Advanced gynecologic malignancies treated with a combination of the VEGF inhibitor bevacizumab and the mTOR inhibitor temsirolimus

Interactions of EGFR/PTEN/mTOR-Pathway Activation and Estrogen Receptor Expression in Cervical Cancer

(1) Objective: Late-line chemotherapy rechallenge in recurrent cervical cancer is associated with modest therapy response but significant side effects. As mTOR pathways modulate cellular growth via estrogen receptor (ER) signaling and combined mTOR and ER inhibition previously demonstrated survival benefits in breast cancer, this exploratory study evaluates mTOR pathway and ER expression interactions in a preclinical cervical cancer model. (2) Methods: Immunostaining of a 126-tumor core tissue microarray was performed to assess phosphorylated-mTOR and ER expression. To identify tumor subsets with different clinical behavior, expression results were matched with clinicopathologic patient characteristics, and both univariate and multivariable survival statistics were performed. (3) Results: phosphorylated-mTOR correlates with ER (r = 0.309, p < 0.001) and loss of PTEN expression (r = -2.09, p = 0.022) in tumor samples across stages but not in matched negative controls. Positive ER expression is observed significantly more often in phosphorylated-mTOR positive samples (30.0% vs. 6.3%, p = 0.001). In the subgroup of phosphorylated-mTOR positive tumors (n = 60), ER expression is associated with improved survival (p = 0.040). (4) Conclusion: ER expression appears closely intertwined with EGFR/PTEN/mTOR-pathway activation and seems to define a subgroup with clinically distinct behavior. Considering limited therapeutic options in recurrent cervical cancer, further validation of combined mTOR and ER inhibition in selected patients could appear promising.

Influence of nitric oxide signaling mechanisms in cancer

Nitric oxide (NO) is a molecule with multiple biological functions that is involved in various pathophysiological processes such as neurotransmission and blood vessel relaxation as well as the endocrine system, immune system, growth factors, and cancer. However, in the carcinogenesis process, it has a dual behavior; at low doses, NO regulates homeostatic functions, while at high concentrations, it promotes tissue damage or acts as an agent for immune defense against microorganisms. Thus, its participation in the carcinogenic process is controversial. Cancer is a multifactorial disease that presents complex behavior. A better understanding of the molecular mechanisms associated with the initiation, promotion, and progression of neoplastic processes is required. Some hypotheses have been proposed regarding the influence of NO in activating oncogenic pathways that trigger carcinogenic processes, because NO might regulate some signaling pathways thought to promote cancer development and more aggressive tumor growth. Additionally, NO inhibits apoptosis of tumor cells, together with the deregulation of proteins that are involved in tissue homeostasis, promoting spreading to other organs and initiating metastatic processes. This paper describes the signaling pathways that are associated with cancer, and how the concentration of NO can serve a beneficial or pathological function in the initiation and promotion of neoplastic events.

A phase I study of AZD2171 and Temsirolimus in patients with advanced gynecological malignancies

PURPOSE

Temsirolimus, a mTOR inhibitor, and AZD2171, a VEGFR inhibitor, have independently shown activity in patients with gynecological malignancies. Understanding the pivotal role of the PI3K/PTEN/AKT/mTOR pathway in regulating angiogenesis, a phase I study utilizing Temsirolimus and AZD2171 was initiated to study the safety of targeting the mTOR and VEGF pathway in patients with recurrent or refractory gynecological malignancies.

METHODS

Patients with advanced gynecological cancers were enrolled in this phase 1 study with Temsirolimus and AZD2171. A traditional 3 + 3 design was followed. The primary objective was to determine the MTD of the combination. Secondary objectives included efficacy, progression free survival (PFS) and toxicity profile. An expansion phase was planned after the MTD was determined.

RESULTS

The study enrolled 11 patients over 16 months. All patients were enrolled in dose level 1. Due to toxicity, the trial was halted at dose level 1. No MTD was determined. The most common grade 3/4 toxicities included hypertension, thrombocytopenia, thromboembolic events, and hypertriglyceridemia. Five patients were evaluable for best overall clinical response. The best overall clinical response was stable disease. Two patients died without documented progression of disease. The median PFS was 7.2 months.

