THE THYROID AND BREAST-CANCER - A SIGNIFICANT ASSOCIATION

The coincidence of thyroid disorders and breast cancer has long been a subject of debate, Associations with hyperthyroidism, hypothyroidism, thyroiditis and nontoxic goitre have been reported, Although no convi ncing evidence exists of a causal role for overt thyroid disease in br east cancer, the preponderance of published work favours an associatio n with hypothyroidism, Geographical variations in the incidence of bre ast cancer have been attributed to differences in dietary iodine intak e and an effect of iodide on the breast has been postulated, Recent re ports have shown a direct association between thyroid enlargement, as assessed by ultrasound, and breast cancer. Although the exact mechanis m for the demonstrated association between diseases of the thyroid and breast cancer remains to be elucidated, there is at least the possibi lity that the presence of thyroid abnormalities may influence breast c ancer progression and this alone should stimulate awareness into the c oincidence of the two disorders.