Early Recurrence of Papillary and Follicular Thyroid Carcinoma Predicts a Worse Outcome

Background: The occurrence of recurrent papillary and follicular thyroid carcinomas is not unusual. Numerous studies have reported the association between risk factors of initial surgery and recurrence of papillary and follicular thyroid carcinomas. However, we do not have sufficient data to analyze the time of postoperative recurrence associated with therapeutic results and cancer mortality. We hypothesized that an early recurrence of papillary and follicular thyroid cancers implies a rapid growth of cancer resulting in high mortality rate. Methods: We conducted a retrospective study in a medical center in northern Taiwan. The investigation included 2148 cases of papillary and follicular thyroid carcinoma, including 325 recurrent cases during the period between 1977 and 2006. The studied cases were categorized into early or late recurrence groups. Cases with an early recurrence were defined as those in which recurrence occurred in the first year following thyroid surgery. Results: Tumor size, radioactive iodide treatment, multifocality, and tumor-node metastasis stage were independent predictors of recurrence. After a mean follow-up of 8.7 +/- 0.1 years, death due to thyroid cancer was observed to occur in 105 (32.3%) recurrent cases. Among the 325 recurrent cases, early recurrence was detected in 185 cases, and late recurrence was detected in 140 cases. Early recurrence was mostly observed in older male patients; a high mortality rate was associated with these cases. Distant metastases were observed in about 80% of the cases in the early recurrence group, whereas localized metastases in the neck region were observed in more than half the cases in the late recurrence group. The percentage of patients with a non-disease-free status and distant metastases in the early recurrence group was higher than that in the late recurrence group. The 10-year disease-specific survival rates were 52.5% and 85.1% for the early and late recurrence groups, respectively. Conclusions: Early recurrent papillary and follicular thyroid carcinomas are associated with high mortalities. Tumor size and multifocality deserve consideration as indicators of recurrence. Therefore, patients whose primary follicular or papillary thyroid carcinoma has features associated with early recurrence should probably receive more aggressive initial treatment.