Randomized phase II study of multiple dose levels of CCI-779, a novel mammalian target of rapamycin kinase inhibitor, in patients with advanced refractory renal cell carcinoma

Pazopanib: the newest tyrosine kinase inhibitor for the treatment of advanced or metastatic renal cell carcinoma

Treatment options for renal cell carcinoma (RCC) have multiplied in the past 5 years. Pazopanib is the third tyrosine kinase inhibitor (TKI) and the sixth targeted therapy that has received US FDA approval for the treatment of advanced or metastatic RCC. The primary mechanism of action of pazopanib in RCC is through its antiangiogenic properties via inhibition of the intracellular tyrosine kinase of vascular endothelial growth factor receptor and platelet-derived growth factor receptor. A placebo-controlled phase III study demonstrated that pazopanib significantly improved response rates and progression-free survival (PFS) in both treatment-naïve and cytokine-pretreated patients. Among treatment-naïve patients, the response rate was 32% and PFS was 11.1 months. In cytokine-pretreated patients, the response rate and PFS were 29% and 7.4 months, respectively. Common adverse effects of pazopanib include diarrhoea, hypertension and elevation of liver enzymes. Overall, the adverse effect profile of pazopanib is similar to that of other TKIs used for the treatment of RCC, but variation in the incidence and severity may exist. Pazopanib has an increased propensity to cause hepatotoxicity, which may be fatal in rare cases. Hepatic function must be monitored closely with dose interruption and/or reduction if elevation of hepatic function tests occurs. Pazopanib is administered on an empty stomach at a dose of 800 mg daily until disease progression, but dose reduction may be required in patients with baseline elevation of hepatic function tests, particularly total bilirubin. The minimum dose recommended for baseline hepatic dysfunction or toxicity is 200 mg daily. The potential for drug interactions exists for pazopanib. It is a substrate of cytochrome P450 (CYP) 3A4, P-glycoprotein and breast cancer resistance protein, and it weakly inhibits CYP3A4, CYP2C8 and CYP2D6, and potently inhibits UGT1A1 and OATP1B1. Currently, no study has directly compared pazopanib with other first- or second-line therapies in RCC. However, published clinical trials of pazopanib show similar efficacy outcomes to those of other targeted therapies. Therefore, pazopanib may be considered a first-line treatment option among other therapies including sunitinib, temsirolimus, and bevacizumab plus interferon-α. After failure of cytokine therapy, pazopanib is a treatment option as well as sorafenib or bevacizumab. No study has evaluated pazopanib treatment after failure of another targeted therapy. Future studies will further clarify the comparative efficacy of pazopanib with other agents as well as optimal sequencing with other agents. If similar efficacy is seen among the TKIs, it is likely that varying incidences of adverse effects may be analysed to tailor therapy according to the patient's individual co-morbidities and preferences.

Molecular targeted therapy in advanced renal cell carcinoma: A review of its recent past and a glimpse into the near future

Renal cell carcinoma (RCC) is the most lethal of all urologic malignancies. Recent translational research in RCC has led to the discovery of a new class of therapeutics that specifically target important signaling molecules critical in the pathogenesis of the disease. It is now clear that these new molecular targeted agents have revolutionized the management of patients with metastatic RCC. However, the exact molecular mechanism accounting for their clinical effect is largely unknown and a significant proportion of patients with metastatic RCC do not respond to these therapeutics. This review presents the relevant background leading to the development of molecular targeted therapy for patients with advanced RCC and summarizes current management issues in particular relating to the emerging problem of treatment resistance and the need for clinical and laboratory biomarkers to predict treatment outcomes in these patients. In addition, this paper will also address surgical issues in the era of molecular targeted therapy including the role of cytoreductive surgery and surgical safety issues post-molecular therapy. Lastly, this review will also address the need to explore new molecular treatment targets in RCC and briefly present our work on one of the promising molecular targets - the type 1 insulin-like growth factor receptor (IGF1R), which may in the near future lead to the development of anti-IGF1R therapy for patients with advanced RCC.

mTOR inhibitors in renal cell carcinoma

The mammalian target of rapamycin (mTOR) is a downstream effector of the PI3-K/Akt/mTOR pathway. Allosteric inhibitors of mTOR, everolimus and temsirolimus, have shown promising clinical activity in advanced renal cell carcinoma but their effect is far from durable and only a subset of patients experience substantial benefit from these agents. The PI3-K/Akt/mTOR pathway represents an intricate network of fine regulation and feedback loops, and resistance to allosteric mTOR inhibitors may be embedded within this complexity. In this article we highlight the molecular elements of the PI3-K/Akt/mTOR pathway, the clinical experience with everolimus and temsirolimus in advanced renal cell carcinoma, and the future directions in terms of sequential therapy, combinational therapy and development of novel therapeutic agents.

Phase I study of temsirolimus in pediatric patients with recurrent/refractory solid tumors

PURPOSE

To determine dose-limiting toxicities, maximum-tolerated dose (MTD), pharmacokinetics, and pharmacodynamics of weekly intravenous temsirolimus, a mammalian target of rapamycin (mTOR) signaling pathway inhibitor, in pediatric patients with recurrent or refractory solid tumors.

PATIENTS AND METHODS

Cohorts of three to six patients 1 to 21 years of age with recurrent or refractory solid tumors were treated with a 1-hour intravenous infusion of temsirolimus weekly for 3 weeks per course at one of four dose levels: 10, 25, 75, or 150 mg/m(2). During the first two courses, pharmacokinetic and pharmacodynamic evaluations (phosphorylation of S6, AKT, and 4EBP1 in peripheral-blood mononuclear cells) were performed.

RESULTS

Dose-limiting toxicity (grade 3 anorexia) occurred in one of 18 evaluable patients at the 150 mg/m(2) level, which was determined to be tolerable, and an MTD was not identified. In 13 patients evaluable for response after two courses of therapy, one had complete response (CR; neuroblastoma) and five had stable disease (SD). Four patients (three SDs + one CR) remained on treatment for more than 4 months. The sum of temsirolimus and sirolimus areas under the concentration-time curve was comparable to values in adults. AKT and 4EBP1 phosphorylation were inhibited at all dose levels, particularly after two courses.

CONCLUSION

Weekly intravenous temsirolimus is well tolerated in children with recurrent solid tumors, demonstrates antitumor activity, has pharmacokinetics similar to those in adults, and inhibits the mTOR signaling pathway in peripheral-blood mononuclear cells. Further studies are needed to define the optimal dose for use in combination with other antineoplastic agents in pediatric patients.

