PAP Smears and HPV

Cervical cancer is the tenth most common cancer in women in the United States with approximately 13,000 new cases and 4,500 deaths per year. This is in comparison to the second most common cancer and the fifth most common cause of cancer deaths in the world. The reduction in number of deaths in the United States is due to patient screening with Pap smears.

Pap smear is a painless test done at the time of a pelvic examination. Currently, the specimen is obtained from the cervix (mouth of the womb) using a small brush, broom, spatula, or swab and placed on a microscope slide directly or into a special solution (liquid-based system) to be processed later.

Liquid-based systems improve the quality of the Pap smear samples over the conventional smears placed directly on a microscope slide. The screening guidelines with a Pap smear for cervical cancer are in the process of changing.

The main cause for cervical cancer is human papillomavirus or HPV, not tobe confused with HSV or the herpes virus. The infection can affect delicate tissues, called mucous membranes, of the cervix, vagina, vulva, anus, rectum, mouth and throat. Papillomaviruses can infect almost any external skin surface in addition to the mucous membranes. It has now been proven that HPV is the cause of the vast majority of cervical cancers. A few rare cancers of the cervix are not related to HPV, with their cause unknown.

 

Risk Factors

The known risk factors for cancer of the cervix include:

  • HPV infection
  • Multiple sexual partners
  • Sexual activity at a young age
  • Parity (having children)
  • HIV (AIDS)
  • Immune status (low immunity)
  • Smoking
  • History of other STD’s
  • Oral contraceptive use
  • Low socioeconomic status
  • Alcoholism
  • Poor diet

More About PAP’s

It has been shown that herpes simplex virus does not cause abnormal Pap smears or cervical cancer. A basic understanding of the kinds of tissue in the vagina, cervix, and uterus is important to better understand what the results of a Pap smear imply. There are two types of cells that are examined by the Pap smear. Squamous cells line the vagina and are found on the face (or outside) of the cervix. When examined under a microscope, the cells look similar to shingles on a roof. The vast majority of abnormal Pap smears involve the squamous cells. Columnar or glandular cells are found inside the cervical canal going up inside the uterus and inside the uterine cavity itself. When examined under a microscope, these cells have the appearance of rows of Coke® bottles side-by-side. Less than 1% of abnormal Pap smears involve the columnar or glandular cells. Another area where terminology is important and can be confusing is that of the Pap smear results and the results of the actual tissue biopsy. Over the years, the reporting systems for the Pap smear and the tissue biopsy have changed. 
The Pap reporting system used for many years was Class 1-5, with Class 1 being normal and Class 5 being invasive cancer. Both on the Pap smear and the tissue biopsy reports, dysplasia has been (and in some cases still is) used to describe the abnormalities. Dysplasia is an abnormal change in cells that may lead to cancer if left untreated and is described as mild, moderate, and severe. Carcinoma-in-situ means superficial cancer and is treated with removal of the affected area of the cervix. To make things more confusing, CIN or cervical intraepithelial neoplasia is a more recent classification system to describe the tissue diagnosis. CIN I corresponds to mild dysplasia, CIN II to moderate dysplasia, and CIN III to severe dysplasia/carcinoma-in-situ. The current system for reporting Pap smears is called TBS (The Bethesda System) and was established in 2001.

The results of the PAP smear (Bethesda 2001 nomenclature) may be returned as follows:

PAP Result and Description:

Negative – negative for pre-cancer or cancer – inflammation or non-HPV infection may be present

ASC-US – atypical squamous cells – uncertain significance may be due to irritation or infection, although other more serious causes cannot be ruled out

ASC-H – atypical squamous cells – HSIL cannot be excluded

AGCUS – atypical glandular cells uncertain significance – these cells originate from higher in the cervix and uterine cavity

LGSIL – low-grade squamous intraepithelial lesion – includes HPV/mild dysplasia/CIN I (cervical intraepithelial neoplasia)

HSIL high grade squamous intraepithelial lesion – includes moderate and severe dysplasia/carcinoma-in-situ)

Squamous cell carcinoma – cancer of the cervix

NOTE: Low-grade lesions (LGSIL) tend to be seen in younger women (teens and 20s), high-grade lesions (HGSIL) in women in their 30s and 40s, and invasive cancers in 50s and 60s. In rare instances, invasive cancer may be seen in young patients.

