Incidence and predictors of infections in patients with advanced non-small cell lung cancer treated with checkpoint inhibitor immunotherapies: A monocentric retrospective cohort study

Immune checkpoint inhibitors (ICIs) represent the cornerstone of the current treatment of non-small cell lung cancer (NSCLC). However, the occurrence of concomitant infections might hamper success. All consecutive patients with advanced NSCLC who started ICIs as a first- or second-line therapy from January 1, 2017 to June 30, 2020 were retrospectively evaluated. The occurrence of infectious events during ICIs was correlated with clinical characteristics, including previous Cytotoxic Chemotherapy (CC), occurrence of immune-related-adverse-events (irAEs). A total of 211 patients were included, 46 (22%) females, with a median (q1-q3) age of 69 (62-76) years. Overall, 85 patients (40%) received ICIs as a first treatment line and 126 (60%) as a second line; 40 patients (19%) had at least one infection during ICIs, and 17 (8%) more than one. Notably, autoimmune diseases (P < .005), neutropenia (P = .001) or infections during previous CC (P = .001), irAEs (P = .006), or steroid therapy for irAEs (P < .001) were associated with infection development. By multivariate Cox-regression, autoimmune diseases (aHR = 6.27; 95%CI = 2.38-16.48; P < .001) and steroid therapy for irAEs (aHR = 2.65; 95%CI = 1.27-5.52; P < .009) were associated with a higher risk of infection during ICIs. Interestingly, autoimmune diseases were confirmed as risk factors in patients treated with ICIs as a first line, while previous infections were the only independent predictor of infections in patients treated with ICIs as a second line. Patients with NSCLC treated with ICIs with concurrent autoimmune disease, receiving steroid therapy for management of irAEs, or having a history of previous infections during CC should be actively monitored for the risk of developing infectious complications.

FoRT 05-BEAT: A phase II randomized trial comparing atezolizumab versus atezolizumab + bevacizumab as first-line treatment in patients with PD-L1 high advanced/metastatic NSCLC

TPS9145

Background: Several ongoing phase III studies are evaluating the efficacy of first-line atezolizumab in combination with chemotherapy in patients with non small-cell lung cancer (NSCLC). Among angiogenesis inhibitors, bevacizumab is approved as first-line therapy in combination with chemotherapy or in combination with erlotinib in patients with NSCLC harboring activating EGFR mutations. Recent evidence (Wallin 2016) suggests that the combination of atezolizumab and bevacizumab increases intra-tumoral CD8+T cells, suggesting that dual VEGF and PD-L1 inhibition improves antigen-specific T-cell migration. In addition, preliminary clinical data suggested a strong synergistic effects of bevacizumab with immune checkpoint inhibitors. There is therefore a strong rationale for investigating the combination of atezolizumab and bevacizumab in patients with advanced/metastatic NSCLC. The FoRT 05-BEAT is a multicenter, Italian, phase II, randomized study comparing atezolizumab monotherapy versus the combination of atezolizumab and bevacizumab in patients with chemo-naive metastatic NSCLC and high levels of PD-L1 expression. Methods: The trial was conducted in 35 Italian centers: chemotherapy naive metastatic NSCLC patients, with high levels of PD-L1 expression (PD-L1 TPS ≥50% or TC/IC 3 scoring) were randomly assigned to atezolizumab monotherapy (1200 mg every 3 weeks) or to the combination of atezolizumab (1200 mg every 3 weeks) and bevacizumab (15 mg/kg every 3 weeks).The primary endpoint is overall survival (OS) rate at 18 months. Secondary endpoints include response rate (RR), PFS, OS according to presence of bone and/or hepatic metastases. Safety considerations will be considered. Exploratory analysis of predictive biomarker on tumor tissue and blood samples has been planned. Sample size has been calculated assuming a 18 months OS of 50% in the atezolizumab arm. Therefore, a total of 186 patients is needed to detect an absolute improvement of 20%, thus obtaining a 18mOS of 70% in the combination arm, with a power of 80% at a significance level of 5%. Taking into account the percentage of patients lost-to-follow-up, the sample size has been increased by 10% (N = 206 patients, 103 per arm). At the drafting of this abstract, 57 patients have already been enrolled (47 randomized). Clinical trial information: NCT03896074.

Incidence of Infections and Predictors of Mortality During Checkpoint Inhibitor Immunotherapy in Patients With Advanced Lung Cancer: A Retrospective Cohort Study

BACKGROUND

Immune checkpoint inhibitors (ICIs) have revolutionized nonsmall cell lung cancer (NSCLC) treatment and significantly increased overall survival of patients. However, the incidence of concurrent infections and their management is still debated.

METHODS

From August 2015 to October 2019, all consecutive patients with NSCLC who received nivolumab or pembrolizumab as first- or second-line therapy were retrospectively evaluated. At the time of analysis all patients had died. Clinical characteristics of patients, type of infections, and predictors of mortality were analyzed.

RESULTS

A total of 118 patients were identified: 74 in the nivolumab group and 44 in the pembrolizumab group. At least 1 infection was recorded in 22% of the nivolumab-group versus 27% of the pembrolizumab-group (P = .178). In both groups, the main infection was pneumonia, followed by skin and soft tissue infections, urinary tract infections, and gastroenteritis. Crude mortality for first infection was 10.7%, followed by 25% and 40% for the second and third recurrence, respectively (p for trend = .146). No opportunistic infections were recorded. It is notable that, by Cox-regression model, the independent predictor of mortality was a higher Eastern Cooperative Oncology Group performance status at baseline (P < .001), whereas the multidisciplinary diagnosis and treatment of concurrent infections was associated with a reduced probability of mortality (adjusted hazard ratio = 0.50; 95% confidence interval = 0.30-0.83; P < .001).

CONCLUSIONS

In patients with NSCLC treated with ICIs, multidisciplinary management of concurrent infections may reduce the risk of mortality. Further studies to investigate risk factors for infections, as well as appropriate management strategies and preventive measures in this setting, are warranted.

Successful treatment of triple EGFR mutation T785A/L861Q/H297_E298 with afatinib

Patients with non‐small cell lung cancer (NSCLC) and uncommon epidermal growth factor receptor (EGFR) mutation are characterized by high heterogeneity, and globally considered to have a worse prognosis than patients with the two common mutations; exon 19 deletion, and exon 21 L858R. Nevertheless, some uncommon mutations do confer sensitivity to tyrosine kinase inhibitors (TKIs) which is comparable with common mutations. In particular, some compound EGFR mutations seem to be characterized by a favorable prognosis. Unfortunately, the rarity of complex EGFR mutations results in difficult clinical decision‐making. Herein, to the best of our knowledge, we report the first case of an NSCLC patient with an EGFR triple mutation containing T785A/L861Q/H297_E298 who was successfully treated with afatinib.

