Cervical Cancer Screening Tests
Currently employed screening tests for cervical cancer include the Papanicolaou (Pap) test and the HPV test. The Pap test, a microscopic examination of cells scraped from the cervix (endocervical canal and ectocervix), is the customary approach used to screen for cervical cancer. Although it has a false negative rate of 20% (primarily resulting from sampling error), data indicates that use of this test reduces the incidence of malignancy by 60% to 90%. Once a sample has been obtained, it should be placed on a slide (e.g., conventional Pap test) or in a preservative solution (e.g., Thin Prep Pap test) and sent for analysis. However, upon physical inspection, if suspicious or abnormal specimens are found. a biopsy should be done regardless of cytologic findings.9

Approved by the US Food and Drug Administration in 2003, the Hybrid Capture II assay for HPV is another method used to screen women for cervical cancer.  This test, which screens for the presence of high-risk HPV DNA, is indicated for women 30 years of age and older, and is to be used in combination with the Pap test. The HPV test may also be used to interpret ambiguous Pap test findings; additional workup is indicated for women with a Pap test result showing atypical squamous cells of undetermined significance (ASC-US), in conjunction with a positive HPV test.9


Continue Reading

Current Screening Guidelines
The American Cancer Society (ACS) and US Preventive Services Task Force (USPSTF) currently recommend that all women commence screening either three years after beginning to engage in vaginal intercourse or at 21 years of age, whichever is earlier9; guidelines recommend yearly screening with conventional Pap tests or biannual screening with liquid-based Pap tests.10 In the absence of high-risk factors (e.g., diethylstilbestrol (DES) exposure, HIV infection, other immunodeficiencies), women 30 years of age and older who have had three consecutive normal Pap test results may extend this screening interval to every two to three years.

An alternate option for women 30 years of age and older is to undergo screening every three years with a Pap test and an HPV DNA test. In addition, according to ACS guidelines, women 70 years of age and older with three or more normal consecutive Pap test results and no abnormal results within the last 10 years may discontinue screening. The USPSTF recommends against routine screening for women older than 65 years of age, who have had recent normal Pap tests and are not otherwise at high risk for developing cancer.  Finally, those who have had a total hysterectomy may discontinue cervical cancer screening, unless they have a history of cervical carcinoma or pre-invasive changes.9

The American Society for Colposcopy and Cervical Pathology (ASCCP) has developed guidelines for the management of abnormal cervical cytology and histology, as detected by Pap and HPV screening tests. These recommendations are delineated in Table 2.11,12

Table 2.  Recommendations for the Management of Cervical Abnormalities11,12

Screening Results

Recommendation

ASC-US, high-risk HPV-positive

Colposcopy

ASC-US, high-risk HPV-negative

Repeat Pap test in 12 months

ASC-H

Colposcopy

LSIL

Colposcopy

HSIL

Loop electrosurgical excision or colposcopy with endosurgical assessment; follow-up with diagnostic excisional procedure or colposcopy and Pap testing at

6 month intervals for 1 year, if CIN II/III not identified

AGC

Colposcopy with endocervical assessment and possible endometrial evaluation; also perform HPV testing if not already done

Colposcopic Findings

Recommendation

CIN I (preceded by ASC-US, ASC-H, or LSIL)

Pap test every 6 to 12 months or high-risk HPV test every 12 months; colposcopy for any abnormality

CIN I (preceded by HSIL or AGC)

Diagnostic excisional procedure or colposcopy and Pap testing at 6-month intervals for 1 year

CIN II

Excision or ablation

CIN III

Excision or ablation

AIS

Hysterectomy preferred; excisional therapy followed by repeat Pap, HPV testing, and colposcopy with endocervical sampling in 6 months is acceptable

AGC = atypical glandular cells; AIS = adenocarcinoma in situ; ASC-H = atypical squamous cells, cannot rule out high-grade squamous intraepithelial lesions; ASC-US = atypical squamous cells of undetermined significance; CIN = cervical intraepithelial neoplasia; HPV = human papillomavirus; HSIL = high-grade squamous intraepithelial lesions; LSIL = low-grade squamous intraepithelial lesions; Pap = Papanicolaou