Bevacizumab plus octreotide and metronomic capecitabine in patients with metastatic well-to-moderately differentiated neuroendocrine tumors: the XELBEVOCT study.

BACKGROUND: We assessed the activity and toxicity of the XELBEVOCT regimen in patients with metastatic well-to-moderately differentiated neuroendocrine neoplasms (WMD-NEN). Ancillary studies evaluated hypertension, proteinuria, and vascular endothelial growth factor (VEGF) polymorphisms in predicting progression-free survival (PFS) and the predictive role of serum vitamin D in progression-free survival and proteinuria onset. METHODS: This prospective phase 2 study included 45 patients with WMD-NEN arising from various primary sites. The treatment regimen was octreotide long-acting release (LAR), 20 mg monthly, metronomic capecitabine, 2000 mg/daily, and intravenous bevacizumab, 5 mg/kg every 2 weeks, without interruption for 9 months. Bevacizumab was continued until disease progression. RESULTS: Partial response was obtained in 8 patients (17.8%, 95% confidence interval [CI], 6.4%-28.2%); tumor response was more frequent in pancreatic than in non-pancreatic malignancies. The median PFS was 14.9 months; median overall survival was not attained. Biochemical and symptomatic responses were observed in 52.9% and 82.3% of cases, respectively. The treatment was well tolerated. Grade 3 toxicities included hand and foot syndrome (11.1%), proteinuria (4.4%), and renal toxicity (2.2%). Proteinuria (all grades) was correlated with longer PFS (p = 0.017). There was an inverse relationship between proteinuria and vitamin D levels. VEGF polymorphisms were not associated with patient outcome. CONCLUSION: The XELBEVOCT regimen is active and well tolerated in patients with metastatic WMD-NEN. Proteinuria correlated with hypovitaminosis D status and was the best predictive factor of treatment efficacy. TRIAL REGISTRATION: Trial registration number NCT01203306.

Chromogranin A as a marker of neuroendocrine neoplasia: an Italian Multicenter Study.

Elevated circulating chromogranin A (CgA) levels are found in neuroendocrine tumors (NETs), but the diagnostic usefulness of this marker is still debatable. To assess the role of CgA for the diagnosis of gastroenteropancreatic (GEP) NETs and the identification of metastatic patients, an Italian multicenter observational study has been performed. CgA was evaluated in 202 GEP NET patients by IRMA and ELISA. The cutoffs for diagnosis and presence of metastases were identified by receiver-operating characteristic (ROC) curve. We found good correlation between IRMA and ELISA. The ROC analysis identified a cutoff of 53 ng/ml for IRMA and 16 U/l for ELISA as discriminating between controls and patients with active disease (sensitivity 71.3 and 84%; specificity 71 and 85% respectively). Metastases were present in 123 patients, having significantly higher CgA levels than patients without metastases. ROC analysis identified a cutoff of 146 ng/ml for IRMA and 67.3 U/l for ELISA as discriminating between patients with and without metastases (sensitivity 57 and 63.3%; specificity 55.6 and 71.4% respectively). For pancreatic NETs positive and negative predictive values were 84 and 78% respectively (90% specificity and 68% sensitivity). We found lower CgA levels in patients with extensive metastatic spread than in those with liver metastases only. These data assess the role of CgA evaluation in GEP NETs, and demonstrate that higher CgA levels associate with metastatic disease, confirming that CgA levels can provide a helpful practical biochemical marker for the clinical management of NETs, but with low sensitivity and specificity.

Comparison between two commercially available chromogranin A assays in detecting neuroendocrine differentiation in prostate cancer and benign prostate hyperplasia.

BACKGROUND: Chromogranin A (CgA) is the neuroendocrine (NE) marker most frequently employed in detecting NE differentiation in prostate cancer patients, either at the tissue level or in the general circulation. METHODS: We compared the two commercially CgA assay kits in detecting NE differentiation, in benign hyperplasia (BPH) or prostate cancer (PC) patients (pts). 170 pts with BPH, 107 with BPH+inflammation, and 136 PC pts entered the study. CgA was measured in each patient with the immunoradiometric assay (IRMA) and with the enzyme-linked immunoabsorbent assay (ELISA). RESULTS: A moderate relationship was found between CgA measured with IRMA and ELISA in the whole population (Spearman's R=0.65, p<0.05), in BPH pts (R=0.76, p<0.05), in BPH+inflammation pts (R=0.53, p<0.05) and in PC pts (R=0.60, p<0.05). Twenty-two out of 62 pts (35.4%) with elevated ELISA CgA did not have increased IRMA CgA; by contrast, 21/61 pts (34.4%) with elevated IRMA CgA were not recognized as abnormal by the ELISA kit. CONCLUSIONS: CgA measured by the two assays provided a significant discordance rate, suggesting that the two kits might elicit different information.

Chromogranin A expression in patients with hormone naïve prostate cancer predicts the development of hormone refractory disease.

PURPOSE: We assessed chromogranin A as a tissue biomarker in prostate needle biopsies or as a plasma biomarker, a risk factor for hormone refractory prostate cancer. MATERIALS AND METHODS: A total of 211 patients with newly diagnosed prostate cancer treated with luteinizing hormone releasing hormone analogues constituted the study cohort. Univariate and multivariate Cox regression analyses were used to assess the predictive role of tissue and plasma chromogranin A expression. RESULTS: Chromogranin A expression in less than 30% or in 30% or more tumor cells was significantly associated with a shorter time to hormone refractory disease on univariate analysis (HR 2.0, 95% CI 1.3-3.1 and HR 6.0, 95% CI 2.7-12.9), or on multivariate analysis after adjusting for Gleason score, serum prostate specific antigen and disease stage (HR 1.7, 95% CI 1.0-2.8 and HR 3.9, 95% CI 1.7-9.0), respectively. Plasma chromogranin A measured at baseline (HR 3.0, 95% CI 1.8-5.2), and after 1 year (HR 5.8, 95% CI 3.1-10.1) and 2 years (HR 3.5, 95% CI 1.6-7.6), was predictive of hormone refractory risk confirming the tissue results. Plasma as well as tissue chromogranin A expression negatively correlated with overall survival. CONCLUSIONS: Chromogranin A expression in prostate cancer biopsies is an independent predictive factor of hormone refractory disease in patients with newly diagnosed prostate cancer on early androgen deprivation therapy. Plasma chromogranin A is also a reliable predictive marker and the predictive significance is maintained over time. These results deserve validation in another data set.