TY - JOUR A1 - Koehler, Viktoria Florentine A1 - Adam, Pia A1 - Fuss, Carmina Teresa A1 - Jiang, Linmiao A1 - Berg, Elke A1 - Frank-Raue, Karin A1 - Raue, Friedhelm A1 - Hoster, Eva A1 - Knösel, Thomas A1 - Schildhaus, Hans-Ulrich A1 - Negele, Thomas A1 - Siebolts, Udo A1 - Lorenz, Kerstin A1 - Allelein, Stephanie A1 - Schott, Matthias A1 - Spitzweg, Christine A1 - Kroiss, Matthias T1 - Treatment of RET-positive advanced medullary thyroid cancer with multi-tyrosine kinase inhibitors — a retrospective multi-center registry analysis JF - Cancers N2 - 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. KW - medullary thyroid cancer KW - rearranged during transfection KW - variant KW - multi-tyrosine kinase inhibitor KW - survival KW - treatment outcome Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-281776 SN - 2072-6694 VL - 14 IS - 14 ER -