Medullary Carcinoma

Abstract

There are 3 main histologic types of thyroid carcinoma: differentiated (including papillary, follicular, and Hürthle), medullary, and anaplastic (aggressive undifferentiated tumor). Of 53,856 patients treated for thyroid carcinoma between 1985 and 1995, 80% had papillary, 11% had follicular, 3% had Hürthle cell, 4% had medullary, and 2% had anaplastic thyroid carcinoma. 1 These NCCN guidelines focus on medullary thyroid carcinoma (MTC). Another NCCN guideline addresses papillary, follicular, Hürthle cell, and anaplastic thyroid carcinomas (see NCCN Clinical Practice Guidelines in Oncology: Thyroid Carcinoma [to view the most recent version of these guidelines, visit the NCCN Web site at www.NCCN.org]). MTC derives from the neuroendocrine parafol-The NCCN Medullary Carcinoma

How has the management of medullary thyroid carcinoma changed with the advent of 18F-FDG and non-18F-FDG PET radiopharmaceuticals

“…For imaging of MTC, neither discontinuation of replacement thyroid hormone nor administration of recombinant human thyroid-stimulating hormone to stimulate radiotracer uptake in tumor tissues is required. Unfortunately there have been too few randomized clinical trials to establish the optimal treatment approach for MTC, and present practice guidelines rely upon a small body of literature [9][10][11]. Nonetheless, guidelines are important to standardize the management of MTC as variable practice patterns have been previously documented [12].…”

Cáncer medular de tiroides: Experiencia quirúrgica en 10 años

“…Sin embargo, la mayoría de los estudios se basan en pruebas de estimulación con pentagastrina para aumentar la especificidad, droga no disponible en todo el mundo, y con rendimiento diagnóstico cuestionable. La American Thyroid Association (ATA) no se muestra a favor ni en contra de su uso rutionario 21 y la National Comprehensive Cancer Network (NCCN) no recomienda su realización en todos los pacientes con enfermedad tiroidea nodular, por ser un tamizaje costoso y con escasos resultados positivos 22 . El CMT se presenta con un componente hereditario en 20% de los casos 3,4 .…”

“…Es conocido que pacientes con CMT no hereditario, presentan hasta en 6% mutaciones de línea germinal del proto-oncogen RET 23,24 , lo cual se podría explicar por una historia familiar incompleta, aparición de mutaciones de novo o formas familiares de expresión tardía 24 . Guías clínicas sugieren el estudio molecular en todos los pacientes con diagnóstico de CMT esporádico 22 . En nuestra serie el estudio clínico (metanefrinas, PTH, etc.)…”

Evolving paradigms for successful molecular imaging of medullary thyroid carcinoma

“…To our knowledge, there are no studies of the use of either PET/CT or SPECT/CT for preoperative MTC staging, although unlike radioiodine imaging in welldifferentiated thyroid cancer, total thyroidectomy is not a prerequisite for successful imaging of in-situ or locoregional metastatic disease in MTC. As recurrence rates of MTC approach 50%, patients should be monitored after initial surgical management with Ct and CEA levels, including calculation of doubling times [1,3,9,11]. Should tumour biomarkers indicate persistent or recurrent disease, accurate restaging of MTC is crucial in subsequent management, whether to pursue a surgically based approach in an attempt to control locoregional disease, or to identify the best time to switch to systemic therapy for distant metastatic disease.…”

“…The lack of efficacy of external beam radiation treatment [3,43,44], the low chemotherapy response rates of only 10-20% [1,45,46], and the modest impact of 131 I-or 90 Y-labelled targeted radionuclide therapies with response rates of approximately 30% [45], provide great impetus for studies of novel multikinase inhibitors as new approaches to therapy [45,46]. The present clinical guidelines recommend that kinase inhibitors are the preferred best "current practice" therapy for inoperable, progressive MTC and should be investigated in clinical trials [6,9,11]. These small-molecule inhibitors, which include vandetanib and sorafenib, block ATP at catalytic sites in the RET tyrosine kinase activation pathway and have been found to have modest efficacy for stabilization of aggressive disease [6][7][8]47].…”