In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 38, No. 15_suppl ( 2020-05-20), p. 6584-6584
Abstract:
6584 Background: Activating RAS mutations are recognized as important drivers in sporadic medullary thyroid cancer (sMTC), with a reported prevalence between 0-43%. However, few studies have looked at correlations between RAS-mutated sMTC and clinicopathologic features. Methods: Patients with sMTC diagnosed between 1992 – 2019 with NGS testing for RET and RAS mutations seen at a tertiary cancer center were retrospectively evaluated. The objective was to analyze demographic and clinical features among patients with RAS-mutated sMTC and to evaluate associations between these features and overall survival (OS). Analyses were performed to correlate patient demographics and pathologic staging with treatment characteristics, disease course, and OS. Results: We identified 42 patients (50% female) with RAS-mutated sMTC out of 218 pts with sMTC. Median age at diagnosis was 50 years (range 24-78 years). 26 (62%) patients had stage IV disease at time of diagnosis. 28 (67%) of patients had HRAS mutations and 14 (33%) had KRAS mutations. HRAS Q61R was the most common HRAS mutation type (n = 19, 45%). Median follow-up time was 64 months (range 23-274 months) during which 11 (26%) patients died. The median OS was 16.2 years, with 5- and 10- year OS of 88% and 73% respectively. Of the 20 (48%) patients who received systemic therapy, 79% had stage IV disease and tended to be older (median age 54). Median time from diagnosis to initiation of systemic therapy was 33 months. Factors associated with worse OS included distant metastases at diagnosis, shorter time interval between diagnosis and treatment, and Ctn/CEA doubling times 〈 6 months. HRAS Q61R mutations were associated with a better prognosis, with 100% 10-year OS compared with 10-year OS of 39% and 51% (p = 0.02) for other HRAS and KRAS mutations respectively. Conclusions: At a tertiary cancer center, patients with RAS-mutated sMTC had a 10-year OS rate of 73%, with significantly worse OS in patients with HRAS/KRAS mutations other than HRAS Q61R. In comparison, prior studies have reported 10-year OS rates between ~71-90% in sMTC and 10-year OS rates as low as 56% for more aggressive RET M918T sMTC mutations. The findings here are consistent with other studies that have suggested patients with RAS-mutated sMTC are at intermediate risk for aggressive disease, though there are limited data on OS rates in RAS or RAS-/RET- sMTC. Future research comparing outcomes between various RAS mutations and in comparison to RET+ and RAS-/RET- patients is needed, especially as systemic therapy use in RAS-mutated sMTC evolves.
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/JCO.2020.38.15_suppl.6584
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2020
detail.hit.zdb_id:
2005181-5
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