The availability of data on risk factors associated with cervical cancer

Home / The availability of data on risk factors associated with cervical cancer

Ailsa Baker1

1Faculty of Health, Medicine and Life Sciences, Maastricht University, The Netherlands.

 

Corresponding author: Dr. Ailsa Baker
Address: Department of International Health, School for Public Health and Primary Care (CAPHRI), Faculty of Health, Medicine and Life Sciences, Maastricht University, The Netherlands;
Telephone: +31617938236; E-mail: a.baker@student.maastrichtuniversity.nl

 

Abstract

Cervical cancer is a prominent public health problem in Europe. In 2012 it caused an estimated 12,977 deaths in the European Union (EU). Incidence and mortality from cervical cancer vary across Europe, with Romania having the highest estimated incidence and mortality rate in the EU in 2012. The significant health threat caused by this disease highlights the need for a comprehensive cervical cancer prevention programme to be fully developed and implemented throughout the EU. Collecting and analysing data on risk factors associated with cervical cancer is a crucial first step to developing a prevention programme. The following risk factors for cervical cancer are discussed in the literature: Human papillomavirus (HPV) infection; smoking; having human immunodeficiency virus (HIV) or another condition that makes it difficult to fight infection; using birth control pills for a long time (five or more years); giving birth to three or more children and having several sexual partners.The goal of this paper is to assess the availability of data in the form of indicators, on risk factors associated with cervical cancer. The first research question addressed is: “What indicators are available in international health databases?” Using Romania as an example, the second research question is: “Do the identified indicators provide data on Romania?” The European Health for All Database (HFA-DB), The Organisation for Economic Co-operation and Development (OECD) and Eurostat are three core international health databases that were used to address the research questions. The results showed indicators were available on smoking, having HIV and giving birth to three or more children. However, not every indicator that was available provided data on Romania. No indicators were available on HPV infection, contraceptive use or having several sexual partners. These results indicate a lack of available indicators related to risk factors associated with cervical cancer in HFA-DB, OECD and Eurostat. In addition, the identified gaps in the availability of data, with regards to Romania, could be detrimental to the development of a comprehensive national cancer prevention programme. .

Keywords:  cervical cancer, data availability, health for all database, Romania.

Introduction

Cervical cancer is the second most common cancer affecting women globally (1). It is a prominent public health problem in Europe, causing an estimated 12,977 deaths in member states of the European Union (EU) in 2012 (2). The incidence and mortality rate among countries in the EU and the World Health Organisation (WHO) European Region differ markedly (3). There are higher rates of incidence and mortality in Central and Eastern Europe compared to countries in Western Europe (3). As illustrated in Figure one, the average estimated incidence rate of cervical cancer in the EU in 2012 was 11.3 per 100,000 (4). Switzerland had the lowest estimated incidence rate of 4.2 per 100,000 in Europe in 2012 (2). Romania, conversely, had the highest estimated incidence rate of 34.9 per 100,000 (4). The estimated mortality rate in Romania of 14.2 per 100,000 in 2012 was significantly higher than the EU estimated average of 3.7 per 100,000 (4). The incidence of cervical cancer in Romania is rising, in contrast to a general trend of reducing incidence in Europe (5). Nessa Childers, Vice President of the Members of European Parliament against Cancer (MAC), explains that the disparity in Europe is “a result of a lack of properly organised prevention programmes and allocation of financial resources” (5).Risk factors associated with cervical cancer are clearly outlined by the Centers for Disease Control and Prevention (CDC). These include: human papillomavirus (HPV) infection; smoking; having human immunodeficiency virus (HIV) or another condition that makes it difficult to fight infection; using birth control pills for a long time (five or more years); giving birth to three or more children and having several sexual partners (6).It has been established through research that HPV infection is the main risk factor for developing cervical cancer (7). More than 100 types of HPV exist (7). Type 16 and 18 cause approximately 70% of all cases of invasive cervical cancer worldwide (8,9). The risk of developing cervical cancer could be further increased by additional risk factors. Tobacco smoking has been linked with an increased risk of developing cervical carcinoma in situ and squamous cell carcinoma of the cervix (10,11). There is inconsistency in the literature regarding the exact number of years of oral contraceptive use and the number of births that would place a women at an increased risk of developing cervical cancer (9,10). Infection with Chlamydia Trichomatis or Herpes Simplex-2 have also been suggested to increase the risk of developing cervical cancer (10,12). Conversely, consuming foods rich in vitamin C and beta carotene have been suggested to reduce the risk (7).

