HPV and Abnormal Pap Smear Results
What is HPV?
The term HPV stands for Human Papilloma Virus. HPV is the virus which causes warts, including the warts commonly seen on the hands and feet. The Human Papilloma Virus is a very common group (there are over 100 different types) of viruses that have been around for hundreds of years.
Some types of the Human Papilloma Virus are spread by sexual contact, which is why HPV is considered a sexually transmitted infection. These types of the virus cause warts that appear on the genitals (vagina, vulva, penis etc.) and anus of women and men. Some of the types that are sexually transmitted cannot be seen and have no symptoms. These are the types of the virus that infect the cervix (the cervix is located in a woman's vagina and is the opening to the uterus) and cause women to have abnormal pap smears.
The Centers for Disease Control estimates that there are currently 20 million men and women infected with HPV that is sexually transmitted and 5.5 million new cases each year, making HPV the most common sexually transmitted infection in the United States. Despite the fact that the HPV virus has been around for hundreds of years, little was understood about the types of the virus, which infect the genitals including the cervix. In the last few years, researchers have begun to understand the virus better.
How can I tell if I have been infected with HPV?
Unless you have visible genital warts you cannot tell that you have HPV. The types of HPV that do not have any symptoms are called sub clinical. Sub clinical means that you cannot see warts and that you have no recognizable symptoms.
Women usually discover that they have sub clinical HPV when they have a pap smear with abnormal results. Recently a test specifically for women has become available which can differentiate between the types of HPV. Men have sub clinical HPV too, but the test for HPV does not work for men, so men with sub clinical HPV rarely know it.
Genital warts that are visible look like small flesh colored bumps or small white "cauliflower"-like bumps, which sometimes multiply in clusters. The visible warts can be seen anywhere in the groin area of women and men. With women, warts are usually seen on the vulva, near the vaginal opening or near the upper thighs. Men can have visible warts on the penis, testicles, or near the upper thighs. Women and men can both have visible genital warts near the anus. Genital warts (HPV) are usually not painful unless they become irritated which may cause them to become sore and itch or bleed.
You can have visible genital warts (HPV) and sub clinical HPV at the same time. Because HPV may have no symptoms or visible warts, it can be difficult to know if you have HPV unless you are tested or have an abnormal pap smear.
Unlike other sexually transmitted infections, HPV is easily transmitted by skin-to-skin contact. Condoms which offer a great deal of protection against other sexually transmitted infections seem to offer little protection against HPV, simply because HPV is transmitted by skin-to-skin contact, meaning that HPV can be transmitted by any sexual contact, including touching. Both heterosexual and lesbian women can get HPV.
Will HPV Go Away?
Most of the time HPV does go away without any kind of treatment.1, 2. Your body's natural defense system (immune system) will usually suppress or eliminate the virus, much like your body gets rid of a common cold (colds are also caused by viruses).
Problems occur when your immune system is unable to get rid of HPV. Research has shown that it may take your body up to 24 months to rid itself of HPV, which seems like a long time, but studies have shown that 92% of young women with a positive HPV test will have a negative test within that 24 month time frame.3 When subclinical HPV (the types of HPV which have no symptoms) invades the cells of the cervix and persists (does not go away) it can cause serious abnormal cell changes in the cervix, which may lead to cervical cancer if allowed to continue without treatment. The process usually takes 10-20 years.
When HPV persists and does not go away there are usually other factors that inhibit your body's natural defense system from doing its job. The factors identified by researchers that affect your body's ability to fight HPV infection are smoking, HIV and other diseases that weaken the immune system, cancer treatments such as chemotherapy, previous Chlamydia or herpes infection, poor nutrition, inability to get health care due to poverty, five or more vaginal births and prolonged use of birth control pills (5 years or longer).4 5
Why does HPV cause abnormal Pap smear results?
HPV causes abnormal Pap smear results because HPV is a virus, which infects skin cells. When subclinical HPV infects the skin cells in the cervix (skin cells on the cervix are called squamous cells) it causes the cells to change and become abnormal. When HPV causes abnormal cell changes on the cervix this is called cervical dysplasia. It is important to note that there are other reasons besides HPV for abnormal Pap smear results such as infection, although the most common reason for abnormal Pap smear results is HPV. Pap smears are screening tests and do not tell you specifically what is causing the abnormal results.
