The Papanicolaou smear test or Pap smear was first used as a screening test for cervical cancer in 1941. It has grown in popularity over the years to the point where it is now part of a screening programme for cervical lesions in most developed countries. The test is performed by inserting a speculum into the vagina and collecting mucus from the opening of the cervix. The mucus is then applied to a slide and fixed with a solution. The slide is observed under a microscope looking for exfoliated cells caught in the mucus. These cells allow us to determine whether the skin on the cervix is normal, precancerous or even cancerous.
Pap smear screening programmes throughout Australia have been responsible for detecting precancerous and early cancerous lesions and reducing the morbidity and mortality from cervical cancer to their current low levels. In Australia, it is recommended that every woman, from the time they become sexually active until the age of 75 should have a pap smear performed every two years or so.
There are some inherent problems with the Pap smear test; namely, the slides can be difficult to read if there are
excessive amounts of blood cells or inflammatory cells on the slide. It is estimated that up to 20% of Pap smears need to be repeated for one reason or another.
Since 2008, we have seen the rise of liquid cytological tests. You may have heard of these tests being called either Thin Prep or Surepath. The Pap smear is collected in the normal way and the mucous is applied to a slide, but the spatula or brush is then put in a bottle full of fluid. The liquid technology has the added advantage of separating blood cells and other inflammatory cells from the cervical
As such, less than 4% of pap smears need to be repeated due to being unsatisfactory. This allows the reading of the pap smears to have improved accuracy. At this time the liquid smear test is not Medicare rebateable and attracts an out of pocket cost of approximately $45 from most pathology companies.
The liquid smear test is particularly helpful in woman who have abnormal menstrual periods with very little break between periods, or woman who are or who have recently been pregnant.