Prognostic Performance of Current Stage III Oral Cancer Patients After Curative Intent Resection: Evidence to Support a Revision of the American Joint Committee on Cancer Staging System.

BACKGROUND: The American Joint Committee on Cancer (AJCC) stage III classification of oral cavity squamous cell carcinoma (OCSCC) represents a heterogeneous group of patients with early local disease with regional metastases (T1N1 and T2N1) and advanced local disease with or without regional metastasis (T3N0 and T3N1). OBJECTIVE: The aim of this study was to evaluate prognostic heterogeneity in the stage III category. METHODS AND PATIENTS: An international retrospective multicenter study of 1815 patients who were treated for OCSCC from 2003 to 2011. RESULTS: Kaplan-Meier survival analysis and multivariate models of stage III patients revealed better overall survival (OS; HR 2.12, 95 % CI 1.03-4.15; p = 0.01) and disease-specific survival (DSS; HR 1.7, 95 % CI 1.16-4.12; p = 0.04) rates for patients with T1-2N1/T3N0 disease than for patients with T3N1 disease. The outcomes of patients with T3N1 and stage IVa disease were similar (p = 0.89 and p = 0.78 for OS and DSS, respectively). Modifying stage classification by transferring the T3N1 category to the stage VIa group resulted in a better prognostic performance [Harrell's concordance index, C index 0.76; Akaike's Information Criterion (AIC) 4131.6] compared with the AJCC 7th edition staging system (C index 0.65; AIC 4144.9) for OS. When DSS was assessed, the suggested staging system remained the best performing model (C index 0.71; AIC 1061.3) compared with the current AJCC 7th edition staging (C index 0.64; AIC 1066.2). CONCLUSIONS: The prognosis of T3N1 and stage IVa disease are similar in OCSCC, suggesting that these categories could be combined in future revisions of the nodal staging system to enhance prognostic accuracy.

Lymph node density in oral cavity cancer: results of the International Consortium for Outcomes Research.

BACKGROUND: Lymph node density (LND) has previously been reported to reliably predict recurrence risk and survival in oral cavity squamous cell carcinoma (OSCC). This multicenter international study was designed to validate the concept of LND in OSCC. METHODS: The study included 4254 patients diagnosed as having OSCC. The median follow-up was 41 months. Five-year overall survival (OS), disease-specific survival (DSS), disease-free survival (DFS), locoregional control and distant metastasis rates were calculated using the Kaplan-Meier method. Lymph node density (number of positive lymph nodes/total number of excised lymph nodes) was subjected to multivariate analysis. RESULTS: The OS was 49% for patients with LND0.07 compared with 35% for patients with LND>0.07 (P<0.001). Similarly, the DSS was 60% for patients with LND0.07 compared with 41% for those with LND>0.07 (P<0.001). Lymph node density reliably stratified patients according to their risk of failure within the individual N subgroups (P=0.03). A modified TNM staging system based on LND ratio was consistently superior to the traditional system in estimating survival measures. CONCLUSION: This multi-institutional study validates the reliability and applicability of LND as a predictor of outcomes in OSCC. Lymph node density can potentially assist in identifying patients with poor outcomes and therefore for whom more aggressive adjuvant treatment is needed.

Clinical nodal stage is a significant predictor of outcome in patients with oral cavity squamous cell carcinoma and pathologically negative neck metastases: results of the international consortium for outcome research.

BACKGROUND: We aimed to study the importance of clinical N classification (cN) in a subgroup of patients with oral cavity squamous cell carcinoma (OSCC) and pathologically negative neck nodes (pN-). METHODS: A total of 2,258 patients from 11 cancer centers who underwent neck dissection for OSCC (1990-2011) had pN- disease. The median follow-up was 44 months. 5-year overall survival (OS), disease-specific survival (DSS), disease free survival, local control, locoregional control, and distant metastasis rates were calculated by the Kaplan-Meier method. cN classification and tumor, node, metastasis classification system staging variables were subjected to multivariate analysis. RESULTS: A total of 345 patients were preoperatively classified as cN+ and 1,913 were classified as cN-. The 5-year OS and DSS of cN- patients were 73.6 and 82.2 %, respectively. The 5-year OS and DSS of cN+ patients were 64.9 and 76.9 %, respectively (p < 0.0001 each). A cN+ classification was a significant predictor of worse OS (p = 0.03) and DSS (p = 0.016), regardless of treatment, depth of invasion, or extent of neck dissection. cN classification was associated with recurrence-free survival (p = 0.01) and locoregional (neck and primary tumor) control (p = 0.004), but not with local (p = 0.19) and distant (p = 0.06) recurrence rates. CONCLUSIONS: Clinical evidence of neck metastases is an independent predictor of outcome, even in patients with pN- nodes.