• When to begin screening: The American College of Obstetricians and Gynecologists (ACOG) guidelines were revised in 2009 and other groups and societies are expected to conform this year.  ACOG’s guideline is to defer screening until age 21, regardless of risk factors including onset of sexual activity.   
• How often should screening occur?

From the onset of screening: ACOG recommends a Pap test every other year from ages 21-29, then every three years for women with a history of negative findings.  Please refer to ASCCP guidelines for follow-up of women with abnormalities.  

• Beginning at age 30: ACOG recommends increasing screening intervals to every three years after prior negative screening.  Both the American Cancer Society (ACS) and ACOG recommend that the screening interval can be increased to 2 to 3 years after 3 consecutive normal Pap tests have been obtained. An alternative option for women age ≥30 is to screen with both a Pap test and a HPV test, and if both are negative, to be re-screened every 3 years.
• High-risk women, defined as those with HIV (or other reasons for being immunocompromised) or DES exposure in-utero, should be screened annually.  Please refer to ASCCP guidelines for management of women with cervical screening abnormalities.  Once negative, women with CIN2,3 should be screened annually for at least 20 years, while women with lesser abnormalities can be screened at longer intervals.
• Conventional and liquid-based cytology techniques appear similarly effective and choice of Pap technology should not alter screening interval.  
• At what age should screening cease?

ACOG recommends that women with at least 3 consecutive documented satisfactory normal Pap tests within the last 10 years can cease cervical screening between the ages of 65-70, while ACS recommends these same women may cease cervical screening at age 70.

The United States Preventive Services Task Force (USPSTF) recommends that women with adequate normal screening in the last 10 years can cease having a Pap at age 65.

• A spatula, or a soft plastic brush that looks like a tiny broom, is brushed entirely around the surface (portio) of the cervix to collect cells. When a spatula is used, a small spiral brush (cytobrush) is inserted into the cervical canal and rotated 180 degrees to collect cells from the endocervix. This may cause mild crampy discomfort for the patient. When two sampling devices are used to collect the cytologic specimen, it is important to obtain the exocervical sample first, followed by the endocervical sample. This will minimize contamination of the specimen by bleeding that often follows rotation of the cytobrush in the endocervical canal.
• The cells on the collection device(s) are either put directly on a glass slide or into a bottle of special liquid (ThinPrep^® or SurePath™) and sent to the lab. If put directly into the liquid, a glass slide is prepared in the lab.
• At the lab the cells are stained and evaluated through a microscope by cytotechnologists (people trained to look for abnormal cells). Many labs now perform the initial evaluation of the Pap slides with an automated computer-guided microscope that identifies the slides most likely to have abnormalities for human review and marks the cells that are abnormal in appearance.

• Specimens for cervical HPV tests can be collected in one of two ways:

Most hrHPV testing is done directly from remaining liquid-based medium remaining after cells have been removed from the liquid-based Pap vial to create the cytology slide. Although this is routinely done from both ThinPrep^® and SurePath™ liquid-based mediums, to date it has only been FDA-approved for ThinPrep^®.

hrHPV tests can also be done by taking a separate brush sample from the cervix with the collection device and placed in a standard transport medium (STM).

• The normal cervix has two types of cells on the surface: squamous cells and columnar (glandular or mucus producing) cells. Additionally, new squamous cells are identified as metaplastic cells.

Squamous cells The skin throughout the vagina and to varying degrees covering the cervix is composed of multiple layers of flat cells called squamous cells.

Columnar or glandular cells The surface of the canal that leads from the outside of the cervix to the endometrial cavity within the uterus is covered by a single layer of cells that produces mucus (part of the liquid in vaginal discharge). These cells stop at the edge of the squamous cells. This junction where the two cell types meet is called the squamocolumnar junction.