An evaluation of masitinib for treating systemic mastocytosis

Introduction: Systemic Mastocytosis (SM) is a complex family of rare diseases, against which pharmacological therapies are still very few. It is a c-kit driven disease, whose disregulation leads to uncontrolled activation and proliferation of mast cells (MCs) with consequent release of effector molecules which are responsible for its clinical manifestations. Areas covered: Masitinib is a relatively new potential drug against SM and its chemical structure strictly derives from imatinib, the first tyrosine kinase inhibitor which entered the pharmaceutical market about 15 years ago. In this review, the authors present masitinib in all its properties, from chemistry to pharmacology and toxicity to its potential clinical application in SM, focusing the discussion on the few clinical trials in which it has been involved, with a particular attention on the still open challenge to determine how to measure the response to therapy. Expert opinion: In spite of their similarity in chemistry and biological activity against submolecular targets, masitinib is much more selective towards c-kit receptors than other tyrosine kinases, such as Bcl-Abl. Furthermore, its ability to inhibit degranulation, cytokine production and MCs migration from bone marrow gives it a great chance to become an important therapeutic option for selected SM patients.

Complete response in a patient with liver metastases from breast cancer employing hepatic arterial infusion 5-fluorouracil based chemotherapy plus systemic nab-paclitaxel

About half of patients with metastatic breast cancer (mBC) have unresectable liver metastases (LMs) or liver-predominant disease (LPD). Unfortunately systemic chemotherapy has limited tumor response due to LMs are supplied by hepatic artery. Hepatic intra-arterial (HAI) have antitumor activity in pretreated patients with LMs. Here we report the case of a 55-year-old woman affected by BCLPD and heavily pretreated. LMs responded to treatment based on HAI with 5-fluorouracil and nab-paclitaxel systemic chemotherapy, and they completely disappeared on a CT-scan. We conclude that this combination chemotherapy is safe and may be very useful for the treatment of patients with BCLPD. Therefore, this combination should be evaluated in a large study.

C-Kit receptor and tryptase expressing mast cells correlate with angiogenesis in breast cancer patients

C-Kit protein is a transmembrane tyrosine kinase (TK) receptor (c-KitR-TK), which is predominantly expressed on mast cells (MCs) playing a role in tumor angiogenesis. It could be also expressed on epithelial breast cancer cells (EBCCs), but no data have been published regarding the correlation between mast cells positive to c-KitR (MCs-c-KitR), EBCCs positive to c-KitR (EBCCs-c-KitR), BC angiogenesis in terms of microvessel density (MVD) and the main clinic-pathological features. This study aims to evaluate the above parameters and their correlations in a series of selected 121 female early BC patients. It has been found a strong correlation between MVD and MCDPT, and MCs-c-KitR, MVD and MCs density positive to tryptase (MCDPT), and MCs-c-KitR and MCDPT by Pearson correlation. These data suggest an involvement of both MCDPT and MCs-c-KitR in BC tumor angiogenesis. Furthermore, BC tissue expressing c-KitR could be a putative predictive factor to c-KitR-TK inhibitors. In this way, selected patients with higher MCs-c-KitR could be candidate to receive c-KitR-TK inhibitors (e.g. masitinib, sunitinib) or tryptase inhibitors (e.g. nafamostat mesilate, gabexate mesilate).

Tyrosine-Kinase Inhibitors Therapies with Mainly Anti-Angiogenic Activity in Advanced Renal Cell Carcinoma: Value of PET/CT in Response Evaluation

Renal cell carcinoma (RCC) is the most frequent renal tumor and the majority of patients are diagnosed with advanced disease. Tumor angiogenesis plays a crucial role in the development and progression of RCC together with hypoxia and glucose metabolism. These three pathways are strictly connected to the cell growth and proliferation, like a loop that is self-feeding. Over the last few years, the ever-deeper knowledge of its contribution in metastatic RCC led to the discovery of numerous tyrosine kinase inhibitors (TKIs) targeting pro-angiogenic receptors at different levels such as sunitinib, sorafenib, pazopanib, axitinib, tivozanib, and dovitinib. As anti-angiogenic agents, TKIs interfere the loop, being able to inhibit tumor proliferation. TKIs are now available treatments for advanced RCC, which demonstrated to improve overall survival and/or progression free survival. Their effects can be detectable early on Positron Emission Tomography/Computed Tomography (PET/CT) by change in ¹⁸F-fluoro-2-deoxy-2-d-glucose (¹⁸F-FDG) uptake, the main radiotracer used to date, as a strong indicator of biological response. ¹⁸F-FDG PET/CT demonstrated an ability to predict and monitor disease progression, allowing an early and reliable identification of responders, and could be used for image-guided optimization and "personalization" of anti-angiogenic regimens. New radiotracers for biometabolic imaging are currently under investigation, which exploit the other pathways involved in the cancer process, including cellular proliferation, aerobic metabolism, cell membrane synthesis, hypoxia and amino acid transport, as well as the angiogenic process, but they require further studies.

Bevacizumab-Based Chemotherapy Combined with Regional Deep Capacitive Hyperthermia in Metastatic Cancer Patients: A Pilot Study

As an angiogenesis inhibitor, bevacizumab has been investigated in combination with different chemotherapeutic agents, achieving an established role for metastatic cancer treatment. However, potential synergic anti-angiogenic effects of hyperthermia have not tested to date in literature. The aim of our study was to analyze efficacy, safety, and survival of anti-angiogenic-based chemotherapy associated to regional deep capacitive hyperthermia (HT) in metastatic cancer patients. Twenty-three patients with metastatic colorectal (n = 16), ovarian (n = 5), and breast (n = 2) cancer were treated with HT in addition to a standard bevacizumab-based chemotherapy regimen. Treatment response assessment was performed, according to the modified Response Evaluation Criteria for Solid Tumors (mRECIST), at 80 days (timepoint-1) and at 160 days (timepoint-2) after therapy. Disease Response Rate (DRR), considered as the proportion of patients who had the best response rating (complete response (CR), partial response (PR), or stable disease (SD)), was assessed at timepoint-1 and timepoint-2. Chi-squared for linear trend test was performed to evaluated the association between response groups (R/NR) and the number of previous treatment (none, 1, 2, 3), number of chemotherapy cycles (<6, 6, 12, >12), number of hyperthermia sessions (<12, 12, 24, >24), and lines of chemotherapy (I, II). Survival curves were estimated by Kaplan-Meier method. DRR was 85.7% and 72.2% at timepoint-1 and timepoint-2, respectively. HT was well tolerated without additional adverse effects on chemotherapy-related toxicity. Chi-squared for linear trend test demonstrated that the percentage of responders grew in relation to the number of chemotherapy cycles (p = 0.015) and to number of HT sessions (p < 0.001) performed. Both overall survival (OS) and time to progression (TTP) were influenced by the number of chemotherapy cycles (p < 0.001) and HT sessions (p < 0.001) performed. Our preliminary data, that need to be confirmed in larger studies, suggest that the combined treatment of bevacizumab-based chemotherapy with HT has a favorable tumor response, is feasible and well tolerated, and offers a potentially promising option for metastatic cancer patients.

