CERVICAL CANCER SCREENING IN RESOURCE-POOR SETTINGS EVIDENCE FROM NICARAGUA AND KENYA

CERVICAL CANCER SCREENING
IN RESOURCE-POOR SETTINGS
EVIDENCE FROM NICARAGUA AND KENYA
Doctoral Thesis submitted to the Faculty of Medicine and Health Sciences
by Patricia Claeys
Promotor: Prof Dr Marleen Temmerman
Dept of Obstetrics and Gynaecology, Ghent University
Co-promotor: Prof Dr Patrick Van der Stuyft
Dept of Public Health, Ghent University

STRUCTURE
Preface ........................................................................................................................................................................... 1
I. Introduction.................................................................................................................................................................. 3
1. Magnitude of the problem............................................................................................................................... 4
2. Aetiology and natural history........................................................................................................................... 7
3. Pathogenesis.................................................................................................................................................. 9
4. Classification................................................................................................................................................. 10
5. Risk factors................................................................................................................................................... 11
6. Aim and rationale for screening.................................................................................................................... 12
7. Screening tests............................................................................................................................................. 13
8. Vaccine development.................................................................................................................................... 15
9. Management of cervical dysplasia................................................................................................................ 16
10. Is screening for cervical cancer effective ?...................................................................................................17
11. General principles of cervical cancer screening............................................................................................ 19
12. Cost effectiveness of cervical cancer screening...........................................................................................21
13. Issues in cervical cancer screening in Developing Countries.......................................................................24
14. Reference list................................................................................................................................................ 28
II. Objectives and methodology .................................................................................................................................... 35
1. General objective.......................................................................................................................................... 37
2. Specific objectives......................................................................................................................................... 37
3. Study sites and study development.............................................................................................................. 38
4. Study design including data collection..........................................................................................................40
5. Dissemination of results................................................................................................................................ 42
III. Results..................................................................................................................................................................... 45
III-1. Prevalence and risk factors of cervical neoplasia in Nicaragua...........................................................................45
III-2. Determinants of cervical cancer screening in a poor area.................................................................................... 55
III-3. Successful involvement of community health workers in the promotion of cervical cancer screening................. 69
III-4. Performance of screening tests............................................................................................................................83
III-4-1. Performance of screening tests in research conditions..................................................................................... 83
III-4-2. Performance of the acetic acid test in field conditions....................................................................................... 99
III-4-3. Improving quality of cytology........................................................................................................................... 111
III-5. Decentralising diagnosis and treatment.............................................................................................................. 121
III-6. Integration of cervical screening in family planning clinics................................................................................. 131
IV. Discussion............................................................................................................................................................. 141
1. Contribution of this work to the field............................................................................................................ 143
2. Relevance of cervical cancer screening programmes in low resource settings.......................................... 144
3. Strategies to reach high-risk groups for screening...................................................................................... 145
4. Selection of a screening test in resource-poor settings.............................................................................. 146
5. Options for service delivery......................................................................................................................... 148
6. Overall conclusions.....................................................................................................................................149
7. Reference list.............................................................................................................................................. 151
V. Executive summary................................................................................................................................................ 153
1. Context and objectives................................................................................................................................ 155
2. Results........................................................................................................................................................ 155
3. Discussion and conclusions........................................................................................................................ 158
VI. Samenvatting ........................................................................................................................................................ 159
1. Achtergrond en objectieven........................................................................................................................ 161
2. Resultaten...................................................................................................................................................162
3. Discussie en conclusies.............................................................................................................................. 165
VII. Abbreviations........................................................................................................................................................167
Acknowledgements.....................................................................................................................................................171

PREFACE
During nearly ten years’ residence in Nicaragua in the period 1985-1994, I
participated, in the health centre, in the examination of thousands of women for
early detection of cervical cancer. Despite the active collaboration of many health-
care workers, each year a number of women of the village died from the disease. As
a clinician I did not question this. At most, I was a bit surprised that the
Papanicolau smears were always reported as being normal.
Later, studying for my masters in public health, I started understanding why our
attempts to prevent women developing cervical cancer were unsuccessful. And
when - almost by coincidence - I started working as a researcher, I decided to study
this in more depth. If cervical cancer is a disease that can be prevented, why are
there nearly 500 000 new cases reported per year ?
And why do the majority of these women live in developing countries ? Is it possible
and feasible to detect and to manage cervical cancer in time in resource-poor
settings ? And how ? The operational research presented in this work tries to
formulate a number of answers to these questions. It is an undertaking that is
carried out with many others and that is certainly not finished, the problems being
too extensive and too diverse. But I dare to hope that the work presented here
contributes to the efforts to improve the reproductive health of women, especially in
developing countries.
1