Metaplastic cells (immature squamous cells) New squamous cells at the squamocolumnar junction are continuously replacing columnar cells. These new squamous cells are called metaplastic cells. The area of cell replacement is called the transformation zone. Metaplastic cells are normal. However, metaplastic cells appear to be most vulnerable to the activity of HPV in causing abnormal cell changes. Therefore, the transformation zone and SCJ are areas where most precancerous change can be found. These cells may also be more vulnerable to the irritative effects of yeast, tampons, intercourse, spermicides, etc. Some abnormal Paps are due to these non-precancerous cell changes.

• Quality of the smear: First, the cytotechnologist reading the Pap indicates whether the quality of the Pap is good (and therefore the Pap can be relied upon), or whether the quality is borderline or poor (and needs to be repeated). There are two possibilities.

Satisfactory: This is a Pap that is readable and has adequate cells. There is no excessive mucus, inflammation, blood or overlapping of cells hindering adequate assessment. One of two of the following descriptors will follow:

Metaplastic and/or columnar cells are present. This is evidence that the area on the cervix at-risk for precancerous changes (the squamocolumnar junction and transformation zone) were sampled.

Metaplastic and/or columnar cells are not present. This, however, is not a definite indication that the transformation zone was not sampled. Most Paps with lack of transformation zone cells should be repeated in one year. The exception is when the Pap is from a woman considered at higher risk due to past Pap history, cervical treatment or immunosuppression, in which the Pap should be repeated in 6 months.

Unsatisfactory: This Pap is of such poor quality that it cannot be relied upon and should be repeated. It does not mean that the Pap is abnormal. - In fact, an abnormal Pap (ASC-US, ASC-H, AGC, LSIL, HSIL, Cancer) must be read as abnormal even if it is of poor quality.

• Normal or Abnormal

Normal:

Negative for intraepithelial lesion or malignancy (NILM): Most women (90-95%) have a normal (NILM) Pap result. This means that no abnormal cells were found and it is most likely that the cervix is normal (although, as explained above, some women will have a normal Pap but still have abnormal cell changes on the cervix, a "false negative" Pap).

Abnormal:

Atypical Squamous Cells (ASC): From 2-10% will have this Pap interpretation. This means that squamous cells are detected that do not entirely look normal, but also not entirely abnormal. There are two subcategories of ASC:

Atypical squamous cells of undetermined significance (ASC-US): Approximately 50-60% of women having this Pap reading are entirely normal (HPV negative and no cervical disease), and 40-50% are hrHPV positive with half of those having detectable cervical changes due to HPV (mostly low-grade [mild dysplasia, CIN I]). Approximately 6-9% will have high-grade changes (moderate or severe dysplasia, CIN2 or 3) and rarely a cervical cancer (approximately 1/1000 ASC-US).

Atypical squamous cells-cannot rule out high grade (ASC-H): A small percentage of ASC Pap test results are ASC-H. This means that some cells are abnormal enough to be suggestive, but not definitive, of a high-grade lesion. From 60-80% of women with ASC-H test positive for hrHPV, and the risk of CIN2,3+ is much higher than that of ASC-US.

Atypical glandular cells (AGC): AGC is an uncommon Pap interpretation (0.2-0.8%). This means that glandular cells are detected that do not look entirely normal, but also not entirely abnormal. Women with AGC Pap results may be normal, or have squamous cervical intraepithelial neoplasia (CIN) or glandular adenocarcinoma in situ (AIS), cervical or endometrial adenocarcinoma, fallopian tube, ovarian or other glandular cancers. Approximately 50-70% or more of women with this Pap reading will be found to be normal, but this Pap interpretation has more risk of squamous and glandular precancer or cancer than any other Pap interpretation other than HSIL. Therefore, women with this Pap result should have colposcopy and endocervical sampling. Additionally, all patients with AGC that are interpreted as "atypical endometrial cells", or have abnormal unexplained bleeding at any age, or a history of anovulation, or are over the age of 35 should also have an endometrial biopsy. As with cervical squamous lesions, most glandular cervical precancer and cancer is associated with hrHPV while uterine cancers found after AGC Pap results are not.

