8%, 83.1%, and 80.2%, respectively (Fig. 1). The 5-, 10-, and 15-year overall survival and disease-free survival rates were 68.9%, 52.2%, and 44.1%, and 81.3%, 79.3%, and 76.3%, respectively. There were a total of 48 local recurrences (LRs) among the 385 patients: 16 LR for the 172 T1 patients, 25 LR for the 167 T2 patients, 5 LR for the 17 T3 patients, and 2 LR for the 14 T4 patients. Nearly, all LRs (40/48) developed in the first 3 years after therapy, the mean time to LR was 20 ± 26 months (Fig. 2). The 5-and 10-year LR-free survival buy GSK458 rates of the entire group according to

tumor size and nodal status were 91.3% and 90.5 for stage T1/2 N0/1 and 80% for stage T1/2 N2, respectively (Fig. 3). For the small number of patients with large tumors such as T3/4 N0/1 or T3/4N2 (31/385), the 5-year LR-free

and overall survival rates were 88.9% and 51.1%, respectively. In the detailed analysis of all patients, we did not identify any statistically significant differences with respect Galunisertib solubility dmso to anatomic site or tumor size. We found a significant influence of the extent of lymph node involvement on treatment results. In N0-/N1- vs. N2-patients, we observed significantly different 5-year LR-free survival rates with values of 92.3% and 73.7%, respectively (p = 0.007, Fig. 4). No other tumor- or patient-related factor showed a significant correlation with treatment results either in univariate or multivariate analysis. Regarding treatment factors, we only identified surgery to have a significant influence Phosphatidylethanolamine N-methyltransferase on treatment results. The 5-year LR-free survival was 93.4% with surgery and 72% without surgery (p = 0.002). In this context, it is important to note that there was a considerable negative selection bias affecting prognosis in patients without surgery—for patients with or without surgery, large tumors (T3/T4) were recorded in 6.5% and 25%, respectively and N2 status in 12.1% and 37.5%, respectively. During

followup, we observed metastases in 41 of 385 patients (10.6%). Only 13 of 385 (3.4%) patients developed regional lymph node metastases, the other 28 of 385 (6.2%) patients developed distant metastases. The median time to appearance of metastases was 12 months. Serious late side effects, such as soft tissue or bone necrosis, were observed in 39 of 385 patients (10.2%) and 18 of 385 patients (4.9%), respectively. In patients with soft tissue necrosis, further surgical treatment was necessary in 13 of 39 (13/385, 3.4%) patients; in patients with bone necrosis, surgical treatment was necessary in 13 of 18 (13/385, 3.4%) patients. For tumors of the oral tongue treated with primary LDR brachytherapy, we know from large retrospective series that the local control rate strongly depends on tumor size and varies between 62–69% for T3 tumors and 88–93% for T1 tumors [2], [3], [4], [5], [6], [7], [8], [10], [21], [23], [24], [25], [26] and [27].