1. Ataur Rahman
Visual Inspection Aided with Acetic Acid (VIA):
A Feasible Approach for Cervical Cancer
Screening in Bangladesh
12th Annual Scientific Conference at ICDDR’B
Dhaka, Bangladesh
9-12 February 2009
2. Cervical Cancer: Magnitude of the Problem
• Cervical cancer is the third most common cancer
worldwide
• Globally 493,000 new cases identified each year
• 83% of the new cases occur in developing
countries
• India alone reported 132,000 new cases in 2002
• Globally at least 274,000 women die of cervical
cancer each year
sources: Ferlay J et al. Globocan 2002
3. Cervical Cancer: Bangladesh
• Leading cause of deaths of all cancer deaths among
women
• Population based studies on cervical cancer are rare
• Hospital data suggests that 25% of all cancer deaths
for women are due to cervical cancer
• No screening system available in present health
system
7. Natural History of Cervical Cancer: Current Understanding
Normal Cervix
HPV-related Changes
Low-Grade Lesion (mild dysplasia)
High-Grade Lesion (severe dysplasia)
Invasive Cancer
About 60%
regress within
2-3 yrs
HPV Infection
About 15% progress within 3-4 yrs
30% - 70% progress within 10 yrs
Source: PATH 1997
8. Limitations of Pap Smears for National Screening
Programs
• Pap smear-based programs require complex logistics,
advanced training, and well managed program
implementation for adequate testing to occur.
• These elements are not available outside large cities in
many low-resource settings.
• Even in large cities, quality Pap smears are possible but
ongoing supervision, refresher training and continued
supplies are not adequate.
• Cytology is not viable as a nationally accessible
screening method in many developing countries.
9. Other Cervical Cancer screening methods
• Visual Inspection aided with acetic acid (VIA)
• Visual Inspection with acetic acid and
magnification (VIAM)
• Cervicography
• Automated Pap smears
• Molecular (HPV/DNA) tests
• Colposcopy
10. Visual Inspection Aided with Acetic Acid
• Looking at the cervix to detect abnormalities after
applying acetic acid
• Acetic acid is used to enhance and “mark” the
acetowhite change of a precancerous lesion or actual
cancer
11. Equipment and material needed for VIA
VIA can be performed in any clinical setting where the
followings are available
• Adequate light source to look at the cervix and
examining its details
• Vaginal speculum, swabs and examination gloves
• Table permitting the examiner to insert the speculum
and view the cervix
• Freshly prepared acetic acid (3-5%, vinegar)
12. Visual Inspection aided with Acetic Acid
Aceto-white lesion with punctation: a pre-cancerous condition
13. Visual Inspection aided with Acetic-Acid
Aceto-white lesion with punctation: a pre-cancerous condition
14. Objectives of the study
To calculate the sensitivity, specificity and positive
predictive values of VIA and Pap smear using
colposcopy with biopsy as the reference test.
To evaluate women’s knowledge and attitude
towards cervical cancer and its prevention through
a screening test in study population.
15. Method and study locations
A cross-sectional population based study compared two
screening systems for cancer cervical
All ever married women attended in one Urban clinic and
resided in two rural locations (‘Modonpur’ and ‘Dhamgor’
Unions) were invited to perform VIA and Pap Smear tests
All VIA or Pap smear positive and every tenth VIA
negative women were sent to a tertiary level hospital for
reference test
16. Positive for Pap Smear
Low-grade intraepithelial lesion or more which correspond
CIN I to CIN III (including carcinoma in situ)
Abnormal finding which corresponds detection of one or
more of the following lesions:
Aceto-white lesion, White plaques, Ulcer, Cauliflower-like
growth, fungating mass
Outcome measures
Positive for VIA
17. Reference test was
Colposcopy with biopsy (where indicated)
• Positive for reference test
- a low threshold of low-grade squamous intraepithelial
lesion (LGIL)
- a high threshold of high-grade squamous
intraepithelial lesion HGIL
18. Number of women participated in different stages
Women
- listed as eligible 8036
- Came to health centre for participation 3290
- Went for VIA screening 2954
- Went for Pap smear collection 2724
Women conducted reference test
As they were VIA positive 288
As they were VIA negative 366
As they Pap positive 10
Women conducted gold test 654
19. Sensitivity and Specificity of VIA
In detecting at least low-grade lesion
95% CI
Sensitivity 68.0% 59 – 76%
Specificity 61.0% 57 – 65%
In detecting high-grade lesion
Sensitivity 79.0% 63 – 90%
Specificity 57.4% 53 – 61%
20. Sensitivity and Specificity for Pap smear
In detecting at least low-grade lesion
95% CI
Sensitivity 2.0% 0.3 – 8.0%
Specificity 98.4 96.2– 99.6%
21. Findings from other studies on Pap Smear
• One meta-analysis, combined data from 59
studies of Pap smear estimated
Sensitivity 11 to 99%
Specificity 14 to 97%
• Pap test was unable to achieve concurrently high
sensitivity and specificity
• Specificity 90-95% correspond to sensitivity 20-
30%
(Fahey MT, 1995)
22. Inter-observer variation of VIA performance
Level
%
95% CI Background of paramedics
Paramedic 1
Sn
Sp
58.3
64.3
45 -71
57 -71
No formal training, worked as
nurse 10 yrs. in a clinic, used to
do PV
Paramedic 2
Sn
Sp
71.4
71.4
52 – 82
58 - 82
With 18 months formal
training, 7 yrs. working
experience, used to do PV
Paramedic 3
Sn
Sp
65.4
64.2
49 – 83
55 -73
Had 6 weeks training on Pap
Smear, worked 3 yrs. in a
diagnostic clinic, used to do PV
