Screening for cervical cancer in women who present to STD clinics or have a history of STDs

Women with a history of STDs are at increased risk of developing cervical cancer, and women who attend STD clinics may have characteristics that place them at even higher risk. Prevalence studies have found that women attending STD clinics are approximately five or more times more likely to have precancerous lesions than women attending family planning clinics.

The Papanicolaou smear (Pap smear) is an effective and relatively inexpensive screening test for invasive cervical cancer, squamous intraepithelial lesions (SILs)*, and precancerous cervical lesions. Screening guidelines from the American College of Obstetricians and Gynecologists and the American Cancer Society recommend annual Pap smears in sexually active women. Although these guidelines state that less frequent Pap smears may be appropriate in some situations, women who present to STD clinics or have a history of STDs should be screened annually because they are at increased risk for cervical cancer. Furthermore, STD clinic reports indicate that many women do not understand the purpose and importance of Pap smears, and many women who undergo vaginal examinations believe that they have had Pap smears taken when in fact they have not.

*In 1998, the Bethesda System for Reporting Cytologic Diagnosis of Cervical and Vaginal Abnormalities introduced the terms squamous intraepithelial lesions (SIL) low-grade and high-grade. The term "low-grade SIL" refers to cellular changes associated with HPV and mild dysplasia/cervical intraepithelial neoplasia 1 (CIN I). The term "high-grade SIL" refers to moderate dysplasia/CIN II, severe dysplasia/CIN III, and carcinoma in situ/CIN III.

Recommendations

When performing a vaginal examination for STD screening, the physician should ask the patient about her most recent Pap smear results and discuss the following information with her:

• The purpose of Pap smears and their importance,
• Did she have a Pap smear test during her clinic visit?
• The need for annual Pap smear testing, and
• Contact details of a doctor or clinic where a Pap smear can be performed, and the possibility of follow-up (if a Pap smear was not taken during this examination).

If a woman has not had a Pap smear in the last 12 months, a Pap smear should be obtained as part of a routine vaginal examination. The health care provider should be aware that after a vaginal examination many women believe they have had a Pap smear when in fact they have not, and may therefore report having had a recent Pap smear. Therefore, in STD clinics, a Pap smear should always be performed as part of a routine clinical examination for women who do not have a clinical record of a normal Pap smear in the last 12 months (either in-clinic or from a centralised system).

It is advisable for the woman to receive a memo with information about the significance of the Pap smear and the fact that the Pap smear was taken during the clinic visit. If possible, a copy of the Pap smear results form should be sent to the patient.

Follow-up observation

Clinics and providers performing Pap smear screening have the option of using cytopathology laboratories that report results according to the Bethesda System. If Pap smear results are abnormal, patients should be cared for according to the recommendations of the Interim Guidelines for Management of Abnormal Cervical Cytology published by the National Cancer Institute Task Force, which are summarized below. If Pap smears reveal features of high-grade PIP, colposcopic examination of the lower reproductive tract and, if indicated, targeted biopsy should be performed. If the Pap smear reveals poorly differentiated PIP or atypical squamous cells of undetermined significance (ASCU), follow-up may be done without colposcopy if follow-up is not available at the institution or if colposcopic examination may aggravate the process. In general, repeat Pap smears are recommended every 4 to 6 months for 2 years until three consecutive negative results are obtained. If repeat Pap smears reveal persistent pathology, colposcopy and targeted biopsy are indicated for both poorly differentiated PIP and ASCU. In women diagnosed as ASCU associated with a severe inflammatory process, repeat Pap smears are performed in 2 to 3 months and then every 4 to 6 months for 2 years until three consecutive negative results are obtained. If a specific infection is detected, follow-up examinations should be performed after appropriate treatment. In all cases of follow-up, when repeat Pap smears are performed, the results should not only be negative, but should also be interpreted by the laboratory as "satisfactory".

Because clinical follow-up of patients with abnormal Pap smears with colposcopy and biopsy is beyond the capacity of many public clinics, including most STD clinics, in most cases women who have high-grade PIP or persistently low-grade PIP or APCNS will require referral to other clinics for colposcopy and biopsy. Clinics and providers that provide Pap screening but do not provide adequate colposcopic follow-up for abnormal Pap smears should establish referral mechanisms to other sites that can 1) ensure appropriate patient evaluation and treatment, and 2) communicate the results of this evaluation to the clinician or other provider. Clinics and providers that provide follow-up of patients with repeat Pap smears should develop protocols for identifying women who have lost their initial referrals for follow-up and use them routinely. The Pap smear results and the type and location of the facility to which the patient is referred should be clearly recorded in the patient's medical record. Colposcopy and biopsy techniques should be trained locally, especially where patients cannot be examined in other facilities and there is no guarantee of follow-up.

Other considerations for patient management

Other considerations regarding Pap smears include the following:

• The Pap smear is not an effective screening test for STDs;
• If a woman is menstruating, the Pap smear should be postponed and the woman advised to return for a Pap smear at the earliest opportunity;
• The presence of mucopurulent discharge may distort the Pap smear result. However, if there is no guarantee that the woman will return for follow-up, the Pap smear should be taken after removing the discharge with a cotton swab soaked in saline.
• Women with external genital warts do not need more frequent Pap tests than women who do not have warts (except in specific cases).
• In STD clinics or other settings where samples are collected for culture or other STD testing, the Pap smear should be the last test performed.
• Women who have had a hysterectomy do not need to have an annual Pap smear, even if the procedure was done for cervical cancer or precancerous lesions. In this case, women should be advised to return for follow-up with their current physician.
• Health care workers who receive basic training in Pap smear collection and clinics that use simple measures to ensure quality Pap smear collection have fewer unsatisfactory Pap smears.
• While type-specific HPV testing to identify patients at high and low risk for cervical cancer may become clinically relevant in the future, the value of this testing for clinical practice is currently uncertain and is not recommended.

Special Notes

Pregnancy

Pregnant women should have Pap smears as part of their routine prenatal care. A brush can be used to obtain Pap smears in pregnant women, although care must be taken not to disturb the mucus plug.

HIV infection

Recent studies have shown an increased prevalence of PIP in women infected with HIV, and many experts believe that HIV may contribute to the progression of precancerous lesions to invasive cervical cancer. The following recommendations for Pap smear screening in HIV-infected women, in part, are based on expert advice on the treatment and care of women with cervical cancer and HIV infection and are consistent with recommendations in other USPHS guidelines.

After obtaining a complete history of previous cervical disease, women with HIV infection should have a complete pelvic examination, including a pelvic examination and Pap smear, as part of a general medical examination. Pap smears should be obtained twice in the first year after diagnosis of HIV infection and, if normal, once per year thereafter. If Pap smear results are abnormal, such patients should be managed according to the Interim Guidelines for Management of Abnormal Cervical Cytology. Women with a cytologic diagnosis of well-differentiated PIP or squamous cell carcinoma should undergo colposcopy and targeted biopsy. HIV infection is not an indication for colposcopy in women with normal Pap smears.

[ 1 ], [ 2 ]