CONCLUSIONS

Despite a conservative dose escalation, the toxicity data demonstrated that the combination of AZD2171 and Temsirolimus was not tolerable. Increased awareness of novel toxicities, pharmacological interactions, coupled with strict patient selection and early mitigation of side effects may enhance phase I clinical trial development.

Exploiting somatic alterations as therapeutic targets in advanced and metastatic cervical cancer

It is estimated that 604,127 patients were diagnosed with cervical cancer worldwide in 2020. While a small percentage of patients will have metastatic disease at diagnosis, a large percentage (15-61%) later develop advanced disease. For this cohort, treatment with systemic chemotherapy remains the standard of care, with a static 5-year survival rate over the last thirty years. Data on targetable molecular alterations in cervical cancer have lagged behind other more common tumor types thus stunting the development of targeted agents. In recent years, tumor genomic testing has been increasingly incorporated into our clinical practice, opening the door for a potential new era of personalized treatment for advanced cervical cancer. The interim results from the NCI-MATCH study reported an actionability rate of 28.4% for the cervical cancer cohort, suggesting a subset of patients may harbor mutations which that are targetable. This review sets out to summarize the key targeted agents currently under exploration either alone or in combination with existing treatments for cervical cancer.

A phase I study of the VEGFR kinase inhibitor vatalanib in combination with the mTOR inhibitor, everolimus, in patients with advanced solid tumors

Purpose Combining small-molecule inhibitors of different targets was shown to be synergistic in preclinical studies. Testing this concept in clinical trials is, however, daunting due to challenges in toxicity management and efficacy assessment. This study attempted to evaluate the safety and efficacy of vatalanib plus everolimus in patients with advanced solid tumors and explore the utility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) studies as a predictive biomarker. Patients and Methods This single-center, phase I trial containing 70 evaluable patients consisted of a dose escalation proportion based on the traditional "3 + 3" design (cohort IA and IB) and a dose expansion proportion (cohort IIA and IIB). Toxicity was evaluated using the Common Terminology Criteria of Adverse Events. Antitumor activity was assessed using the Modified Response Evaluation Criteria in Solid Tumors. Results The maximum tolerated doses were determined to be vatalanib 1250 mg once daily or 750 mg twice daily in combination with everolimus 10 mg once daily. No treatment-related death occurred. The most common toxicities were hypertriglyceridemia, hypercholesterolemia, fatigue, vomiting, nausea and diarrhea. There was no complete response. Nine patients (12.9%) had partial response (PR) and 41 (58.6%) had stable disease (SD). Significant antitumor activity was observed in neuroendocrine tumors with a disease-control rate (PR + SD) of 66.7% and other tumor types including renal cancer, melanoma, and non-small-cell lung cancer. Conclusions The combination of vatalanib and everolimus demonstrated reasonable toxicity and clinical activity. Future studies combining targeted therapies and incorporating biomarker analysis are warranted based on this phase I trial.

Kinase Inhibitors and Ovarian Cancer

Ovarian cancer is fifth in the rankings of cancer deaths among women, and accounts for more deaths than any other gynecological malignancy. Despite some improvement in overall-(OS) and progression-free survival (PFS) following surgery and first-line chemotherapy, there is a need for development of novel and more effective therapeutic strategies. In this mini review, we provide a summary of the current landscape of the clinical use of tyrosine kinase inhibitors (TKIs) and mechanistic target of rapamycin (mTOR) inhibitors in ovarian cancer. Emerging data from phase I and II trials reveals that a combinatorial treatment that includes TKIs and chemotherapy agents seems promising in terms of PFS despite some adverse effects recorded; whereas the use of mTOR inhibitors seems less effective. There is a need for further research into the inhibition of multiple signaling pathways in ovarian cancer and progression to phase III trials for drugs that seem most promising.

