We read with interest that McAllum et al reported a 62% regression rate of cervical intraepithelial neoplasia (CIN) 2 for women aged <25 years. This observation is consistent with an overall regression rate of 70% within 3 years in a prospective study of CIN 2 in adolescents and young women. We agree that routine treatment of CIN 2 may not be necessary in these patients and discuss additional aspects.

In 1990, Richart proposed a 2-tier terminology based on histological criteria only: “low-grade CIN” comprised koilocytic atypia and CIN 1; and “high-grade CIN” comprised CIN 2 and CIN 3. The high-grade lesions were considered true precursors of invasive cancer. This is the reason that cases of CIN 2 only are treated at many institutions like CIN 3. However, it is fundamental to recognize that CIN 2 will not obligatorily progress to invasive cancer.

At our colposcopic clinic, indications for conization are CIN 3, adenocarcinoma in situ, early stromal invasion, persistent CIN 2 for 1 year, persistent CIN 1 for 2 years, and rare cases with persistent abnormal cytology with negative histology, but not an initial diagnosis of CIN 2, independent of age. In a consecutive series of 385 patients at our clinic from 2007 through 2011, only 28 (12%) patients needed treatment for persistent CIN 2, suggesting that persistent CIN 2 is rare. On the other hand, definitive cone histology after persistent CIN 2 in colposcopically guided biopsies revealed in 55% a CIN 3, indicating either a high percentage of underdiagnosis of CIN 3 in biopsies or a potential of CIN 2 to progress to CIN 3.

It is generally accepted that, in addition to persistent high-risk human papillomavirus infection, several cofactors are needed in cervical carcinogenesis. Syrjänen et al demonstrated that cofactors involved in progression from normal epithelium to CIN 1 are different from those associated with progression to CIN 2 and from those in CIN 3 suggesting distinct entities with unique risk profiles.

Growing evidence calls for a modification of the concept of Richart, possibly by including additional reproducible biomarkers, in which CIN 1 and CIN 2 at initial diagnosis should be managed as low-grade lesions with a watchful waiting policy while persistent CIN 2 should be referred to immediate treatment. Such a modified approach may improve management of CIN and prevent overtreatment of CIN 2, which is especially important for women of childbearing age.