Could Somatostatin Enhance the Outcomes of Chemotherapeutic Treatment in SCLC?

Somatostatin and Somatostatin Receptors in Tumour Biology

Somatostatin (SST), a growth hormone inhibitory peptide, is expressed in endocrine and non-endocrine tissues, immune cells and the central nervous system (CNS). Post-release from secretory or immune cells, the first most appreciated role that SST exhibits is the antiproliferative effect in target tissue that served as a potential therapeutic intervention in various tumours of different origins. The SST-mediated in vivo and/or in vitro antiproliferative effect in the tumour is considered direct via activation of five different somatostatin receptor subtypes (SSTR1-5), which are well expressed in most tumours and often more than one receptor in a single cell. Second, the indirect effect is associated with the regulation of growth factors. SSTR subtypes are crucial in tumour diagnosis and prognosis. In this review, with the recent development of new SST analogues and receptor-specific agonists with emerging functional consequences of signaling pathways are promising therapeutic avenues in tumours of different origins that are discussed.

Predictive Value of 99MTC-hynic-toc Scintigraphy in Lung Neuroendocrine Tumor Diagnosis

Background:

Νeuroendocrine tumors of the lungs are rare arising in the thymus and gastro-entero-pancreatic tract and belonging to foregut of neuroendocrine tumors. The aim of the present prospective study was to estimate the potential impact of single-photon emission computed tomography somatostatin receptor scintigraphy using 99mTc-Tektrotyd on diagnosis, treatment response, and prognosis in patients with neuroendocrine tumors of the lungs.

Methods:

Thirty-six patients with neuroendocrine tumors of the lungs were evaluated by using 99mTc-HYNIC-TOC scintigraphy. The scintigraphic results were compared to liver tissue uptake (Krenning score). Likewise, the functional imaging results were compared with biochemical indices including chromogranin A, neuroendocrine-specific enolase, and insulin-like growth factor 1 at the time of diagnosis (baseline) and disease progression.

Results:

The number of somatostatin receptors, expressed with Krenning score, did not show any correlation with the survival of patients both at baseline (P = .08) and at disease progression (P = .24), and scintigraphy results did not relate significantly to progression-free survival. Comparing the results of 99mTc-HYNIC-TOC scintigraphy according to the response of patients in the initial treatment, a statistically significant negative correlation was observed both in the first and in the second scintigraphy with patients’ response (P = .001 and P < .001, respectively). The concentrations of biochemical markers were in accordance with scintigraphy results in the diagnosis.

Conclusion:

This study indicates that 99mTc-HYNIC-TOC scintigraphy appears to be a reliable, noninvasive technique for detection of primary neuroendocrine tumors and their locoregional or distant metastases, although it cannot be used as a neuroendocrine tumors of the lungs predictive technique.

Maintenance with lanreotide in small-cell lung cancer expressing somatostatine receptors: A multicenter, randomized, phase 3 trial

OBJECTIVES

Considering the frequent expression of somatostatine receptors, we designed the G04.2011 trial to investigate the efficacy of the somatostatine analogue lanreotide in maintenance for SCLC patients after response to standard treatment.

MATERIALS AND METHODS

A multicenter, randomized, phase 3 trial was conducted in SCLC expressing somatostatine receptors at baseline Octreoscan, responding after platinum-based chemotherapy with/without radiotherapy. Patients were randomized 1:1 to receive maintenance lanreotide 120 mg subcutaneously every 28 days, up to 1 year or progression versus observation. Randomization was stratified according to stage (limited/extended, LD/ED). The primary end-point was progression-free survival (PFS). Secondary endpoints were overall survival (OS) and safety.

RESULTS

Seventy-one patients were randomly assigned (39 to lanreotide, 32 to observation) in 9 Italian institutions. Median PFS was 3.6 (95% CI 3.2-3.9) with lanreotide versus 2.3 months (95% CI 1.7-2.9) with observation (HR 1.51, 95% CI 0.90-2.50; P = 0.11). Stage was an independent predictor for PFS (HR 3.14, 95% CI 1.77-5.57; P < 0.0001). Median PFS was 7.0 (95% CI <1-13.5) with lanreotide versus 3.8 months (95% CI <1-8.6) with observation in LD (P = 0.21), and 3.0 (95% CI 2.2-3.8) versus 2.2 (95% 1.7-2.7) in ED (P = 0.19). Median OS was 9.5 (95% CI 4.8-14.3) with lanreotide versus 4.7 months (95% CI <1-16.6) with observation (P = 0.47). Treatment-related adverse events occurred in 28% of patients with lanreotide (grade 3 in two patients).

CONCLUSION

Although survival outcomes were not significantly prolonged with lanreotide as a maintenance in SCLC expressing somatostatin receptors after response to standard treatment, lanreotide showed a slight PFS benefit in LD SCLC deserving further investigations.

Long non-coding RNA HOTTIP promotes BCL-2 expression and induces chemoresistance in small cell lung cancer by sponging miR-216a

Despite progress in treatment of small cell lung cancer (SCLC), its multidrug chemoresistance and poor prognosis still remain. Recently, we globally assessed long non-coding RNAs (lncRNAs) for contributions to SCLC chemoresistance using microarray data, in vitro and in vivo assays. Here we reported that HOTTIP, encoding a lncRNA that is frequently amplified in SCLC, was associated with SCLC cell chemosensitivity, proliferation, and poor prognosis of SCLC patients. Moreover, mechanistic investigations showed that HOTTIP functioned as an oncogene in SCLC progression by binding miR-216a and abrogating its tumor-suppressive function in this setting. On the other hand, HOTTIP increased the expression of anti-apoptotic factor BCL-2, another important target gene of miR-216a, and jointly enhanced chemoresistance of SCLC by regulating BCL-2. Taken together, our study established a role for HOTTIP in SCLC progression and chemoresistance suggest its candidacy as a new diagnostic and prognostic biomarker for clinical management of SCLC.

