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.