Treatment of Thoracic SMARCA4-Deficient Undifferentiated Tumors: Where We Are and Where We Will Go.

Recently, the fifth edition of the WHO classification recognized the thoracic SMARCA4-deficient undifferentiated tumor (SMARCA4-UT) as a separate entity from conventional non-small cell lung cancer with SMARCA4 deficiency because of the different clinicopathological characteristics of these two diseases. SMARCA4-UT mainly occurs in young to middle-aged adults and involves a large mass compressing the tissues surrounding the mediastinum and lung parenchyma. Unfortunately, SMARCA4-UT shows a high probability of recurrence after upfront surgery as well as radiotherapy resistance; moreover, chemotherapy has low efficacy. Moreover, given the recent classification of SMARCA4-UT, no data concerning specific clinical trials are currently available. However, several case reports show immunotherapy efficacy in patients with this disease not only in a metastatic setting but also in a neoadjuvant manner, supporting the development of clinical trials. In addition, preclinical data and initial clinical experiences suggest that inhibiting pathways such as CDK4/6, AURKA, ATR, and EZH2 may be a promising therapeutic approach to SMARCA4-UT.

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.

What Are the Biomarkers for Immunotherapy in SCLC?

Small-cell lung cancer (SCLC) is an aggressive malignancy that exhibits a rapid doubling time, a high growth fraction, and the early development of widespread metastases. The addition of immune checkpoint inhibitors to first-line chemotherapy represents the first significant improvement of systemic therapy in several decades. However, in contrast to its effects on non-SCLC, the advantageous effects of immunotherapy addition are modest in SCLC. In particular, only a small number of SCLC patients benefit from immune checkpoint inhibitors. Additionally, biomarkers selection is lacking for SCLC, with clinical trials largely focusing on unselected populations. Here, we review the data concerning the major biomarkers for immunotherapy, namely, programmed death ligand 1 expression and tumour mutational burden. Furthermore, we explore other potential biomarkers, including the role of the immune microenvironment in SCLC, the role of genetic alterations, and the potential links between neurological paraneoplastic syndromes, serum anti-neuronal nuclear antibodies, and outcomes in SCLC patients treated with immunotherapy.

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.

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.

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.

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 ± 124.14µ(2) and 186.73 ± 67.22µ(2) , 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.

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.

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.

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.

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.

Successful treatment of a non-small-cell lung cancer patient harboring HIP1-ALK (H28:A20) and CTNNB1 p.S45del with alectinib.

This is the first case report of a non-small-cell lung cancer (NSCLC) patient harboring HIP1-ALK (H28:A20) and CTNNB1 p.S45del treated with first-line alectinib. Approximately 5% of NSCLC patients are reported to have anaplastic lymphoma kinase (ALK) rearrangements, and among these EML4-ALK is the most frequent fusion variant. However, in recent years the use of next-generation sequencing (NGS) in clinical laboratories has become increasingly widespread, identifying a lot of new ALK fusion partners as well as a large quantity of co-occurring genomic alterations. Unfortunately, the growing number of genomic alterations detected by NGS does not always correspond to adequate knowledge of their clinical significance, often resulting in an empiric treatment of patients harboring uncommon mutations.

Complete response to second line Paclitaxel every 2 weeks of eyelid kaposi sarcoma: a case report.

A 77-year-old male patient presented to our attention with violaceous nodular lesions on the skin of his hands and lower extremities. Clinical and histologic examination supported the diagnosis of Kaposi sarcoma. A first-line systemic chemotherapy based on liposomal doxorubicin at a dosage of 40 mg/m2 every 3 weeks for 5 cycles was carried out, resulting in partial resolution of skin lesions. However, 1 year later, a relapse of the disease in the lower limbs and a new lesion of the left eyelid were found, therefore the patient began a second-line therapy with 100 mg/m2 paclitaxel every 2 weeks. After 8 cycles of therapy, we observed a complete remission of eyelid tumor and a partial response of lower limbs lesions up to 6 months of follow up. In conclusion, eyelid Kaposi sarcoma was successfully treated with paclitaxel every 2 weeks, obtaining a complete response.

Immunotherapy in Elderly Patients Affected by Non-Small Cell Lung Cancer: A Narrative Review.

Lung cancer is the leading cause of cancer-related deaths worldwide. Non-small cell lung cancer (NSCLC) accounts for approximately 80% of all lung cancers, and most NSCLC is diagnosed in the advanced stage. The advent of immune check point inhibitors (ICIs) changed the therapeutic scenario both in metastatic disease (in first and subsequent lines) and earlier settings. Comorbidities, reduced organ function, cognitive deterioration, and social impairment give reasons for a greater probability of adverse events, making the treatment of elderly patients challenging. The reduced toxicity of ICIs compared to standard chemotherapy makes this approach attractive in this population. The effectiveness of ICIs varies according to age, and patients older than 75 years may benefit less than younger patients. This may be related to the so-called immunosenescence, a phenomenon that refers to the reduced activity of immunity with older age. Elders are often under-represented in clinical trials, even if they are a large part of the patients in a clinical practice. In this review, we aim to explore the biological aspects of immunosenescence and to report and analyze the most relevant and recent literature findings on the role of immunotherapy in elderly patients with NSCLC.

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.

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.

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.

Oxaliplatin-Based Intra-arterial Chemotherapy in Colo-Rectal Cancer Liver Metastases: A Review from Pharmacology to Clinical Application.

Liver metastases (LM) are often consequences of colo-rectal cancer (CRC)and the majority of patients have unresectable LM. Oxaliplatin-based intravenous chemotherapy represents the gold standard treatment for CRC. Intravenous oxaliplatin has several side effects i.e., nephrologic, hematologic and neurological toxicity. Moreover, hepatic arterial infusion (HAI) of antitumor drugs deeply modifies the treatment of LMCRC due to the knowledge that LM are perfused by the hepatic artery network, whereas healthy tissue is perfused by the portal vein. Therefore, oxaliplatin-based HAI becomes an interesting possibility to treat LMCRC. The aim of this review is to shed light on the important impact of the oxaliplatin-based chemotherapy from a non-conventional clinical point of view, considering that, being universally accepted its antitumor effect if administered intravenously, fragmentary information are known about its clinical applications and benefits deriving from intra-arterial administration in loco-regional chemotherapy.

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).