Deregulation of E2-EPF ubiquitin carrier protein in papillary renal cell carcinoma

Molecular pathways associated with pathogenesis of sporadic papillary renal cell carcinoma (PRCC), the second most common form of kidney cancer, are poorly understood. We analyzed primary tumor specimens from 35 PRCC patients treated by nephrectomy via gene expression analysis and tissue microarrays constructed from an additional 57 paraffin-embedded PRCC samples via immunohistochemistry. Gene products were validated and further studied by Western blot analyses using primary PRCC tumor samples and established renal cell carcinoma cell lines, and potential associations with pathologic variables and survival in 27 patients with follow-up information were determined. We show that the expression of E2-EPF ubiquitin carrier protein, which targets the principal negative regulator of hypoxia-inducible factor (HIF), von Hippel-Lindau protein, for proteasome-dependent degradation, is markedly elevated in the majority of PRCC tumors exhibiting increased HIF1α expression, and is associated with poor prognosis. In addition, we identified multiple hypoxia-responsive elements within the E2-EPF promoter, and for the first time we demonstrated that E2-EPF is a hypoxia-inducible gene directly regulated via HIF1. These findings reveal deregulation of the oxygen-sensing pathway impinging on the positive feedback mechanism of HIF1-mediated regulation of E2-EPF in PRCC.

Inhibition of angiogenic and non-angiogenic targets by sorafenib in renal cell carcinoma (RCC) in a RCC xenograft model

Background:

It is widely recognised that sorafenib inhibits a range of molecular targets in renal cell carcinoma (RCC). In this study, we aim to use patient-derived RCC xenografts to delineate the angiogenic and non-angiogenic molecular targets of sorafenib therapy for advanced RCC (aRCC).

Methods:

We successfully generated three patient RCC-derived xenografts in severe combined immunodeficient mice, consisting of three different RCC histological subtypes: conventional clear cell, poorly differentiated clear cell RCC with sarcomatoid changes, and papillary RCC. This study also used clear cell RCC cells (786-0/EV) harbouring mutant VHL to investigate the clonogenic survival of cells transfected with survivin sense and antisense oligonucleotides.

Results:

All three xenografts retain their original histological characteristics. We reported that sorafenib inhibited all three RCC xenograft lines regardless of histological subtypes in a dose-dependant manner. Sorafenib-induced growth suppression was associated with not only inhibition of angiogenic targets p-PDGFR-β, p-VEGFR-2, and their downstream signalling pathways p-Akt and p-ERK, cell cycle, and anti-apoptotic proteins that include cyclin D1, cyclin B1, and survivin but also upregulation of proapoptotic Bim. Survivin knockdown by survivin-specific antisense-oligonucleotides inhibited colony formation and induced cell death in clear cell RCC cells.

Conclusion:

This study has shed light on the molecular mechanisms of sorafenib in RCC. Inhibition of non-angiogenic molecules by sorafenib could contribute in part to its anti-tumour activities observed in vivo, in addition to its anti-angiogenic effects.

Phase I trial of capecitabine plus everolimus (RAD001) in patients with previously treated metastatic gastric cancer

Purpose

Everolimus is a novel inhibitor of the mammalian target of rapamycin pathway, which is aberrantly activated in cancer cell. We conducted a phase I study of capecitabine plus everolimus (RAD001) in refractory gastric cancer patients.

Methods

Patients with metastatic gastric cancer and progression after prior chemotherapy were eligible. Four dose levels were planned as follows: Level 1, 5 mg bid/day of everolimus (D1-D21) and 500 mg/m² bid/day of capecitabine (D1-14); Level 2, 5 mg bid/day of everolimus (D1-D21) and 750 mg/m² bid/day of capecitabine (D1-14); Level 3, 5 mg bid/day of everolimus (D1-D21) and 1000 mg/m² bid/day of capecitabine (D1-14); and Level 4, 10 mg bid/day of everolimus (D1-D21) and 1000 mg/m² bid/day of capecitabine (D1-14). Treatment was repeated every 3 weeks until disease progression, patient refusal, or any serious adverse event.

Results

Fifteen patients were enrolled in this study between November 2009 and April 2010. Fifteen patients were enrolled (median age, 50 years; men, 9). Six patients had received two previous chemotherapy regimens; six patients had three previous chemotherapy regimens before the study treatment. Thus, the majority of patients were heavily pretreated. The dose-limiting toxicities were grade 3 infection, grade 3 mucositis, and grade 3 hyperglycemia and hyponatremia. After a median follow-up duration of 5.6 months (range, 2.3–8.1 months), median PFS was 1.8 months (95% CI, 0.8–2.8 months). The maximum best change observed was a 28.7% decrease in sum of longest diameters when compared with baseline.

Conclusions

The combination of capecitabine and everolimus showed satisfactory toxicity profile and modest clinical benefit in patients with refractory gastric cancer. The recommended dose of capecitabine and everolimus was 650 mg/m² twice daily and 5 mg twice daily, respectively.

Common toxicities of mammalian target of rapamycin inhibitors

The toxicities of newer targeted therapies are different from those seen with the traditional chemotherapy. Mammalian target of rapamycin (mTOR) inhibitors are evolving into an important class of drugs in oncology, and this class of drugs presents with a variety of different toxicities. Although similar to the toxicities seen in transplantation, these rapamycin analogs have unique side effects when compared to traditional chemotherapy agents. While most of the toxicities are mild, few can be severe and require routine monitoring. Mucositis and rash are the most common side effects. The metabolic toxicities, hyperglycemia, hyperlipidemia, and hypophosphatemia are different from the side effects traditionally seen with chemotherapy. This review will focus on the common toxicities seen with the mTOR inhibitors.

The Akt-specific inhibitor MK2206 selectively inhibits thyroid cancer cells harboring mutations that can activate the PI3K/Akt pathway

CONTEXT

The phosphoinositide 3-kinase (PI3K)/Akt pathway is widely postulated to be an effective therapeutic target in thyroid cancer.

OBJECTIVE

The aim of the study was to test the therapeutic potential of the novel Akt inhibitor MK2206 for thyroid cancer.

DESIGN

We examined the effects of MK2206 on thyroid cancer cells with respect to the genotypes of the PI3K/Akt pathway.

RESULTS

Proliferation of thyroid cancer cells OCUT1, K1, FTC133, C643, Hth7, and TPC1, which harbored PIK3CA, PTEN, Ras, or RET/PTC mutations that could activate the PI3K/Akt pathway, was potently inhibited by MK2206 with IC(50) values mostly below or around 0.5 μm. In contrast, no potent inhibition by MK2206 was seen in most of the Hth74, KAT18, SW1736, WRO, and TAD2 cells that did not harbor mutations in the PI3K/Akt pathway. The inhibition efficacy was also genetic-selective. Specifically, the average inhibition efficacies were 59.2 ± 11.3 vs. 36.4 ± 8.8% (P = 0.005) at 1 μm MK2206 and 64.4 ± 11.5 vs. 38.5 ± 18.9% (P = 0.02) at 3 μm MK2206 for cells with mutations vs. cells without. The SW1736 cell, lacking mutations in the PI3K/Akt pathway, had minimal response to MK2206, but transfection with exogenous PIK3CA mutants, PIK3CA H1047R and E545K, significantly increased its sensitivity to MK2206. MK2206 also completely overcame the feedback activation of Akt from temsirolimus-induced mammalian target of rapamycin suppression, and the two inhibitors synergistically inhibited thyroid cancer cell growth.

CONCLUSIONS

Our study demonstrates a genetic selectivity of MK2206 in inhibiting thyroid cancer cells by targeting the PI3K/Akt pathway, supporting a clinical trial in thyroid cancer.

