PAP Smear and Cervical Cancer Vaccine
Cervical cancer (cancer of the lowermost part of the uterus) is a leading cause of deaths in the Indian subcontinent and it is the number one cause of cancer-related deaths in India.
Globally, each year, 500,000 women are diagnosed with cervical cancer and 270,000 women die from it. In India itself, each year, 1,32,000 women are diagnosed with cervical cancer and 74,000 women die from it!
The irony is that the western world, which has fewer cases, is far more active in taking preventive steps like early screening (PAP Smears) and vaccination, while the developing world which as got most of the cases of cervical cancer, is still struggling to educate its masses to undergo screening and vaccination.
What is screening?
As we all know, most cancers do not cause symptoms until it is too late. Hence, screening for cancer is the single most important step in cancer prevention. Screening is looking for cancer before a person has any symptoms. This can help detect cancer at an early stage, when it may be curable. By the time symptoms appear, cancer is likely to have begun to spread.
What is the PAP test?
The PAP test is a simple and routine test to detect cell changes which occur before cancer develops. The PAP test can be performed in any clinic, is painless and does not require anaesthesia. The report is available in about a week’s time.
Do I need to prepare for a PAP test?
You do not need any special preparation. However, you should avoid intercourse and not use any vaginal creams, tablets or insert a tampon for 48 hours before the test. Also, remember to not take the test during your monthly period.
When should I have a PAP test?
Have your first Pap test about 3 years after the first time you have sex, or when you reach age 21 (whichever comes first).
Keep getting Pap tests every 1 to 3 years. Your gynaecologist will advise you on this, depending on your risk profile. If you are 30 or older, an HPV test may be done along with the Pap test.
A PAP test is a part of annual gynaecological check-up.
Regular use of the Pap test has greatly reduced the number of cases of cervical cancer in the United States and other developed countries. Indians should follow the example.
What does an abnormal PAP report mean?
Abnormal cell changes which occur due to HPV infection can be identified by a PAP test.
These abnormal cells show early precancer changes called dysplasia or cervical epithelial neoplasia (CIN ). Dysplasia/CIN are graded as mild, moderate, or severe. Mild dysplasia (CIN 1) usually goes away on its own. Moderate (CIN 2) and severe (CIN 3) dysplasia indicate more serious changes and need further testing and counselling.
The PAP is not a diagnostic test and any abnormal report has to be confirmed by a biopsy. Conversely, abnormal cell changes may be missed by a routine PAP test. Hence, a normal PAP test does not always exclude cancerous or pre-cancerous changes.
What has HPV infection to do with cervical cancer?
HPV or the Human Papilloma Virus infection is a sexually transmitted viral infection which may lead to cancer development. The HPV can infect many organs in the human body, of which one is the cervix. The infection may cause no symptoms or harm at all or it may cause the development of warts and in an occasional case, it may lead to abnormal cell changes leading to cancer.
How does the cervix get infected with HPV?
HPV infection of the cervix is mainly sexually transmitted. It can spread by skin to skin genital contact and does not necessarily require sexual intercourse for transmission. The use of condoms reduces but does not eliminate the risk of cervical cancer. Worldwide, HPV infection is the commonest sexually transmitted disease.
What is liquid cytology and how is it different from a PAP test?
Liquid cytology is a relatively new technique for screening for cellular changes and offers some advantage over the PAP test that it is more accurate and also that the same sample can be used to test for HPV DNA testing (infection with HPV). It has been approved by the FDA and has replaced the PAP test in many developed countries for cervical cancer screening. Of course, it costs a little more than the PAP alone.
How does the cervical cancer vaccine work?
We now know that HPV infection leads to later cervical cancer development. The vaccine protects us from infection by most of the types of HPV (not all types) which may cancer.
How do I take the vaccine?
There are two types of vaccine available in India today – the bivalent vaccine (which protects against two common types of HPV) and the quadrivalent vaccine (which protects against 4 different types of HPV and also warts).
Both are to be taken for 3 doses over 6 months.
How effective is the vaccine?
Both the vaccines are more than 95% effective and for more than 8 years, however, we do not know the duration of efficacy as the vaccines are relatively recent. Experts believe that the protection is likely to last a lifetime, however, the possibility that booster does may be needed in the future, cannot be ruled out.
Do we all need to take the vaccine?
The USFDA has approved the vaccine for women and girls between the ages 9 and 45 years. The WHO recommends routine vaccination of young girls and cervical cancer vaccination is part of the routine national immunisation schedule of many countries such as the United States, Canada, Australia and most European nations.
The maximum benefit of vaccination is for women before they have had their first sexual intercourse. However, not just virgins benefit from it. Studies have shown that the vaccine does protect sexually active women too. However, the greater the number of sexual partners, higher is the chance of having contracted HPV infection before vaccination. Every woman should take a decision for vaccination after understanding the potential benefits with a counsellor/gynaecologist.