MAGE-A4 and MAGE-A1 Immunohistochemical Expression in High-grade Endometrial Cancer

The aim was to investigate MAGE-A4 and MAGE-A1 protein expression in high-grade endometrial cancer and determine its correlation with histologic subtype, FIGO stage, presence of vascular invasion, disease free, and overall survival. Immunohistochemical staining was performed by using 77B (MAGE-A1) and 57B (MAGE-A4) monoclonal antibodies on paraffin-embedded sections from high-grade endometrial cancers diagnosed in University Hospital Split between 1998 and 2011 (n=77). Median follow-up time for survivors was 48 mo. MAGE-A4 was found to be expressed in 33% of endometrioid type endometrial cancers grade 3 and in 27% of serous and clear cell carcinomas. MAGE-A1 was found to be expressed in 93% endometrioid endometrial cancer grade 3 and 86% of serous and clear cell carcinomas. Univariate analysis showed that positive immunohistochemical staining for MAGE-A4 was associated with decreased disease free and overall survival in patients with high-grade endometrial cancer. Multivariate analysis showed an association between MAGE-A4 overexpression and decreased disease free but not overall survival in high-grade endometrial cancer. No correlation was found between MAGE-A1 immunohistochemical expression and patient survival. There was no significant correlation between MAGE-A4 and MAGE-A1 expression and histologic subtype, FIGO stage, lymph node metastasis, muscular infiltration, and lymphovascular invasion. MAGE-A4 immunohistochemical expression is associated with decreased disease free and overall survival in patients with high-grade endometrial cancer. Our findings suggest that MAGE-A1 may be expressed in the epithelial cells of the normal endometrium. MAGE-A1 is highly expressed in high-grade endometrial cancer, with no impact on survival.

Randomized phase II trial of bevacizumab plus everolimus versus bevacizumab alone for recurrent or persistent ovarian, fallopian tube or peritoneal carcinoma: An NRG oncology/gynecologic oncology group study

PURPOSE

Bevacizumab (BV) monotherapy leads to compensatory upregulation of multiple signaling pathways, resulting in mTOR activation. We evaluated combining BV and everolimus (EV), an mTOR kinase inhibitor, to circumvent BV-resistance in women with recurrent or persistent ovarian, fallopian tube or primary peritoneal cancer (OC).

PATIENTS AND METHODS

Eligible OC patients had measurable (RECIST1.1) or detectable disease, 1-3 prior regimens, performance status (PS) 0-2, and no prior m-TOR inhibitor. All patients received BV 10 mg/kg IV every 2wks. Patients were randomized (1:1) to oral EV (10 mg daily) or placebo stratified by platinum-free interval (PFI), measurable disease and prior BV. Primary endpoint was progression-free survival (PFS); secondary endpoints included safety and response.

RESULTS

150 patients were randomized to BV with (n = 75) and without (n = 75) EV. Arms were well-balanced for age (median 63: range 28-92), PS (0: 73%, 1-2: 27%), prior regimens (1: 37%, 2: 47%, 3: 16%), prior BV (11%), PFI (<6mos: 65%) and measurable disease (81%). The BV + EV vs BV median PFS was 5.9 vs 4.5 months (hazard ratio [HR] 0.95 (95% CI, 0.66-1.37, p = 0.39)). Median OS was 16.6 vs 17.3 months (HR 1.16 (95% CI, 0.72-1.87, p = 0.55). Objective measurable responses were higher with BV + EV (22% vs 12%). Study removal due to toxicity was higher with BV + EV (29% vs 12%). Toxicity (≥grade 3) from BV + EV were "other GI (mucositis)" (23 vs 1%) and "metabolic/nutrition" (19 vs. 7%); common ≥ grade 2 toxicities with BV + EV were cytopenia, nausea, fatigue and rash.

CONCLUSION

The combination regimen (BV + EV) did not significantly reduce the hazard of progression or death relative to BV and was associated with higher rates of adverse events and study discontinuation when compared to BV alone.