Next-generation mTOR inhibitors in clinical oncology: how pathway complexity informs therapeutic strategy

Mammalian target of rapamycin (mTOR) is a PI3K-related kinase that regulates cell growth, proliferation, and survival via mTOR complex 1 (mTORC1) and mTORC2. The mTOR pathway is often aberrantly activated in cancers. While hypoxia, nutrient deprivation, and DNA damage restrain mTORC1 activity, multiple genetic events constitutively activate mTOR in cancers. Here we provide a brief overview of the signaling pathways up- and downstream of mTORC1 and -2, and discuss the insights into therapeutic anticancer targets - both those that have been tried in the clinic with limited success and those currently under clinical development - that knowledge of these pathways gives us.

Temsirolimus for the treatment of mantle cell lymphoma

Although recent progress has been made in the treatment of mantle cell lymphoma (MCL) the majority of patients experience relapse and ultimately die of their disease. The translocation t(11;14) is a prerequisite for the diagnosis of MCL and results in overexpression of cyclin D1. Its protein translation is controlled by mTOR, a key element of the PI3K/Akt pathway, and mTOR constitutes an attractive therapeutic target. Temsirolimus, a specific inhibitor of mTOR, has been evaluated in two Phase II trials in patients with relapsed MCL, and promising response rates up to 40% were found. Subsequently, a randomized Phase III trial was initiated, in which superiority in remission induction and progression-free survival could be demonstrated for a regimen of temsirolimus 175 mg for 3 weeks, followed by a 75-mg weekly application in comparison with established agents. This adds temsirolimus to the therapeutic armamentarium for the treatment of MCL. Further developments target combination therapy in MCL and other lymphoid neoplasms.

Drug-related pneumonitis in patients with advanced renal cell carcinoma treated with temsirolimus

PURPOSE

Pneumonitis has occurred in patients treated with inhibitors of the mammalian target of rapamycin (mTOR). In a phase III study of patients with previously untreated, poor-prognosis, advanced renal cell carcinoma (ARCC), the mTOR inhibitor temsirolimus improved survival compared with interferon. We performed a retrospective, independent, blinded radiographic review of chest computed tomography (CT) images of patients in this study to characterize temsirolimus-related pneumonitis.

PATIENTS AND METHODS

Patients were treated with intravenous temsirolimus 25 mg once weekly or subcutaneous interferon alfa 3 million units, with an increase to 18 million units, thrice weekly. Drug-related pneumonitis was identified based on sequential chest CT images, required every 8 weeks, showing changes consistent with pneumonitis and not pneumonia (infection) or disease progression as correlated with clinical data. Cumulative probability of drug-related pneumonitis was estimated using the Kaplan-Meier method.

RESULTS

Eight (6%) of 138 and 52 (29%) of 178 evaluable patients on interferon and temsirolimus treatment, respectively, developed radiographically identified drug-related pneumonitis. Time to onset of pneumonitis was significantly shorter on the temsirolimus arm than on the interferon arm (log-rank P < .001). Estimated cumulative probability of pneumonitis at 8 and 16 weeks from first dose was 21% and 31%, respectively, on the temsirolimus arm and 6% and 8%, respectively, on the interferon arm. Respiratory symptoms were observed around time of onset of radiographically diagnosed temsirolimus-related pneumonitis in 16 (31%) of 52 patients.

CONCLUSION

Patients with ARCC receiving temsirolimus should be monitored closely for development of pneumonitis, and their management should be altered if clinical symptoms appear.

A phase II trial of gefitinib and pegylated IFNα in previously treated renal cell carcinoma

BACKGROUND

This study was conducted to evaluate the efficacy of the epidermal growth factor receptor tyrosine kinase inhibitor gefitinib with pegylated-IFNα (PEG-IFNα) in patients with advanced renal cell carcinoma.

METHODS

Progression-free survival (PFS) rate at 6 months >50% was considered promising for further evaluation. Patients with unresectable or metastatic disease, unlimited prior therapies, and adequate performance status and end-organ function were eligible. PEG-IFNα was dosed subcutaneously once weekly (initially 6 μg/kg/week, later reduced to 4 μg/kg/week) for 12 weeks. Gefitinib was given 250 mg orally once daily until progression or intolerance.

RESULTS

Twenty-one patients were accrued. Fourteen patients had a prior nephrectomy, and twelve had prior systemic therapy. The 6-month PFS was 29% (95%CI 15-56%). Best responses by RECIST criteria: complete, partial (1, plus 3 unconfirmed) stable (Uhlman et al. Clin Cancer Res 1:913-920, 1995), and progression (Sirotnak et al. Clin Cancer Res 6:4885-4892, 2000). Response duration: complete response (35+ months) and partial response (2, 3, 3, 37 months). Median PFS and overall survival were 5.3 (95%CI 3-10.1) and 13.6 (95%CI 10.3-NA) months, respectively. Most common toxicities included myelosuppression, rash, and nausea.

CONCLUSIONS

Although generally well tolerated, gefitinib plus PEG-IFNα did not meet the pre-specified 6-month PFS rate >50%. Further evaluation of similar regimens would require appropriate molecular selection of subjects most likely to benefit. Thus, preclinical studies to determine candidate predictive markers for this combination are warranted.

Mammalian target of rapamycin: biological function and target for novel anticancer agents

PURPOSE

The biological function of the mammalian target of rapamycin (mTOR) and mechanisms of action of mTOR inhibitors currently available for clinical use are described.

SUMMARY

mTOR is a target for anticancer agents due to its role in cancer development, progression, and resistance to other antineoplastic agents. Currently, two mTOR inhibitors, temsirolimus and everolimus, are approved for the treatment of patients with advanced renal cell carcinoma (RCC). Clinical trials comparing single-agent temsirolimus with interferon alfa-2a demonstrated an improvement in overall survival and progression-free survival (PFS) in patients with metastatic RCC. Clinical studies comparing everolimus with placebo indicated improved PFS in advanced RCC patients whose disease had progressed on or after vascular endothelial growth factor (VEGF) inhibitor therapy. Due to its role in the phosphatidylinositol 3-kinase (PI3K) signaling pathway, mTOR is a rational target for inhibition in combination with other agents, including traditional chemotherapy and agents that are affected by or target the PI3K pathway. Data from these studies review the use of mTOR inhibitors in non-Hodgkin's lymphoma and endometrial, breast, and neuroendocrine tumors. Common toxicities of mTOR inhibitors include mucositis, stomatitis, rash, asthenia, fatigue, and myelosuppression. Additional toxicities requiring monitoring include hyperglycemia, hyperlipidemia, and pneumonitis.

CONCLUSION

The mTOR signaling pathway is upregulated in a variety of solid and hematologic tumors. Two inhibitors of this pathway, temsirolimus and everolimus, have been approved for use in metastatic RCC. Although relatively safe, these drugs are associated with some unique adverse effects, such as hyperlipidemia, hyperglycemia, and pneumonitis, that require monitoring and may require clinical intervention.

