastern Africa

Rate per 100,000 population

IncidenceMortality


Age-standardised incidence &

mortality rates,

Of cervical cancer by region of the

world, 2002 estimates

European age-standardised incidence of and mortality,cervical cancer by deprivation category, England

and Wales, 1990-93

0

5

10

15

20

25

30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Deprivation category

Rat

e p

er 1

00,0

00 w

om

en

incidence mortality

Affluent Deprived


The graph below shows the incidence rates in the U.S. for cervical cancer from 1975–2004 by race and ethnicity.

Cervical Cancer

‡Source: Surveillance, Epidemiology, and End Results (SEER) Program, National Cancer Institute, NCI accessed 16/4/08

Secondary prevention -Cervical Screening

• Screening ages (years) 25-64; (previously 20-65) 3.4m screened 06/07

• Screening interval (years) 3 years for ages 25-49, every 5 years for ages 50-64

• • Lifetime number of recommended smears 12?

• 79.2% in 2006 of eligible women had Pap test in last 5 years. Compared with 79.5% last year and 82% in 1997

• Smear taker - General practitioners or general practicenurses

• Cervical screening - including the cost of treating cervical abnormalities - has been estimated to cost around £157 million a year in England

Sources: Office for National Stats. Bulletin: 2007/14/HSCIC –Cervical Screening Programme England 2006-07 & http://www.cancerscreening.nhs.uk/cervical/ accessed 6/4/08

Primary prevention – HPV Vaccine

• difficult to prevent HPV infections. Most adults will have had HPV at some time in their lives. Direct Transmission mode person to person

• Condoms are not effective - because HPV has a field effect, it found on skin not covered by the condom and skin-to-skin contact transmits HPV.

• Available vaccines for HPV 16 & 18. They may provide protectection against a few other types, but not all types of HPV.

• Cost - £100m a year routine programme vaccinate girls 12-13 from September 2008

• Catch up programme £200m over 2009/10 and 2010/11.

HPV VACCINE ISSUES

• Very expensive

• Targeted vs. universal vaccinations

• the age and gender of vaccine recipients

• the acceptability of this vaccine to health care providers, adolescents, and parents

• the effect of this vaccine on cervical cancer screening.

About Data from Cancer Registries!!

• It is dynamic and only ever a snapshot in time.• It is mandatory for deaths to be registered within

five days. • It is not mandatory for incidence data to be

reported. It comes from a number of sources, it is usually 2 years

• National coverage in UK was not achieved until 1962

……………and lots of other things too!!

New – Invasive Cancer Audit

• Future Developments - For all newly diagnosed cervical cancers a review will be conducted of a woman’s complete screening history by Quality Assurance Reference Centres across England.

• It’s purpose - to measure the effectiveness of cervical screening programme, to identify areas of good practice and identify where improvements can be made

Thank you for listening!

cervical cancer epidemiology of a chronic disease exercise by mary murphy april 2008

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