NEW YORK (Reuters Health) – All women found to have vulvar intraepithelial neoplasia (VIN) require some form of treatment and follow-up surveillance, according to recommendations from The American College of Obstetricians and Gynecologists (ACOG) Committee on Gynecologic Practice.

“Three modes of therapy are acceptable,” Dr. L. Stewart Massad from Washington University, St. Louis, Missouri told Reuters Health in an email, “surgical excision, laser ablation, and topical imiquimod; excision is required when a component of invasive cancer is suspected but otherwise all three are acceptable.”

According to the report published in the November Obstetrics & Gynecology, the incidence of VIN more than quadrupled between 1973 and 2000. In the latest diagnostic classification from the International Society for the Study of Vulvovaginal Disease (ISSVD), only high-grade disease qualifies as VIN.

The Committee Opinion notes that the quadrivalent HPV vaccine decreases the risk of VIN and should be recommended for women who qualify for the vaccine.

Screening has not been shown to prevent vulvar cancer through early detection of VIN, and diagnosis is limited to visual assessment, usually with the help of colposcopy or other forms of magnification of the vulva.

The committee recommends biopsy of presumed genital warts in postmenopausal women and in women in whom topical treatments have failed.

Wide local excision is preferred when clinical or pathologic findings suggest invasive cancer, whereas laser ablation is acceptable when cancer is not suspected. Medical therapy with topical imiquimod is also effective for the treatment of VIN, although imiquimod is not FDA-approved for this indication.

Recurrence rates after treatment can reach 50%, so women with VIN should be considered to be at risk of recurrent VIN and vulvar cancer throughout their lifetimes. For this reason, the committee recommends follow-up visits at 6 and 12 months after initial treatment, followed by annual monitoring for women found not to have any new lesions.

“They should consider inspecting vulvar skin every few months and should continue Pap testing with at least annual clinician inspection of the vulva,” Dr. Massad said. “Smoking contributes to risk for VIN and women with VIN who smoke should stop.”

“Women should be aware of their vulvar skin and should see a clinician if changes occur,” Dr. Massad concluded. “They should ask clinicians doing pelvic exams if any lesions were seen, to ensure careful inspection. Clinicians should have a high suspicion for VIN and should consider biopsy for new lesions.”

Committee Opinion No. 509: Management of Vulvar Intraepithelial Neoplasia

Obstet Gynecol 2011;118:1192-1194.