Plasma total cell-free DNA (cfDNA) is a surrogate biomarker for tumour burden and a prognostic biomarker for survival in metastatic melanoma patients.

INTRODUCTION: Tumour burden is a prognostic biomarker in metastatic melanoma. However, tumour burden is difficult to measure and there are currently no reliable surrogate biomarkers to easily and reliably determine it. The aim of this study was to assess the potential of plasma total cell free DNA as biomarker of tumour burden and prognosis in metastatic melanoma patients. MATERIALS AND METHODS: A prospective biomarker cohort study for total plasma circulating cell-free DNA (cfDNA) concentration was performed in 43 metastatic melanoma patients. For 38 patients, paired blood collections and scan assessments were available before treatment and at first response evaluation. Tumour burden was calculated as the sum of volumes from three-dimensional radiological measurements of all metastatic lesions in individual patients. RESULTS: Baseline cfDNA concentration correlated with pre-treatment tumour burden (ρ = 0.52, P < 0.001). Baseline cfDNA levels correlated significantly with hazard of death and overall survival, and a cut off value of 89 pg/µl identified two distinct prognostic groups (HR = 2.22 for high cfDNA, P = 0.004). Patients with cfDNA ≥89 pg/µl had shorter OS (10.0 versus 22.7 months, P = 0.009; HR = 2.22 for high cfDNA, P = 0.004) and the significance was maintained when compared with lactic dehydrogenase (LDH) in a multivariate analysis. We also found a correlation between the changes of cfDNA and treatment-related changes in tumour burden (ρ = 0.49, P = 0.002). In addition, the ratio between baseline cfDNA and tumour burden was prognostic (HR = 2.7 for cfDNA/tumour volume ≥8 pg/(µl*cm3), P = 0.024). CONCLUSIONS: We have demonstrated that cfDNA is a surrogate marker of tumour burden in metastatic melanoma patients, and that it is prognostic for overall survival.

Distinct subclonal tumour responses to therapy revealed by circulating cell-free DNA.

BACKGROUND: The application of precision medicine in oncology requires in-depth characterisation of a patient's tumours and the dynamics of their responses to treatment. PATIENTS AND METHODS: We used next-generation sequencing of circulating cell-free DNA (cfDNA) to monitor the response of a KIT p.L576P-mutant metastatic vaginal mucosal melanoma to sequential targeted, immuno- and chemotherapy. RESULTS: Despite a KIT mutation, the response to imatinib was mixed. Unfortunately, tumours were not accessible for molecular analysis. To study the mechanism underlying the mixed clinical response, we carried out whole-exome sequencing and targeted longitudinal analysis of cfDNA. This revealed two tumour subclones; one with a KIT mutation that responded to imatinib and a second KIT-wild-type subclone that did not respond to imatinib. Notably, the subclones also responded differently to immunotherapy. However, both subclones responded to carboplatin/paclitaxel, and although the KIT-wild-type subclone progressed after chemotherapy, it responded to subsequent re-administration of paclitaxel. CONCLUSION: We show that cfDNA can reveal tumour evolution and subclonal responses to therapy even when biopsies are not available.

Baseline neutrophils and derived neutrophil-to-lymphocyte ratio: prognostic relevance in metastatic melanoma patients receiving ipilimumab.

