Yield of Cytology Surveillance after High-Grade Vulvar Intraepithelial Neoplasia or Cancer

Objectives The aim of the study was to estimate the risk of high-grade cervical and vaginal intraepithelial neoplasia (CIN/VAIN 2+) and cancer among women treated surgically for high-grade vulvar intraepithelial neoplasia (HGVIN) and vulvar cancer. Materials and Methods We performed a retrospective cohort study of women who underwent surgery for HGVIN/vulvar cancer between 2006 and 2010. Univariate and multivariate analyses using stepwise selection were used to identify correlates of abnormal cytology after treatment for VIN and vulvar cancer. Results Among 191 women under surveillance for a median of 3.7 years who underwent treatment for HGVIN/vulvar cancer, primary vulvar lesions included VIN 2 (10, 5%), VIN 3 (102, 53%), and carcinoma (79, 41%). During follow-up, 71 (37%) had abnormal cytology, including 47 (25%) low grade, 23 (12%) high grade, and 1 (0.5%) carcinoma. Subsequent risk for VAIN 2+ was 11% (6/57) after previous hysterectomy and 8% for CIN 2+ (10/124) with intact cervix. Overall risk for CIN 3+ was 5%. Correlates of high-grade cytology after treatment for HGVIN/vulvar cancer included nonwhite race (odds ratio [OR] = 3.3, 95% CI = 1.50-7.36), immunodeficiency (OR = 4.2, 95% CI = 1.76-9.94), and previous abnormal cytology (OR = 2.7, 95% CI = 1.29-5.78). Stepwise multivariate analysis revealed immunosuppression as the only significant correlate of high-grade cytology after vulvar treatment (adjusted OR = 3.7, 95% CI = 1.26-10.83). Conclusions Women with HGVIN/cancer should have cervical/vaginal cytology before vulvar surgery. Those with a negative cervical or vaginal cytology result should undergo cytology testing at 1- to 3-year intervals, based on the threshold for CIN 3+ set forth by the American Society for Colposcopy and Cervical Pathology.