Clinical outcome and pathologic features associated with NRAS mutation in cutaneous melanoma.

8500 Background: Mutations in NRAS and BRAF are common in cutaneous melanoma leading to constitutive activation of the MAPK pathway controlling cell proliferation. We examined the effect of NRAS mutations on the pathologic features and clinical outcomes in patients with cutaneous melanoma when compared to tumors containing BRAF mutations and those wild-type (WT) for both. Methods: Clinical outcome data was obtained from a prospective cohort study of 251 patients with cutaneous melanoma from Australian melanoma centers. Mutations in exon 2 of NRAS (N61R) and exon 15 of BRAF were detected by high resolution melting and sequence verified. Cox proportional hazards regression was performed to examine the significance of NRAS and BRAF mutations on pathologic features, overall survival (OS), melanoma specific survival (MSS) and disease free survival. Results: 249 patients with a median follow-up of 47 months were available. NRAS mutations were found in 36 (14%) patients, BRAF mutations in 112 (45%) and 101 (41%)...