Tryptase mast cell density, protease-activated receptor-2 microvascular density, and classical microvascular density evaluation in gastric cancer patients undergoing surgery: possible translational relevance

BACKGROUND

Mast cells (MCs) can stimulate angiogenesis, releasing several proangiogenic cytokines stored in their cytoplasm. In particular, MCs can release tryptase, a potent in vivo and in vitro proangiogenic factor via protease-activated receptor-2 (PAR-2) activation and mitogen-activated protein kinase (MAPK) phosphorylation. Nevertheless, no data are available concerning the relationship among tryptase MC density (TMCD), endothelial cells (ECs) positive to PAR-2 microvascular density (PAR-2-MVD) and classical MVD (C-MVD) in gastric cancer (GC) angiogenesis.

METHODS

In this study, we analyzed the correlation of TMCD, PAR-2-MVD, C-MVD with each other and with the main clinicopathological features in GC patients who underwent surgery. A series of 77 GC patients with stage T_2-3N_2-3M₀ (classified by the American Joint Committee on Cancer for Gastric Cancer, 7th edition) were selected and then underwent surgery.

RESULTS

Tumour tissue samples were evaluated by mean of immunohistochemistry and image analysis methods in terms of numbers of TMCD, PAR-2-MVD and C-MVD. A significant correlation between the TMCD, PAR-2-MVD and C-MVD groups with each other was found by Pearson t-test analysis (r ranged from 0.64 to 0.76; p value ranged from 0.02 to 0.03). There was no other significant correlation between the above parameters and clinicopathological features.

CONCLUSIONS

Our in vivo preliminary data suggest that TMCD and PAR-2-MVD may play a role in GC angiogenesis and they could be further evaluated as a target of antiangiogenic therapy.

Restoring TRAIL Induced Apoptosis Using Naturopathy. Hercules Joins Hand with Nature to Triumph Over Lernaean Hydra

Cancer is a multifaceted disease. Our deepened knowledge about genetic and biological mechanisms of cancer cells presents an opportunity to explore the inter-individual differences in the body’s ability to metabolize and respond to different nutrients. It is becoming progressively more understandable that the deregulation of several signaling pathways and the alterations in apoptotic response are some of the major determinants that underpin carcinogenesis. Tumor necrosis factor-Related Apoptosis-Inducing Ligand (TRAIL)-mediated signaling has gained a remarkable appreciation because of its ability to selectively induce apoptosis in cancer cells leaving normal cells intact. However, technological advances have started to shed light on underlying mechanisms of resistance against TRAIL-induced apoptosis in cancer cells. The impairment of TRAIL-mediated apoptosis includes various factors ranging from the loss or down regulation of TRAIL receptors or pro-apoptotic proteins to the up regulation of anti-apoptotic proteins. Intriguingly to mention that there is an ever-increasing number of natural herbal extracts (phytometabolites), which have been explored to date for their potential action in restoring apoptosis TRAIL-mediated in cancer cells. In this review, we will highlight the progress in understanding the mechanisms opted by phenolic compounds in overcoming TRAIL resistance.

New Frontiers in Promoting TRAIL-Mediated Cell Death: Focus on Natural Sensitizers, miRNAs, and Nanotechnological Advancements

Cancer is a multifaceted and genomically complex disease, and rapidly emerging scientific evidence is emphasizing on intra-tumor heterogeneity within subpopulations of tumor cells and rapidly developing resistance against different molecular therapeutics. There is an overwhelmingly increasing list of agents currently being tested for efficacy against cancer. In accordance with the concept that therapeutic agents must have fewer off target effects and considerable efficacy, TRAIL has emerged as one among the most deeply investigated proteins reportedly involved in differential killing of tumor cells. Considerable killing activity of TRAIL against different cancers advocated its entry into clinical trials. However, data obtained through preclinical and cell culture studies are deepening our understanding of wide-ranging mechanisms which induce resistance against TRAIL-based therapeutics. These include downregulation of death receptors, overexpression of oncogenes, inactivation of tumor suppressor genes, imbalance of pro- and anti-apoptotic proteins, and inactivation of intrinsic and extrinsic pathways. Substantial fraction of information has been added into existing pool of knowledge related to TRAIL biology and recently accumulating evidence is adding new layers to regulation of TRAIL-induced apoptosis. Certain hints have emerged underscoring miR135a-3p- and miR-143-mediated regulation of TRAIL-induced apoptosis, and natural agents have shown remarkable efficacy in improving TRAIL-based therapeutics by increasing expression of tumor suppressor miRNAs. In this review, we summarize most recent breakthroughs related to naturopathy and strategies to nanotechnologically deliver TRAIL to the target site in xenografted mice. We also set spotlight on positive and negative regulators of TRAIL-mediated signaling. Comprehensive knowledge of genetics and proteomics of TRAIL-based signaling network obtained from cancer patients of different populations will be helpful in getting a step closer to personalized medicine.

A pilot study employing hepatic intra-arterial irinotecan injection of drug-eluting beads as salvage therapy in liver metastatic colorectal cancer patients without extrahepatic involvement: the first southern Italy experience

BACKGROUND

The main aim of this prospective study was to evaluate the efficacy of drug-eluting beads with irinotecan (DEBIRI) for liver metastases from colorectal cancer. Secondary aims were to evaluate survival and toxicity.

METHODS

Twenty-five patients with metastases in <50% of the liver and without extrahepatic involvement were enrolled. Treatment response assessment was performed by multidetector contrast enhancement computed tomography (MDCT) with evaluation of the enhancement pattern of the target lesion and tumor response rates according to modified Response Evaluation Criteria in Solid Tumors (mRECIST, Version 1.1). All adverse events were recorded by the Cancer Therapy Evaluation Program Common Terminology Criteria for Adverse Events, Version 3.0. Associations of tumor response and variables were calculated using the chi-squared test. Overall survival (OS) was calculated using the Kaplan-Meier method. Comparisons were made using the log-rank test.

RESULTS

According to mRECIST, complete response (CR) was observed in 21.8% of patients, partial response (PR) in 13%, stable disease (SD) in 52.2% and progressive disease (PD) in 13% of patients. Response rate (RR = CR + PR) was 34.8%. No associations between treatment response and variables such as Dukes' classification, grading and Kras status were found (P>0.05). The median OS was 37 months (95% CI: 13.881 to 60.119). Cox regression model showed that neither site, Dukes' classification, grading, Kras status nor number of chemotherapy treatments pre-DEBIRI influenced the OS. The log-rank test showed no statistically significant difference in OS among patients who underwent 1, 2 or 3 DEBIRI treatments (χ²=2.831, P=0.09). In our study, the main toxicities included postembolization syndrome (PES), hypertransaminasemia and fever.