HPV or human papilloma virus:

  •  is easily transmitted (usually by sexual intercourse),
  • has a high spontaneous remission rate (goes away by itself),
  • may be present for many years,
  • and causes cancer in relatively few cases (compared to the number of women infected with the virus).

HPV types – there are different forms of the virus called types. The HPV types were numbered in the order they were discovered. The most common low-risk HPV types include 6 and 11 and are not likely to cause cancer. The low risk types are commonly found in venereal warts (condyloma) on the vulva and are found in 20% of women who have LGSIL (see above). The most common high-risk HPV types include 16 and 18 and have the potential to cause cancer. High-risk HPV types are found in 80% of the women who have LGSIL and almost all who have HGSIL and cervical cancer. HPV typing is performed using a special DNA test.
Most HPV infections go away by themselves, with the patients never knowing they had the infection. There is currently no treatment for the virus. Approximately 5% of infected women have persistence of the virus and are at risk for developing dysplasia and/or cancer. It should be noted that transmission of the virus does not require sexual penetration or intercourse but can occur with only intimate contact.  

We are seeing increasing numbers of throat cancer associated with high-risk HPV in both women and men.

 

Colposcopy

Evaluation of Abnormal PAP Smears When a woman has ASC-US, she should be tested for high-risk HPV types from the liquid remaining in the Pap collection bottle. If the test is negative for high-risk HPV types, the patient should have a repeat Pap in 12 months. If the test is positive for high-risk HPV types, the patient should have a colposcopy. Colposcopy is a procedure done in the office using a special microscope with a high-intensity light. This photo shows a colposcope.

colposcope 

The cervix is examined, and a biopsy is obtained from abnormal areas seen at the time of the procedure. If a woman is post-menopausal and has ASC-US on Pap smear, she should be treated with estrogen cream for three weeks and have the Pap smear repeated one week following treatment. A woman who is immunosuppressed (patient is HIV positive or certain other medical conditions are present) and has ASC-US on Pap smear, she should have a colposcopy. When ASC-H is present, a colposcopy should be performed .

All patients with AGCUS should have colposcopy and endocervical sampling. Endocervical sampling is performed by scraping the canal inside the cervix with a special instrument called a curette.

If atypical endometrial cells (cells from the cavity of the uterus) are reported and/or if the patient has abnormal vaginal bleeding, the lining of the cavity of the uterus should be biopsied. In certain cases, other procedures may be appropriate with AGC. These may include conization of the cervix, ultrasound examination, and hysteroscopy.

Women with LGSIL should have a colposcopy. Endocervical sampling is performed along with the colposcopy. If CIN (cervical intraepithelial neoplasia) is not diagnosed on biopsy, Pap smear may be repeated at 12 months. As with ASC-US, if a woman is post-menopausal and has LGSIL on Pap smear, she should be treated with estrogen cream for three weeks and have the Pap smear repeated one week following treatment.

Treatment of Abnormal PAP Smears

The Best Treatment Is Prevention
The best treatment of abnormal PAP smears is prevention. Both females and males should minimize known risk facts as described above. Use of condoms during sex will reduce but not absolutely prevent HPV infection. Vaccines (Gardasil®) are available for both girls and boys between the ages of 9 and 26 years. Gardasil® will prevent HPV infection for 70% of the types that cause cervical cancer.

We are learning that certain abnormal PAP’s may simply be observed, especially in younger patients. Treatment of CIN may be with excisional techniques such as LEEP, cold-knife conization, or laser excison; or with ablative techniques such as laser vaporization or cryocautery. Excisional techniques provide a specimen that is sent to the laboratory, whereas an ablative technique destroys the tissue. If there is any uncertainty whether or not invasive cancer is present, an excisional technique should be used. Invasive cervical cancer should be treated by a gynecological oncologist.

 

The information provided by Advanced Healthcare for Women and E. Daniel Biggerstaff, III, M.D. is for informational purposes only. As each woman is unique, do not rely on this information for diagnosis and treatment. We cannot guarantee the accuracy of the content and advise that you see a qualified Health Care Professional for individual needs and care.

 

 Advanced Healthcare for Women
5354 Reynolds Street, Suite 518
Candler Professional Building
Savannah, Georgia 31405
 
Telephone 912-355-7717
Fax 912-355-0979
gyndoc@bellsouth.net