Thyroid cancer and thyroiditis in Salta, Argentina: a 40-yr study in relation to iodine prophylaxis

Endocr Pathol. 2002 Fall;13(3):175-81. doi: 10.1385/ep:13:3:175.


The natural history of thyroid cancer and thyroiditis in relation to iodine prophylaxis in the region of Salta, Argentina, where goiter is common was investigated over a time span of 40 yr. For analysis of thyroid cancer, the specimens were divided into two periods. The first 15 yr (59 cases), including 5 yr before prophylaxis, was compared with the second 25 yr (182 cases), a period well after salt iodination. Papillary carcinomas formed the largest group of tumors in both periods, with a significant increase in their proportion in the second period (44 vs 60%, chi(2): p < 0.05), while the percentage of follicular and undifferentiated carcinomas decreased and medullary carcinoma remained about the same. The ratio of papillary to follicular carcinoma rose from 1.7:1 in the first period to 3.1:1 in the second. Four thyroid lymphomas of non-Hodgkin's B-cell type occurred in the second period in females over age 50. A severe lymphoid thyroiditis was present in the two cases with assessable background thyroid tissue. The frequency of moderate to severe lymphoid infiltrate in females rose from 2 of 12 (16.6%) in the preprophylaxis period to 34 of 114 (28.0%) in the last 25 yr after prophylaxis. After salt prophylaxis, thyroiditis was more frequent in patients with papillary carcinoma (36.2%) than in those with nonpapillary tumors (14.7%) (chi(2), p < 0.02). These observations indicate that a high dietary intake of iodine may be associated with a high frequency of papillary carcinoma and thyroiditis, and that thyroiditis is more commonly associated with papillary carcinoma than with other thyroid tumors. The occurrence of non-Hodgkin's lymphomas only in the postprophylaxis period may be linked to an increase in thyroiditis.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Argentina / epidemiology
  • Carcinoma / epidemiology*
  • Carcinoma / etiology
  • Carcinoma / prevention & control
  • Diet
  • Female
  • Goiter, Endemic / epidemiology
  • Goiter, Endemic / etiology
  • Goiter, Endemic / prevention & control
  • Humans
  • Iodine / administration & dosage*
  • Iodine / deficiency
  • Lymphoma, B-Cell / epidemiology*
  • Lymphoma, B-Cell / etiology
  • Male
  • Middle Aged
  • Thyroid Neoplasms / epidemiology*
  • Thyroid Neoplasms / etiology
  • Thyroid Neoplasms / prevention & control
  • Thyroiditis, Autoimmune / epidemiology*
  • Thyroiditis, Autoimmune / etiology
  • Thyroiditis, Autoimmune / prevention & control


  • Iodine