Long-Term Recurrence of Small Papillary Thyroid Cancer and Its Risk Factors in a Korean Multicenter Study
Authors
Yul Hwangbo ; Jung Min Kim ; Young Joo Park ; Eun Kyung Lee ; You Jin Lee ; Do Joon Park ; Young Sik Choi ; Kang Dae Lee ; Seo Young Sohn ; Sun Wook Kim ; Jae Hoon Chung ; Dong Jun Lim ; Min Hee Kim ; Min Joo Kim ; Young Suk Jo ; Min Ho Shong ; Sung-Soo Koong ; Jong Ryeal Hahm ; Jung Hwa Jung ; Ka Hee Yi
Citation
JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM, Vol.102(2) : 625-633, 2017
CONTEXT: Small papillary thyroid cancer (PTC) generally has an excellent prognosis. However, long-term recurrence is not uncommon and sometimes leads to morbidity or mortality.
OBJECTIVE: To identify high-risk factors for long-term recurrence in patients with small PTC by stratifying their pathologic characteristics.
DESIGN, SETTING, AND PATIENTS: We conducted a nationwide, retrospective, multicenter study of 3282 patients with PTC sized ≤2 cm from 9 high-volume hospitals in Korea.
MAIN OUTCOME MEASURES: The maximally selected χ2 method was used to find the best cutoff points of tumor size, the number of metastatic lymph nodes (LNs), and the ratio of metastatic/examined LNs (LNR) to predict recurrence. Kaplan-Meier analysis and the Cox proportional hazards regression model were used to analyze recurrence and risk factors.
RESULTS: The optimal tumor size cutoff was 1.8 cm (10-year recurrence rates for tumors sized 0.1 to 1.7 cm and 1.8 to 2.0 cm: 7.7% vs 17.2%, respectively). Metastatic LNs ≤1 and ≥2 provided optimal estimates of recurrence (10-year recurrence rates: 4.0% vs 16.8%, respectively). The LNR of 0.19 was the optimal cutoff point for predicting the risk of recurrence (10-year recurrence rates for LNRs of 0 to 0.18 and 0.19 to 1: 2.7% vs 16.2%, respectively). LN metastasis, lobectomy, tumor size ≥1.8 cm, and bilateral tumors were independent risk factors for recurrence.
CONCLUSIONS: Long-term recurrence was increased in patients who underwent lobectomy or with tumor sized ≥1.8 cm, 2 or more metastatic LNs, or bilateral tumors. For patients with these high-risk features, total thyroidectomy could be considered to avoid reoperation.