Autophagy as an emerging therapy target for ovarian carcinoma

Autophagy is a conserved cellular self-digestion pathway for maintenance of homeostasis under basal and stressed conditions. Autophagy plays pivotal roles in the pathogenesis of many diseases, such as aging-related diseases, autoimmune diseases, cardiovascular diseases, and cancers. Of special note is that accumulating data suggest an intimate relationship between autophagy and ovarian carcinoma. Autophagy is well identified to act as either as a tumor-suppressor or as a tumor-promoter in ovarian carcinoma. The exact function of autophagy in ovarian carcinoma is highly dependent on the circumstances of cancer including hypoxic, nutrient-deficient, chemotherapy and so on. However, the mechanism underlying autophagy associated with ovarian carcinoma remains elusive, the precise role of autophagy in ovarian carcinoma also remains undetermined. In this review, we tried to sum up and discuss recent research achievements of autophagy in ovarian cancer. Moreover, waves of novel therapies ways for ovarian carcinoma based on the functions of autophagy were collected.

Advanced malignancies treated with a combination of the VEGF inhibitor bevacizumab, anti-EGFR antibody cetuximab, and the mTOR inhibitor temsirolimus

BACKGROUND

Bevacizumab and temsirolimus are active agents in advanced solid tumors. Temsirolimus inhibits mTOR in the PI3 kinase/AKT/mTOR pathway as well as CYP2A, which may be a resistance mechanism for cetuximab. In addition, temsirolimus attenuates upregulation of HIF-1α levels, which may be a resistance mechanism for bevacizumab.

RESULTS

The median age of patients was 60 years (range, 23-80 years). The median number of prior systemic therapies was 3 (range, 1-6). The maximum tolerated dose (MTD) was determined to be bevacizumab 10 mg/kg biweekly, temsirolimus 5 mg weekly and cetuximab 100/75 mg/m2 weekly. Grade 3 or 4 toxicities were seen in 52% of patients with the highest prevalence being hyperglycemia (14%) and hypophosphatemia (14%). Eighteen of the 21 patients were evaluable for response. Three patients were taken off the study before restaging for toxicities. Partial response (PR) was observed in 2/18 patients (11%) and stable disease (SD) lasting ≥ 6 months was observed in 4/18 patients (22%) (total = 6/18 (33%)). In 8 evaluable patients with squamous cell carcinoma of the head and neck (HNSCC) there were partial responses in 2/8 (25%) patients and SD ≥ 6 months in 1/8 (13%) patients (total = 3/8, (38%)).

PATIENTS AND METHODS

We analyzed safety and responses in 21 patients with advanced solid tumors treated with bevacizumab, cetuximab, and temsirolimus.

CONCLUSION

The combination of bevacizumab, cetuximab, and temsirolimus showed activity in HNSCC; however, there were numerous toxicities reported, which will require careful management for future clinical development.

Prediction of novel target genes and pathways involved in bevacizumab-resistant colorectal cancer

