THYROID-DISORDERS AND BREAST-CANCER

We have investigated the controversial association between diseases of the thyroid gland and breast carcinoma using methodology which allows positive exclusion of cases of breast disease from control groups and the defection of subclinical alterations in thyroid volume using high resolution ultrasonography, thus addressing the deficiencies of earli er studies, Whereas the prevalence of hyperthyroidism and hypothyroidi sm in patients with breast carcinoma and in healthy controls without c linical evidence of breast disease was similar, non-toxic goitre was m ore than twice as common in the breast carcinoma patients, Thyroid vol umes were also significantly higher in breast carcinoma patients than in control; using World Health Organisation criteria, 45.5% of breast carcinoma patients had thyroid enlargement compared with only 10.5% of controls, Finally, antithyroid peroxidase autoantibodies were twice a s common in breast cancer patients than in controls, These findings pr ovide clear evidence of a relationship between thyroid disease and bre ast carcinoma, although the mechanisms underlying this relationship re quire further study, future studies of breast cancer risk factors shou ld therefore include assessment of thyroid function, antibody status a nd volume.