Is a second recombinant human thyrotropin stimulation test useful? The value of postsurgical undetectable stimulated thyroglobulin level at the time of remnant ablation on clinical outcome

The Frequency of Differentiated Thyroid Cancer Recurrence in 2302 Patients With Excellent Response to Primary Therapy

CONTEXT

Discrepant data on the recurrence rate of differentiated thyroid cancer (DTC) are reported.

OBJECTIVE

To evaluate the frequency and risk factors of true recurrence in DTC patients with excellent responses (ExR) to initial therapy.

METHODS

A retrospective analysis of the 2302 consecutive DTC patients with ExR to primary therapy, treated during 24 years at single center. The percentage of recurrence and cumulative recurrence rate (CRR) were analyzed. Risk factors for recurrence for patients with papillary thyroid cancer (PTC) were investigated and methods for establishing a diagnosis of recurrence were evaluated.

RESULTS

Of DTC patients, 32 (1.4%) experienced recurrence. PTC patients with recurrence were more likely to have younger age (P = .0182), larger tumor size (P = .0013), lymph node metastases (P = .0013), incomplete resection (P = .0446), higher ATA risk (P = .0002), and had more frequently been treated with 131I (P = .0203). CRRs at 5, 10, 15, 20, and 24 years after surgery were 1.2%, 1.9%, 2.5%, 2.9%, and 2.9%, respectively. The CRRs according to histological type were highest for poorly differentiated thyroid cancer (PDTC), lower for oncocytic (OTC) and follicular thyroid cancer (FTC), and lowest for PTC. Most recurrences occurred within the first 5 years of observation. The most effective method for detecting local recurrence was ultrasonography with fine needle aspiration cytology, and for distant metastases, 18F-FDG PET.

CONCLUSION

True recurrence is rare in DTC patients. PTC patients with ExR to primary therapy and N0/Nx can be dismissed from oncological follow-up. Despite ExR to primary therapy, DTC patients with N1, and PDTC, OTC, FTC should remain under oncological follow-up.

Back so soon? Is early recurrence of papillary thyroid cancer really just persistent disease?

BACKGROUND

Papillary thyroid carcinoma has excellent survival, yet recurrence remains a challenge. We sought to determine the proportion of reoperations performed for persistent, rather than truly recurrent, disease.

METHODS

We conducted a retrospective review of a prospectively maintained database. Patients with papillary thyroid carcinoma who underwent reoperation for disease from 2000-2016 were included. We defined recurrence as disease that developed after a patient had an undetectable thyroglobulin and a negative ultrasonography within 1 year of operation.

RESULTS

A total of 69 patients underwent 92 reoperations. On initial pathology, mean tumor size was 2.6 cm, 51% were multifocal, and 42% had extrathyroidal extension. Half (46%) of the patients underwent a central/lateral neck dissection at the initial operation, and 77% were treated with postoperative radioactive iodine. The median time to first reoperation was 21 months (range, 1-292), and 42% occurred within 1 year. Only 3 operations met criteria for true "recurrence," while 71 operations were categorized as persistent disease.

CONCLUSION

Many reoperations for papillary thyroid carcinoma are for management of persistent disease. More than half of the patients required reoperation within the first 2 years, which suggests strongly that improvements in the preoperative assessment and adequacy of initial operative therapy need to be made to improve the care of patients with thyroid cancer.