Bevacizumab combined with cytotoxic chemotherapy is the backbone of metastatic colorectal cancer (mCRC) therapy; however, its treatment efficacy is hampered by therapeutic resistance. Therefore, understanding the mechanisms underlying bevacizumab resistance is crucial to increasing the therapeutic efficacy of bevacizumab. The Gene Expression Omnibus (GEO) database (dataset, GSE86525) was used to identify the key genes and pathways involved in bevacizumab-resistant mCRC. The GEO2R web tool was used to identify differentially expressed genes (DEGs). Functional and pathway enrichment analyses of the DEGs were performed using the Database for Annotation, Visualization, and Integrated Discovery(DAVID). Protein–protein interaction (PPI) networks were established using the Search Tool for the Retrieval of Interacting Genes/Proteins database(STRING) and visualized using Cytoscape software. A total of 124 DEGs were obtained, 57 of which upregulated and 67 were downregulated. PPI network analysis showed that seven upregulated genes and nine downregulated genes exhibited high PPI degrees. In the functional enrichment, the DEGs were mainly enriched in negative regulation of phosphate metabolic process and positive regulation of cell cycle process gene ontologies (GOs); the enriched pathways were the phosphoinositide 3-kinase-serine/threonine kinase signaling pathway, bladder cancer, and microRNAs in cancer. Cyclin-dependent kinase inhibitor 1A(CDKN1A), toll-like receptor 4 (TLR4), CD19 molecule (CD19), breast cancer 1, early onset (BRCA1), platelet-derived growth factor subunit A (PDGFA), and matrix metallopeptidase 1 (MMP1) were the DEGs involved in the pathways and the PPIs. The clinical validation of the DEGs in mCRC (TNM clinical stages 3 and 4) revealed that high PDGFA expression levels were associated with poor overall survival, whereas high BRCA1 and MMP1 expression levels were associated with favorable progress free survival(PFS). The identified genes and pathways can be potential targets and predictors of therapeutic resistance and prognosis in bevacizumab-treated patients with mCRC.

PI3K/AKT/mTOR Pathway in Ovarian Cancer Treatment: Are We on the Right Track?

The high recurrence rate and the low overall survival in ovarian cancer suggest that a more specific therapeutic approach in addition to conventional treatment is required. Translational and clinical research is investigating new molecular targets in order to find an alternative way to affect tumor growth and to minimize the overlap of toxicity of antiblastic agents. Given its implication in many cellular activities including regulation of cell growth, motility, survival, proliferation, protein synthesis, autophagy, transcription, as well as angiogenesis, PI3K/AKT/mTOR is one of the most investigated intracellular signaling pathways. A dis-regulation of this pathway has been shown in several tumors, including ovarian cancer. In this setting, mTor proteins represent a potential target for inhibitors, which could ultimately play a pivotal role in counteracting cellular proliferation. Recently, mTor inhibitors have been approved in the treatment of pancreatic neuroendocrine tumors, mantle cell lymphoma and renal cancer. Clinical trials have assessed the safety of these drugs in ovarian cancer patients. Ongoing phase I and II studies are evaluating the oncologic outcome of mTor inhibitor treatment and its effect in combination with conventional chemotherapy and target agents.

PI3K/AKT/mTOR Pathway in Ovarian Cancer Treatment: Are We on the Right Track?

The high recurrence rate and the low overall survival in ovarian cancer suggest that a more specific therapeutic approach in addition to conventional treatment is required. Translational and clinical research is investigating new molecular targets in order to find an alternative way to affect tumor growth and to minimize the overlap of toxicity of antiblastic agents. Given its implication in many cellular activities including regulation of cell growth, motility, survival, proliferation, protein synthesis, autophagy, transcription, as well as angiogenesis, PI3K/AKT/mTOR is one of the most investigated intracellular signaling pathways. A dis-regulation of this pathway has been shown in several tumors, including ovarian cancer. In this setting, mTor proteins represent a potential target for inhibitors, which could ultimately play a pivotal role in counteracting cellular proliferation. Recently, mTor inhibitors have been approved in the treatment of pancreatic neuroendocrine tumors, mantle cell lymphoma and renal cancer. Clinical trials have assessed the safety of these drugs in ovarian cancer patients. Ongoing phase I and II studies are evaluating the oncologic outcome of mTor inhibitor treatment and its effect in combination with conventional chemotherapy and target agents.

PI3K/AKT/mTOR Pathway in Ovarian Cancer Treatment: Are We on the Right Track?