Somatostatin analogs in the treatment of neuroendocrine tumors: current and emerging aspects

INTRODUCTION

Neuroendocrine tumors (NETs) harbor somatostatin receptors and there is a strong rationale for using somatostatin analogs (SSAs) for treatment of NETs. Areas covered: This article discusses i) pharmacology of somatostatin and its analogs; ii) antisecretory and anti-proliferative effects of SSAs in NETs; iii) efficacy and safety of emerging therapeutic regimens with first generation SSAs administered at either high doses or in combination with antineoplastic drugs; iv) efficacy and safety of pasireotide and chimeric molecules; v) efficacy of radionuclide therapy of NETs using SSAs. Expert opinion: SSAs are the first-line medical therapy for functioning and non-functioning well-differentiated NETs. In patients not responder to first generation SSAs, the increase of drug dose over the conventional regimens, the combination of SSAs with other biotherapies or molecular targeted therapies, the switch to pasireotide or the use of SSAs in radionuclide therapy may improve the therapeutic success.

Strategy for chemotherapeutic delivery using a nanosized porous metal-organic framework with a central composite design

BACKGROUND

Enhancing drug delivery is an ongoing endeavor in pharmaceutics, especially when the efficacy of chemotherapy for cancer is concerned. In this study, we prepared and evaluated nanosized HKUST-1 (nanoHKUST-1), nanosized metal-organic drug delivery framework, loaded with 5-fluorouracil (5-FU) for potential use in cancer treatment.

MATERIALS AND METHODS

NanoHKUST-1 was prepared by reacting copper (II) acetate [Cu(OAc)₂] and benzene-1,3,5-tricarboxylic acid (H₃BTC) with benzoic acid (C₆H₅COOH) at room temperature (23.7°C±2.4°C). A central composite design was used to optimize 5-FU-loaded nanoHKUST-1. Contact time, ethanol concentration, and 5-FU:material ratios were the independent variables, and the entrapment efficiency of 5-FU was the response parameter measured. Powder X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and nitrogen adsorption were used to determine the morphology of nanoHKUST-1. In addition, 5-FU release studies were conducted, and the in vitro cytotoxicity was evaluated.

RESULTS

Entrapment efficiency and drug loading were 9.96% and 40.22%, respectively, while the small-angle X-ray diffraction patterns confirmed a regular porous structure. The SEM and TEM images of the nanoHKUST-1 confirmed the presence of round particles (diameter: approximately 100 nm) and regular polygon arrays of mesoporous channels of approximately 2-5 nm. The half-maximal lethal concentration (LC₅₀) of the 5-FU-loaded nanoHKUST-1 was approximately 10 µg/mL.

CONCLUSION

The results indicated that nanoHKUST-1 is a potential vector worth developing as a cancer chemotherapeutic drug delivery system.

Somatostatin Analog Therapy in Small Cell Lung Cancer

Chemotherapy represents the cornerstone of treatment for patients with small cell lung cancer (SCLC); however, standard therapy has reached a plateau in improving patient survival with overall disappointing results. The demonstration that SCLC expresses neuroendocrine markers, such as somatostatin (SST) receptors, has led to use SST analogs or radiolabeled SST analogs in the treatment of SCLC patients. In the current review, we would focus on the possible role of SST analogs in SCLC.

Tyrosine Kinase Inhibitors for the Elderly

Until few years ago non-specific cytotoxic agents were considered the tip of the arrow as first line treatment for lung cancer. However; age > 75 was considered a major drawback for this kind of therapy. Few exceptions were made by doctors based on the performance status of the patient. The side effects of these agents are still severe for several patients. In the recent years further investigation of the cancer genome has led to targeted therapies. There have been numerous publications regarding novel agents such as; erlotinib, gefitinib and afatinib. In specific populations these agents have demonstrated higher efficiency and this observation is explained by the overexpression of the EGFR pathway in these populations. We suggest that TKIs should administered in the elderly, and with the word elderly we propose the age of 75. The treating medical doctor has to evaluate the performance status of a patient and decide the best treatment in several cases indifferent of the age. TKIs in most studies presented safety and efficiency and of course dose modification should be made when necessary. Comorbidities should be considered in any case especially in this group of patients and the treating physician should act accordingly.

Drug Eluting Stents for Malignant Airway Obstruction: A Critical Review of the Literature

Lung cancer being the most prevalent malignancy in men and the 3(rd) most frequent in women is still associated with dismal prognosis due to advanced disease at the time of diagnosis. Novel targeted therapies are already on the market and several others are under investigation. However non-specific cytotoxic agents still remain the cornerstone of treatment for many patients. Central airways stenosis or obstruction may often complicate and decrease quality of life and survival of these patients. Interventional pulmonology modalities (mainly debulking and stent placement) can alleviate symptoms related to airways stenosis and improve the quality of life of patients. Mitomycin C and sirolimus have been observed to assist a successful stent placement by reducing granuloma tissue formation. Additionally, these drugs enhance the normal tissue ability against cancer cell infiltration. In this mini review we will concentrate on mitomycin C and sirolimus and their use in stent placement.