BACKGROUND: Clinical responses to ipilimumab are variable in terms of onset, magnitude and duration. Upfront identification of patients who are more likely or unlikely to benefit from treatment is a major need. PATIENTS AND METHODS: Prospectively collected data from 720 advanced melanoma patients treated with ipilimumab 3 mg/kg within the Italian expanded access program were analyzed. The derived neutrophil-to-lymphocyte ratio (dNLR) was calculated from baseline peripheral blood cell counts, and receiver operating characteristic curve was used to evaluate the best cutoff for this marker. Patients were stratified according to dichotomized baseline absolute neutrophil counts (ANC), dNLR and their combination. The prognostic values of ANC and dNLR for survival were assessed using multivariate Cox proportional hazard models. A subgroup analysis including LDH in the models was also carried out. RESULTS: The median follow-up was 16.5 months. The optimal cutoff for dNLR was 3. Baseline ANC and dNLR were significantly associated with the outcome of ipilimumab-treated melanoma patients, in terms of disease progression and death (P < 0.0001 for all). Furthermore, for each elevated variable, prognosis worsened. Patients with both ANC ≥ 7500 and dNLR ≥ 3 had a significantly and independently increased risk of death [hazard ratio(HR) = 5.76; 95% confidence interval (CI) 4.29-7.75] and of progression (HR = 4.10; 95% CI 3.08-5.46) compared with patients with both lower ANC and dNLR. Patients with one of the two factors elevated displayed an intermediate risk of progression and death. The 1- and 2-year survival rates were 2% and 0%, respectively, for patients with ANC ≥ 7500 and dNLR ≥ 3, and 43% and 24%, respectively, for patients with both lower ANC and dNLR. CONCLUSIONS: Although these findings need to be confirmed and validated, we suggest that a neutrophil-based index may help risk-group stratification and assist disease-management strategies. Furthermore, the potential predictive value of this index for response to ipilimumab should be investigated in randomized clinical trials.

Clinical implication of tumor-associated and immunological parameters in melanoma patients treated with ipilimumab.

Ipilimumab, the first immune-checkpoint inhibitor extending overall survival (OS) in metastatic melanoma patients, has a survival benefit only in a proportion of patients and the development of reliable predictive biomarkers is still an unmet need. To meet this request, we used a multivariate statistical approach to test whether myeloid-derived suppressor cells (MDSC) or other tumor-associated and immunological parameters may serve as predictive or prognostic biomarkers in melanoma patients receiving ipilimumab. By using a standardized approach to determine the circulating levels of four MDSC subsets, we observed a significant expansion of three MDSC subsets at baseline, as compared to controls and, upon treatment, that high levels of CD14+/IL4Rα+ MDSCs were an independent prognostic factor of reduced OS. On the contrary, longer OS was associated to low levels of the proinflammatory proteins IL-6 and CRP and tumor-associated factors S100B and LDH both at baseline and after treatment. Increasing number of total T cells and especially of PD-1+/CD4+ T cells were associated with better prognosis, and upregulation of PD-1+ expression on CD4+ T cells upon treatment was associated with lower toxicity. As several parameters were associated to OS, we included these factors in a multivariate survival model, and we identified IL-6 and ECOG PS as independent biomarkers associated with improved OS, whereas high levels of LDH and CD14+/IL4Rα+ MDSCs were negative independent markers of reduced OS.

Electrochemotherapy in the Treatment of Cutaneous Metastases from Breast Cancer: A Multicenter Cohort Analysis.

BACKGROUND: The management of breast cancer (BC) skin metastases represents a therapeutic challenge. Electrochemotherapy (ECT) combines the administration of bleomycin with temporary permeabilization induced by locally administered electric pulses. Preliminary experience with ECT in BC patients is encouraging. METHODS: A total of 125 patients with BC skin metastases who underwent ECT between 2010 and 2013 were enrolled onto a multicenter retrospective cohort study. The treatment was administered following the European Standard Operative Procedures of Electrochemotherapy. Tumor response was clinically assessed adapting the Response Evaluation Criteria in Solid Tumors, and toxicity was evaluated according to Common Terminology Criteria for Adverse Events 4.0. Cox regression analysis was used to identify predictive factors. RESULTS: Response was evaluable in 113 patients for 214 tumors (median 1 per patient, range 1-3). The overall response rate after 2 months was 90.2 %, while the complete response (CR) rate was 58.4 %. In multivariate analysis, small tumor size (P < 0.001), absence of visceral metastases (P = 0.001), estrogen receptor positivity (P = 0.016), and low Ki-67 index (P = 0.024) were significantly associated with CR. In the first 48 h, 10.4 % of patients reported severe skin pain. Dermatologic toxicity included grade 3 skin ulceration (8.0 %) and grade 2 skin hyperpigmentation (8.8 %). Tumor 1-year local progression-free survival was 86.2 % (95 % confidence interval 79.3-93.8) and 96.4 % (95 % confidence interval 91.6-100) in the subgroup of those with CR. CONCLUSIONS: In this study, small tumor size, absence of visceral metastases, estrogen receptor positivity, and low Ki-67 index were predictors of CR after ECT. Patients who experienced CR had durable local control. ECT represents a valuable skin-directed therapy for selected patients with BC.

