Clinical aggressiveness and long-term outcome in patients with papillary thyroid cancer and circulating anti-thyroglobulin autoantibodies.
OBJECTIVE
The association between papillary thyroid cancer (PTC) and Hashimoto's thyroiditis is widely recognized, but less is known about the possible link between circulating anti-thyroglobulin antibody (TgAb) titers and PTC aggressiveness. To shed light on this issue, we retrospectively examined a large series of PTC patients with and without positive TgAb.


METHODS
Data on 220 TgAb-positive PTC patients (study cohort) were retrospectively collected in 10 hospital-based referral centers. All the patients had undergone near-total thyroidectomy with or without radioiodine remnant ablation. Tumor characteristics and long-term outcomes (follow-up range: 2.5-24.8 years) were compared with those recently reported in 1020 TgAb-negative PTC patients with similar demographic characteristics. We also assessed the impact on clinical outcome of early titer disappearance in the TgAb-positive group.


RESULTS
At baseline, the study cohort (mean age 45.9 years, range 12.5-84.1 years; 85% female) had a significantly higher prevalence of high-risk patients (6.9% vs. 3.2%, p<0.05) and extrathyroidal tumor extension (28.2% vs. 24%; p<0.0001) than TgAb-negative controls. Study cohort patients were also more likely than controls to have persistent disease at the 1-year visit (13.6% vs. 7.0%, p=0.001) or recurrence during subsequent follow-up (5.8% vs. 1.4%, p=0.0001). At the final follow-up visit, the percentage of patients with either persistent or recurrent disease in the two cohorts was significantly different (6.4% of TgAb-positive patients vs. 1.7% in the TgAb-negative group, p<0.0001). At the 1-year visit, titer normalization was observed in 85 of the 220 TgAb-positive individuals. These patients had a significantly lower rate of persistent disease than those who were still TgAb positive (8.2% vs. 17.3%. p=0.05), and no relapses were observed among patients with no evidence of disease during subsequent follow-up.


CONCLUSIONS
PTC patients with positive serum TgAb titer during the first year after primary treatment were more likely to have persistent/recurrent disease than those who were consistently TgAb-negative. Negative titers at 1 year may be associated with more favorable outcomes.
1 Department of Internal Medicine and Medical Specialties, University of Rome Sapienza , Rome, Italy .
Cosimo
C
Durante
Sara
S
Tognini
Teresa
T
Montesano
Fabio
F
Orlandi
Massimo
M
Torlontano
Efisio
E
Puxeddu
Marco
M
Attard
Giuseppe
G
Costante
Salvatore
S
Tumino
Domenico
D
Meringolo
Rocco
R
Bruno
Fabiana
F
Trulli
Maria
M
Toteda
Adriano
A
Redler
Giuseppe
G
Ronga
Sebastiano
S
Filetti
Fabio
F
Monzani
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000276:immunology / Q000473:pathology* / Q000601:surgery; D011379:Prognosis; D012189:Retrospective Studies; D013954:Thyroglobulin / Q000276:immunology*; D013964:Thyroid Neoplasms / Q000097:blood / Q000276:immunology / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy; D055815:Young Adult
D001323:Autoantibodies; C006606:anti-thyroglobulin; D013954:Thyroglobulin