In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 31, No. 15_suppl ( 2013-05-20), p. 9049-9049
Abstract:
9049 Background: The natural history of BRAF and NRAS mutant (mut) melanoma (mel) has been described, but prognostic implications of KIT mut mel have not. Methods: We performed a single-center retrospective review of 180 patients (pts) enriched for mucosal, acral or chronic sun-damaged skin (CSD) mel and screened for KIT, BRAF, and NRAS mut from 4/07 - 4/10 as a part of a phase II imatinib study. Pt/disease characteristics were compared using the Kruskal-Wallis or Chi-square tests. Factors associated with outcomes were assessed by Kaplan-Meier methods and multivariable Cox regression. Results: Median age, 63.7 years; 54.4% male. Primary site: 40% mucosal, 29% acral, 22% CSD, 9% others. Mut rate: 18% KIT, 16% BRAF, 14% NRAS, 52% wild-type (wt). Pathologic subtype differed by genetic subgroup (p 〈 .001) while age, gender, and stage did not (all p 〉 0.05). 18/26 (69%) KIT mut pts received imatinib in the metastatic (met) setting; 6/18 received 〉 1 other KIT inhibitor. 3/25 (12%) BRAF mut pts received vemurafenib. 8/27 (30%) KIT mut, 4/27 (15%) BRAF mut, 6/20 (30%) NRAS mut, and 6/20 (30%) wt pts received ipilimumab. 149/180 (83%) pts developed mets at a median of 2.15 years (95% CI: 1.72, 2.72). Median follow-up (FU) of pts not developing mets was 3.91 yrs (range: 0.25, 14.34). Older age (HR: 1.02, 95% CI: 1.00, 1.03) and pathologic subtype (mucosal vs CSD HR: 1.70, 95% CI: 1.02, 2.84; non-CSD/unknown vs CSD HR: 2.05, 95% CI: 1.00, 4.21) were associated with increased risk of mets but not with time from mets to death. Of 149 pts who progressed, 123 (83%) died during FU. Median time from met to death was 1.21 years (95% CI: 0.91, 1.67). Median FU from time of mets among those alive at last FU was 2.53 yrs (range: 0.06, 6.85). Mut status including KIT mut was not associated with time to first met or time from met to death. Pts who received ipilimumab from time of first distant met had reduced risk of death (HR: 0.55, 95% CI: 0.36, 0.87) independent of mut status. No impact was observed with KIT inhibition. Conclusions: KIT mut status is not an independent predictor of time to mets or survival in pts with mets. Ipilimumab improved pt outcomes regardless of mut status. The lack of impact of KIT inhibitors is likely due to the heterogeneity of KIT mut in mel but does not preclude efficacy in appropriately selected pts.
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/jco.2013.31.15_suppl.9049
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2013
detail.hit.zdb_id:
2005181-5
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