Results
Overall, 236 patients were diagnosed with oral tongue cancer between January 2011 and December 2016; however, 45 patients had no pre-operative CT or MRI scan imaging, 118 patients had no pathologic lymph node, and three patients were non-Thais. Finally, 70 patients were included in the study.
Males were predominant (67.1%). The mean age (SD) was 58 (SD) years old. 62.8% of the patients were in stage IVA, and 70% of the histopathological results were well-differentiated squamous cell carcinoma (SCCA). For overall survival analysis, the patients’ median survival time was 13 months, the 1-year survival rate was 51%, and the 3-year survival rate was 24%.
Recurrence of the disease was found in 17 patients (24.2%), which the sites of recurrence were oral tongue (14 patients) and cervical lymph node (3 patients). The distant metastasis was present in 19 patients, including lungs (12 patients), bones (4 patients), and other sites (3 patients).
The mean (SD) nodal volume was 5.31 (SD) cm3. In ROC curve analysis, the optimal cut-off value for the nodal volume was 3.95 cm3 (Area under the curve (AUC) = 0.672, Sensitivity = 65.5%, and Specificity = 73.3%) (Figure 2). Regarding the optimal nodal volume cut-off value, the patients were classified into 1) the nodal volume of <3.95 cm3 group (30/70 patients, 42.9%) and 2) the nodal volume of ≥3.95 cm3group (40/70 patients, 57.1%). The patients’ demographics and clinical characteristics are illustrated in Table 1.
Additionally, the median (IQR) nodal volume of the patients in the dead group was significantly higher than the alive group (6.5 cm3 (2.49-23.12) vs 3.1 cm3(1.9-7.7), p = 0.043). The nodal volume of the patients with distant metastasis was likely to be larger than the patients with no metastasis. (Table 2)