An Overview of the Pap Smear
Dr. D. Glass
Dr George Papanicolaou was an anatomist and researcher who first described the changes that occur in vaginal and cervical cells with menstrual cycles. He soon realised that cytology could also be used to diagnose abnormal cells and in 1943 published a book on the diagnosis of uterine cancers with the Pap smear. This simple procedure has become the symbol of effective screening technology – providing a simple, relatively cheap and effective method of early detection of abnormalities long before the onset of cancer. It has now also become a helpful adjunct to the management of vaginal and cervical infections.
Because it is only a screening test, and only samples a very small number of the millions of cells of the cervix, it is possible to miss abnormal areas or under diagnose the extent of abnormality. For this reason it is important to have regular Pap smears and thus reduce the risk of missing abnormalities. Fortunately it can take 10 to 15 years for the change from normality to cancer of the cervix. Thus Pap smears done yearly or every second year are normally effective at preventing the development of cancer.
Changes of the cells are graded according to their appearance and recorded as cervical intraepithelial neoplasia (CIN) 1, 2 or 3. CIN 3 is very close to cancer, whereas CIN1 may actually revert to normal without any treatment in up to 80% of cases. A more modern classification refers to squamous intraepithelial lesion (SIL) as being low grade or high grade. The higher grade abnormalities are treated more aggressively than the low grade lesions.
Up to 99% of cervical cancers are caused by the human papilloma virus (wart virus). Of the almost 80 different types affecting humans only a small number can cause cancer. If the Pap smear shows the presence of HPV more vigilant monitoring is required. If the Pap smear shows abnormalities we may repeat the smear in about 3 to 6 months. If the abnormality is persistent we perform a colposcopy – a microscopic examination of the cervix to assess the extent of the abnormality.
Treatment of abnormalities consists of a simple removal of the abnormal areas. If the abnormalities have progressed to CIN 3 or low grade cancer more extensive surgery may be required.
Your first Pap smear should be done after the onset of sexual activity. In the first few years it should be performed yearly. If one is in a mutually faithful relationship, the Pap smear may be performed every 2 or 3 years. A Pap smear is usually no longer necessary after a hysterectomy.
The performance of a Pap smear is simple and should not be painful at all. It should be done with dignity and respect and gentleness.