Association of differentiated thyroid carcinoma with HLA-DR7.
Seventy-four American white thyroid cancer patients were typed for HLA-A, B, and DR antigens. A significant increase in HLA-DR7 was found in the nonradiation-associated thyroid cancer patients (42.5%, 20/47 cases), compared to 22.8% of 979 normal controls. The association is stronger in the follicular and mixed papillary-follicular subgroup (52.0%, 13/25 cases, P corrected less than 0.01). The occurrence of various malignancies in family members was found in 57.9% of HLA-DR7 positive patients, versus 20% of HLA-DR7 negative patients, in a retrospective record review. Although the frequency of HLA-DR7 was not increased in the radiation-associated thyroid cancer patients (22.2%, 6/27 cases), the interval from the irradiation date to the onset date of thyroid cancer was shorter in HLA-DR7 positive cases (17.3 +/- 6.2 years) than in HLA-DR7 negative patients (29.4 +/- 11.5 years). This data suggest that HLA-DR7 is associated with and may influence development of thyroid cancer.