Cervical screening is very important in the prevention of cervical cancer as cervical cancer has a long precancerous stage prior to becoming cancer and is one of the best examples of how screening prevents disease.
Cervical screening has shown to decrease the incidence of cervical cancer and the introduction of the HPV vaccine will decrease this further.
The incidence of cervical cancer in a female under the age of 25 is 4:100,000.
Types of screening methods
There are two systems in relation to screening the USA model where screening starts at 21 years and the UK system which starts at 25 years.
St Vincent and the Grenadines uses the USA model where screening begins at 21 and is done every 3 years to 29 years and then every 5 years till 65; an HPV test should be done from 30 years old. Yearly smears are not statistically significant and cost more in relation to preventing disease.
The aim of the screening is to prevent cervical cancer by picking up preinvasive disease (precancerous).
Liquid based cytology should be used as it is associated with less inadequate smears when compared to the traditional pap-smear.
Management/Treatment of abnormal Smears
There are several abnormalities that can be detected, these include borderline abnormality (ASGUS) which is a low grade abnormality, if there is a positive HPV along with the low grade abnormality the patient would need colposcopy, this is a procedure where a low powered microscope is used to look at the cervix and when acetic acid is applied it shows up abnormal cells on the cervix this is because abnormal cells have more protein in them and they stain whiter than the normal cells and the more abnormal the cell is the whiter it stains.
Mild abnormalities (mild dyskarosis) are referred to colposcopy and can either be biopsied within 2 years and conservatively managed or treated via freezing (Cryotherapy) or by heat treatment (Cold Coagulation).
Moderate and severe abnormalities should be treated by excisional techniques at the first visit (see and treat) when the patient comes to their colposcopy appointment, a procedure called a LLETZ where some cervical issue is removed.
The LLETZ procedure has a small risk of preterm labour in subsequent pregnancies but these pregnancies should be screened with cervical length ultrasounds in early pregnancy to detect those patients at risk.
In conclusion, cervical screening is very important in the prevention of cervical cancer and colposcopy is used to investigate abnormal smears.
Patients should be adequately counselled about the benefits and risks of these procedures to make an informed decision with the aim to decrease their risk of developing cervical cancer.
Dr John Barker Bsc MBBS MRCOG, Dip (Risk Management) is an Obstetrician/Gynaecologist at Arnos Vale Medical Center, Consultant Obstetrician/Gynaecologist UK
He has completed the Advanced Training Skills Module in Gynaecological Oncology in the UK and runs gynaecological oncology clinics for diagnosis and management of suspected and confirmed female genital cancers.