The effect of mTOR inhibition alone or combined with MEK inhibitors on brain metastasis: an in vivo analysis in triple-negative breast cancer models

mTOR inhibitor rapamycin and its analogs are lipophilic, demonstrate blood-brain barrier penetration, and have shown promising antitumor effects in several types of refractory tumors. We thus try to explore the therapeutic effects of mTOR inhibitors on brain metastasis models. We examined the effects of different dose of mTOR inhibitors (rapamycin, Temsirolimus-CCI-779) on cell invasion in two brain metastatic breast cancer cell lines (MDA-MB231-BR and CN34-BrM2). Antibody microarray and immunoblotting were applied to detect signaling pathways underlying the dose differential drug effects. The in vivo effects of single drug (CCI-779), and drug combination of CCI-779 with SL327 (a brain penetrant MEK inhibitor) to eliminate the unfavorable activation of MAPK pathway were evaluated in MDA-MB231-BR brain metastases xenograft mice. The two mTOR inhibitors, rapamycin and CCI-779, inhibited the invasion of brain metastatic cells only at a moderate concentration level, which was lost at higher concentrations secondary to activation of the MAPK signaling pathway. Pharmacological inhibition of ERK1/2 by PD98059 and SL327 restored the anti-invasion effects of mTOR inhibition in vitro. In vivo, a significant decrease was noted in the average number of micro and large metastatic lesions as well as the whole brain GFP expression in the CCI-779 1 mg/kg/day treated group compared with that in the vehicle group (P < 0.05). However, 10 mg/kg CCI-779 treatment did not show significant anti-metastasis effect on the animal model. High-dose CCI-779 eliciting the ERK MAPK activation in the brain metastatic lesion was corroborated. Combined with the brain penetrant MEK inhibitor SL327, high-dose CCI-779 significantly reduces the brain metastasis, and the combination treatment prohibited perivascular invasion of tumor cells and inhibits tumor angiogenesis in vivo. This study provides evidence on the potential value of CCI-779 as well as CCI-779 + SL327 in prohibiting breast cancer brain metastasis.

Characteristics of thoracic malignancies that occur after solid-organ transplantation

BACKGROUND

Chronic immunosuppression after solid-organ transplantation is associated with increased risk of developing malignancies. The purpose of this study was to determine the clinical characteristics and the outcome of thoracic malignancies in patients who have undergone solid-organ transplantation.

METHODS

Among a cohort of 2831 patients who received a transplant at our institution and were followed between 1984 and 2009, 24 patients (0.85%) developed thoracic malignancies. Risk factors for lung cancer, as well as demographic, cancer, and transplantation characteristics, were analyzed. Survival data were also collected.

RESULTS

Twenty-four patients were included (21 men, median age 61.7 years). Twenty-two patients were smokers. The most frequent histologic types were squamous cell carcinoma (n = 11, 46%) and adenocarcinoma (n = 9, 37%). The median time period between transplantation and diagnosis of lung cancer was 6.6 years. Ten lung malignancies occurred after kidney transplantation (0.5%), eight after liver transplantation (1.3%), and six after heart transplantation (2.8%). Seven patients underwent surgery, three had radiotherapy, four had chemotherapy, and six had multimodal treatment. The median survival time was 1.5 years, ranging from 6 months for stage IV to 3.7 years for stage I.

CONCLUSION

Solid-organ transplantation is associated with a high risk of lung cancer and may have an important synergetic part with other risk factors for lung cancer (tobacco). However, survival rates from lung cancer in our study population are similar to those of nontransplanted patients. In addition, surgery can result in favorable survival results.

Inhibition of bladder tumour growth by sirolimus in an experimental carcinogenesis model

OBJECTIVE

To investigate the anticarcinogenic effects of sirolimus 2 mg/kg/day on a rat model of urinary bladder carcinogenesis induced with N-butyl-N(4-hydroxybutyl)nitrosamine (BBN).

MATERIALS AND METHODS

Thirty-six male Wistar rats were divided into four groups: 1, a control group (eight), given tap water only; 2, a sirolimus control group (eight), given 2 mg/kg/day; 3, a carcinogen (BBN) group (12) exposed to 0.05% BBN; 4, a treatment group (sirolimus/BBN; eight) given 2 mg/kg/day + 0.05% BBN. In the tumour-induction phase, from week 1 to week 8, rats from groups 3 and 4 received BBN ad libitum in drinking water. In the treatment phase, from week 8 to week 20, rats from groups 2 and 4 received sirolimus 2 mg/kg/day by an oesophageal cannula. At week 20 the rats were killed humanely, and the number and size of tumours recorded. The bladders were collected for histological, immunohistochemical and gene expression evaluation. Blood was collected for the determination of several serum proliferative and inflammatory markers. Lipid peroxidation, through serum malondialdehyde (MDA) content, and total antioxidant status (TAS) were also evaluated.

RESULTS

Sirolimus caused a marked inhibition of bladder tumour growth. When compared with group 3, group 4 had a reduced proportion of rats with tumour (three of eight vs eight of 12), and significantly fewer tumours per rat, with a mean (sd) of 1.00 (0.0) vs 1.88 (0.35), and tumour volume per tumour, of 0.30 (0.11) vs 66.1 (48.9) mm³, with less aggressive histological changes, i.e. a marked reduction in hyperplasia (four of eight vs 12/12), high-grade dysplasia (four of eight vs 11/12) and urothelial tumour. Rats in group 4 had no infiltrative bladder cancers and had a lower incidence of high-grade tumours than rats in group 3. The rats in group 4 had decreased serum levels of transforming growth factor-β1, higher levels of tumour necrosis factor-α, and higher levels of serum TAS and a better serum MDA/TAS ratio, a marker of more favourable redox status. Furthermore, the down-regulation of bladder caspase 3 gene expression and the increased Ki67 immunostaining in group 3 were significantly attenuated in group 4.

CONCLUSIONS

Sirolimus given as an oral agent, 2 mg/kg/day, significantly inhibited rat bladder carcinogenesis. Sirolimus reduced the number and volume of tumours and induced a less aggressive histological behaviour. This might be due to antiproliferative and antioxidant properties, as well as to the restoration of apoptotic pathways.

Immunotherapy in renal cell carcinoma

Treatment of metastatic renal cell cancer is still challenging due to its resistance to conventional therapies, such as radiotherapy or chemotherapy. Immunotherapeutic approaches with IL-2 and/or IFN-alpha have become standard regimens in treating metastatic renal cell cancer. Furthermore, molecularly targeted therapies, such as VEGF-pathway inhibition or use of mammalian target of rapamycin inhibitors, have demonstrated promising results and might become even more important in the following years. Finally, vaccination therapies have gained increasing interest and have been tested in multiple clinical trials. There is a vast choice of different application and production types of these vaccines, ranging from dendritic cell-based principals to the application of naked RNA. The development of new immune-enhancing strategies led to the option of interesting, potent combination regimes. This review has a focus on vaccination therapies in renal cell cancer, especially dendritic cell-based principals, and aims to give an overview of this rapidly changing field of investigation.