The abnormal cell changes can be mildly abnormal or seriously abnormal. The degree of abnormal cells on the Pap smear is what helps your healthcare provider make recommendations for your follow-up. The most common categories of abnormal cell changes on the cervix (dysplasia) are listed below.
ASCUS (Atypical squamous cells of undetermined significance).
This means your Pap smear results are borderline, between normal and abnormal.
ASC-H (Atypical squamous cells of undetermined significance-cannot exclude HSIL). This means your Pap smear results are borderline but may be more serious.
LSIL (Low grade squamous intraepithelial lesion). This means that there are mildly abnormal cell changes on your cervix.
HSIL (High grade squamous intraepithelial lesion). This means that the cell changes on your cervix are more serious.
There are more categories of Pap smear results including ones which indicate cervical cancer, but because cervical cancer is such a slowly progressing cancer, it is unusual for young women or women who have been getting regular screening to have these results. Sometimes bacteria or other viruses such as Herpes are identified on Pap smear results. When this happens, Women's Health Specialists may attempt to contact you to offer you further evaluation and treatment.
Does HPV cause cervical cancer?
Most women with HPV and/or abnormal Pap smear results do not get cervical cancer. Researchers now believe that almost all cervical cancer is caused by HPV6. Cervical cancer is diagnosed in 12,900 women in the United States each year and 4,400 women die of cervical cancer in the U.S. each year. There are currently 140 million women and girls living in the United States. The majority of women who are diagnosed with cervical cancer are over the age of 30 and have not had access to healthcare or regular Pap smears.
The medical community now views cervical cancer as a preventable cancer because Pap smears can detect abnormal cell changes in the cervix long before they become cancerous. Also not all types of HPV cause the cell changes that can lead to cancer of the cervix. The HPV test, which is now available, can tell generally what types of HPV you have. Results of the HPV test do not specify exactly what type you have but do distinguish between the high risk types of HPV and low risk types. Both the low risk types and the high risk types of HPV can cause abnormal cell changes in the cervix and abnormal Pap smear results. Researchers now know that 90% of Pap smears with results that are classified as LSIL and 70% of Pap smears that are HSIL will become normal once your body's defense system has cleared the HPV virus.7 8 The types of HPV which cause the genital warts you can see are not the high risk types that can lead to cervical cancer.
What are my options for follow-up of an abnormal Pap smear?
If your pap smear is mildly abnormal (ASCUS or LSIL) you can choose to repeat the Pap smear in 6 months or have a colposcopy.
If the Pap smear is HSIL the recommendation is for you to have a colposcopy. A colposcope allows your healthcare provider to view the cells on your cervix more closely (it's like looking under a microscope) and possibly take samples of abnormal cells for further evaluation by a laboratory. This is called a biopsy.
You may also choose to have a test for HPV. This test will tell you if you have the high or low risk types of HPV. The HPV test is helpful if the results indicate that you have the low risk types of HPV because you will know that there is little chance that the cell changes found on your Pap smear will get worse. If the HPV test comes back with results that indicate the high risk types of HPV it is helpful because you may choose to get close follow-up.
Remember both high risk and low risk types of HPV can go away within 24 months.8
ACOG Announces New Pap Smear and Cancer Screening Guidelines
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¹ Hildesheim A, Schiffman MH, Gravitt PE, Greer CE, Zhang T, et al. Persistence of type specific human papillomavirus infection among cytologically normal women. JInfect Dis 1994: 169:235-40
² Holowaty P, Miller AB, Rohan T, To T. Natural history of dysplasia of the uterine cervix. J Natl Cancer Inst. 1999; 91: 252-8
³ Ho Gy, et al. Natural history of cervicovaginal papillomavirus infection in young women. N Engl J Med. 1998; 338:423-28
4 Moreno V, Bosch FX, Munoz N, et al. Lancet. 2002; 359: 1085-1092
5 Moscicki AB, et al. JAMA 2001; 285:2995-3002
6 Walboomers JM, Jacobs MV, Manos MM, Bosch FX, Kummer JA, Shah KV, et al. Human papillomavirus is a necessary cause on invasive cancer worldwide. JPathol; 189:12-19
7 NashJD, BurkeTW, Hoskins VJ. Biologic course of cervical human papillomavirus infection. OBGYN 1983:61:609-14
8 Moscicki AB, Hills N, Shiboski S. High regression of LSIL in adolescents. Abstract presented at: Pediatric Academic Society Annual Meeting; May4-7, 2002: Baltimore, MD.