Effect of Tumor Size and Minimal Extrathyroidal Extension in Patients with Differentiated Thyroid Cancer.

INTRODUCTION: Risk-stratified treatment strategies have become a focus in the treatment of differentiated thyroid cancer (DTC). In the 2015 American Thyroid Association treatment guidelines, adjuvant treatment with radioactive iodine (RAI) is considered in the presence of minimal extrathyroidal extension (mETE). This study aimed to investigate the prognostic significance of mETE and tumor size in patients with DTC. METHODS: A retrospective review was undertaken of 2323 consecutive patients treated surgically for T1-T3 (defined per seventh edition of the American Joint Committee on Cancer staging criteria) and M0 DTC from 2000 to 2015 at The University of Texas MD Anderson Cancer Center. Patients were divided into four groups according to the size of the tumor (≤4 cm vs. >4 cm) and the presence of mETE. Predictors of disease-free survival (DFS), disease-specific survival, locoregional failure (LRF), and distant metastatic failure (DMF) were compared using the log-rank test and Cox's proportional hazards models. RESULTS: There were only seven DTC-related deaths, limiting the clinical significance of the analysis, especially of overall and disease-specific survival. Following multivariate analysis, patients with tumors >4 cm did worse than patients with tumors ≤4 cm with respect to DFS (group 3 [>4 cm without mETE] adjusted hazard ratio (HRadj) = 2.1 [confidence interval (CI) 1.1-3.8]; group 4 [>4 cm with mETE] HRadj = 2.9 [CI 1.6-5.1]). However, patients did not differ according to DFS, regardless of the presence of mETE within each size category (group 2 [≤4 cm with mETE] vs. group 1 [≤4 cm without mETE] HRadj = 1.3 [CI 0.9-1.8]; group 4 [>4 cm without mETE] vs. group 3 [>4 cm with mETE] HRadj = 1.0 [CI 0.5-2.3]). For LRF and DMF, size but not mETE was also an independent risk factor. CONCLUSION: Tumor size, but not the presence of mETE, was an independent predictor of DFS, LRF, and DMF in DTC.

[SURGICAL TREATMENT OF LOCALLY ADVANCED WELL DIFFERENTIATED THYROID CARCINOMA].

AIMS: We aimed to better define the most appropriate therapeutic protocol for this type of tumor. BACKGROUND: The incidence of well-differentiated thyroid carcinoma is rising and the mortality from the disease remains low for patients with early disease. Nevertheless, the survival of patients with advanced disease has not improved during the last four decades and a controversy still exists in the literature regarding the optimal treatment in patients with locally advanced (T4) differentiated thyroid carcinoma. METHODS: Meta-analysis of the literature and our institutional experience, in treating patients with advanced papillary/follicular thyroid carcinoma. The main outcome measures were overall survival (OS) and disease-specific survival (DSS). RESULTS: The study group consisted of 38 patients with locally advanced thyroid carcinoma (T4). Regional spread to nodal metastases was present in 25 (65.7%) patients. Tracheal invasion was diagnosed in 29 (76.3%), of those 10 (26.3%) patients had airway obstruction. Recurrent laryngeal nerve (RLN) paralysis was revealed with clinical evidence during diagnosis in 23 (60.5%) patients. The 5-years OS was 66% and DSS was 87%. Multivariate analysis of outcome showed that undifferentiated carcinoma foci and vocal cord paralysis were associated with significantly reduced 5-years OS, and vocal cord paralysis was the only independent prognostic variable for DSS. Male gender and adjuvant radioactive iodine treatment were significant prognostic variables for disease free survival but not OS or DSS. CONCLUSIONS: Surgical resection remains the mainstay of treatment for locally advanced differentiated thyroid cancers. Foci of poorly differentiated cells, vocal cord paralysis and male gender are associated with poor prognosis. Radioactive iodine treatment improved local control but did not not affect OS. These patients should be managed by a multidisciplinary team in university centers specializing in treating complicated cancer patients.

Primary tumor staging for oral cancer and a proposed modification incorporating depth of invasion: an international multicenter retrospective study.

IMPORTANCE: The current American Joint Committee on Cancer (AJCC) staging system for oral cancer demonstrates wide prognostic variability within each primary tumor stage and provides suboptimal staging and prognostic information for some patients. OBJECTIVE: To determine if a modified staging system for oral cancer that integrates depth of invasion (DOI) into the T categories improves prognostic performance compared with the current AJCC T staging. DESIGN, SETTING, AND PARTICIPANTS: Retrospective analysis of 3149 patients with oral squamous cell carcinoma treated with curative intent at 11 comprehensive cancer centers worldwide between 1990 and 2011 with surgery ± adjuvant therapy, with a median follow-up of 40 months. MAIN OUTCOMES AND MEASURES: We assessed the impact of DOI on disease-specific and overall survival in multivariable Cox proportional hazard models and investigated for institutional heterogeneity using 2-stage random effects meta-analyses. Candidate staging systems were developed after identification of optimal DOI cutpoints within each AJCC T category using the Akaike information criterion (AIC) and likelihood ratio tests. Staging systems were evaluated using the Harrel concordance index (C-index), AIC, and visual inspection for stratification into distinct prognostic categories, with internal validation using bootstrapping techniques. RESULTS: The mean and median DOI were 12.9 mm and 10.0 mm, respectively. On multivariable analysis, DOI was a significantly associated with disease-specific survival (P < .001), demonstrated no institutional prognostic heterogeneity (I² = 6.3%; P = .38), and resulted in improved model fit compared with T category alone (lower AIC, P < .001). Optimal cutpoints of 5 mm in T1 and 10 mm in T2-4 category disease were used to develop a modified T staging system that was preferred to the AJCC system on the basis of lower AIC, visual inspection of Kaplan-Meier curves, and significant improvement in bootstrapped C-index. CONCLUSIONS AND RELEVANCE: We propose an improved oral cancer T staging system based on incorporation of DOI that should be considered in future versions of the AJCC staging system after external validation.