Personalised medicine: Development and external validation of a prognostic model for metastatic melanoma patients treated with ipilimumab.

PURPOSE: The purpose of this study was to set up a prognostic model for the identification of survival predictors specific for melanoma patients treated with ipilimumab. EXPERIMENTAL DESIGN: The following prospectively collected data were utilised: patient and primary tumour characteristics, relapse-free-interval, site and number of metastases, previous therapies and level of serum biomarkers (lactic dehydrogenase (LDH), C-reactive protein, ß2-microglobulin, vascular endothelial growth factor (VEGF), IL2, IL6, S-100, alkaline phosphatase (ALP), transaminases, leucocyte count, lymphocytes subpopulations). A multivariate prognostic model was developed using the Cox regression model fitted to the data of 113 consecutive metastatic patients treated with ipilimumab (3 mg/kg, q3w) at Veneto Institute of Oncology (IOV). External validation was obtained using the data of 69 and 34 patients treated at European Oncology Institute (IEO) and University of Torino (UT), respectively. RESULTS: Median survival was 8.3, 4.9 and 7.1 months from first ipilimumab administration at IOV, IEO and UT, respectively. Both higher baseline levels of LDH (Hazard Ratio [HR] v=1.36, 95% Confidence Interval [CI] 1.16-1.58, P<.001) and neutrophils (HR=1.76, 95% CI 1.41-2.10, P<.001) were associated with worse prognosis. Model performance was satisfactory both upon internal validation (Dxy=0.42) and external validation (Dxy=0.40). Serum LDH and neutrophil count discriminated patients who lived more (low neutrophils and low LDH) or less (high LDH or neutrophils) than 24 months. CONCLUSION: Serum LDH and neutrophil count were significant independent prognostic factors. This externally validated prognostic nomogram, could help clinicians to identify the patients who would benefit most from ipilimumab and consequently to improve resource allocation. These easily available biomarkers deserve further validation.

The value of electrochemotherapy in the treatment of peristomal tumors.

Electrochemotherapy (ECT) holds promise as a minimally invasive palliative tool for selected patients with peristomal tumors. We present the favorable short-term outcome of three patients (two with head and neck cancer, one with gastric cancer) successfully palliated by ECT. Treatment effectiveness and clinical benefit for patients with unresectable stoma recurrence need to be confirmed in future multicenter studies.

Electrochemotherapy for disseminated superficial metastases from malignant melanoma.

BACKGROUND: The aim of the study was to determine predictive factors for effectiveness, toxicity and local disease control in patients with malignant melanoma treated with bleomycin-based electrochemotherapy (ECT). METHODS: Electrochemotherapy was offered to patients with superficially disseminated melanoma metastases unsuitable for resection and unresponsive to chemotherapy. RESULTS: Eighty-five patients were treated with up to six ECT cycles with minimal, mainly dermatological, toxicity. One month after the first ECT, an objective response was observed in 80 patients (94 per cent). After retreatment because of a partial response in 39 patients, a complete response was achieved in 19 patients. Among the 41 (48 per cent) complete responders at first ECT, 19 patients received a second cycle because of new lesions after a median of 6 (range 2-14) months. After a median follow-up of 26 months, six patients experienced local recurrence with a 2-year local progression-free survival rate of 87 per cent. In multivariable analysis, significant predictive factors for response were tumour size (odds ratio (OR) 0·23, 95 per cent confidence interval (c.i.) 0·19 to 0·86; P = 0·003) and number of lesions (OR 0·38, 0·28 to 0·88; P = 0·002). An increasing number of electrode applications (hazard ratio (HR) 2·18, 95 per cent c.i. 1·22 to 3·44; P = 0·041) and ECT cycles (HR 0·46, 0·22 to 0·95; P = 0·005) were predictors of local control. There were no predictors of toxicity. Melanoma thickness and lower limb location of metastases were prognostic for survival. CONCLUSION: The most suitable candidates for ECT were patients with few and small metastases on the lower limb treated with multiple electrode applications and ECT cycles.