How should thyroid-stimulating hormone (TSH) be managed so its levels can be maintained within the normal range after total thyroidectomy for cancer of the papillary thyroid? Despite monthly monitoring of T3, my patient experienced hypo/hyperthyroidism three times in a year. What would be the ideal TSH level for these patients? Should we monitor for other biomarkers? —Name withheld on request
Suppression of thyroid-stimulating hormone (TSH) after thyroidectomy for low-risk cancer can increase the risk of osteoporosis in women without cutting back on cancer recurrence, according to some reports.1 TSH suppression was defined as a median level of 0.4 mU/L or less. According to a retrospective study, those women who were found to suppress their TSH levels had a more than three-fold increased risk of osteoporosis than those whose levels were not suppressed.1
TSH is known to help stimulate tumor growth, invasion, angiogenesis, and thyroglobulin secretion in postoperative patients who are placed on thyroid hormone, which is approximately 1 mg/lb dose. For those who are considered to be low-risk patients, the recommendation is to maintain the serum TSH level just below the lower limit of the normal range, 0.1 to 0.4 mU/ mL.2 In high-risk patients, the dosage is adjusted to maintain a serum TSH level of less than 0.1 mU/ mL, and this has been reported to improve tumor free survival. The goal of the therapeutic efforts should focus on avoiding harm in the aftermath of the total thyroidectomy for cancer of the papillary thyroid.2 —Abimbola Farinde, PharmD, MS, BCPP, CGP, LCDC, PM/PRC, FASCP, FACA, FNAP, Rsci, ARSPharmS
1. Fiore K. TSH suppression: More harm than good after cancer surgery? Medpage Today Web site. 2015. http://www.medpagetoday.com/MeetingCoverage/ATA/42381. Accessed September 2, 2015.
2. Endocrine surgery: Long-term follow-up of thyroid cancer. Weill Cornell Medical College Web site. http://www.cornellsurgery.org/pro/services/endocrine/thyroid-follow-up.html. Accessed September 2, 2015.