Transcript CERVICAL CANCER SCREEN IN A RURAL SET UP

Screening for
Cervical Cancer
by
Visual Inspection Techniques
Dr Aruna Batra
VMMC & SJH
Cervical Cancer- Facts
• A significant public health problem
• 2nd commonest cancer in ώ worldwide
• Annually 3,70,000 new cases of cervical
cancer, 80% in developing countries
• Leading cause of death in developing countries,
often killing women at young ages
Cervical Cancer- Facts
• Cause: virtually all cases of cervical
cancer are caused by persistent cervical
infection with some types of Human
Papilloma Virus (STI)
• Develops slowly, has a detectable and
treatable precancerous stage
• Preventable disease
Cervical Cancer- Why preventable?
Easy accessibility of Cx & TZ
Natural History of Cervical Cancer
Normal Cervix
About
60%
regress
within
2-3 yrs
HPV Infection
HPV-related Changes
Low-Grade SIL
15% progress êin 3-4 yrs
High-Grade SIL
30 - 70% progress êin 10 yrs
Invasive Cancer
Cofactors
High-Risk HPV
Cervical Cancer- Risk Factors
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Early age at marriage
Multiple sexual partners
Sexually transmitted infections
Poor socio-economic status
Smoking
Immunological factors
Prevention of Cervical Cancer
• Primary prevention:
– Education to ↓ high risk sexual behaviour
– Measures to avoid exposure to HPV & STIs
• Secondary prevention:
– Detection & Treatment of precancerous
lesions before they progress to cervical cancer
Cervical Cancer Screening
Methods available
• Papanicolou smear (cytology)
• Visual Inspection techniques
• Colposcopy, Cervicography
• Molecular (HPV DNA) tests
Limitations of Pap Smears for
National Screening Programs
• Primary screening is repetitive,
labour intensive, time consuming
• Subject to errors of interpretation
• Sensitivity 60-70%
• Complex logistics, advanced
training, good program
implementation required
Limitations of Pap Smears for
National Screening Programs
• Pap Smear as a screening methods may
not be appropriate or adequate for many
low-resource settings
• Even in large cities, quality Pap smears
possible but require ongoing supervision,
refresher training & continued supplies.
Cytology is not viable as a nationally accessible
screening method in many developing countries
Visual Inspection Techniques
* Unaided Visual Inspection
* Visual inspection with acetic acid (VIA)
* Visual inspection with acetic acid and
magnification (VIAM)
* Visual inspection with Lugol’s Iodine (VILI)
Unaided Visual Inspection of Cervix
- Dx at stage III & IV
↓from 85% to 55%
- Dx at stage I & II: ↑
from 15% to 45%
Kerala Study 1977-87
Unaided Visual Inspection of Cervix
- 60% of Early disease could be identified
- 11% were false positive
- Only 15-20% of pre-cancerous lesions
could be detected
Singh V et al 1992
Good for Clinical Down staging
Misses Precancerous lesions
Visual inspection with acetic acid
VIA
• Looking at the cervix
to detect
abnormalities after
applying acetic acid
• Acetic acid is used to
enhance and “mark”
the aceto-white
change of a precancerous lesion or
actual cancer
VIA- Basis
• Produced due to osmolar changes after
acetic acid application, causing water of
the cell to leave
• Collapse of the cell membrane around
the abnormal and enlarged nucleus
• Altered lesion appears white due to
reflection of the incidental light
VIA positive
HPV lesion
Dysplastic lesion
VIA Negative
Normal Cervix
VIAM (Visual Inspection with Acetic
Acid Using Magnification)
• VIAM is visualization of cervix after application of
acetic acid using low power magnification (2.5x
to 4x)
Magnascope (4X)
VILI
Positive
Normal squamous epithelium
Negative
Columnar epithelium
Comparison of Screening Methods
Method
Sensitivity (%)
Specificity (%)
Cytology
45-85
80-98
VIA
60-90
66-96
HPV DNA
65-95
70-96
NEJM Nov17,2005
Screening Costs
Ca Cx prevention in Thailand:
Single visit: VIA & Cryosurgery
• 5999 women tested by VIA
-13.3% VIA + counseled for immediate Cryo
- Accepted by 98.5%
- Minor side effects: 2.2%, Major Cp: nil
- 83.2% came for follow up, > 95% satisfied
Safe, acceptable, feasible
RTCOG: Lancet 2003; 361: 814-820
Visual Inspection Techniques
in Low resource setting
• Noninvasive, easy to perform, inexpensive
• All requirements are available locally
• Can be performed by all levels of
healthcare workers, in almost any setting
• Results are available immediately
• Initial treatment can be provided at the
time of the examination
Conclusion
RCH program can act as a powerful tool in
preventing Cervical cancer:
* Creating Awareness
* Using Simple Screening methods