Weekly administration of temsirolimus for heavily pretreated patients with clear cell carcinoma of the ovary: a report of six cases

Clear cell carcinoma (CCC) of the ovary is well-known to be chemotherapy resistant compared with other histologic subtypes. An inhibitor against the mammalian target of rapamycin, temsirolimus (TEM) has been reported to be effective in renal CCC. Therefore, we investigated the effects of TEM in patients with CCC of the ovary. Six patients with CCC of the ovary who had been heavily pretreated by more than 4 regimens were given TEM: the cycle consisted of weekly TEM (10 mg/m(2)) for 3 weeks followed by 1 week off. The treatment was continued until development of either progressive disease, or unmanageable adverse effects. Response evaluation was based upon the Response Evaluation Criteria in Solid Tumors version 1.0. Adverse effects were analyzed according to Common Terminology Criteria for Adverse Events version 3.0. The median cycle of weekly TEM was 3 (range 2-14). Among five cases in which responses could be evaluated, partial response was observed in one case (20%) and stabilized disease was seen in another case (20%). There were no toxicities greater than grade 3, and no case developed severe toxicity requiring discontinuation of weekly TEM. The patient who showed a partial response obtained a progression-free period of 14 months. In conclusion, weekly TEM shows a potential therapeutic benefit for patients with CCC of the ovary. Further studies including a translational approach are needed to select candidates for whom TEM therapy would be beneficial.

Surgical treatment of hepatic metastases from colorectal cancer

Colorectal carcinoma is one of the most frequent cancers in Western societies with an incidence of around 700 per million people. About half of the patients develop metastases from the primary tumor and liver is the primary metastatic site. Improved survival rates after hepatectomy for metastatic colorectal cancer have been reported in the last few years and these may be the result of a variety of factors, such as advances in systemic chemotherapy, radiographic imaging techniques that permit more accurate determination of the extent and location of the metastatic burden, local ablation methods, and in surgical techniques of hepatic resection. These have led to a more aggressive approach towards liver metastatic disease, resulting in longer survival. The goal of this paper is to review the role of various forms of surgery in the treatment of hepatic metastases from colorectal cancer.

Novel targets for treatment of adult acute lymphocytic leukemia

The treatment of acute lymphocytic leukemia (ALL) results in long-term disease-free survival in only 30-40% of adults. Conventional chemotherapy is toxic and woefully ineffective. Therefore, novel agents are being investigated. Among these agents are monoclonal antibodies such as rituximab, epratuzumab, and alemtuzumab and targeted therapies such as tyrosine kinase inhibitors, mTOR inhibitors, and mitogen-activated protein kinase (MEK) inhibitors. This article discusses such novel targets for the treatment of ALL.

Everolimus: a new mammalian target of rapamycin inhibitor for the treatment of advanced renal cell carcinoma

OBJECTIVE

To review clinical trials and main characteristics of everolimus, with focus on treatment of advanced renal cell carcinoma.

DATA SOURCES

Pertinent data were identified primarily through a search of MEDLINE and PubMed (1966-November 2010) using the primary search terms everolimus, RAD001, renal cell carcinoma, and mTOR inhibitors.

STUDY SELECTION AND DATA EXTRACTION

Studies evaluating the safety and efficacy of everolimus in patients with cancer were evaluated, including Phase 1, 2, and 3 trials. Preference was given to Phase 2 and 3 studies evaluating use of everolimus in patients with renal cell carcinoma.

DATA SYNTHESIS

Everolimus is an oral mammalian target of rapamycin (mTOR) inhibitor approved for the management of patients with advanced renal cell carcinoma who progressed on tyrosine kinase inhibitor therapy. Actions of everolimus within the mTOR pathway result in decreased protein synthesis and cell cycle arrest, as well as decreased angiogenesis. A usual starting dose for patients with renal cell carcinoma is 10 mg daily. Everolimus undergoes extensive hepatic metabolism, primarily through the CYP3A4 isoenzyme, which predisposes it to drug interactions with inducers and inhibitors of this enzyme. Most commonly reported adverse events associated with everolimus include anemia, hyperglycemia, hypercholesterolemia, mucositis, fatigue, and rash. Approval of everolimus was based on the results of a Phase 3 trial that demonstrated an increase in median progression-free survival by 2.1 months in patients receiving everolimus therapy as compared to placebo. The drug was recently added to the National Comprehensive Cancer Network guidelines as a treatment option for patients with advanced renal cell carcinoma who have progressed on tyrosine kinase therapy.

CONCLUSIONS

Based on a review of the currently available literature, everolimus provides a safe and efficacious treatment option for patients with renal cell carcinoma who have progressed on treatment with sunitinib and/or sorafenib.

Renal cell carcinoma: focus on safety and efficacy of temsirolimus

Metastatic renal cell carcinoma has harboured a poor prognosis for decades with immunotherapy being the only available therapy with high toxicity and modest effect. Dependance of renal cell carcinoma oncogenesis on the mTOR pathway has led to clinical development of temsirolimus in this setting. This sirolimus derivative has shown clinical efficacy in monotherapy for poor-risk renal cell carcinoma leading to an overall survival of 10.8 months in the pivotal phase III trial of this agent. Its specific adverse events consist of metabolic dysregulation (hyperlipemia, hyperglycemia), mucositis, rash and pneumonitis which can be severe and need careful monitoring and management. In this review, we will discuss of the clinical development of this molecule, its efficacy, its safety profile and future perspectives.

Different gene expressions are associated with the different molecular subtypes of inflammatory breast cancer

The goal of this study was to determine whether gene expression differences exist between inflammatory breast cancers (IBC) and T stage-matched non-IBC patients stratified by hormone receptor and HER2 status. We used Affymetrix GeneChips to analyze 82 tumor samples (25 T4d patients, and 57 T4a-c patients) of newly diagnosed breast cancers. Genes that were differentially expressed between the IBC and non-IBC specimens were identified using the t test, and differential expression of gene sets was assessed using gene set analysis. Three distinct clinical subtypes of IBC and non-IBC were compared: ER-positive/HER2-normal, HER2-amplified, and ER-negative/HER2-normal. When we compared expression data from all IBC with all non-IBC, we found no significant differences after adjusting for multiple testing. When IBC and non-IBC tumors were compared by clinical subtype, however, significant differences emerged. Complement and immune system-related pathways were overexpressed in ER-positive/HER2-normal IBC. Protein translation and mTOR signaling were overexpressed in HER2-amplified IBC. Apoptosis-, neural-, and lipid metabolism-related pathways were overexpressed in ER-negative/HER2-normal IBC compared with non-IBC of the same receptor phenotype. In this T stage-matched case-control study, the survival curves of patients with IBC and non-IBC were similar for all three clinical subtypes. IBC tumors can be divided into molecular and clinical subtypes similar to those of non-IBC. Clinical subtypes of IBC show molecular differences compared with similar subtypes of non-IBC.

Inhibitors of mTOR

Inhibitors of mammalian target of rapamycin (mTOR) have been approved for the treatment of renal cell carcinoma and appear to have a role in the treatment of other malignancies. The primary objective of this drug review is to provide pharmacokinetic and dynamic properties of the commonly used drugs everolimus and temsirolimus. Additionally, information on clinical use, mechanism of action, bioanalysis, drug-drug interactions, alterations with disease or age, pharmacogenetics, and drug resistance is given. This overview should assist the treating medical oncologist in adjusting treatment with mTOR inhibitors to individual patient circumstances.