Figure 1. Estimated Incidence and Mortality Rates from Cervical Cancer in Europe, 2012. Source: European Cancer Observatory (2)

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 One of the key strategies to reducing the incidence and mortality from cervical cancer is establishing an effective prevention programme (5). Figure two outlines a framework for developing a comprehensive cancer prevention programme (13). Analysing data on risk factors responsible for developing cancer is a crucial element of the first phase.

figure2framework_for_comprehensive_cancer_prevention_and_control_programme

Primary prevention of cervical cancer focuses on preventing initial infection with HPV. Currently, the WHO recommends primary prevention of cervical cancer to involve vaccinating girls who have not yet become sexually active (14). The current guidelines advise vaccinating girls between nine and thirteen years old (1,14). Looking specifically at Romania, the HPV vaccination programme was initially introduced in 2008 (15). However, this programme suffered poor uptake and nationwide coverage despite providing vaccination free of charge to the target population (females aged nine to twelve years old) (15). The vaccination programme was re-launched in February 2010, provoking a mainly negative reaction from the general public and consequent low coverage of the target population (15). The programme was discontinued in 2011, but was launched for the third time in April 2013 (15).

Secondary prevention of cervical cancer involves cytological evaluation of the Papanicolaou smear (Pap smear) (1,14). This allows detection of cytological abnormalities at the earliest possible point (1,14). Currently, the WHO recommends that secondary prevention commences in women over the age of thirty (1).

Representatives of the European Commission state that well-organised prevention programmes, that involve comprehensive treatment and follow-up of patients with abnormal cervical cytology, have proven to reduce the incidence of cervical cancer by at least eighty percent (5). A key element of well-organised prevention programmes that achieve high coverage is their ability to reach women who are at risk of cervical cancer. Opportunistic screening, on the other hand, is less successful at reaching this at risk group (5). According to expert opinion, the majority of cervical cancer screening in Romania is opportunistic (5).

The European Institute of Women’s Health (EIWH) calls for the development of a comprehensive European framework for cervical cancer prevention and for immediate action to be taken to develop and implement effective prevention programmes throughout the whole of the EU (5).

The goal of this paper is to assess the availability of data in the form of indicators, on risk factors associated with cervical cancer because gathering knowledge is a crucial first step in the development of a prevention programme. The first research question addressed is: “What indicators are available in international health databases?” The second research question is: “Do the identified indicators provide data on Romania?” The example of Romania is discussed in this paper as the availability of data on risk factors would be particularly important for developing prevention strategies in Romania as it has the highest estimated incidence and death rate from cervical cancer in Europe (2).

 

Methods

The CDC outlines six distinct risk factors associated with cervical cancer, as highlighted in the introduction. The availability of indicators reflecting these risk factors was assessed on three core international health databases: European Health for All Database (HFA-DB), Organisation for Economic Co-operation and Development (OECD) and Eurostat.

These three international health databases were selected as they provide data for countries in the EU and WHO European Region. HFA-DB is part of the WHO (16). Eurostat is the main statistical office of the EU and part of the European Commission(16,17).The OECD receives input from the European Commission. It provides statistics on health and healthcare systems for the 34 member countries (18).

The online version of the HFA-DB was accessed on 18th September 2013. Individual indicators, definitions and the source of each individual indicator were accessed on the online version of the database. In order to identify the most recent data on Romania, a retrospective search was performed. The search started in 2012 and concluded in 1997. The search was not extended beyond 1997 because indicators did not provide any data on Romania prior to this date.