CONCLUSION

The favorable tumor response and the favorable toxicity profile make DEBIRI treatment a potential third-line therapy. Although further larger studies are needed to confirm these data, we can state that DEBIRI is an attractive emerging treatment in these patients.

Mast cells positive to tryptase, endothelial cells positive to protease-activated receptor-2, and microvascular density correlate among themselves in hepatocellular carcinoma patients who have undergone surgery

BACKGROUND

Mast cells (MCs) can stimulate angiogenesis, releasing several proangiogenic cytokines stored in their cytoplasm. In particular MCs can release tryptase, a potent in vivo and in vitro proangiogenic factor via proteinase-activated receptor-2 (PAR-2) activation and mitogen-activated protein kinase phosphorylation. Nevertheless, no data are available concerning the relationship between MC density positive to tryptase (MCDPT), endothelial cells positive to PAR-2 forming microvascular density (PAR-2-MVD), and classical MVD (C-MVD) in hepatocellular carcinoma (HCC) angiogenesis. This study analyzed the correlation between MCDPT, PAR-2-MVD, and C-MVD, each correlated to the others and to the main clinicopathological features, in early HCC patients who underwent surgery.

METHODS

A series of 53 HCC patients with early stage (stage 0 according to the Barcelona Clinic Liver Cancer Staging Classification) were selected and then underwent surgery. Tumor tissue samples were evaluated by means of immunohistochemistry and image analysis methods in terms of number of MCDPT, PAR-2-MVD, and C-MVD.

RESULTS

A significant correlation between MCDPT, PAR-2-MVD, and C-MVD groups, each correlated to the others, was found by Pearson t-test analysis (r ranged from 0.67 to 0.81; P-value ranged from 0.01 to 0.03). No other significant correlation was found.

CONCLUSION

Our in vivo pilot data suggest that MCDPT and PAR-2-MVD may play a role in HCC angiogenesis and could be further evaluated as a target of antiangiogenic therapy.

Tumour-associated macrophages correlate with microvascular bed extension in colorectal cancer patients

Tumour‐associated macrophages (TAMs) represent pivotal components of tumour microenvironment promoting angiogenesis, tumour progression and invasion. In colorectal cancer (CRC), there are no conclusive data about the role of TAMs in angiogenesis‐mediated tumour progression. In this study, we aimed to evaluate a correlation between TAMs, TAM immunostained area (TAMIA) microvascular density (MVD), endothelial area (EA) and cancer cells positive to VEGF‐A (CCP‐VEGF‐A) in primary tumour tissue of locally advanced CRC patients undergone to radical surgery. A series of 76 patients with CRC were selected and evaluated by immunohistochemistry and image analysis. An anti‐CD68 antibody was employed to assess TAMs and TAMIA expression, an anti‐CD34 antibody was utilized to detect MVD and EA expression, whereas an anti‐VEGF‐A antibody was used to detect CCP‐VEGF‐A; then, tumour sections were evaluated by image analysis methods. The mean ± S.D. of TAMs, MVD and CCP‐VEGF‐A was 65.58 ± 21.14, 28.53 ± 7.75 and 63% ± 37%, respectively; the mean ± S.D. of TAMIA and EA was 438.37 ± 124.14μ² and 186.73 ± 67.22μ², respectively. A significant correlation was found between TAMs, TAMIA, MVD and EA each other (r ranging from 0.69 to 0.84; P ranging from 0.000 to 0.004). The high level of expression of TAMs and TAMIA in tumour tissue and the significant correlation with both MVD and EA illustrate that TAMs could represent a marker that plays an important role in promoting angiogenesis‐mediated CRC. In this context, novel agents killing TAMs might be evaluated in clinical trials as a new anti‐angiogenic approach.

Mast cells positive to tryptase and tumour-associated macrophages correlate with angiogenesis in locally advanced colorectal cancer patients undergone to surgery

OBJECTIVE

The density of mast cells positive to tryptase (MCDPT) and tumor-associated macrophages (TAMs) were evaluated in a series of 87 patients with stage B and C colorectal cancer who had undergone radical surgery.

METHODS

MCDPT, TAMs, microvascular density (MVD), endothelial area (EA) and CD8(+) tumor infiltrating lymphocytes (CD8(+) TILs) were evaluated in tumor tissue samples by immunohistochemistry and image analysis. Each of the above parameters was correlated with the others and with the main clinico-pathological features.

RESULTS

A significant correlation between MCDPT, TAMs, MVD and EA was found by Pearson t-test analysis. With special references to the clinico-pathological features a minimal correlation using univariate analysis was found but it was not retained at multivariate analysis.

CONCLUSIONS

Our data suggest that MCDPT and TAMs are linked in the tumor microenvironment and play a role in CRC angiogenesis in a synergistic manner. The assessment of the combination MCDPT and TAMs could be evaluated as a target of novel anti-angiogenic therapies in colorectal cancer patients.

Targeting mast cells in gastric cancer with special reference to bone metastases

Bone metastases from gastric cancer (GC) are considered a relatively uncommon finding; however, they are related to poorer prognosis. Both primary GC and its metastatic progression rely on angiogenesis. Several lines of evidence from GC patients strongly support the involvement of mast cells (MCs) positive to tryptase (MCPT) in primary gastric tumor angiogenesis. Recently, we analyzed infiltrating MCs and neovascularization in bone tissue metastases from primary GC patients, and observed a significant correlation between infiltrating MCPT and angiogenesis. Such a finding suggested the involvement of peritumoral MCPT by infiltrating surrounding tumor cells, and in bone metastasis angiogenesis from primary GC. Thus, an MCPT-stimulated angiogenic process could support the development of metastases in bone tissue. From this perspective, we aim to review the hypothetical involvement of tumor-infiltrating, peritumoral MCPT in angiogenesis-mediated GC cell growth in the bone microenvironment and in tumor-induced osteoclastic bone resorption. We also focus on the potential use of MCPT targeting agents, such as MCs tryptase inhibitors (gabexate mesylate, nafamostat mesylate) or c-KitR tyrosine kinase inhibitors (imatinib, masitinib), as possible new anti-angiogenic and anti-resorptive strategies for the treatment of GC patients affected by bone metastases.

Classical and non-classical proangiogenic factors as a target of antiangiogenic therapy in tumor microenvironment

Angiogenesis is sustained by classical and non-classical proangiogenic factors (PFs) acting in tumor microenvironment and these factors are also potential targets of antiangiogenic therapies. All PFs induce the overexpression of several signaling pathways that lead to migration and proliferation of endothelial cells contributing to tumor angiogenesis and survival of cancer cells. In this review, we have analyzed each PF with its specific receptor/s and we have summarized the available antiangiogenic drugs (e.g. monoclonal antibodies) targeting these PFs, some of these agents have already been approved, others are currently in development for the treatment of several human malignancies.