Targeted therapy and hand-foot skin reaction in advanced renal cell carcinoma

IMPORTANCE OF THE FIELD

Targeted therapy has significantly prolonged the survival of patients with advanced renal cell carcinoma (RCC). As first-line treatment, sunitinib, temsirolimus and bevacizumab plus IFN-alpha are demonstrated to prolong progression-free survival and/or overall survival. As second-line treatment, sorafenib was active mainly for patients in whom cytokine therapy failed. Recently, second-line treatment with everolimus has been shown to benefit patients progressing through tyrosine kinase inhibitors. Meanwhile, FDA has just approved pazopanib for the treatment of patients with advanced RCC. Various toxicities were associated with these agents. These toxicities were generally well tolerated. However, a high frequency of severe skin and bone marrow toxicities has been reported in Asian countries.

AREAS COVERED IN THIS REVIEW

We have reviewed the literature of current targeted therapeutic agents and hand-foot skin reaction (HFSR) in advanced RCC available in MEDLINE and meeting reports of ASCO, ECCO-ESMO and the 2009 Genitourinary Cancers Symposium.

WHAT THE READER WILL GAIN

Readers will know of the efficacy and safety, including HFSR, of current targeted therapy.

TAKE HOME MESSAGE

Careful monitoring and appropriate management of the toxicities, especially HFSR, are needed.

Sirolimus plus sorafenib in treating HCC recurrence after liver transplantation: A case report

A case of hepatocellular carcinoma (HCC) with pulmonary recurrence after liver transplantation for HCC is presented in this report. The patient showed disease progression on sorafenib therapy demonstrated by computed tomography scans as well as serial serum α-fetoprotein (AFP) elevation. After his immunosuppression therapy was successfully transitioned to sirolimus and a continuation of sorafenib, he achieved partial remission based on RECIST criteria and normalization of AFP. Mammalian target of rapamycin inhibitors including sirolimus alone or in conjunction with sorafenib may be useful in the treatment of post transplant HCC.

FoxOs enforce a progression checkpoint to constrain mTORC1-activated renal tumorigenesis

mTORC1 is a validated therapeutic target for renal cell carcinoma (RCC). Here, analysis of Tsc1-deficient (mTORC1 hyperactivation) mice uncovered a FoxO-dependent negative feedback circuit constraining mTORC1-mediated renal tumorigenesis. We document robust FoxO activation in Tsc1-deficient benign polycystic kidneys and FoxO extinction on progression to murine renal tumors; murine renal tumor progression on genetic deletion of both Tsc1 and FoxOs; and downregulated FoxO expression in most human renal clear cell and papillary carcinomas, yet continued expression in less aggressive RCCs and benign renal tumor subtypes. Mechanistically, integrated analyses revealed that FoxO-mediated block operates via suppression of Myc through upregulation of the Myc antagonists, Mxi1-SRα and mir-145, establishing a FoxO-Mxi1-SRα/mir-145 axis as a major progression block in renal tumor development.

Combination of temsirolimus (CCI-779) with chemoradiation in newly diagnosed glioblastoma multiforme (GBM) (NCCTG trial N027D) is associated with increased infectious risks

PURPOSE

The mammalian target of rapamycin (mTOR) functions within the phosphoinositide 3-kinase/Akt signaling pathway as a critical modulator of cell survival.

METHODS

The mTOR inhibitor temsirolimus (CCI-779) was combined with chemoradiotherapy in glioblastoma multiforme (GBM) patients in a dose-escalation phase I trial. The first 12 patients were treated with CCI-779 combined with radiation/temozolomide and adjuvant temozolomide. A second cohort of 13 patients was treated with concurrent CCI-779/radiation/temozolomide followed by adjuvant temozolomide monotherapy.

RESULTS

Concomitant and adjuvant CCI-779 was associated with a high rate (3 of 12 patients) of grade 4/5 infections. By limiting CCI-779 treatment to the radiation/temozolomide phase and using antibiotic prophylaxis, the rate of infections was reduced, although 2 of 13 patients developed exacerbation of pre-existing fungal or viral infections. Dose-limiting toxicities were observed in 2 of 13 patients with this modified schedule. Weekly CCI-779 (50 mg/week) combined with radiation/temozolomide is the recommended phase II dose and schedule. The immune profile of patients in the second cohort was assessed before, during, and after CCI-779 therapy. There was robust suppression of helper and cytotoxic T cells, B cells, natural killer, cells and elevation of regulatory T cells during CCI-779/radiation/temozolomide therapy with recovery to baseline levels during adjuvant temozolomide of cytotoxic T cells, natural killer cells, and regulatory T cells.

CONCLUSIONS

The increased infection rate observed with CCI-779 combined with chemoradiotherapy in GBM was reduced with antibiotic prophylaxis and by limiting the duration of CCI-779 therapy. The combined suppressive effects of CCI-779 and temozolomide therapy on discrete immune compartments likely contributed to the increased infectious risks observed.

Deciphering the role of PI3K/Akt/mTOR pathway in breast cancer biology and pathogenesis

The phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway mediates multiple cellular functions critical to tumor initiation, progression, and outcomes, including growth and proliferation, metabolism, motility, migration, invasion, angiogenesis, survival, and autophagy. Tight regulation of this pathway is paramount to ensure that multiple cellular inputs are integrated for appropriate cellular outcomes. Frequent deregulation and aberrations of this pathway have been implicated in breast cancer development and progression. This review focuses on the biology of this pathway and its role in breast cancer pathogenesis. The role of therapies directed at targeting mTOR in the PI3K/Akt/mTOR pathway, which are currently being evaluated in clinical trials, will also be reviewed.

Utilizing targeted cancer therapeutic agents in combination: novel approaches and urgent requirements

The rapid development of new therapeutic agents that target specific molecular pathways involved in tumour cell proliferation provides an unprecedented opportunity to achieve a much higher degree of biochemical specificity than previously possible with traditional chemotherapeutic anticancer agents. However, the lack of specificity of these established chemotherapeutic drugs allowed a relatively straightforward approach to their use in combination therapies. Developing a paradigm for combining new, molecularly targeted agents, on the other hand, is substantially more complex. The abundance of molecular data makes it possible, at least in theory, to predict how such agents might interact across crucial growth control networks. Initial strategies to examine molecularly targeted agent combinations have produced a small number of successes in the clinic. However, for most of these combination strategies, both in preclinical models and in patients, it is not clear whether the agents being combined actually hit their targets to induce growth inhibition. Here, we consider the initial approach of the US National Cancer Institute (NCI) to the evaluation of combinations of molecularly targeted anticancer agents in patients and provide a description of several new approaches that the NCI has initiated to improve the effectiveness of combination-targeted therapy for cancer.

