Target therapies plus somatostatin analogs in NETs: a network meta-analysis

Although combination therapy is not recommended in patients with gastro-entero-pancreatic (GEP) neuroendocrine tumors (NETs), this strategy is widely used in clinical practice. This network meta-analysis of randomized trials evaluates targeted therapies and somatostatin analogues in GEP-advanced NETs, either alone or in combination, comparing the efficacy of different, single or combined treatment strategies in terms of progression-free survival (PFS). Interventions were grouped as analogs, everolimus, everolimus plus SSAs, sunitinib and placebo. In a secondary analysis, we also assessed the efficacy of individual-specific pharmacological treatments vs placebo or each other. From 83 studies identified, 8 randomized controlled trials were selected, with a total of 1849 patients with either functioning or non-functioning NETs. The analysis confirmed the superiority of all treatments over placebo (HR ranging from 0.34, 95% CI: 0.24-0.37 with the combination of everolimus plus SSAs to 0.42, 0.31-0.57 with the analogs; moderate quality of evidence). On ranking analysis, the combination of everolimus plus SSA (P score = 0.86) and then everolimus alone (P score = 0.65) ranked highest in increasing PFS. On comparative evaluation of different interventions, pasireotide (P score = 0.96) and everolimus + octreotide (P score = 0.82) ranked as the best pharmacological treatment options. Our findings support the use of combination therapy in the treatment of functioning and non-functioning GEP NETs. The role of pasireotide should be explored in selected subgroups of patients. Lastly, the combination of everolimus and octreotide appears promising and should be more widely considered in clinical practice.

Treatment personalization in gastrointestinal neuroendocrine tumors

OPINION STATEMENT

The clinical scenario of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) is continuously changing due to significant improvements in the definition of their molecular landscapes and the introduction of innovative therapeutic approaches. Many efforts are currently employed in the integration of the genetics/epigenetics and clinical information. This is leading to an improvement of tumor classification, prognostic stratification and ameliorating the management of patients based on a personalized approach.

Characterization and sub-cellular localization of SS1R, SS2R, and SS5R in human late-stage prostate cancer cells: effect of mono- and bi-specific somatostatin analogs on cell growth

Somatostatin (SST) and SST receptors (SS1R, SS2R, SS3R, SS4R and SS5R) appear to play a significant role in the progression of human prostate cancer (PCa), which is associated with heterogeneity of SSRs expression and specific cell localization as we already demonstrated in the LNCaP cell line, an in vitro model of human androgen-dependent PCa. In this study, PC-3 and DU-145 human castration-resistant PCa cells were found to express all SSRs, while LNCaP expressed all but SS4R. A 48-h treatment with BIM-23244 (SS2R/SS5R) or BIM-23926 (SS1R) SST analogs was more effective in inhibiting cell proliferation, compared to BIM-23120 (SS2R), BIM-23206 (SS5R) and BIM-23704 (SS1R/SS2R). BIM-23926 (SS1R) treatment increased the amount of p21 and decreased phosphorylated (p) ERK1/2. BIM-23244 (SS2R/SS5R) led to p21 increment only in PC-3 cells, and to pERK1/2 reduction in both cell lines. SS1R/SS2R and SS2R/SS5R receptor dimers were natively present on cell membrane and their amount was increased by BIM-23704 (SS1R/SS2R) or BIM-23244 (SS2R/SS5R) treatment, respectively. SS1R, SS2R and SS5R were differently distributed among nuclear, lysosomal and microsomal compartment, according to their different recycling dynamics. These results show that, in PC-3, DU-145 and LNCaP cells, activation of SS1R and SS2R/SS5R leads to relevant antiproliferative effects.