Low-grade squamous intraepithelial lesion (LSIL): From 2-4% or more will have this Pap result. In younger women (≤35) this Pap test reading is almost always due to an active HPV infection as 83-94% would test positive for HPV if tested. Women over the age of 35 may have cell changes that are not related to HPV but are read as LSIL. Most of these "misclassified" cell changes are due to declining estrogen levels or other effects of the aging process on our skin cells. As a result only about 50% of women over the age of 35 with a LSIL Pap would test positive for HPV. In order to triage LSIL in estrogen-weak environments such as that in post-menopausal women, an acceptable triage option would be to test for hrHPV and if negative, to repeat the cytology in a year. Over all age groups, about 70% of women will have cervical or vaginal cell changes due to HPV that can be identified on further evaluation (colposcopy). Most of these changes are low-grade [mild dysplasia, CIN I] but approximately 10-28% will have high-grade changes (moderate or severe dysplasia, CIN2 or 3).

High-grade squamous intraepithelial lesion (HSIL): Typically from 0.3-0.8% will have this Pap result. Over 90% with HSIL will have cell changes due to hrHPV. The majority have high-grade cervical changes (moderate or severe dysplasia, CIN2 or 3), but some will have only low-grade changes or no abnormality detected at colposcopy. Any woman with a high-grade Pap (HSIL) should be evaluated by colposcopy to determine whether CIN2,3 or cancer requiring treatment is present.

Cancer: Rarely a Pap will be read as suspicious for cancer. Women with this reading should be evaluated immediately.

• Colposcopy: This is the first step in management of all women ages 21 years and older with any abnormal Pap result except ASC-US.  A colposcope is a microscope mounted on a stand which is placed outside the vagina allowing the clinician to look at the cervix for cell changes. Colposcopy is the cornerstone in the initial evaluation of all abnormal cytology results. There are only three situations in which the initial evaluation of an abnormal Pap may be by means other than by colposcopy. These are (1). Adolescents age 20 and under should not be evaluated initially by colposcopy, (2). Women age 21 and over with ASC-US have the option of initial triage with either repeat Pap at 6 and 12 months or "reflex" hrHPV testing, and (3). Post-menopausal women with LSIL have the option of "reflex" hrHPV testing.
• Repeating the Pap test: The ASCCP Guidelines provide the option of repeating the Pap in the initial management of women of any age with ASC-US and for adolescents with ASC-US or LSIL. Repeating the Pap every 6 months until there are two consecutive normal Pap results is also an option for women age 21 and over not found to have CIN2,3 or AIS at colposcopy when originally referred for the evaluation of ASC-US, ASC-H, or LSIL. Repeat cytology at 12 months is recommended for all adolescents with ASC-US or LSIL.
• HPV testing: The 2006 ASCCP Guidelines provide the option of testing for HPV in the initial triage of women age 21 and over with ASC-US and post-menopausal women with LSIL. HPV testing should never be used in the evaluation of adolescents nor in the initial management of women with any other Pap abnormality. HPV testing is also an option in the post-colposcopy management of women not found to have CIN2,3 or AIS at colposcopy and originally referred for the evaluation of ASC-US, ASC-H, AGC-NOS or LSIL. It is not used in the post-colposcopy management of women referred for evaluation of AGC "cannot rule out high grade" or HSIL.

• hrHPV testing is incorporated in both screening guidelines of the American Cancer Society (ACS) and American College of Obstetricians and Gynecologists (ACOG) and in the American Society for Colposcopy and Cervical Pathology (ASCCP) and ACOG guidelines for the management of abnormal cervical cytology and cervical neoplasia.
• HPV testing must be for hrHPV types only and should use a Food and Drug Administration (FDA)-approved or equivalent test that has undergone peer review in a rigorous, masked evaluation involving an adequate sample size.
• Testing for low-risk HPV types that do not cause cervical cancer has no clinical benefit and cannot be justified for clinical testing.
• Other than the indications listed below in the section "Screening" and the section "Management" HPV testing generally should not be done because it potentially creates more harm than benefit.