The head of the probe catches the return signals from the woman's cervical cells and compares them with a computer library of cancer cells. In one comparison test, fluorescent spectroscopy was more accurate than the Pap smear but not as effective as other screening methods. Antibody-Based Tests . Experts are working on an antibody-based method for improving the identification of true cancerous cells in a cervical smear, which could significantly reduce the need for expensive and distressing tests in women who do not actually have cancer. The cells viewed in a cervical smear sample are classified on a scale representing the spectrum of cell changes from normal to cancerous.
Controversy exists over whether adenocarcinoma has a poorer outlook than squamous cell cancers.
The Pap smear only shows the presence of abnormal cells and is useful only as a screening test that identifies women who may have preinvasive or early cancerous changes. For a definitive diagnosis, the next step is usually colposcopy, during which the cervix is visualized under low power magnification. The surgeon takes samples of suspicious cells for biopsies. The Procedure . Colposcopy can be performed in a doctor's office without anesthesia in 10 to 15 minutes.