Predictive factors to targeted treatment in gastrointestinal carcinomas

Most cancers are traditionally treated with either chemotherapeutic agents, radiotherapy, or both. Identification of specific molecular characteristics of tumors and the advent of molecular-targeted drugs not only enhance the efficacy but also decrease the toxicity of treatment. These new therapies may target pathways critical to tumor development or specific driver mutations in cancer cells. This understanding of the molecular pathways of cancer cells has led to the ability to predict cancer development, behaviour and prognosis, as well as response or resistance to current therapeutic agents. As a result, pathologic analyses play a vital role in the detection of cancer biomarkers, which are important not only in the diagnosis of cancers but also in the selection of appropriate therapeutic agents and in the development of new targeted therapies.

Microvascular density and endothelial area correlate with Ki-67 proliferative index in surgically-treated pancreatic ductal adenocarcinoma patients

Previous experimental and clinical data have indicated that tumour cell proliferation is associated with angiogenesis; in addition, an increased microvascular density (MVD) of tumours has been associated with poor prognosis in solid and haematological malignancies. However, limited data exists regarding the association between tumour cell proliferation and angiogenesis in primary tumour tissue from pancreatic ductal adenocarcinoma (PDAC) patients; therefore, the present study aimed to investigate this association. A series of 31 PDAC patients with stage Tumour (T)_2-3 Node (N)_0-1 Metastasis (M)₀ were recruited into the present study and subsequently underwent surgery. PDAC tissue and adjacent normal tissue (ANT), resected during surgery, were evaluated using immunohistochemistry and image analysis methods to determine MVD, endothelial area (EA) and Ki-67 expression, which is an indicator of cell proliferation rate. The results demonstrated a correlation between the above parameters with each other as well as the main clinico-pathological features of PDAC. Significant differences were identified in MVD, EA and Ki-67 proliferation index between PDAC and ANT. It was demonstrated that MVD, EA and Ki-67 proliferation index were significantly correlated with each other in tumour tissue (r=0.69-0.81; P=0.001-0.003). However, no other significant correlations were identified. These data therefore suggested that angiogenesis and cell proliferation rate were significantly increased in PDAC compared with ANT, which provides a biological basis for the potential use of novel combinations of angiogenesis inhibitors and anti-proliferative chemotherapeutic drugs in the treatment of PDAC.

Vascular endothelial growth factor and tryptase changes after chemoembolization in hepatocarcinoma patients

AIM: To evaluate vascular endothelial growth factor (VEGF) and tryptase in hepatocellular cancer (HCC) before and after trans-arterial chemoembolization (TACE).

METHODS: VEGF and tryptase serum concentrations were assessed from 71 unresectable HCC patients before and after hepatic TACE performed by binding DC-Beads^® to doxorubicin. VEGF levels were examined for each serum sample using the Quantikine Human VEGF-enzyme-linked immuno-absorbent assay (ELISA), whereas tryptase serum concentrations were assessed for each serum sample by means of fluoro-enzyme immunoassay (FEIA) using the Uni-CAP100 tool. Differences between serum VEGF and tryptase values before and after TACE were evaluated using Student t test. Person's correlation was used to assess the degree of association between the two variables.

RESULTS: VEGF levels and serum tryptase in HCC patients before TACE had a mean value and standard deviation (SD) of 114.31 ± 79.58 pg/mL and 8.13 ± 3.61 μg/L, respectively. The mean levels and SD of VEGF levels and serum tryptase in HCC patients after TACE were 238.14 ± 109.41 pg/mL and 4.02 ± 3.03 μg/L. The changes between the mean values of concentration of VEGF and tryptase before treatment and after treatment was statistically significant (P < 0.000231 and P < 0.00124, by Wilcoxon-Mann-Whitney respectively). A significant correlation between VEGF levels before and after TACE and between tryptase levels before and after TACE was demonstrated (r = 0.68, P = 0.003; r = 0.84, P = 0.000 respectively).

CONCLUSION: Our pilot results suggest that the higher serum VEGF levels and the lower tryptase levels following TACE may be potential biomarkers changing in response to therapy.

Infiltrating mast cells correlate with angiogenesis in bone metastases from gastric cancer patients

While gastric cancer is a well established angiogenesis driven tumor, no data has been published regarding angiogenesis stimulated by mast cells (MCs) positive for tryptase in bone metastases from gastric cancer patients (BMGCP). It is well established that MCs play a role in immune responses and more recently it was demonstrated that MCs have been involved in tumor angiogenesis. We analyzed infiltrating MCs and neovascularization in BMGCP diagnosed by histology. A series of 15 stage T3-4N2-3M1 (by AJCC for Gastric Cancer Staging 7th Edition) BMGCP from bone biopsies were selected. Tumour tissue samples were evaluated by mean of immunohistochemistry and image analysis methods in terms of MCs density positive to tryptase (MCDPT), MCs area positive to tryptase (MCAPT), microvascular density (MVD) and endothelial area (EA). A significant correlation between MCDPT, MCAPT, MVD and EA groups to each other was found by Pearson and t-test analysis (r ranged from 0.68 to 0.82; p-value ranged from 0.00 to 0.02). Our very preliminary data suggest that infiltrating MCs positive for tryptase may play a role in BMGCP angiogenesis, and could be further evaluated as a novel target of anti-angiogenic therapy.

In vivo model for mastocytosis: A comparative review

Human mastocytosis are heterogeneous group of neoplastic diseases characterized by a different degree of uncontrolled mast cell (MC) proliferation and activation. Interestingly, human mastocytosis share several biological and clinical features with canine mast cell disorders, so called canine mast cell tumors (CMCTs). These CMCTs are the most common spontaneous cutaneous tumors found in dogs representing a valid model to study neoplastic mast cell disorders. It has been discovered that the pathological activation of c-Kit receptor (c-KitR), expressed by MCs, has been involved in the pathogenesis of neoplastic MC disorders. In this review we have focused on human mastocytosis in terms of: (i) epidemiology and classification; (ii) pathogenesis at molecular levels; (iii) clinical presentation. In addition, we have summarized animal models useful to study neoplastic MC disorders including CMCTs and murine transgenic models. Finally, we have revised therapeutic approaches mostly common in human and canine MCTs and novel tyrosine kinase inhibitors approved for CMCTs and recently translated in human clinical trials.

