Researchers described the characteristics, biomarker testing, treatment patterns, and clinical outcomes of patients with advanced/metastatic medullary thyroid carcinoma (MTC) in a real-world setting in the US and identified gaps in the care of these patients, as published in Thyroid Research.
The medical records of 203 patients with advanced MTC, aged 12 years and older who have initiated 1 or more lines of systemic treatment for advanced/metastatic disease between January 2013 and December 2018 were reviewed retrospectively.
The mean age of the patients was 52.2 years and the mean duration of follow-up from the beginning of first-line treatment was 24.5 months. The majority of the patients (82.8%) initially received a diagnosis of stage 4A, 4B, or 4C cancer.
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A total of 121 patients were tested for RET mutations and 37.2% of them had RET-mutant disease. This meant that more than one-third of patients were not tested for RET mutation as national guidelines recommend. The most common mutations were M918T reported in 64.3% of patients and C634R reported in 32.1% of patients.
Most patients (75.9%) received 1 line of systemic treatment and 36% were still undergoing first-line therapy. The most commonly used first-line treatments were cabozantinib, vandetanib, sorafenib, and lenvatinib.
A total of 49 patients received second-line treatment. Most of these were treated with cabozantinib, vandetanib, lenvatinib, or sunitinib. The patients’ median progression-free survival was 26.6 months from the start of first-line treatment and 15.3 months from the start of the second-line treatment.
The median overall survival from the start of the first-line treatment was 63.8 months and 22.4 months from the start of the second-line treatment. This was consistent with that observed from surveillance, epidemiology, and end results data for metastatic MTC.
“Considering the recent approval of selective RET inhibitors for patients with RET-mutant MTC, future research should investigate how treatment patterns evolve for these patients,” the researchers concluded.
Parikh R, Hess LM, Esterberg E, Bhandari NR, Kaye JA. Diagnostic characteristics, treatment patterns, and clinical outcomes for patients with advanced/metastatic medullary thyroid cancer. Thyroid Res. 2022;15(2). doi:10.1186/s13044-021-00119-9