Pretreatment features and risk of death from BRAF-positive metastatic melanoma patients treated with vemurafenib.

Abstract

e21028 Background: Clinicopathologic features of BRAF-positive metastatic melanoma patients were identified. No study to date has examined influence on risk of death features at baseline before starting treatment with vemurafenib. The purpose of the study is to identify demographic, clinical, biochemical, and tumor-related features at baseline before treatment with vemurafenib that are related with increase risk of death in BRAF-positive metastatic melanoma patients. Methods: 323 consecutive patients with metastatic melanoma tested for BRAF mutation were analysed. The presence of BRAF gene V600 mutation was evaluated by the cobas 4800 BRAF V600 Mutation Test. The pretreatment features were collected prospectively after inclusion patients for BRAF inhibitor treatment but before treatment was started. Results: 204 patients had a BRAF mutation. Of these, 115 were treated with vemurafenib. The median time of treatment with vemurafenib was 198 days. Death occurred more frequently among patients with: pretreatment disease symptoms (p = 0.003), ECOG PS ≥1 (p = 0.03), CNS metastases at baseline (p = 0.049) [χ2 test]. The pretreatment elevated serum LDH level (p < 0.0005), leukocytosis (p = 0.042), and hipoalbuminemia (p = 0.002) had an impact on higher incidence of death. AJCC stage 3 was reported more frequently in patients who have died (AJCC 1-2 vs. AJCC 3; p = 0.025, χ2 test). Higher incidence of death in patients with ≥4 localisations of metastases (different organs) was noted (1-3 vs 4-8; p = 0.001, χ2test). The maximum metastasis dimension was greater in the group of patients who have died (p = 0.009; Mann-Whitney test). In the analysed population, all patients whose pretreatment metastasis dimension exceeded 56 mm have died. Age, BMI, and sex were not related with higher risk of death. Conclusions: Pretreatment features may identify patients at higher risk of death. Those with features at baseline such as: disease symptoms, poor performance status, elevated LDH, leukocytosis, hipoalbuminemia, increased metastatic tumor burden, especially when brain is one of the metastatic localisation are in higher risk of death among all patients treated with vemurafenib.