Why the LBC/HPV CO-TEST is the preferred screening method.

Cervical cancer screening is the process of detecting and removing abnormal cells in the cervix before cervical cancer develops. Screening methods include:

• Pap test (also known as Pap smear)
• Liquid Based Cytology (LBC)
• Human Papillomavirus (HPV) DNA testing
• Visual inspection with acetic acid (VIAA)

The Pap smear is done by collecting cells from the cervix and smearing them on a glass slide. This method is fraught with errors of collection and analysis as there is a large amout of debris admixed with the cells of the cervix thereby hampering interpretation.

The LBC is an improvement on the Pap smear. The cervical cells are collected in a liquid vial and then spun to remove the accompanying debris. The liquid can also be used for HPV testing.

HPV testing is the gold standard for screening. HPV is the causative agent of cervical cancer. This test detects the presence of HPV infected cells in the cervix. It can also specify if the HPV strain is low or high risk.

VIAA is done by smearing the cervix with acetic acid and visually observing the colour changes that result. A huge disadvantage of this method is that inflammation and atrophy could mimic cancerous changes and result in over-treatment of the patient.

Why is the HPV/LBC CO-TEST the preferred screening method?

The LBC test can be prone to false negatives and false positives. This is due to anatomic changes in the cell for example in atrophy and inflammation. It cannot reliably detect the presence of HPV
The HPV test can detect the presence of HPV but the presence of HPV does not imply that there are pre-neoplastic changes present. It is known that HPV infections can be cleared by the body’s own immune system and therefore the presence of HPV does not indicate a certain progression to cervical cancer.
The purpose, then, of the HPV/LBC co-test is to merge the strengths of the two screening tests to derive maximum benefit. The HPV test detects the presence (or absence) of HPV in the cells and if they are high risk strains. If high risk strains are present, the LBC test then
looks for changes in the morphology of the cells indicating a progression to cancer. In other words, the HPV test acts as a triage before the LBC test making it a cost-effective screening measure.

The HPV/LBC co-test is to be repeated every five years and so is more convenient.

At The Specialist Laboratories, the HPV/LBC co-test is done in a licensed laboratory by our trained scientists and consultants.