The Analysis of Tumor Aggressiveness According to Tumor Size in Papillary Thyroid Carcinoma Less Than 2 cm in Size in Korean Patients

Abstract

Purpose: Papillary thyroid carcinomas (PTC) less than 2 cm in size are believed to be a less aggressive subset of PTC which behave more like benign lesions and are often more conservatively treated. However, it is unclear whether carcinoma no larger than 2.0 cm in diameter can be expected to have a similar favorable clinical behavior as tumors no larger than 1.0 cm. Therefore, to address this question and to characterize the biology and optimal treatment for PTC less than 2 cm, we performed a retrospective chart review. Methods: From October 2001 to March 2013, 649 patients underwent surgery for PTC less than 2 cm. Data from these patients were retrospectively analyzed. Results: The mean age of these patients was 43.2 years and 91.7% were female. 52.9% of the patients underwent a total or near-total thyroidectomy. Of the 649 patients, 2196 (30.2%) had lymph node metastases. The patients present with signs of aggressiveness including multifocality (42.5%), bilaterality (24.3%), capsular invasion (44.5%). Lymph node metastases were associated with tumor size (p=0.008) only, but not capsular invasion, bilaterality, multifocality, age and sex. With follow-up of up to 138 months, 7 patients had a local recurrence (recurrence rate=1.1%), 2 patients had a distant metastasis. No patients have died during this period. Conclusion: In PTC less than 2 cm in size, progressively increasing frequency of signs of tumor aggressiveness including bilaterality, capsular invasion and lymph node metastasis with increasing tumor size.