The high recurrence rate and the low overall survival in ovarian cancer suggest that a more specific therapeutic approach in addition to conventional treatment is required. Translational and clinical research is investigating new molecular targets in order to find an alternative way to affect tumor growth and to minimize the overlap of toxicity of antiblastic agents. Given its implication in many cellular activities including regulation of cell growth, motility, survival, proliferation, protein synthesis, autophagy, transcription, as well as angiogenesis, PI3K/AKT/mTOR is one of the most investigated intracellular signaling pathways. A dis-regulation of this pathway has been shown in several tumors, including ovarian cancer. In this setting, mTor proteins represent a potential target for inhibitors, which could ultimately play a pivotal role in counteracting cellular proliferation. Recently, mTor inhibitors have been approved in the treatment of pancreatic neuroendocrine tumors, mantle cell lymphoma and renal cancer. Clinical trials have assessed the safety of these drugs in ovarian cancer patients. Ongoing phase I and II studies are evaluating the oncologic outcome of mTor inhibitor treatment and its effect in combination with conventional chemotherapy and target agents.

A Review of mTOR Pathway Inhibitors in Gynecologic Cancer

The treatment of advanced gynecologic cancers remains palliative in most of cases. Although systemic treatment has entered into the era of targeted drugs the antitumor efficacies of current therapies are still limited. In this context there is a great need for more active treatment and rationally designed targeted therapies. The PI3K/AKT/mTOR is a signaling pathway in mammal cells that coordinates important cell activities. It has a critical function in the survival, growth, and proliferation of malignant cells and was object of important research in the last two decades. The mTOR pathway emerges as an attractive therapeutic target in cancer because it serves as a convergence point for many growth stimuli and, through its downstream substrates, controls cellular processes that contribute to the initiation and maintenance of cancer. Aberrant PI3K-dependent signaling occurs frequently in a wide range of tumor types, including endometrial, cervical, and ovarian cancers. The present study reviewed the available evidence regarding the potential impact of some mTOR pathway inhibitors in the treatment of gynecological cancer. Few advances in medical management have occurred in recent years in the treatment of advanced or recurrent gynecological malignancies, and a poor prognosis remains. Rationally designed molecularly targeted therapy is an emerging and important option in this setting; then more investigation in PI3K/AKT/mTOR pathway-targeted therapies is warranted.

Targeting mTOR pathway in gynecological malignancies: Biological rationale and systematic review of published data

BACKGROUND

mTOR inhibitors are widely used in different malignancies with several trials testing their efficacy and safety in gynecological malignancies. We aimed to review the current evidence that support the expansion of using such drugs in the treatment of advanced gynecological cancers.

METHODS

A comprehensive systematic review of literature has been conducted to include prospective trials that used everolimus, temsirolimus or ridaforolimus in the management of gynecological cancers and have available efficacy and toxicity results.

RESULTS

A total of 23 studies including 980 patients were considered eligible for our review. Our review included 16 phase II and 7 phase I studies with the majority of patients having uterine cancers. Regarding Endometrial cancer, the CBR ranged from 21% to 60% and median PFS from 2.8 months to 7.3 months. In Ovarian cancers, CBR ranged from 24% to 50% and median PFS from 3.2 months to 5.9 months. In the single phase II study in cervical cancer the CBR was 61% and median PFS was 3.5 months. The toxicity profile was consistent with what was observed previously in other malignancies with fatigue, mucositis, and hematological toxicities being the most common adverse events observed.

CONCLUSION

mTOR inhibitors seem to be a promising option in the second line management of advanced gynecological cancers with best safety and efficacy outcomes when given as a single agent or in combination with hormonal treatment. More research is needed for better patient selection.

Global strategies for the treatment of early-stage and advanced cervical cancer

PURPOSE OF REVIEW

Recent peer-reviewed publications on the treatment of early, locally advanced and advanced cervical cancer patients are reviewed to gain insight into the main research done in the field.

RECENT FINDINGS

In early-stage patients where cure is offered to most patients, research focuses on more conservative or less morbid approaches to increase quality of life and reduce the treatment-related sexual dysfunction. No major advances have occurred for treating locally advanced disease since the introduction of concurrent chemoradiation, but efforts are directed to increase efficacy while reducing toxicity with the use of combination chemoradiation and modern radiation technologies. Molecular-targeted therapy and identification of targetable gene alterations as well as immunotherapy are actively pursued in patients with advanced disease.

