Abstract
Background: Radioiodine (RAI)-refractory differentiated thyroid cancer (DTC) has a poor prognosis. Constitutive MAPK activation, frequently driven by BRAF V600E or RAS alterations, suppresses thyroid-specific genes and sodium-iodide symporter expression. Short-course BRAF and/or MEK inhibition before RAI aims to restore iodine avidity.
Methods: We conducted a systematic review and meta-analysis in accordance with PRISMA 2020. PubMed, Embase, CENTRAL, ClinicalTrials.gov, and Google Scholar were searched from inception through March 31, 2025, for prospective studies of short-course BRAF and/or MEK inhibition undertaken with the protocolized intention of restoring RAI uptake before therapeutic RAI (PROSPERO: CRD1371813). Random-effects models with REML estimation and logit transformation were used for proportions. Risk of bias was assessed with ROBINS-I and certainty with GRADE.
Results: Five non-randomized single-arm studies (N=72) met the revised eligibility criteria; four studies (n=48) contributed to the primary meta-analysis. The pooled proportion with restored detectable RAI uptake was 62.3% (95% CI 47.8%-74.8%; I²=0%). When the therapeutic dosimetric threshold reported by Ho et al. was used, the pooled estimate was 57.8% (95% CI 44.0%-71.5%). Excluding Ho et al., it yielded 63.5% (95% CI 45.7%-81.4%). No included study published a hazard ratio for progression-free survival; progression-free and overall survival were therefore synthesized narratively. Adverse-event rates were not pooled because attribution, grading, and exposure duration differed across studies. No treatment-related deaths were reported. Certainty of the evidence was very low for all outcomes.
Conclusions: Short-course MAPK inhibitor-based redifferentiation can restore RAI uptake in selected patients with RAI-refractory DTC, but uptake is a surrogate outcome and does not establish survival benefit. The evidence is insufficient to determine whether efficacy differs by mutation subtype. Controlled, biomarker-stratified trials using standardized imaging and clinically relevant outcomes are needed.
References
Bray F, Laversanne M, Sung H, Ferlay J, Siegel RL, Soerjomataram I, et al. Global cancer statistics 2022: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2024;74(3):229-263. https://doi.org/10.3322/caac.21834
Haugen BR, Alexander EK, Bible KC, Doherty GM, Mandel SJ, Nikiforov YE, et al. 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid. 2016;26(1):1-133. https://doi.org/10.1089/thy.2015.0020
The Cancer Genome Atlas Research Network. Integrated genomic characterization of papillary thyroid carcinoma. Cell. 2014;159(3):676-690. https://doi.org/10.1016/j.cell.2014.09.050
Schlumberger M, Brose M, Elisei R, Leboulleux S, Luster M, Pitoia F, et al. Definition and management of radioactive iodine-refractory differentiated thyroid cancer. Lancet Diabetes Endocrinol. 2014;2(5):356-358. https://doi.org/10.1016/S2213-8587(13)70215-8
Brose MS, Nutting CM, Jarzab B, Elisei R, Siena S, Bastholt L, et al. Sorafenib in radioactive iodine-refractory, locally advanced or metastatic differentiated thyroid cancer: A randomised, double-blind, phase 3 trial. Lancet. 2014;384(9940):319-328. https://doi.org/10.1016/S0140-6736(14)60421-9
Schmidt A, Iglesias L, Klain M, Pitoia F, Schlumberger MJ. Radioactive iodine-refractory differentiated thyroid cancer: An uncommon but challenging situation. Arch Endocrinol Metab. 2017;61(1):81-89. https://doi.org/10.1590/2359-3997000000245
Xing M. BRAF mutation in thyroid cancer. Endocr Relat Cancer. 2005;12(2):245-262. https://doi.org/10.1677/erc.1.0978
Nikiforov YE, Nikiforova MN. Molecular genetics and diagnosis of thyroid cancer. Nat Rev Endocrinol. 2011;7(10):569-580. https://doi.org/10.1038/nrendo.2011.142
Naoum GE, Morkos M, Kim B, Arafat W. Novel targeted therapies and immunotherapy for advanced thyroid cancers. Mol Cancer. 2018;17(1):51. https://doi.org/10.1186/s12943-018-0786-0
Knostman K, Jhiang S, Capen CC. Genetic alterations in thyroid cancer: The role of mouse models. Vet Pathol. 2007;44(1):1-14. https://doi.org/10.1354/vp.44-1-1
Hong CM, Ahn BC. Redifferentiation of radioiodine refractory differentiated thyroid cancer for reapplication of i-131 therapy. Front Endocrinol (Lausanne). 2017;8:260. https://doi.org/10.3389/fendo.2017.00260
Ho AL, Grewal RK, Leboeuf R, Sherman EJ, Pfister DG, Deandreis D, et al. Selumetinib-enhanced radioiodine uptake in advanced thyroid cancer. N Engl J Med. 2013;368(7):623-632. https://doi.org/10.1056/NEJMoa1209288