The OECD database was accessed on 22nd September 2013. Individual indicators were identified under the health theme. The definition of each indicator and data source was outlined on this online database.

Eurostat was accessed on 25th September 2013. All available indicators were identified under the population and social conditions theme. The definition of each indicator and data source was outlined in the reference metadata section.

 

Results

Table two outlines the available indicators identified in each of the three international health databases. Table two also displays the definition of each indicator; the availability of data on Romania and the source of this data. When an indicator provides data on Romania, the most recent year of data available is also recorded.

A search of the three international health databases showed there were no available indicators for the three following risk factors: HPV infection; using an oral contraceptive for five years or more and having several sexual partners. Data could not be obtained for Romania because these indicators were not available.

Smoking was the risk factor with the most abundant number of indicators. Seven indicators were identified across the three internal health databases. Two indicators were identified in HFA-DB, three in OECD and two in Eurostat. Out of a total of seven indicators, only four indicators provided data specifically on the female population. These were: percentage of regular smokers, aged 15 years or older and female (provided by HFA-DB); percentage of females aged 15 years or older who are daily smokers (provided by OECD); daily cigarette smokers who are female (provided by Eurostat) and female smokers by number of cigarettes (provided by Eurostat). Data on Romania was available in three of these four indicators, as illustrated in table two. The most recent data available for women who smoke in Romania was in 2012. This was provided by the indicator: percentage of regular smokers, aged 15 years or older who are female (provided by HFA-DB). The source of data was different for the above mentioned indicators. The global adult tobacco survey provided data for the indicator in HFA-DB, whilst the European health survey provided data for the two indicators in Eurostat. No data was provided on Romania in any of the smoking indicators within OECD.

Only one indicator was identified in relation to incidence of HIV. This was only available in one out of the three databases. No indicators on HIV prevalence were identified in the international health databases. Data on HIV incidence in Romania was available for 2011 in HFA-DB. Data for Romania came from two possible sources, as detailed in table two.

Total fertility rate was used to represent the risk factor of having given birth to three or more children. This indicator was available in HFA-DB and Eurostat. Both databases provided data for Romania. The definition of this indicator differed slightly between the databases and it is unclear if the data sources were the same for each indicator. Eurostat provided the most up to date data on total fertility rate in Romania.                                                                                                                            

                                                                                                                                             

                                                            Table 1. Key for Results

 

Abbreviation

Description

Risk Factor A

HPV Infection

Risk Factor B

Smoking

Risk Factor C

Having HIV

Risk Factor D

Using oral contraceptive for 5  years or more

Risk Factor E

Having given birth to three or more children

Risk Factor F

Having several sexual partners

n/a

not available

*

indicator not adjusted for sex

 

 

Table 2. Indicators for Risk Factor Associated with Cervical Cancer: The example of Romania [Source: HFA-DB, OECD and Eurostat (17,19,20)]

Risk Factor

Database where a relevant indicator is available

Indicator

Definition of indicator provided by database

Data available for Romania

Source of indicator for Romania

Most recent year of data available

A

n/a

n/a

n/a

n/a

n/a

n/a

B

HFA-DB

Percentage of regular smokers, age 15+, female

No clear definition provided

Yes

Global adult tobacco Survey- Romania 2011

2012

HFA-DB

Number of cigarettes consumed  per person per year*

Total number of cigarettes sold/ consumed in the country. Calculated from official national statistics on production, import and export of cigarettes.

Yes

Tobacco Journal International

1997

OECD

Grams per capita (15+)*

Annual consumption of tobacco items (e.g. cigarettes, cigars) in grams per person aged 15 years old or more.

No data available from 1960

n/a

n/a

OECD

Cigarettes per smoker per day*

The average number of cigarettes per smoker per day.

No data available from 1960

n/a

n/a

OECD

Percentage of females aged 15+ who are daily smokers

Daily smokers is defined as the percentage of the population aged 15 years old or over who report

that they are daily smokers. 

