Risk factors for unrecognized invasive carcinoma in patients with vulvar high-grade squamous intraepithelial lesion at vulvoscopy-directed biopsy

OBJECTIVE To evaluate the prevalence and risk factors for unrecognized invasive carcinoma in a series of patients undergoing surgical excision after an office biopsy of vulvar high-grade squamous intraepithelial lesion (VHSIL). METHODS Two hundred and sixteen consecutive patients treated in a tertiary-level referral center for vulvar disease in north-western Italy were recruited. Patients' records were reviewed by trained personnel. Factors showing a statistically significant (p<0.05) association with detection of stromal invasion at excisional surgery in univariate analysis were further examined in a backward stepwise multiple logistic regression model. RESULTS The median patient age was 50 years (range, 19-88). More than 25% patients with VHSIL at biopsy had associated cervical/vaginal intraepithelial neoplasia, and more than 35% had a multifocal lesion. Invasive carcinoma was detected in surgical specimens from 24 patients (11%). The depth of stromal invasion varied between 0.1 mm and 3.0 mm with a median of 0.5 mm. In multivariate analysis, the risk of invasive carcinoma detection was greater for patients in the highest tertile of age (p=0.008), for patients with a lesion ≥20 mm in size (p=0.013) and with clitoral involvement (p<0.001), and for patients presenting with a nodular lesion (p=0.078). CONCLUSION Our study suggests that patient age, lesion size, clitoral involvement and nodular appearance in patients with VHSIL at vulvoscopy-directed biopsy are independently associated with the risk of unrecognized invasive carcinoma.