Early squamous cell carcinoma of the oral tongue with histologically benign lymph nodes: A model predicting local control and vetting of the eighth edition of the American Joint Committee on Cancer pathologic T stage

• Published in: Cancer Vol. 125; no. 18; pp. 3198 - 3207
• Main Authors: Sridharan, Shaum, Thompson, Lester D. R., Purgina, Bibianna, Sturgis, Charles D., Shah, Akeesha A., Burkey, Brian, Tuluc, Madalina, Cognetti, David, Xu, Bin, Higgins, Kevin, Hernandez‐Prera, Juan C., Guerrero, Dominick, Bundele, Manish M., Kim, Seungwon, Duvvuri, Umamaheswar, Ferris, Robert L., Gooding, William E., Chiosea, Simion I.
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 15.09.2019
• Subjects: Adult; Aged; Aged, 80 and over; American Joint Committee on Cancer (AJCC) staging; Benign; Cancer; depth of invasion; Depth perception; Female; glossectomy; Hazards; Head and Neck Neoplasms - pathology; Health hazards; Humans; local disease recurrence; Lymph nodes; Lymph Nodes - pathology; Lymphatic system; Male; Middle Aged; Multivariate analysis; Neck; Neoplasm Invasiveness; Neoplasm Recurrence, Local - epidemiology; Neoplasm Staging; Nomograms; Oncology; oral tongue; pathologic T stage (pT); Prediction models; Predictive control; Prognosis; Proportional Hazards Models; Regression analysis; Regression models; Squamous cell carcinoma; Squamous Cell Carcinoma of Head and Neck - pathology; Statistical analysis; Tongue; Tongue Neoplasms - pathology; Tumors; Young Adult; depth of invasion; oral tongue; local disease recurrence; American Joint Committee on Cancer (AJCC) staging; glossectomy; pathologic T stage (pT); squamous cell carcinoma
• ISSN: 0008-543X; 1097-0142
• DOI: 10.1002/cncr.32199

Background The eighth edition of the American Joint Committee on Cancer staging manual (AJCC8) added depth of invasion to the definition of pathologic T stage (pT). In the current study, the authors assess pT stage migration and the prognostic performance of the updated pT stage and compare it with other clinicopathologic variables in patients with early squamous cell carcinoma of the oral tongue (OTSCC; tumors measuring ≤4 cm) with histologically benign lymph nodes (pN0). Methods A multi‐institutional cohort of patients with early OTSCC was restaged as per AJCC8. Primary endpoints were local recurrence (LR) and locoregional recurrence (LRR). Influential variables were identified and an LR/LRR prediction model was developed. Results There were a total of 494 patients, with 49 LR and 73 LRR. AJCC8 pT criteria resulted in upstaging of 37.9% of patients (187 of 494 patients), including 34.5% (64 of 185 patients) from pT2 to pT3, without improving the prognostication for LR or LRR. Both LR and LRR were found to be similar for patients with AJCC8 pT2 and pT3 disease. On multivariate analysis, LR was only found to be associated with distance to the closest margin (hazard ratio, 0.36; 95% CI, 0.20‐0.64 [P = .0007]) and perineural invasion (hazard ratio, 1.92; 95% CI, 1.10‐0.64 [P = .046]). Based on these 2 predictors, a final proportional hazards regression model (which may be used similar to a nomogram) was developed. The proposed model appeared to be superior to AJCC pT stage for estimating the probability of LR and LRR for individual patients with early OTSCC. Conclusions AJCC8 pT criteria resulted in pT upstaging of patients with pN0 disease without improved LR or LRR prognostication. The proposed model based on distance to the closest margin and perineural invasion, status outperformed pT as a predictor of LR and LRR in patients with early OTSCC. In this study, pT criteria based on the eighth edition of the American Joint Committee on Cancer result in pT upstaging of patients with pN0 disease without improved prognostication of local control. The model, based on distance to the closest margin and perineural invasion, is noted to outperform pT as a predictor of local control in patients with early carcinoma of the oral tongue.