Treatment - Cervical Intraepithelial Neoplasia

Treatment

Both excisional and ablative techniques are used to treat CIN. The underlying concept in the treatment of CIN is that excision or ablation of the precursor lesion prevents progression to carcinoma.  

Ablative methods destroy the affected cervical tissue and include cryotherapy, laser ablation, electrofulguration, and cold coagulation, all of which are outpatient procedures that can be performed with regional anesthesia. Ablative methods should be used only with an adequate colposcopy and appropriate correlation between Pap test results and colposcopically directed biopsy.

Laser therapy is now only rarely performed in the United States. Cryotherapy is a commonly used out-patient method used to treat persistent CIN 1. The pro-cedure involves covering the SCJ and all identified lesions with a stainless steel probe, which is then supercooled with liquid nitrogen or compressed gas (carbon dioxide or nitrous oxide). The size and shape of the probe depends on the size and shape of the cervix and the lesion to be treated. The most common technique involves a 3-minute freeze followed by a 5-minute thaw, with a repeat 3-minute freeze. The thaw period between the two freezing episodes allows the damaged tissue from the first freeze to become edema-tous and swell with intracellular fluid. With the second freeze, the edematous cellular architecture is refrozen and extends the damaged area slightly deeper into the tissue. Healing after cryotherapy may take up to 4 or 5 weeks, because the damaged tissue slowly sloughs and is replaced by new cervical epithelium. This process is associated with profuse watery discharge often mixed with necrotic cellular debris. The healing process is complete within 2 months. A follow-up Pap test is usually preformed 12 weeks following the freezing to ascertain the effective-ness of the procedure. The cure rate for CIN 1 using this technique approaches 90%.

Excisional methods remove the affected tissue andprovide a specimen for pathologic evaluation. These meth-ods include cold-knife conization (CKC), loop electrosurgi-cal excision procedures (LEEP or large loop excision of the transformation zone [LLETZ]), laser conization, and elec-trosurgical needle conization. These procedures are per-formed under regional or general anesthesia. A cone-shaped specimen is removed from the cervix, which encompasses the SCJ, all identified lesions on the ectocervix, and a por-tion of the endocervical canal, the extent of which depends on whether the ECC was positive or negative. Because LEEP uses electrosurgical energy, thermal damage may occur at the margins of the specimen, obscuring the histol-ogy. Thermal damage is usually not considered a problem in the evaluation of squamous epithelial abnormalities, but it may be a substantial issue in the evaluation of glandular epithelial lesions, where abnormal cells in the bottom of glandular crypts may be altered. In cases of glandular abnor-malities, CKC may be more appropriate.

If the margins of the biopsy are not free of disease, the patient should have either repeat conization or close follow-up because of the possibility that disease remains. If the margins are positive for a high-grade epithelial lesion or carcinoma in situ, the most appropriate treat-ment may be hysterectomy, if the patient has no desire for future childbearing. If the patient wants to preserve her fertility, colposcopy with ECC and HPV-DNA testing is an acceptable management protocol.

Excisional procedures are also indicated in the follow-ing situations:

·      When an ECC is positive

·      Unsatisfactory colposcopy: If the SCJ is not visualized in its entirety or if the margins of abnormal areas are not seen in their entirety during colposcopy, the colpo-scopic assessment is termed unsatisfactory and other evaluation such as cervical conization or endocervical curettage (ECC) is indicated.

·      If a substantial discrepancy is seen between the screening Pap test and the histologic data from biopsy and ECC (i.e., the biopsy does not explain the source of the abnor-mal Pap test).: In this situation, which occurs in approx-imately 10% of colposcopies with directed biopsies and ECC, more tissue needs to be obtained by an excisional procedure for further testing.

CKC is associated with an increased risk of preterm labor, low–birth-weight infants, and cesarean delivery. LEEP and LLETZ are also associated with an increased risk of preterm labor, low–birth-weight infants, and pre-mature rupture of membranes. Both types of excisional procedures are also associated with the usual risks of any surgery (bleeding, infection, and anesthetic risks).