Recurrence factors and prevention of complications of pediatric differentiated thyroid cancer.

BACKGROUND/OBJECTIVE: To investigate the factors associated with recurrence of differentiated thyroid cancer in children. We combined the clinical and pathological features to guide surgical treatment options, ensure efficacy, and reduce complications.

METHODS

A prospective analysis of clinical data of 43 cases of pediatric differentiated thyroid cancer from March 2008 to June 2014 admitted in our department, including 38 cases of papillary cancers and five cases of follicular cancer; 40 cases were Stage I and three cases were Stage II (Union for International Cancer Control [UICC] Tumor Node Metastasis classification [TNM] staging). We performed the operations according to the condition of lesions and lymph nodes. Operations included subtotal resection in 36 cases, total resection in seven cases. We applied statistical methods to investigate the risk factors of recurrence and postoperative complications.

RESULTS

The pathologic lymph node metastasis rate was 67.44% (29/43): Area VI lymph nodes metastases in 20 cases and Area III/IV or Area II/V lymph nodes metastases in nine cases. Postoperative hypocalcemia symptoms were seen in three cases and hoarseness in three cases, for a total rate of 13.95% (6/43). Until December 2015, patients were followed up from 1.5 years to 8.7 years, with a median of 4.9 years. There were three cases of cervical lymph node recurrence, one case of local recurrence, and one case of lung metastasis, for a total recurrence rate of 11.63% (5/43); all patients survived. Log-rank test of Kaplan-Meier curves and Cox stepwise regression analysis showed that lesion number, extrathyroidal extension, and lymph nodes metastases were the risk factors for postoperative recurrence; the relative risk values were, respectively, 3.117, 2.816, and 4.628 (p=0.041, p=0.048, and p=0.031, respectively) and the 95% confidence intervals (CI) were, respectively, 1.094∼8.735, 1.046∼7.932, and 1.189∼10.205. However, the lesion excision approach was not a risk factor for postoperative recurrence (p=0.107). The logistic stepwise regression model showed that lesion excision approach was a risk factor for postoperative hypocalcemia and hoarseness; the odds ratio value was 2.537 (p=0.037) and the 95% CI was 1.034∼6.983.

CONCLUSION

Pediatric differentiated thyroid cancer has a high metastatic rate to lymph nodes and distant organs, but the total prognosis is good. Application of total resection cannot necessarily reduce the relapse rate of pediatric differentiated thyroid cancer, but it may increase the postoperative hypocalcemia and hoarseness. The authors propose strictly adhering to various operation indicators, and carrying out various operations with a full understanding of the local lesion and lymph nodes in order to reduce relapse and postoperative complications.