The slow development of cervical cancer makes early detection by means of the simple and inexpensive Pap smear test significant in its prevention and early treatment.
Pap smear is a screening test wherein sample cells from the cervical area are collected by means of a small wooden stick or spatula inserted into the vagina, and smeared onto the glass slide, then stained for examination by a cytotechnologist or pathologist.
The test derives its name from the physician George Papanicolaou who introduced it in 1928 following years of observation and study of vaginal cytology.
It is important that women undergo this test as part of a routine health check. The gradual progression of cervical cancer through its precancerous stages allows for early detection and treatment of this type of cancer.
RISK FACTORS
The most important risk factor in the development of cervical cancer is infection with Human Papillomavirus (HPV), although not all HPV infections lead to cervical cancer.
Other risk factors are: smoking, having multiple sex partners or having a sex partner with multiple sexual partners, having sex as a teenager or at a young age, exposure to diethylstilbestrol (DES) before birth, using oral contraceptives, having multiple full-term pregnancies, and having a weakened immune system (such as brought by immune-suppressing drugs or HIV infection).
Additional risk factors currently under study are: chlamydia infection, diet (a diet low in fruit and vegetables and lacking certain vitamins such as A, C and E may increase the risk), and family history of cervical cancer.
THE TEST
Preparation
These preparations are done in order to avoid interference with the results :
- Avoid sexual intercourse for 1 to 2 days before the test.
- Avoid using vaginal douche, vaginal medications, spermicidal creams, foams or gels for 48 hours before the test.
- Avoid having the test during your menstruation period. The best time to schedule the test is between 10 and 20 days after the first day of your last menstrual period.
Procedure
- The patient is instructed to lie down with knees bent and the heels rested on the stirrups.
- An instrument called a speculum (which is a clear plastic or metal device) is gently inserted into the vagina in order to widen it.
- Using a special wooden stick (spatula) and/or cervical brush, sample cells from the cervix are scraped.
- Cells collected are smeared onto the glass slide.
- Smeared glass slide is preserved with a fixative and is sent to the laboratory, where it is stained, then examined under the microscope.
Test Results
Results of the Pap smear are based on the observation of the presence or absence of abnormal cells and atypical cells, precancerous cells and cancer cells, and changes in the size and shape of cells, on microscopic examination of the smeared glass slide. Normal result means there are no abnormal cells detected.
Pap smear is a screening test and does not diagnose cervical cancer. Abnormal test results will prompt the doctor to request another Pap smear. Further tests may be done to provide a definitive diagnosis, which include colposcopy and biopsy.
Many factors can cause false-negative results such as inadequate collection of cells, inaccessible location of the lesion, mimicking of abnormal cells as benign, and abnormal cells being obscured by other cells. But since cervical cancer usually takes several years to develop, a yearly exam will be helpful in order to detect those abnormal cells not detected during the previous test.
Recent development of liquid-based Pap tests moreover minimizes false-negative results.
TREATMENT
There are treatments aimed at removing abnormal cells that have not yet become invasive. Procedures available are:
- Cone biopsy (Conization),
- Loop Electrosurgical Excision Procedure (LEEP),
- Cryosurgery, and
- Laser surgery.
When left undetected or untreated, abnormal cells may progress to becoming invasive cancer.
References:
- Paraskos, John A. and Patrick Jucker-Kupper. “George Nicholas Papanicolaou.” 15 November 2007 <http://www.whonamedit.com/doctor.cfm/2402.html>.
- Canadian Cancer Society. Cancer Information Service. 14 November 2007.
- Mayo Clinic. “Pap Smear: Screening Test for Cervical Cancer.” 10 March 2006. 15 November 2007 <http://www.mayoclinic.com/health/pap-smear/HQ01177>.
- National Cancer Institute (USA). “The Pap Test: Questions and Answers” 29 March 2007. 15 November 2007 <http://www.cancer.gov/cancertopics/factsheet/Detection/Pap-test>.