SUMMARY

Although global statistics indicate a trend for decreased age-standardized incidence rates, social and economical factors impede the uptake of therapeutic advances achieved as many patients have no access even to basic resources for treating cancer. The adherence to quality indicators in delivery of optimized standard concurrent chemoradiation and adherence to guidelines in cervical cancer surgery must not be underestimated. Major efforts are needed in both the scientific and social aspects of cervical cancer treatment to reduce mortality.

Potential impact of mTOR inhibitors on cervical squamous cell carcinoma: A systematic review

The aim of the present systematic review was to analyze the potential impact of mammalian target of rapamycin (mTOR) inhibitors on the treatment of cervical squamous cell carcinoma (CSCC). A systematic literature search was conducted in PubMed, PMC, Scopus, Cochrane Library, LILACS, Web of Science, Google Scholar and ScienceDirect on January 19, 2015, without time and language restrictions. Studies that evaluated women of any age with CSCC and who received mTOR inhibitors alone or in association with other treatments were considered. Randomized and non-randomized clinical trials were included, and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist was followed. Selected studies were methodologically appraised according to the Grades of Recommendation, Assessment, Development and Evaluation method to assess the quality of evidence. Of 642 identified citations, 43 studies were fully reviewed; however, only 3 studies met the inclusion criteria and were used for qualitative analysis. Of these, two studies were phase 1 and one was a phase 2 clinical trial. The studies included were not conclusive with regard to the association between mTOR inhibitor treatment and cervical cancer. The main analysis of secondary endpoints revealed that individuals treated with other drugs in association with mTOR inhibitors achieved partial responses (15.4-33.3%) or stable disease (17.6-28%). Treatment with mTOR inhibitors in general was well tolerated in patients with metastatic disease. The predominant toxicities were grade 1 and 2. The phase 1 trials included in this review demonstrated that mTOR inhibitor treatments are feasible and safe. However, the currently available evidence is insufficient to determine the effect of mTOR inhibitors on CSCC, and further investigation in high-quality, randomized clinical trials is required.

Changes in metabolic profile, iron and ferritin levels during the treatment of metastatic renal cancer - A new potential biomarker?

Metastatic renal cell carcinoma (mRCC) develops in approximately 33% of all renal cancer patients. First line treatment of mRCC includes drugs such as sunitinib, temsirolimus and pazopanib, with overall survival now reaching up to 43,6months in patients with favorable-risk metastatic disease. Several side-effects in mRCC treatment, such as hypothyroidism, can be used as positive prognostic factors and indicate good response to therapy. Hypercholesterolemia and hypertriglyceridemia independent of hypothyroidism are reported as side-effects in temsirolimus treatment and recently in sunitinib treatment, but the exact mechanism and significance of the changes remains elusive. Most likely, metabolic changes are caused by inhibition of mechanistic target of rapamycin (mTOR), a positive target of tumor growth suppression, but also a regulator of iron homeostasis. There are no clinical studies reporting changes in iron and ferritin levels during mRCC biotherapy, but we hypothesize that inhibition of mTOR will also affect iron and ferritin levels. If both lipid and iron changes correlate, there is a high possibility that both changes are primarily caused by mTOR inhibition and the level of change should correlate with the inhibition of mTOR pathway and hence the efficacy of targeted treatment. We lastly hypothesize that mRCC biotherapy causes hypercholesterolemia with a possibly improved cholesterol profile due to increase HDL/LDL ratio, so statins might not have a role as supplementary treatment, whereas a sharp rise in triglyceride levels seems to be the primary target for additional therapy.

A phase I study of mTOR inhibitor everolimus in association with cisplatin and radiotherapy for the treatment of locally advanced cervix cancer: PHOENIX I

BACKGROUND

Cervix cancer (CC) represents the fourth most common cancer in women. Treatment involving cisplatin and radiotherapy has been the standard for locally advanced disease. Everolimus inhibits the aberrant activity of mTOR that is part of carcinogenesis in CC. Further everolimus inactivates the HPV E7 oncoprotein and inhibits its proliferation. Preclinical models have suggested that everolimus sensitizes tumoral cells and vasculature to cisplatin and radiotherapy.