Targeting mast cells tryptase in tumor microenvironment: a potential antiangiogenetic strategy

Angiogenesis is a complex process finely regulated by the balance between angiogenesis stimulators and inhibitors. As a result of proangiogenic factors overexpression, it plays a crucial role in cancer development. Although initially mast cells (MCs) role has been defined in hypersensitivity reactions and in immunity, it has been discovered that MCs have a crucial interplay on the regulatory function between inflammatory and tumor cells through the release of classical proangiogenic factors (e.g., vascular endothelial growth factor) and nonclassical proangiogenic mediators granule-associated (mainly tryptase). In fact, in several animal and human malignancies, MCs density is highly correlated with tumor angiogenesis. In particular, tryptase, an agonist of the proteinase-activated receptor-2 (PAR-2), represents one of the most powerful angiogenic mediators released by human MCs after c-Kit receptor activation. This protease, acting on PAR-2 by its proteolytic activity, has angiogenic activity stimulating both human vascular endothelial and tumor cell proliferation in paracrine manner, helping tumor cell invasion and metastasis. Based on literature data it is shown that tryptase may represent a promising target in cancer treatment due to its proangiogenic activity. Here we focused on molecular mechanisms of three tryptase inhibitors (gabexate mesylate, nafamostat mesylate, and tranilast) in order to consider their prospective role in cancer therapy.

Serum tryptase, mast cells positive to tryptase and microvascular density evaluation in early breast cancer patients: possible translational significance

Background

Tryptase is a serine protease released from mast cells that plays a role in tumor angiogenesis. In this study we aimed to evaluate serum tryptase levels in 105 female early breast cancer patients before (STLBS) and after (STLAS) radical surgical resection, mast cell density positive to tryptase (MCDPT) and microvascular density (MVD).

Methods

STLBS and STLAS were assessed using the UniCAP Tryptase Fluoroenzyme immunoassay. Tumor sections were immunostained with a primary anti-tryptase antibody and an anti-CD-34 antibody by means of immunohistochemistry.

Results

The mean ± 1 standard deviation STLBS and STLAS was 7.18 ± 2.63 μg/L, and 5.13 ± 2.21 respectively and a significant difference between mean levels was found (p = 0.0001) by student t-test. A strong correlation between STLBS and MVD (r = 0.81, p = 0.0001); STLBS and MCDPT (r = 0.69, p = 0.003); and MCDPT and MVD (r = 0.77; p = 0.0001) was found.

Conclusions

Results demonstrated higher STLBS in breast cancer patients, indicating an involvement of MC tryptase in breast cancer angiogenesis. Therefore, serum tryptase levels may play a role as a novel surrogate angiogenic marker predictive of response to radical surgery in breast cancer patients. In this patients setting, it’s intriguing to hypothesize that tryptase inhibitors might be evaluated in clinical trials.

Possible prognostic and therapeutic significance of c-Kit expression, mast cell count and microvessel density in renal cell carcinoma

Renal cell carcinoma (RCC) is the most frequent renal tumor and its incidence is increasing worldwide. Tumor angiogenesis is known to play a crucial role in the etiopathogenesis of RCC and over the last few years an even deeper knowledge of its contribution in metastatic RCC development has led to the development of numerous molecular targeting agents (such as sunitinib, sorafenib, pazopanib, axitinib, tivozanib, and dovitinib). The above agents are principally directed against vascular endothelial growth factor receptor (VEGFR) members and also against c-Kit receptor (c-KitR). The role of c-kitR inhibition on clear cell RCC (ccRCC), the main RCC subtype, is less well established. Whether c-kitR activation through its ligand, stem cell factor (SCF) contributes significantly to the effects of tyrosine kinase inhibitors (TKIs) treatment remains to be established. It is important to underscore that the c-KitR is expressed on mast cells (MCs) and cancer cells. After an examination of the c-KitR/SCF pathway, we review here the principal studies that have evaluated c-Kit expression in RCC. Moreover, we summarize some investigations that have observed the distribution of MCs in primary renal cancer and in adjacent normal tissue with appropriate histological immunohistochemical techniques. We also focus on few studies that have evaluated the correlation between RCC proliferation, MC count and microvessel density (MVD), as hallmarks of tumor angiogenesis. Thus, the aim of this review of the literature is to clarify if c-KitR expression, MC count and MVD could have prognostic significance and the possible predictive therapeutic implications in RCC.

Possible biological and translational significance of mast cells density in colorectal cancer

Mast cells (MCs), located ubiquitously near blood vessels, are descended from CD34⁺ hematopoietic stem cells. Initially, although their role has been well defined in hypersensitivity reactions, the discovery of their sharing in both innate and adaptive immunity has allowed to redefine their crucial interplay on the regulatory function between inflammatory and tumor cells through the release of mediators granule-associated (mainly tryptase and vascular endothelial growth factor). In particular, in several animal and human malignancies it has been well demonstrated that activated c-Kit receptor (c-KitR) and tryptase (an agonist of the proteinase-activated receptor-2) take pivotal part in tumor angiogenesis after the MCs activation, contributing to tumor cells invasion and metastasis. In this review, we focused on crucial MCs density (MCD) role in colorectal cancer (CRC) development and progression angiogenesis-mediated; then, we will analyze the principal studies that have focused on MCD as possible prognostic factor. Finally, we will consider a possible role of MCD as novel therapeutic target mainly by c-KitR tyrosine kinase inhibitors (imatinib, masitinib) and tryptase inhibitors (gabexate and nafamostat mesylate) with the aim to prevent CRC progression.

Correlation between serum tryptase, mast cells positive to tryptase and microvascular density in colo-rectal cancer patients: possible biological-clinical significance

Background

Tryptase is a serin protease stored and released from mast cells (MCs) that plays a role in tumour angiogenesis. In this study we aimed to evaluate serum tryptase levels in colo-rectal cancer (CRC) patients before (STLBS) and after (STLAS) radical surgical resection. We also evaluated mast cell density positive to tryptase (MCDPT) and microvascular density (MVD) in primary tumour tissue.

Methods

A series of 61 patients with stage B and C CRC (according to the Astler and Coller staging system) were selected. Serum blood samples were collected from patients one day before and one day after surgery. Tryptase levels were measured using the UniCAP Tryptase Fluoroenzymeimmunoassay (Pharmacia, Uppsala, Sweden). Tumour sections were immunostained with a primary anti-tryptase antibody (clone AA1; Dako, Glostrup, Denmark) and an anti CD-34 antibody (QB-END 10; Bio-Optica Milan, Italy) by means of immunohistochemistry and then evaluated by image analysis methods.

Results

The mean ± s.d. STLBS and STLAS was 5.63±2.61 µg/L, and 3.39±1.47 µg/L respectively and a significant difference between mean levels was found: p = 0.000 by t-test. The mean ± s.d. of MCDPT and MVD was 8.13±3.28 and 29.16±7.39 respectively. A strong correlation between STLBS and MVD (r = 0.83, p = 0.000); STLBS and MCDPT (r = 0.60, p = 0.003); and MCDPT and MVD (r = 0.73; p = 0.001) was found.

