@article{KoehlerAdamFussetal.2022, author = {Koehler, Viktoria Florentine and Adam, Pia and Fuss, Carmina Teresa and Jiang, Linmiao and Berg, Elke and Frank-Raue, Karin and Raue, Friedhelm and Hoster, Eva and Kn{\"o}sel, Thomas and Schildhaus, Hans-Ulrich and Negele, Thomas and Siebolts, Udo and Lorenz, Kerstin and Allelein, Stephanie and Schott, Matthias and Spitzweg, Christine and Kroiss, Matthias}, title = {Treatment of RET-positive advanced medullary thyroid cancer with multi-tyrosine kinase inhibitors — a retrospective multi-center registry analysis}, series = {Cancers}, volume = {14}, journal = {Cancers}, number = {14}, issn = {2072-6694}, doi = {10.3390/cancers14143405}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-281776}, year = {2022}, abstract = {Background: RET (rearranged during transfection) variants are the most prevalent oncogenic events in medullary thyroid cancer (MTC). In advanced disease, multi-tyrosine kinase inhibitors (MKIs) cabozantinib and vandetanib are the approved standard treatment irrespective of RET status. The actual outcome of patients with RET-positive MTC treated with MKIs is ill described. Methods: We here retrospectively determined the RET oncogene variant status with a targeted DNA Custom Panel in a prospectively collected cohort of 48 patients with advanced MTC treated with vandetanib and/or cabozantinib at four German referral centers. Progression-free survival (PFS) and overall survival (OS) probabilities were estimated using the Kaplan-Meier method. Results: In total, 44/48 (92\%) patients had germline or somatic RET variants. The M918T variant was found in 29/44 (66\%) cases. In total, 2/32 (6\%) patients with a somatic RET variant had further somatic variants, while in 1/32 (3\%) patient with a germline RET variant, additional variants were found. Only 1/48 (2\%) patient had a pathogenic HRAS variant, and no variants were found in 3 cases. In first-line treatment, the median OS was 53 (95\% CI (95\% confidence interval), 32-NR (not reached); n = 36), and the median PFS was 21 months (12-39; n = 33) in RET-positive MTC patients. In second-line treatment, the median OS was 18 (13-79; n = 22), and the median PFS was 3.5 months (2-14; n = 22) in RET-positive cases. Conclusions: RET variants were highly prevalent in patients with advanced MTC. The treatment results in RET-positive cases were similar to those reported in unselected cohorts.}, language = {en} }