Phase 3 trial of everolimus for metastatic renal cell carcinoma : final results and analysis of prognostic factors

BACKGROUND

A phase 3 trial demonstrated superiority at interim analysis for everolimus over placebo in patients with metastatic renal cell carcinoma (mRCC) progressing on vascular endothelial growth factor receptor-tyrosine kinase inhibitors. Final results and analysis of prognostic factors are reported.

METHODS

Patients with mRCC (N = 416) were randomized (2:1) to everolimus 10 mg/d (n = 277) or placebo (n = 139) plus best supportive care. Progression-free survival (PFS) and safety were assessed to the end of double-blind treatment. Mature overall survival (OS) data were analyzed, and prognostic factors for survival were investigated by multivariate analyses. A rank-preserving structural failure time model estimated the effect on OS, correcting for crossover from placebo to everolimus.

RESULTS

The median PFS was 4.9 months (everolimus) versus 1.9 months (placebo) (hazard ratio [HR], 0.33; P < .001) by independent central review and 5.5 months (everolimus) versus 1.9 months (placebo) (HR, 0.32; P < .001) by investigators. Serious adverse events with everolimus, independent of causality, in ≥ 5% of patients included infections (all types, 10%), dyspnea (7%), and fatigue (5%). The median OS was 14.8 months (everolimus) versus 14.4 months (placebo) (HR, 0.87; P = .162), with 80% of patients in the placebo arm crossed over to everolimus. By the rank-preserving structural failure time model, the survival corrected for crossover was 1.9-fold longer (95% confidence interval, 0.5-8.5) with everolimus compared with placebo only. Independent prognostic factors for shorter OS in the study included low performance status, high corrected calcium, low hemoglobin, and prior sunitinib (P < .01).

CONCLUSIONS

These results established the efficacy and safety of everolimus in patients with mRCC after progression on sunitinib and/or sorafenib.

Schedule-dependent inhibition of T-cell lymphoma cells by cotreatment with the mTOR inhibitor everolimus and anticancer drugs

OBJECTIVE

Everolimus (RAD001) is a novel mammalian target of rapamycin (mTOR) inhibitor, and anti-proliferative activity in various malignancies has been reported. This study evaluated the anti-tumor effects and schedule-dependent synergism of everolimus in combination with other chemotherapeutic agents in T-cell lymphoma cell lines.

MATERIALS AND METHODS

Human T-cell lymphoma cell lines Hut-78 and Jurkat were treated with increasing doses of everolimus, alone or in combination with doxorubicin, etoposide, vincristine, or bortezomib, using different dosing schedules. Anti-tumor effects were measured by assays for cell proliferation, apoptosis, and cell cycle distribution. Drug interactions were determined by median effect analysis.

RESULTS

Exposure to everolimus alone induced G1 phase cell cycle arrest without significant apoptosis. With certain dosing schedules, everolimus showed synergism with doxorubicin, etoposide, and bortezomib, but antagonism with vincristine. Cytotoxic synergism was observed following cotreatment with doxorubicin and everolimus, bortezomib and everolimus, doxorubicin followed by everolimus, and bortezomib followed by everolimus. By contrast, cell exposure to everolimus followed by doxorubicin or followed by bortezomib resulted in antagonistic effects. Sequential exposure to doxorubicin or bortezomib followed by everolimus effectively prevented potential negative interactions, and resulted in drug synergism. Drug combination synergisms or antagonisms were associated with variable effects on the cell cycle distribution.

CONCLUSIONS

Everolimus effectively inhibited the growth of T-cell lymphoma cells in vitro. Specific schedule-dependent combinations of everolimus with other anti-tumor agents which avoid potential drug antagonism and produce effective synergism may lead to clinically effective treatments for T-cell lymphoma.

Profile of temsirolimus in the treatment of advanced renal cell carcinoma

Temsirolimus is a potent inhibtor of the mammalian target of rapamycin (mTOR). In various clinical trials temsirolimus has shown an overall survival benefit for patients with metastatic renal cell carcinoma (mRCC). Thus it is approved for first-line therapy in high-risk mRCC patients. We discuss the indication, side effects and clinical implications of temsirolimus treatment.

Expanding therapeutic targets in bladder cancer: the PI3K/Akt/mTOR pathway

A complex equilibrium of biological signals exists within the human body to regulate normal cellular function and growth. Unfortunately, there are various ways in which disruption of these signaling pathways can result in uncontrollable cell growth--an important element in oncogenesis. In particular, the mammalian target of rapamycin (mTOR) pathway appears to play a central role in the development of multiple cancers, including urothelial cell carcinoma (UCC). Although often called 'a master regulator,' mTOR is but one signal in an intricate signaling cascade that controls cell growth and angiogenesis in both normal and cancerous conditions. Other important factors in this pathway include upstream activators such as phosphatidylinositol 3 kinase (PI3K) and Akt, negative regulators such as the tuberous sclerosis complex (TSC) 1/2, and downstream effectors such as p70 S6 kinase and eukaryotic initiation factor eIF4E. On the basis of its important role in tumor growth, efforts have focused on developing means to effectively target the mTOR pathway in hopes of designing new treatments for various tumor types. To address the role of mTOR pathway activity in UCC, we will first review the basic elements of the PI3K/Akt/mTOR pathway and then apply this pathway to bladder cancer oncogenesis. As will be evident, significant progress has been made in defining the role of this pathway in UCC; however, continued research into the nuances of pathway regulation and the usage of targeted inhibition in bladder cancer patients is necessary to define mTOR as a promising target in this disease.

The mammalian target of rapamycin pathway is widely activated without PTEN deletion in renal cell carcinoma metastases

BACKGROUND

Inhibitors of the mammalian target of rapamycin (mTOR) are emerging as promising therapies for metastatic renal cell carcinoma (RCC). Because rational treatment strategies require understanding the activation status of the underlying signaling pathway being targeted at the desired stage of disease, the authors examined the activation status of different components of the mTOR pathway in RCC metastases and matched primary tumors.

METHODS

The authors immunostained metastatic RCC samples from 132 patients and a subset of 25 matched primary RCCs with antibodies against phosphatidylinositol 3'-kinase, PTEN, phospho-Akt, phospho-mTOR, and p70S6. PTEN genomic status was assessed by fluorescent in situ hybridization. Marker expression was correlated to clinicopathologic variables and to survival.

RESULTS

The mTOR pathway showed widespread activation in RCC metastases of various sites with strong correlation between different components of this signaling cascade (P<.0001), but without significant PTEN genomic deletion. Only cytoplasmic phospho-mTOR showed independent prognostic significance (P = .029) and fidelity between primary RCCs and their matched metastases (P = .004).

CONCLUSIONS

Activation of various components of the mTOR signaling pathway in metastatic RCC lesions across various tumor histologies, nuclear grades, and metastatic sites suggests the potential for vertical blockade of multiple steps of this pathway. Patient selection may be improved by mTOR immunostaining of primary RCC.