Conclusion

Results demonstrated higher STLBS in CRC patients, indicating an involvement of MC tryptase in CRC angiogenesis. Data also indicated lower STLAS, suggesting the release of tryptase from tumour-infiltrating MCs. Serum tryptase levels may therefore play a role as a novel bio-marker predictive of response to radical surgery. In this context tryptase inhibitors such as Gabexate and Nafamostat Mesilate might be evaluated in adjuvant clinical trials as a new anti-angiogenic approach.

Surgical resection of locally advanced epidermal growth factor receptor (EGFR) mutated lung adenocarcinoma after gefitinib and review of the literature

Gefitinib is the current first-line treatment for advanced lung adenocarcinoma with epidermal growth factor receptor (EGFR) gene mutations. The possibility of using gefitinib as neoadjuvant therapy is interesting because of the low toxicity profile of tyrosine kinase inhibitors. Here we report the case of a 67-year-old nonsmoking woman affected by locally advanced lung adenocarcinoma, in whom one-year treatment with gefitinib rendered the tumor amenable to surgical removal. The results of ongoing clinical trials exploring the ability of preoperative gefitinib to achieve better results than can be obtained with chemotherapy in patients selected on the basis of EGFR mutations are urgently awaited.

Molecular targeting agents associated with transarterial chemoembolization or radiofrequency ablation in hepatocarcinoma treatment

Hepatocellular carcinoma (HCC) is the fifth most common cause of cancer in the world. According to Barcelona Clinic Liver Cancer modified criteria, patients with early stage disease are candidate to radiofrequency ablation (RFA), while patients with intermediate stage HCC are usually treated by transarterial chemoembolization (TACE). TACE and RFA induce a transient devascularisation effect followed by strong neo-angiogenic stimulus. In fact, after these procedures, it has been demonstrated an up-regulation of pro-angiogenic and growth factors such as vascular endothelial growth factor-A, which might contribute to accelerated progression in patients with incomplete response. Several studies have demonstrated that MAP-kinase and AKT pathways, in addition to neo-angiogenesis, have an important role in the development of HCC. In advanced HCC, anti-angiogenic therapy and tyrosine kinases inhibitors showed potential clinical benefit. Actually, a number of clinical studies are ongoing testing these agents in combination with TACE or RFA. In this paper, we have reviewed the most recent preclinical and clinical results of such trials.

Masitinib (AB1010), from canine tumor model to human clinical development: where we are?

Masitinib mesylate (AB1010) is a novel potent and selective tyrosine kinase inhibitor, targeting mainly wild-type and mutated c-Kit receptor (c-KitR), Platelet Derived Growth Factor Receptor-alfa/beta (PDGFRa/ß), Lymphocyte-specific kinase (Lck), Lck/Yes-related protein (LYn), Fibroblast Growth Factor Receptor 3 (FGFR3) and Focal Adhesion Kinase (FAK). It is the first anticancer therapy approved in veterinary medicine for the treatment of unresectable canine mast cell tumors (CMCTs), harboring activating c-KitR mutations, at dose of 12.5mg/kg once daily. Considering its anti-proliferative action, principally given by inhibiting the MCs c-KitR anti-angiogenic pathway that leads cancer progression, and its role as chemosensitizer, masitinib is under clinical investigation in several human malignancies (Gastro-Intestinal Stromal Tumors, acute myeloid leukemia, systemic mastocytosis, pancreatic cancer, multiple myeloma, non-small cell lung cancer, melanoma, ovarian and prostate cancer), which are characterized by similar canine c-KIT proto-oncogene mutations. Here, we analyze masitinib structure activity, its pharmacokinetics compared to imatinib, the c-KitR pathway referring to the most frequent c-KIT mutations sensitive or resistant to this novel drug compared to imatinib, and masitinib safety profile. We, also, explore preclinical and clinical (completed and ongoing) trials with the aim to emphasize as this recent anti-angiogenic therapy, at first approved in CMCTs and, currently in development for the treatment of several human neoplasms, could be represent a milestone in translational oncology, in which the murine experimental model of cancer research could be integrated by canine spontaneous tumor model.

Surgical resection of locally advanced epidermal growth factor receptor (EGFR) mutated lung adenocarcinoma after gefitinib and review of the literature

Gefitinib is the current first-line treatment for advanced lung adenocarcinoma with epidermal growth factor receptor (EGFR) gene mutations. The possibility of using gefitinib as neoadjuvant therapy is interesting because of the low toxicity profile of tyrosine kinase inhibitors. Here we report the case of a 67-year-old nonsmoking woman affected by locally advanced lung adenocarcinoma, in whom one-year treatment with gefitinib rendered the tumor amenable to surgical removal. The results of ongoing clinical trials exploring the ability of preoperative gefitinib to achieve better results than can be obtained with chemotherapy in patients selected on the basis of EGFR mutations are urgently awaited.

Partial response of liver metastases treated with abiraterone in castration-resistant prostate cancer: A case report

Docetaxel is the current first-line treatment for castration-resistant prostate cancer (CRPC), following failure to respond to maximal androgen blockade (MAB). Patients who fail to respond to docetaxel may receive cabazitaxel or abiraterone; however, there are no recommendations on which of these two agents should be used first. Here, we present a case of a male patient suffering from CRPC with liver and lymph node metastases, in which abiraterone achieved a partial response, according to RECIST criteria. In the literature, visceral involvement in patients with advanced prostate cancer is an infrequent occurrence; it affects 18–22% of patients. In the pivotal study concerning docetaxel-resistant patients, abiraterone was compared with a placebo and the forest plot for survival demonstrated that patients with visceral involvement have significantly benefited from abiraterone. In the TROPIC trial comparing cabazitaxel with mitoxantrone, the proportion of patients with visceral disease was ∼25% in both arms and there was no difference in overall survival in this subgroup of patients. In our case, we observed a significant activity of abiraterone in lymph node and liver metastases. If confirmed in large studies, this observation may raise concerns over whether to treat patients suffering from CRPC and visceral metasis with chemotherapy or hormone therapy.

Novel plant-derived target drugs: a step forward from licorice?

Isoliquiritigenin (ISL) is a chalcone compound with valuable pharmacological properties such as antioxidant, anti-inflammatory, anticancer and anti-allergic activities. With regard to anticancer property, ISL was able to suppress HIF-1α level, VEGF expression and secretion, cell migration and to decrease the expression and secretion of MMP-9/-2. These effects may be mediated through inhibition of p38, PI3K/Akt and NF-κB signaling pathways. Thus, low concentration of ISL may have therapeutic potential in the treatment of aggressive breast carcinoma and other neoplasms.

