Radiosensitization by BRAF inhibitor therapy-mechanism and frequency of toxicity in melanoma patients.

BACKGROUND: Recent evidence suggests that ionizing radiation may be associated with unexpected side-effects in melanoma patients treated with concomitant BRAF inhibitors. A large multicenter analysis was carried out to generate reliable safety data and elucidate the mechanism. METHODS: A total of 161 melanoma patients from 11 European skin cancer centers were evaluated for acute and late toxicity, of whom 70 consecutive patients received 86 series of radiotherapy with concomitant BRAF inhibitor therapy. To further characterize and quantify a possible radiosensitization by BRAF inhibitors, blood samples of 35 melanoma patients were used for individual radiosensitivity testing by fluorescence in situ hybridization of chromosomal breaks after ex vivo irradiation. RESULTS: With radiotherapy and concomitant BRAF inhibitor therapy the rate of acute radiodermatitis ≥2° was 36% and follicular cystic proliferation was seen in 13% of all radiotherapies. Non-skin toxicities included hearing disorders (4%) and dysphagia (2%). Following whole-brain radiotherapy, rates of radiodermatitis ≥2° were 44% and 8% (P < 0.001) for patients with and without BRAF inhibitor therapy, respectively. Concomitant treatment with vemurafenib induced acute radiodermatitis ≥2° more frequently than treatment with dabrafenib (40% versus 26%, P = 0.07). In line with these findings, analysis of chromosomal breaks ex vivo indicated significantly increased radiosensitivity for patients under vemurafenib (P = 0.004) and for patients switched from vemurafenib to dabrafenib (P = 0.002), but not for patients on dabrafenib only. No toxicities were reported after stereotactic treatment. CONCLUSION: Radiotherapy with concomitant BRAF inhibitor therapy is feasible with an acceptable increase in toxicity. Vemurafenib is a more potent radiosensitizer than dabrafenib.

A multicenter DeCOG study on predictors of vemurafenib therapy outcome in melanoma: pretreatment impacts survival.

BACKGROUND: Kinase inhibitors targeting the BRAF V600 mutation have become standard in the treatment of metastatic melanoma. Albeit in wide clinical use, the patterns associated with therapy outcome are not fully elucidated. The present study was aimed to identify predictive factors of therapy response and survival under the BRAF inhibitor vemurafenib. PATIENTS AND METHODS: This multicenter retrospective study analyzed patient, tumor, and pretreatment characteristics collected in BRAF V600-mutated stage IV melanoma patients before single-agent therapy with the BRAF inhibitor vemurafenib. RESULTS: A total of 300 patients from 14 centers were included into this study with a median follow-up time of 13.0 months. Median progression-free survival (PFS) was 5.1 months; median overall survival (OS) was 7.6 months. Best response under vemurafenib was associated with serum lactate dehydrogenase (LDH; ≤ versus >upper normal limit; P = 0.0000001), Eastern Cooperative Oncology Group (ECOG) overall performance status (OPS) (0 versus ≥ 1; P = 0.00089), and BRAF mutation subtype (V600E versus V600K; P = 0.016). Multivariate analysis identified ECOG OPS ≥ 1 [hazard ratio (HR) = 1.88; P = 0.00005], immunotherapy pretreatment (HR = 0.53; P = 0.0067), elevated serum LDH (HR = 1.45; P = 0.012), age >55 years (HR = 0.72; P = 0.019), and chemotherapy pretreatment (HR = 1.39; P = 0.036) as independent predictors of PFS. For OS, elevated serum LDH (HR = 1.99; P = 0.00012), ECOG OPS ≥ 1 (HR = 1.90; P = 0.00063), age >55 years (HR = 0.65; P = 0.011), kinase inhibitor pretreatment (HR = 1.86; P = 0.014), immunotherapy pretreatment (HR = 0.57; P = 0.025), chemotherapy pretreatment (HR = 2.17; P = 0.039), and male gender (HR = 0.70; 95% confidence interval 0.50-0.98; P = 0.039) were found as predictors. CONCLUSION: Our data demonstrate that the type of pretreatment strongly influences the outcome of vemurafenib therapy, with a precedent immunotherapy showing a positive, and a prior chemotherapy and kinase inhibitors showing a negative impact on survival, respectively. Moreover, we show that the patient's OPS, serum LDH, age, and gender independently impact vemurafenib therapy outcome. These findings should be taken into account for the future design of therapy sequencing in BRAF V600 mutation-positive melanoma patients.

Characterizing psychosocial distress in melanoma patients using the expert rating instrument PO-Bado SF.

BACKGROUND: Although psychosocial distress has been evaluated well in cancer entities like breast or prostate cancer, its impact on melanoma patients still needs to be characterized. The objectives of this study were to (i) evaluate psychosocial distress in melanoma patients using an expert rating instrument [basic documentation for psycho-oncology short version (PO-Bado SF)]; (ii) determine associated demographic and clinical variables; and (iii) assess the acceptance of using PO-Bado SF as a routine procedure in a skin cancer unit. METHODS: A cross-sectional group of 696 melanoma patients was recruited. During the routine contact, doctors assessed the patients subjective distress using PO-Bado SF. Sociodemographic data, tumour data, treatment and the course of the disease were extracted from the patients' charts. RESULTS: PO-Bado SF was completed in 688 of 696 (99%) participating patients, revealing a high acceptance. In 51 (7%) patients, the PO-Bado SF cut-off score indicated the potential need of psychosocial support. Patients with previous or ongoing radiotherapy, a history of major surgery due to organ metastases, younger age and shorter time since diagnosis were considered significantly more distressed than patients without these criteria. Patients were most distressed by suffering from anxiety/worries and/or tensions. In younger patients emotional variables and other problems like social or family problems were deemed more relevant while functional limitations in daily living were reasons for higher distress in older patients. CONCLUSION: PO-Bado SF is a useful, well-accepted, practical and economic screening tool to identify distressed melanoma patients. Although most melanoma patients seem to cope well with their disease, special attention should be given to young patients in the first years after initial diagnosis and to patients with advanced disease, radiotherapy and major surgery due to their disease. Combination of expert rating tools with self-report screening instruments could further characterize the specific sources of distress to optimize psychosocial support.