METHODS

In a 3 + 3 design, the trial aimed to treat three dose levels of at least three patients with daily doses of everolimus (2.5, 5 and 10 mg/day), cisplatin and radiotherapy delivered in a 9-week interval in CC patients, stage IIB, IIIA or IIIB. Patients received everolimus from day -7 up to the last day of brachytherapy. Primary objective was to evaluate safety, toxicity and the maximum-tolerated dose (MTD) of everolimus in association with cisplatin and radiotherapy. Pharmacokinetic (PK) parameters and response rates were analyzed as secondary objectives.

RESULTS

Thirteen patients were enrolled, 6 at 2.5 mg, 3 at 5 mg and 4 at 10 mg. Four patients did not complete the planned schedule, 1 at 2.5 mg presented grade 4 acute renal failure interpreted as dose-limiting toxicity (DLT) and 3 at 10 mg: 1 with disease progression, and 2 with DLTs-1 grade 3 rash and 1 grade 4 neutropenia. PK results were characterized by dose-dependent increases in AUC and C max.

CONCLUSIONS

The MTD of everolimus in combination with cisplatin and radiotherapy has been defined as 5 mg/day. The data regarding safety and response rates support further studies.

An overview of tyrosine kinase inhibitors for the treatment of epithelial ovarian cancer

INTRODUCTION

Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy and the fifth most common cause of cancer-related deaths in women. Initial treatment with surgery and chemotherapy has improved survival significantly. However, the disease progresses or recurs in most patients. Thus, there is an urgent need to develop more effective treatment strategies.

AREAS COVERED

This article provides an overview of tyrosine kinase inhibitors (TKIs) for the treatment of EOC, which is based on English peer-reviewed articles on MEDLINE and related abstracts presented at major conferences. The authors highlight the data from the published clinical trials in EOC patients who were treated with TKIs or TKI-based regimens.

EXPERT OPINION

EOC is responsive to most chemotherapeutic drugs and/or biological agents and represents an ideal disease model for investigating novel anti-cancer agents. Numerous small-molecule TKIs targeting the VEGFR, PARP, PI3K-AKT-mTOR, MAPK, Src, PKC, Wee1 and HER1/2 signaling pathways are currently being tested in clinical trials. Research is needed for devising regimens combining TKIs with other agents in an optimal timing schedule and for identifying potential biomarkers predictive of response and survival.

p70 S6 kinase drives ovarian cancer metastasis through multicellular spheroid-peritoneum interaction and P-cadherin/b1 integrin signaling activation

Peritoneal dissemination as a manifestation of ovarian cancer is an adverse prognostic factor associated with poor clinical outcome, and is thus a potentially promising target for improved treatment. Sphere forming cells (multicellular spheroids) present in malignant ascites of patients with ovarian cancer represent a major impediment to effective treatment. p70 S6 kinase (p70^S6K), which is a downstream effector of mammalian target of rapamycin, is frequently hyperactivated in human ovarian cancer. Here, we identified p70^S6K as an important regulator for the seeding and successful colonization of ovarian cancer spheroids on the peritoneum. Furthermore, we provided evidence for the existence of a novel crosstalk between P-cadherin and β1 integrin, which was crucial for the high degree of specificity in cell adhesion. In particular, we demonstrated that the upregulation of mature β1 integrin occurred as a consequence of P-cadherin expression through the induction of the Golgi glycosyltransferase, ST6Gal-I, which mediated β1 integrin hypersialylation. Loss of p70^S6K or targeting the P-cadherin/β1-integrin interplay could significantly attenuate the metastatic spread onto the peritoneum in vivo. These findings establish a new role for p70^S6K in tumor spheroid-mesothelium communication in ovarian cancer and provide a preclinical rationale for targeting p70^S6K as a new avenue for microenvironment-based therapeutic strategy.