GPP14: Risk factors associated with persistent disease, recurrence and evidence of disease 5 years after treatment in papillary thyroid cancers smaller than 2cm with and without gross invasion
Assistant Professor Gachon University College of Medicine Incheon, Republic of Korea
Introduction Papillary thyroid carcinomas (PTC) often demonstrate persistent disease, recurrence and evidence of disease 5 years after treatment. The aim of this study was to analyze the risk factors associated with these factors in PTCs smaller than 2cm. Methods We conducted a retrospective analysis of PTC smaller than 2cm patients who received operations from 2002 to 2017. Patients were divided into two groups: PTC ≤2cm and T1 PTC. Results Patients with PTC ≤ 2cm have a higher risk of recurrence with T4a, and N1a/N1b status whereas T1 stage PTC patients tend to recur in younger, margin positive, and N1a/N1b patients. Furthermore, patients with PTC ≤ 2cm regardless of gross invasion status tend to show persistent disease and evidence of disease 5 years after treatment in N1aN1b patients and ETE positive, N1b patients, respectively. Only the patient with persistent metastatic disease in both the lung and bone died during the study period. There were several significant difference between patients with and without persistent disease. Patients with persistent disease tended to have larger lesions (p = 0.141) demonstrated more frequent multifocality (p=0.040), bilaterality (p=0.002), lymph node metastasis (p < 0.001), and a larger proportion of higher T, N, M, and TNM stage (p < 0.001). Further logistic regression demonstrated odds ratios of 3.52 and 14.96 for N1a and N1b patients respectively, to experience persistent disease. Conclusions In conclusion, patients with PTC ≤ 2cm have a higher risk of recurrence with T4a (i.e., gross invasion), and lymph node metastasis whereas T1 stage PTC patients tend to recur in younger patients, patients with positive resections margins, and lymph node metastasis. Furthermore, patients with PTC ≤ 2cm regardless of gross invasion status have a higher risk of persistent disease and evidence of disease 5 years after treatment in N1aN1b patients and ETE positive, N1b patients, respectively.