Residual anogenital lichen sclerosus after cancer surgery has a high risk for recurrence: a clinicopathological study of 75 women.

OBJECTIVES: Despite the strong association of lichen sclerosus (LS) and vulvar squamous cell carcinoma (SCC), the role of LS as precancerous lesion is unclear and the risk for recurrent SCC in residual LS after surgery for a LS-associated SCC is unknown.
METHODS: Recurrences in residual vulvar LS after complete resection of a LS-associated SCC were analyzed in 75 women. Primary SCC, recurrences and 19 biopsies obtained 1-6 months before recurrent SCC were evaluated histologically, and for presence of HPV and monoclonally rearranged T-cell receptor gamma locus (mTRG@).
RESULTS: 40/75 patients (53%; primary SCC 25pT2, 9pT1b, 6pT1a) had no recurrence for 64 months (range 10-176 months), but 35/75 women (47%; primary SCC 1pT3, 18pT2, 13pT1b, 3pT1a) developed recurrences after 42 months (range 3-156 months). Twenty-five women had 1 recurrence: 13SCC within 18 months, 1SCC after 26 months, 10SCC and 1 differentiated vulvar intraepithelial neoplasia (d-VIN) after 74 months (range 52-136 months). Ten patients suffered multiple recurrences: 3 women had 2 recurrent d-VIN, 7 patients had multiple successive de-novo SCC with lymphocytes with mTRG@ in 6 patients. Wider resections correlated with no/late recurrences. Nineteen HPV-negative biopsies before diagnosis of recurrent SCC revealed 4 classical d-VIN and 15 verrucous, atrophic or flat intraepithelial proliferations different from d-VIN.
CONCLUSION: With a 50% recurrence rate after cancer surgery, residual anogenital LS has a high risk for de-novo cancer. Extent of resection of LS-affected skin and activity of residual LS with lymphocytes with mTRG@ are important criteria for recurrences, which develop rapidly through a variety of HPV-negative intraepithelial lesions.