Feb 14, 2009 11:30PM - edited Feb 14, 2009 11:36PM by anondenet
The researchers below found an association between the size/swelling/volume of the thyroid and the stage of breast cancer. Swollen thyroid usually indicates hypothyroidism where the thyroid is expanding to create more surface to absorb iodine from the bloodstream.
Those with no breast disease (the controls) had smaller, healthy thyroids. Those with fibrocystic (benign) disease and cancers had larger thyroids.
Journal of Clinical Endocrinology & Metabolism, Vol 81, 937-941, Copyright © 1996 by Endocrine Society
A direct relationship between thyroid enlargement and breast cancer
PP Smyth, DF Smith, EW McDermott, MJ Murray, JG Geraghty and NJ O'Higgins
Department of Medicine, St. Vincent's Hospital, University College, Dublin, Ireland.
Despite extensive study, evidence to support a direct relationship between diseases of the thyroid and breast has not been established. In this study thyroid volume was assessed by ultrasound in 200 patients with breast cancer and 354 with benign breast disease. Results were compared to appropriate female control groups. Both mean thyroid volume (21.1 +/- 1.4 mL) and the percentage of individual patients with enlarged (> 18.0 mL) thyroid glands (41.5%) were significantly greater in the breast cancer group than equivalent values (13.2 +/- 0.5 mL and 10.5%, respectively) in age-matched controls (P < 0.01 in both cases). The mean thyroid volume of 14.5 +/- 0.34 mL in patients with benign breast disease was also significantly greater than that of 12.5 +/- 0.38 mL in younger controls (P < 0.01). The results support a direct association between breast cancer and increased thyroid volume as mean thyroid volumes and the percentage of individual patients with enlarged thyroid glands were similar in those studied both before (20.8 +/- 1.3 mL and 43.0%) and after (21.4 +/- 1.6 mL and 40.0%) therapies for breast cancer. Although there is no evidence that thyroid enlargement represents a risk factor for breast cancer, the results emphasize the importance of raising the consciousness of the coincidence of both disorders.