Thyrotrophin suppression to prevent thyroid cancer recurrence

Fron reading the Amercan Thyroid Association;s thyroid cancer guidlines I had assumed that the notion that TSH supression to reduce risk of cancer recurrence was both widely accepted and clearly demonstrated by underlying mechanistic studies and by emperical clinical data. The notion is widely accepted but a mechanistic rational is controversal with there being in vitro data that both support and deny the role of TSH in cancer growth and emperical data are contradictory. A 1998 report from the NTCTcs (Cooper DS,THyroid 1998)TSH suppresion was independly associated with disease progression in high risk patients but only in univariate analysis and not in multivariant models. A 2007 report from NTCTCS (Jonklass j, et al ) which was said by the authors to be the first to show superior outocme with THST They reported improved outcomes in high risk patients ( stage 111 and iv) The 2015 report (Carhill, AA etd al ) from NTCTCS recomended "moderate" but not " aggresssive therapy" Moderate was defined as a TSH level 2 -2.9 with aggresssive 1.0 to 1.99,.They found no additional benefit with the aggessive therapy and recommended at least three years of THST in high risk patients Kekebew et al have published data that challenged the paradigm which indicates suppressive therapy for thyroid cancer patients with either high or intermediate risk. The issue becomes a more high leverage decision ( a currently popular basevball jaron term ) in elderly patients as .as the cardiac risks are of concern and in women the bone loss issue .Basically TSH supression means the iatrogenic generation of subclinical hyperthroidism,a condition that is not comletely benign. Klubo-Gwiezdzinske et al studied retrospectively 1012 cases of DTC (41 with follicular) treated with near total thyroidectomy and remnant ablation and found no improvement in PFS ( authors state their study was under powered to detect a difference in OS) in intermediate and high risk DTC with TSH suppression.( Association of thyrotropin suppression with survival outcomes in patients with interemediate and high risk differentiated thyroid cancer. JAMA opoen network oncology 2019 2 (2) e 1187754