What is CIN 2 and how should it be treated? The debate over whether cervical intraepithelial neoplasia grade 2 is a real, distinct entity continues.(Gynecology)(Cervical intraepithelial neoplasia )

LAS VEGAS -- Experts are divided on how aggressively cervical intraepithelial neoplasia grade 2 should be treated, and on whether observation is an acceptable option, especially in low-risk populations.

Cervical intraepithelial neoplasia (CIN) has been regarded as a preinvasive condition, with progressively higher grades being associated with an increasing risk of cancer. As most CIN 1 lesions regress without treatment, it has been suggested that CIN 2 may also have limited potential to progress to a more invasive disease.

"The goal of treatment for CIN is to prevent cancer by eliminating lesions with true malignant potential," Dr. Mark Spitzer said at a meeting of the American Society for Colposcopy and Cervical Pathology. "And we also want to avoid unnecessary treatment of lesions with little or no premalignant potential."

The data are mixed, said Dr. Spitzer of New York University, New York. Some studies show that CIN 2 is an intermediate entity that lies between CIN 1 and CIN 3 and has some premalignant potential although not as great as that of CIN 3. Other studies show that it is much closer to CIN 1 or benign disease, so it does not have real premalignant potential.

That raises the question, "Is the diagnosis of CIN 2 a reliable or reproducible diagnosis?" Dr. Spitzer said.

He pointed out that a few studies have assessed that question, and one concluded that interobserver variation is fair to good for the diagnosis of benign conditions, CIN 3, or invasive cancer, but poor for the diagnosis of CIN 1 or CIN 2. There is also poorer correlation between colposcopic and histologic diagnosis with CIN 2, compared with CIN 1 and CIN 3.

"The problem with CIN 2 is that we don't really know what it is," Dr. Spitzer said. Any system of grading an intraepithelial lesion, in which there is a lesional continuum, is essentially artificial. A grading system that is based on light microscopy is subject to inter- and intraob-server variations in reporting, and treating all patients with CIN 2 will clearly result in the overtreatment of many of them.