Temsirolimus in the treatment of relapsed or refractory mantle cell lymphoma

Mantle cell lymphoma (MCL) is a rare and aggressive subtype of lymphoma associated with a poor prognosis. Chemotherapy is the mainstay of frontline treatment for patients with this disease. Despite high response rates to combination chemotherapy regimens, the majority of patients relapse within a few years of treatment. Therefore, finding efficacious treatments for relapsed or refractory disease has become a growing area of clinical research. The mammalian target of rapamycin (mTOR) is responsible for integrating cell signals from growth factors, hormones, and nutrients and communicating energy status. Scientific research on aberrant molecular pathways in cancer has revealed that several proteins along the mTOR pathway may be upregulated in this and other types of lymphoma. Temsirolimus is the first mTOR inhibitor that has shown clinical efficacy in treating MCL that has relapsed after frontline treatments.

Updates of mTOR inhibitors

Mammalian target of rapamycin (mTOR) is a central controller of cell growth, proliferation, metabolism and angiogenesis. mTOR signaling is often dysregulated in various human diseases and thus attracts great interest in developing drugs that target mTOR. Currently it is known that mTOR functions as two complexes, mTOR complex 1/2 (mTORC1/2). Rapamycin and its analogs (all termed rapalogs) first form a complex with the intracellular receptor FK506 binding protein 12 (FKBP12) and then bind a domain separated from the catalytic site of mTOR, blocking mTOR function. Rapalogs are selective for mTORC1 and effective as anticancer agents in various preclinical models. In clinical trials, rapalogs have demonstrated efficacy against certain types of cancer. Recently, a new generation of mTOR inhibitors, which compete with ATP in the catalytic site of mTOR and inhibit both mTORC1 and mTORC2 with a high degree of selectivity, have been developed. Besides, some natural products, such as epigallocatechin gallate (EGCG), caffeine, curcumin and resveratrol, have been found to inhibit mTOR as well. Here, we summarize the current findings regarding mTOR signaling pathway and review the updated data about mTOR inhibitors as anticancer agents.

Granulosa cell tumor with activated mTOR-HIF-1alpha-VEGF pathway

The DNA-binding activity of hypoxia-inducible factor-1 alpha (HIF-1alpha) has been analyzed for various gynecological tumors. Among the tumors that were studied, there was a finding of a high level of DNA-binding HIF-1alpha activity, although it was limited to one case of adult type granulosa cell tumor (GCT). In this case a 60-year-old female had marked immunohistochemical expression of HIF-1alpha. The expressions of the mammalian target of rapamycin (mTOR) and phosphorylated-mTOR (p-mTOR) were also marked, and vascular endothelial growth factor (VEGF) was moderately expressed. To compare the expression profiles, 11 consecutive cases with adult type GCT were used. All cases showed marked expressions of HIF-1alpha and mTOR, but p-mTOR expression was moderately to markedly observed in four of the 12 cases. VEGF was expressed in all cases in varying degrees. Based on the evidence that downregulation of the mTOR pathway due to treatment with rapamycin (everolimus) would suppress tumor cell growth, an experimental study using the GCT cell line was designed to clarify whether HIF-1alpha and VEGF expressions decline. As a result, the expressions of p-mTOR, HIF-1alpha and VEGF were suppressed, but those of mTOR were not. It was concluded that mTOR-targeted therapy may represent a promising strategy for some GCT with an activated mTOR-HIF-1alpha-VEGF pathway.

Perspectives in drug development for metastatic renal cell cancer

Patients with renal cell carcinoma (RCC) exhibit a spectrum of clinical outcomes, with some patients following an indolent clinical course and others displaying rapidly advancing disease. As evidence points to RCC being largely refractory to traditional chemotherapy and radiotherapy strategies, immunotherapeutic approaches played a dominant role in the management of metastatic RCC for a quarter of a century. Management of this challenging tumor has been revolutionized by the incorporation of molecularly targeted therapies such as inhibitors of pathways involving tyrosine kinase signaling and the mammalian target of rapamycin (mTOR). The improvements in disease stabilization and survival seen with these agents has meant that molecularly targeted therapy now forms the foundation for treating RCC and has resulted in a multitude of studies investigating similar compounds for efficacy in RCC. Despite this, the rationale for using immunomodulatory regimens remains strong and its ongoing place in this era of targeted treatments continues to pose interesting clinical questions. The challenge of maintaining durable responses from our current therapies persists and this review highlights the plethora of options now available in RCC treatment and the directions in which modern management are heading.

Interventions for treating oral mucositis for patients with cancer receiving treatment

BACKGROUND

Treatment of cancer is increasingly effective but associated with short and long term side effects. Oral side effects, including oral mucositis (mouth ulceration), remain a major source of illness despite the use of a variety of agents to treat them.

OBJECTIVES

To assess the effectiveness of interventions for treating oral mucositis or its associated pain in patients with cancer receiving chemotherapy or radiotherapy or both.

SEARCH STRATEGY

Electronic searches of Cochrane Oral Health Group and PaPaS Trials Registers (to 1 June 2010), CENTRAL via The Cochrane Library (to Issue 2, 2010), MEDLINE via OVID (1950 to 1 June 2010), EMBASE via OVID (1980 to 1 June 2010), CINAHL via EBSCO (1980 to 1 June 2010), CANCERLIT via PubMed (1950 to 1 June 2010), OpenSIGLE (1980 to 1 June 2010) and LILACS via the Virtual Health Library (1980 to 1 June 2010) were undertaken. Reference lists from relevant articles were searched and the authors of eligible trials were contacted to identify trials and obtain additional information.

SELECTION CRITERIA

All randomised controlled trials comparing agents prescribed to treat oral mucositis in people receiving chemotherapy or radiotherapy or both. Outcomes were oral mucositis, time to heal mucositis, oral pain, duration of pain control, dysphagia, systemic infection, amount of analgesia, length of hospitalisation, cost and quality of life.

DATA COLLECTION AND ANALYSIS

Data were independently extracted, in duplicate, by two review authors. Authors were contacted for details of randomisation, blindness and withdrawals. Risk of bias assessment was carried out on six domains. The Cochrane Collaboration statistical guidelines were followed and risk ratio (RR) values calculated using fixed-effect models (less than 3 trials in each meta-analysis).

MAIN RESULTS

Thirty-two trials involving 1505 patients satisfied the inclusion criteria. Three comparisons for mucositis treatment including two or more trials were: benzydamine HCl versus placebo, sucralfate versus placebo and low level laser versus sham procedure. Only the low level laser showed a reduction in severe mucositis when compared with the sham procedure, RR 5.28 (95% confidence interval (CI) 2.30 to 12.13).Only 3 comparisons included more than one trial for pain control: patient controlled analgesia (PCA) compared to the continuous infusion method, therapist versus control, cognitive behaviour therapy versus control. There was no evidence of a difference in mean pain score between PCA and continuous infusion, however, less opiate was used per hour for PCA, mean difference 0.65 mg/hour (95% CI 0.09 to 1.20), and the duration of pain was less 1.9 days (95% CI 0.3 to 3.5).

AUTHORS' CONCLUSIONS

There is weak and unreliable evidence that low level laser treatment reduces the severity of the mucositis. Less opiate is used for PCA versus continuous infusion. Further, well designed, placebo or no treatment controlled trials assessing the effectiveness of interventions investigated in this review and new interventions for treating mucositis are needed.