Management trends and mortality risk of oral cavity severe dysplasia/carcinoma in situ.

OBJECTIVE(S): Oral cavity severe dysplasia/carcinoma in situ (CIS) represents a management conundrum. The rate of malignant progression, comparative effectiveness of treatment approaches, and prognosis are poorly defined. Existing data support resection, ablation, or surveillance. Such conflicting reports lead to undertreatment/overtreatment of a controversial condition. We investigate severe dysplasia treatment patterns and outcomes. MATERIALS/METHODS: U.S. cancer registry data (2004-2021) were used to analyze severe dysplasia and oral cavity carcinoma. Cases with regional or distant metastases were excluded. Multivariable Cox regression models were constructed to determine associations between covariates and overall survival (OS). RESULTS: Overall, 3,502 TisN0 cases and 42,887 T1-T4N0 cases were identified across 1298 institutions (Tis (7.5%), T1 (41.9%), T2 (25.0%), T3 (9.6%), T4 (16.0%)). On univariate analysis, higher T-classification correlated with poorer outcomes (10-yr OS: Tis (60.6%), T1 (56.6%), T2 (46.1%), T3 (40.1%), T4 (32.9%)) (p < 0.001). Tis cases undergoing wide resection performed better than those with local excision/ablation (10 yr OS: 62.4% vs. 58.8%, p = 0.01). Tis cases resected with negative margins performed better than those with positive margins or under observation (10 yr OS: 61.6% vs. 55.7% vs. 52.1%, p = 0.02). On multivariable analysis, positive margins (HR 1.21 [95% CI 0.98-1.50], p = 0.008), observation (HR 1.06 [95% CI 0.80-1.40], p = 0.007), and local excision/ablation (HR 1.08 [95% CI 0.94-1.24], p = 0.006) were associated with worse OS. Landmark analysis at one year confirmed these results. CONCLUSION: Large-scale, long-term analysis supports that severe dysplasia outcomes perform similarly to that of early-stage oral cavity malignancy, with inferior outcomes when undertreated. Definitive resection with negative margins appears predictive of improved mortality risk.