Tumor size rather than the thyroid invasion affects the prognosis of parathyroid carcinoma without lymph node or distant metastasis.

PURPOSE: This study aimed to explore the prognostic value of thyroid invasion of parathyroid carcinoma without lymph node or distant metastasis. METHODS: Two hundred and nine cases of parathyroid carcinoma from the SEER (1989-2014) were eligible for this study. A Chi-squared test, t test, X-tile, Kaplan-Meier curves, and multivariate Cox proportional hazard regression were used for analysis. RESULTS: Thyroid invasion, sex, race, age, radiation, and surgery were not significantly associated with cancer-specific survival by multivariate analysis. However, tumor size ≥ 4 cm was significantly associated with worse cancer-specific survival (P < 0.001). CONCLUSION: Thyroid invasion, which was the criterion for T1 and T2 staging criteria of parathyroid carcinoma according to the AJCC, did not affect the prognosis of patients with parathyroid carcinoma without local lymph node or distant metastasis. Our study indicates that a tumor size ≥ 4 cm may be an appropriate indicator of T1 and T2 cancer staging.

Role of primary tumor resection in patients with metastatic medullary thyroid cancer who have unresectable distant metastases.

BACKGROUND: Whether patients with medullary thyroid carcinoma (MTC) who have unresectable synchronous distant metastases should undergo primary surgical resection (PTR) remains controversial. This study aimed to identify predictive factors associated with the survival of such patients. METHODS: We conducted a retrospective study of patients with MTC who were registered in the Surveillance, Epidemiology, and End Results registry. The overall and cancer-specific mortality rates were assessed using risk-adjusted Cox proportional hazards regression modeling and stratified propensity score matching. RESULTS: One hundred and eight matched patients were assessed. Patients in the PTR group had lower overall mortality than did those in the non-PTR group. The 1-, 3-, and 5-year overall and cancer-specific survival rates in the PTR group were significantly higher. CONCLUSIONS: PTR appears to be the most appropriate intervention for patients with good performance status. Such patients are likely to benefit from surgery and to experience long-term stable disease.