Thyroid autoantibodies in thyroid cancer: incidence and relationship with tumour outcome.
In the present investigation we studied serum anti-thyroglobulin and anti-thyroid microsomal autoantibodies, measured by hemagglutination technique, in 600 patients with thyroid cancer seen by us from 1975 to 1985 (mean follow-up 46 months). Positive thyroglobulin antibodies and/or microsomal antibodies were found in 138 (23%) patients (23.9% with papillary, 25% with follicular, 16.1% with anaplastic, and 4.1% with medullary thyroid carcinomas). The incidence of positive tests was similar in each decade of life (ranging between 21.9% and 27.9%), whereas in a normal sex-matched population with no evidence of thyroid disease, the frequency of positive tests was very low in young people and increased to 23% in people older than 60. In 64 patients with no evidence of residual or metastasic thyroid tissue after surgery and radioiodine, initially positive antibody titres became negative in 54.6%, decreased in 32.8%, did not change in 3.1%, and increased in 9.3%. On the contrary, antibody titres of patients with persistent disease became undetectable in 8.3%, decreased in 16.6%, remained unchanged in 25%, and increased in 50%. The clinical course of differentiated thyroid cancer was unaffected by the presence of thyroid antibodies and no difference was found in the death rate between antibody-positive and antibody-negative patients (11.5% and 13.6%, respectively). In conclusion, our data indicate that: 1) autoimmune phenomena are not an infrequent finding in thyroid cancer; 2) as in non-malignant thyroid diseases, positive-antibody tests are more frequently observed in females than in males; 3) at variance with normal controls, no age-dependent increase in serum anti-thyroid antibodies was found in thyroid cancer; 4) the presence of metastatic thyroid tissue seems to be necessary to perpetuate the autoantibody synthesis, and 5) anti-thyroid autoantibodies are not a protective or worsening factor in the tumour outcome.
Pacini
F
F
Cattedra di Endocrinologia e Medicina Costituzionale, University of Pisa, Italy.
Mariotti
S
S
Formica
N
N
Elisei
R
R
Anelli
S
S
Capotorti
E
E
Pinchera
A
A
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001323:Autoantibodies / Q000032:analysis*; D002277:Carcinoma / Q000276:immunology*; D002291:Carcinoma, Papillary / Q000276:immunology; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008861:Microsomes / Q000276:immunology; D008875:Middle Aged; D011379:Prognosis; D012737:Sex Factors; D013954:Thyroglobulin / Q000276:immunology; D013961:Thyroid Gland / Q000276:immunology*; D013964:Thyroid Neoplasms / Q000276:immunology*
D001323:Autoantibodies; D013954:Thyroglobulin