Busaidy NL, Konda B, Wei L, Wirth LJ, Devine C, Daniels GA, et al. Dabrafenib versus dabrafenib + trametinib in BRAF-mutated radioactive iodine refractory differentiated thyroid cancer: Results of a randomized, phase 2, open-label multicenter trial. Thyroid. 2022;32(10):1184-1192. https://doi.org/10.1089/thy.2022.0115
Rothenberg SM, McFadden DG, Palmer EL, Daniels GH, Wirth LJ. Redifferentiation of iodine-refractory BRAF V600E-mutant metastatic papillary thyroid cancer with dabrafenib. Clin Cancer Res. 2015;21(5):1028-1035. https://doi.org/10.1158/1078-0432.CCR-14-2915
Leboulleux S, Do Cao C, Zerdoud S, Attard M, Bournaud C, Lacroix L, et al. A phase II redifferentiation trial with dabrafenib-trametinib and 131i in metastatic radioactive iodine refractory BRAF p.V600E-mutated differentiated thyroid cancer. Clin Cancer Res. 2023;29(13):2401-2409. https://doi.org/10.1158/1078-0432.CCR-23-0046
Leboulleux S, Benisvy D, Taieb D, Attard M, Bournaud C, Terroir-Cassou-Mounat M, et al. MERAIODE: A phase II redifferentiation trial with trametinib and (131)I in metastatic radioactive iodine refractory RAS mutated differentiated thyroid cancer. Thyroid. 2023;33(9):1124-1129. https://doi.org/10.1089/thy.2023.0240
Tchekmedyian V, Dunn L, Sherman E, Baxi SS, Grewal RK, Larson SM, et al. Enhancing radioiodine incorporation in BRAF-mutant, radioiodine-refractory thyroid cancers with vemurafenib and the anti-ErbB3 monoclonal antibody CDX-3379: Results of a pilot clinical trial. Thyroid. 2022;32(3):273-282. https://doi.org/10.1089/thy.2021.0565
Higgins JPT, Thomas J, Chandler J, Cumpston M, Li T, Page MJ, et al., editors. Cochrane Handbook for Systematic Reviews of Interventions version 6.5 [Internet]. Cochrane; 2024 [updated Aug 2024]. Available from: https://www.cochrane.org/handbook
Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, et al. The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. BMJ. 2021;372:n71. https://doi.org/10.1136/bmj.n71
Sterne JAC, Hernán MA, Reeves BC, Savovi? J, Berkman ND, Viswanathan M, et al. ROBINS-I: A tool for assessing risk of bias in non-randomised studies of interventions. BMJ. 2016;355:i4919. https://doi.org/10.1136/bmj.i4919
Guyatt GH, Oxman AD, Vist GE, Kunz R, Falck-Ytter Y, Alonso-Coello P, et al. GRADE: An emerging consensus on rating quality of evidence and strength of recommendations. BMJ. 2008;336(7650):924-926. https://doi.org/10.1136/bmj.39489.470347.AD
Wan X, Wang W, Liu J, Tong T. Estimating the sample mean and standard deviation from the sample size, median, range and/or interquartile range. BMC Med Res Methodol. 2014;14:135. https://doi.org/10.1186/1471-2288-14-135
Balduzzi S, Rücker G, Schwarzer G. How to perform a meta-analysis with R: A practical tutorial. Evid Based Ment Health. 2019;22(4):153-160. https://doi.org/10.1136/ebmental-2019-300117
Viechtbauer W. Conducting meta-analyses in R with the metafor package. J Stat Softw. 2010;36(3):1-48. https://doi.org/10.18637/jss.v036.i03
Higgins JP, Thompson SG, Deeks JJ, Altman DG. Measuring inconsistency in meta-analyses. BMJ. 2003;327(7414):557-560. https://doi.org/10.1136/bmj.327.7414.557
Egger M, Davey Smith G, Schneider M, Minder C. Bias in meta-analysis detected by a simple, graphical test. BMJ. 1997;315(7109):629-634. https://doi.org/10.1136/bmj.315.7109.629
Eisenhauer EA, Therasse P, Bogaerts J, Schwartz LH, Sargent D, Ford R, et al. New response evaluation criteria in solid tumours: Revised RECIST guideline (version 1.1). Eur J Cancer. 2009;45(2):228-247. https://doi.org/10.1016/j.ejca.2008.10.026
Schlumberger M, Tahara M, Wirth LJ, Robinson B, Brose MS, Elisei R, et al. Lenvatinib versus Placebo in radioiodine-refractory thyroid cancer. N Engl J Med. 2015;372(7):621-630. https://doi.org/10.1056/NEJMoa1406470
Lee M, Morris LG. Genetic alterations in thyroid cancer mediating both resistance to BRAF inhibition and anaplastic transformation. Oncotarget. 2024;15:36-48. https://doi.org/10.18632/oncotarget.28544
Landa I, Ibrahimpasic T, Boucai L, Sinha R, Knauf JA, Shah RH, et al. Genomic and transcriptomic hallmarks of poorly differentiated and anaplastic thyroid cancers. J Clin Invest. 2016;126(3):1052-1066. https://doi.org/10.1172/JCI85271
Subbiah V, Kreitman RJ, Wainberg ZA, Gazzah A, Lassen U, Stein A, et al. Dabrafenib plus trametinib in BRAFV600E-mutated rare cancers: The phase 2 ROAR trial. Nat Med. 2023;29(5):1103-1112. https://doi.org/10.1038/s41591-023-02321-8

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Copyright (c) 2026 Revista Colombiana de Endocrinología, Diabetes & Metabolismo