No data available from 1960

n/a

n/a

Eurostat

Daily cigarette smokers, female

Proportion of female people reporting to smoke cigarettes daily

Yes

European Health Interview Survey

2008

Eurostat

Smokers by number of cigarettes, female

Proportion of female persons who smoke less / more than 20 cigarettes per day

Yes

European Health Interview Survey

2008

C

HFA-DB

HIV incidence per 100 000*

Number of new persons to whom HIV seropositive test was found during the calendar year.

Yes

Strategic Health Authority (SHA) unit at WHO/EURO or from the European
Centre for AIDS monitoring in Paris.

2011

D

n/a

n/a

n/a

n/a

n/a

n/a

E

HFA-DB

Total Fertility Rate

The average number of children that would be born per woman if all women lived to the end of theirchildbearing years and bore children according to a given set of age-specific fertility rates

Yes

Data usually provided by Central Statistics Office. Additional sources are the report of the World Bank, United Nations Development Programme and country statistical yearbooks.

2010

Eurostat

Total Fertility Rate

The mean number of children that would be born alive to a woman during her lifetime if she were to pass through her childbearing years conforming to the fertility rates by age of a given year

Yes

National Statistics Institutes

2011

F

n/a

n/a

n/a

n/a

n/a

n/a

                                   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 

 

 

 

 

 

 

Discussion

The results from a search of three international health databases showed there were indicators available for three out of the six risk factors associated with cervical cancer: smoking, HIV, and giving birth to three or more children. One can conclude from these findings that indicators reflecting the risk factors associated with cervical cancer are not readily available on these international health databases. In addition, data on Romania was not provided by all the available indicators, highlighting a gap in data availability.

Infection with HPV is pivotal to the development of cervical cancer. One of the main findings in this paper was the lack of availability of indicators on HPV infection. Ideally, data on the incidence, prevalence and type of HPV infection within female populations would be available and provided on international databases. This is highlighted as an important area for further research due to its key role in cervical cancer development. One suggestion for addressing this lack of data would be to regard HPV vaccination as a protective factor for developing cervical cancer. As a result, not having the HPV vaccine could be considered a risk factor for developing cervical cancer. Consequently, data on HPV vaccination uptake and coverage could be indicators utilised in international health databases. However, it is important to highlight that HPV vaccines do not provide protection from all types of HPV and there is still a great deal of controversy regarding the vaccine, undoubtedly affecting its rate of uptake (21).

There were notable limitations to this study. One of the limitations was that three of the indicators for smoking were not adjusted for sex. As a result, these indicators could not be used reliably for analysing cervical cancer risk factors as the data would not solely represent the female population. Another potential limitation was the discrepancy amongst the databases in the source of data for the indicators. Taking one individual indicator into consideration, this is unlikely to pose a significant problem. However, with multiple indicators for a single risk factor (as seen with smoking), the different sources of data are likely to produce differing results, potentially limiting the accurate identification of risk factors.

Another challenge encountered in this study was the lack of indicators outlining the years of contraceptive use and number of sexual partners. Both these quantifiable variables could theoretically be collected. However, the lack of data on international databases suggests that this data is not available at a national or local level. Collecting data on the number of sexual partners could be a particular challenge due to the sensitive nature of this topic. However, this is an area that has been highlighted for further research as it could aid identification of the population at risk of cervical cancer.

In order to deliver a well-suited prevention programme or to implement policy change, it is essential that data on risk factors are as current as possible. The most recent available data for Romania ranged from 2012 back to 1997. This inconsistency may result from different sources and methods used for data collection. It is clear that the lack of current data on these international databases could be a hindrance to the initial phase of developing an effective prevention programme.

This paper has identified the lack of available indicators reflecting the risk factors associated with cervical cancer in HFA-DB, OECD and Eurostat. In addition, the identified gaps in the availability of data, with regards to Romania, could be detrimental to the development of a comprehensive national cancer prevention programme. Future research on international, national or regional levels is required to fully assess the risk factors associated with cervical cancer and henceforth suitably inform policy formation. .

Conflicts of interest: None declared.

 

References

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