The Pap test (named after Georgios Papanicolaou, Greek physician who pioneered cytology and early cancer detection), also called exfoliative cytology or Pap smear, is performed to diagnose cervical cancer.
The purpose of this test is to find changes in cervical cells that are precursors to cancer, before they start to cause symptoms which allows the treatments to be effective. Cervical cancer is a 90% preventable disease, if the Pap test is done regularly. This test should be taken by all women have a sexual life once a year for two or three consecutive years, and if the results are negative to be repeated every three to five years if there is no risk factors up to the age of 65.. If there are risk factors for cervical (Heredity, age, early onset of sexual intercourse, HPV infection or personal history of STDs, smoking, multiparity, immunosuppression or oral contraceptives) cancer monitoring must be year.
The samples used for this test are taken from three sites:
• Endocervix, which is the orifice communicating with the uterus.
• cervix, which is the outermost part of the uterus, and communicating directly with the vagina.
If the study is performed during pregnancy, the sample is not taken from the endocervix, but only the outer cervix and vagina.
Although this is a test with low sensitivity (50-60%) and a high rate of false negatives (30%), in many cases these errors occur in sampling or laboratory. Technique can be improved using the liquid based cytology consisting of diluting the sample at a set processing solution (that also allows the study of HPV infection).
If the result is positive, according to the particular circumstances and the specific outcome of each case, there are several options: it can be done again taking after six months or even a test called colposcopy, which allows the observation of suspicious lesions in situ and to take a biopsy. A healthcare professional should direct the patient, taking into account all the data from the clinical history.
The Pap test is a cheap, easy and simple test that any doctor or nurse can do and effectively contributes to the early diagnosis of cervical cancer. The sample should be analyzed by doctors specializing in pathology with specific training. It´s use has reduced deaths from cervical cancer by over 50%.
The emergence of HPV vaccines could change in the coming years for early diagnosis of cervical cancer and therefore modify the relevance of this technique for the detection of HPV.