Pentraxin 3 (PTX3) inhibits plasma cell/stromal cell cross-talk in the bone marrow of multiple myeloma patients

Pentraxin 3 (PTX3) is a soluble pattern recognition receptor that binds with high affinity and selectivity to fibroblast growth factor-2 (FGF2), thus inhibiting its pro-angiogenic activity. Here we investigated the effects of PTX3 on monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM) patient-derived bone marrow (BM) plasma cells (PCs), endothelial cells (ECs), and fibroblasts (FBs), and assessed whether PTX3 can modulate the cross-talk between PCs and those microenvironment cells. PTX3 and FGF2 expression was evaluated by ELISA. Functional studies, including cell viability, wound healing, chemotaxis, and Matrigel(®) assays, were performed on MGUS and MM ECs and FBs upon the PTX3 treatment. Through western blot PTX3-induced modulation in FGF2/FGF receptor signalling pathways was evaluated in MGUS and MM ECs and FBs through western blot. Co-cultures between MM ECs/FBs and human PC lines were used to evaluate possible PTX3 indirect effects on MM PCs. Adhesion molecules were studied by flow cytometry. PTX3 provides a direct time- and dose-dependent apoptotic effect on MM ECs and FBs, but not on either MM primary PCs or human PC lines. PTX3 inhibits migration of MM ECs and FBs in a dose-dependent manner, and impacts in vitro and in vivo FGF2-mediated MM angiogenesis. Co-cultures of PCs and ECs/FBs show that PTX3 treatment indirectly impairs PC viability and adhesion. We conclude that PTX3 is an anti-angiogenic factor in MM and behaves as a cytotoxic molecule on MM cells by inhibiting the cross-talk between PCs and ECs/FBs.

Pharmacokinetic and metabolism determinants of fluoropyrimidines and oxaliplatin activity in treatment of colorectal patients

Fluoropyrimidines and oxaliplatin continued to be the mainstay of therapeutic regimens in the treatment of colorectal cancer (CRC). For this reason, pharmacokinetic and metabolism of these drugs were analyzed and the identification of accurate and validated predictive, prognostic and toxicity markers became necessary to develop an effective therapy adapted to the patient's molecular profile, while minimizing life-threatening toxicities. In this review, we discuss literature data, defining predictive and prognostic markers actually identified in the treatment of CRC. We analyzed predictive markers of fluoropyrimidines effectiveness, principally for 5-Fluorouracil (5- FU) and also for oral fluoropyrimidines, as thymidylate Synthase (TS), dihydropyrimidine dehydrogenase (DPD), orotate phosphoribosyl transferase (OPRT), methylenetetrahydrofolate reductase (MTHFR), deoxyuridine triphosphate nucleotidohydrolase (dUTPase), microsatellite instability. DPD represent the more studied 5-FU toxicity marker, followed by TS and OPRT. Oxaliplatin effectiveness is principally regulated by nucleotide excision repair (NER) pathway, including excision repair cross-complementation group 1 (ERCC1), X-ray cross-complementing group 1 (XRCC1) and xeroderma pigmentosum group D (XDP). The major oxaliplatin toxicity marker is represented by glutathione S-transferase (GST). All these results are based principally on retrospective studies. The future challenge became to validate molecular markers and their association with clinical outcomes in prospective trials, refining technologic platforms and bioinformatics to accommodate the complexity of the multifaceted molecular map that may determine outcome, and determining CRC patients most likely to benefit from therapeutic interventions tailored specifically for them.

Novel strategies in the treatment of castration-resistant prostate cancer (Review)

Prostate cancer is the most common cancer in men in Europe and the United States, and the third leading cause of death from cancer in Europe. Survival of prostate cancer cells is dependent on the activation of androgen receptors (AR), that are overexpressed in this tumor. Furthermore, ~90% of prostate cancer patients that respond to first-line androgen deprivation therapy (ADT) undergo rapid progression. This condition is defined as castration-resistant prostate cancer (CRPC). Docetaxel-based regimens significantly improve overall survival (OS) in patients with CRPC and represent the only treatment strategy approved by the Food and Drug Administration (FDA). Recently, abiraterone (second hormonal therapy) and cabazitaxel (new taxane) have been shown to improve survival in patients with CRPC who progressed following docetaxel-based chemotherapy. Vaccine therapy has also been demonstrated to improve OS in patients with asymptomatic or minimally symptomatic metastatic CRPC. Additional therapeutic targets have been analyzed in prostate cancer, including apoptosis, angiogenic receptors, vitamin D and Src pathways. Several phase II studies are ongoing. The high frequency of prostate cancer-related metastatic bone disease has led to consider this pathway as a therapeutic target. To this end, several bone-targeted agents have been investigated, most notably zoledronic acid, which is highly effective at stabilizing the bone and preventing skeletal complications. More recently, a nuclear factor-β ligand (RANKL) inhibitor, denosumab, has been developed for the treatment of bone metastases.

Dasatinib: an anti-tumour agent via Src inhibition

Dasatinib (BMS-354825, Sprycel®) is an oral, multitargeted inhibitor of receptor tyrosine kinases (RTKs), including BCR-ABL fusion protein, stem cell factor receptor (c-KIT), platelet-derived growth factor receptor (PDGFR), and Src family kinases (SFKs). Several early- and late-phase clinical trials for chronic myelogeneous leukaemia (CML) have demonstrated the direct inhibition of BCR-ABL fusion protein and SFKs, which led to dasatinib approval by the Food and Drug Administration (FDA) and the European Union for the treatment of imatinib-resistant or -intolerant CML, and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL). Phase III dose-optimization study was performed to compare different regimens, stating that dasatinib 100 mg once daily is now the recommended schedule for patients with chronic CML, and 140 mg once daily for patients with accelerated phase or myeloid or lymphoid blast phase CML, and for patients with Ph+ ALL until progression. Because of the myriad of critical roles of SFKs in biological processes, SFKs inhibition could induce numerous biological responses. Ongoing clinical trials evaluate dasatinib in the treatment of several solid tumours, including gastrointestinal stromal tumours (GIST), prostate cancer, malignant pleural mesothelioma, sarcomas, NSCLC, colorectal cancer, glioblastoma and other haematologic malignancies as multiple myeloma. Ongoing pre-clinical studies assess the therapeutic potential of dasatinib in other solid tumours, including melanoma, head and neck cancer, breast cancer and ovarian cancer. Dasatinib is generally well tolerated. Myelosuppression is the common adverse event which is, however, reversible by dose reduction, discontinuation, or interruption. Thrombocytopenia is more significant than neutropenia and associated to gastrointestinal bleeding and CNS haemorrhage. The most common non-haematologic adverse events include gastrointestinal symptoms (diarrhoea, nausea, vomiting, abdominal pain and anorexia), headache, peripheral edema, and pleural effusion. In respect of these encouraging studies investigating dasatinib in the treatment of patients with GIST, prostate cancer, multiple myeloma and sarcomas, ongoing phase III clinical trials warrant the drug evaluation as recommended agent for the treatment of these diseases, also in association with chemotherapy or other targeted therapies.