Donald Poon

Management of hepatocellular carcinoma in Asia: consensus statement from the Asian Oncology Summit 2009

Asia has a disproportionately large share of the worlds hepatocellular carcinoma (HCC), mainly because of the endemic status of chronic hepatitis B and C viruses, which leads to liver cirrhosis and an increased risk of HCC. This etiological factor presents important opportunities for prevention, early detection, diagnosis, and treatment of HCC. This consensus statement reviews the available medical evidence for management of HCC in Asia, and gives treatment recommendations that are adapted to resource availability in this diverse region with disparate health-care delivery systems.

Analysis of Prognostic Factors of Comprehensive Geriatric Assessment and Development of a Clinical Scoring System in Elderly Asian Patients With Cancer

PURPOSE To determine the impact of each comprehensive geriatric assessment (CGA) domain on overall survival (OS) and develop a prognostic scoring system for elderly patients with cancer. PATIENTS AND METHODS A retrospective analysis of CGA data collected from 249 consecutive patients with cancer who attended the outpatient geriatric oncology clinic at the National Cancer Center Singapore age 70 years or older was performed. Univariate and multivariate analyses were performed using Cox proportional hazards method to identify significant prognostic factors within the CGA. A simple nomogram to predict OS was developed using regression coefficients from the multivariate model. Concordance between predicted and observed response of the individual patient score was evaluated by means of Harrells c-index. Calibration was performed using simulated data via bootstrap. RESULTS Median age of the patients was 77 years (range, 70 to 94 years). In our model, age (hazard ratio [HR], 1.04; 95% CI, 1.01 to 1.07), abnormal albumin level (HR, 1.97; 95% CI, 1.23 to 3.15), poor Eastern Cooperative Oncology Group performance status (≥ 2 v < 2: HR, 1.77; 95% CI, 1.15 to 2.72), abnormal geriatric depression scale status (HR, 1.81; 95% CI, 1.29 to 2.56), high malnutrition risk (high v low risk: HR, 1.84; 95% CI, 1.17 to 2.87), and advanced disease stage (late v early: HR, 1.71; 95% CI, 0.98 to 2.95) were independent predictors of survival. CONCLUSION Results confirm the importance of the CGA in assessment of elderly patients with cancer. The development of this nomogram incorporating these prognostic factors helps predict OS of patients, for further intervention.

RAD001 (everolimus) inhibits tumour growth in xenograft models of human hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide and highly resistant to available chemotherapies. Mammalian target of rapamycin (mTOR) functions to regulate protein translation, angiogenesis and cell cycle progression in many cancers including HCC. In the present study, subcutaneous patient‐derived HCC xenografts were used to study the effects of an mTOR inhibitor, RAD001 (everolimus), on tumour growth, apoptosis and angiogenesis. We report that oral administration of RAD001 to mice bearing patient‐derived HCC xenografts resulted in a dose‐dependent inhibition of tumour growth. RAD001‐induced growth suppression was associated with inactivation of downstream targets of mTOR, reduction in VEGF expression and microvessel density, inhibition of cell proliferation, up‐regulation of p27Kip1 and down‐regulation of p21Cip1/Waf1, Cdk‐6, Cdk‐2, Cdk‐4, cdc‐25C, cyclin B1 and c‐Myc. Our data indicate that the mTOR pathway plays an important role in angiogenesis, cell cycle progression and proliferation of liver cancer cells. Our study provides a strong rationale for clinical investigation of mTOR inhibitor RAD001 in patients with HCC.

Sorafenib and rapamycin induce growth suppression in mouse models of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide. Vascular endothelial growth factor, platelet derived growth factor and the Raf/mitogen‐activated protein kinase/extracellular signal regulated kinase (Raf/MEK/ERK) signalling pathway regulates the growth, neovascularization, invasiveness and metastatic potential of HCC. In this study, we investigated the in vivo antitumour activity and mechanisms of action of sorafenib tosylate on four patient‐derived HCC xenografts. Sorafenib dosed at 50 mg/kg and 100 mg/kg inhibited tumour growth by 85% and 96%, respectively. Sorafenib‐induced growth suppression and apoptosis were associated with inhibition of angiogenesis, down‐regulation of phospho‐platelet‐derived growth factor receptor β Tyr1021, phospho‐eIF4E Ser209, phospho‐c‐Raf Ser259, c‐Raf, Mcl‐1, Bcl‐2, Bcl‐x and positive cell cycle regulators, up‐regulation of apoptosis signalling kinase‐1, p27 and p21. Expression of IGF‐1Rβ and phosphorylation of c‐Raf Ser338, MEK1/2 Ser217/221 and ERK1/2 Thr202/Tyr204 were increased by sorafenib treatment. Phosphorylation of mammalian target‐of‐rapamycin (mTOR) targets (p70S6K, S6R and 4EBP1) was reduced by sorafenib in sorafenib‐sensitive lines but activated in sorafenib‐less‐sensitive 10–0505 xenograft. Sorafenib‐induced phosphorylation of c‐met, p70S6K and 4EBP1 was significantly reduced when 10–0505 cells were co‐treated with anti‐human anti‐HGF antibody, suggesting that treatment with sorafenib leads to increased HGF secretion and activation of c‐met and mTOR targets. Treatment of 10–0505 tumours with sorafenib plus rapamycin resulted in growth inhibition, inhibition of vascular endothelial growth factor receptor‐2 phosphorylation, increased apoptosis and completely blocked sorafenib‐induced phosphorylation of mTOR targets and cyclin B1 expression. These data also provide a strong rationale for clinical investigation of sorafenib in combination with mTOR inhibitors in patients with HCC.

AZD6244 enhances the anti-tumor activity of sorafenib in ectopic and orthotopic models of human hepatocellular carcinoma (HCC).

BACKGROUND & AIMS Hepatocellular carcinoma (HCC) is a particularly vascularized solid tumor where the Raf/MEK/ERK pathway is activated; suggesting that inhibition of this pathway may have therapeutic potential. METHODS We treated patient-derived HCC xenografts with (i) sorafenib, (ii) AZD6244 (ARRY-142886), and (iii) sorafenib plus AZD6244. Western blotting was employed to determine pharmacodynamic changes in biomarkers relevant to both angiogenesis and MEK signaling. Apoptosis, microvessel density, and cell proliferation were analyzed by immunohistochemistry. RESULTS We report here that sorafenib treatment resulted in suppression of tumor growth, reduction in cell proliferation, induction of apoptosis and inhibition of mTOR targets. Sorafenib-induced elevation of the insulin-like growth factor receptor 1 (IGF-1R), phospho-c-Raf Ser338, phospho-MEK Ser217/221 and phospho-ERK Thr202/Tyr204 was attenuated by co-treating cells with anti-human IGF-1R antibody or over-expression of activated mutant p70S6K. Pharmacological inhibition of the MEK/ERK pathway by AZD6244 enhanced the anti-tumor effect of sorafenib in both orthotopic and ectopic models of HCC. Such inhibition led to a further increase in pro-apoptotic Bim, apoptosis and a profound inhibition of cell proliferation. CONCLUSION Our findings underscore the potential of a combined therapeutic approach with sorafenib and MEK inhibitors in the treatment of HCC.

Phase III study of pasireotide long-acting release in patients with metastatic neuroendocrine tumors and carcinoid symptoms refractory to available somatostatin analogues

In a randomized, double-blind, Phase III study, we compared pasireotide long-acting release (pasireotide LAR) with octreotide long-acting repeatable (octreotide LAR) in managing carcinoid symptoms refractory to first-generation somatostatin analogues. Adults with carcinoid tumors of the digestive tract were randomly assigned (1:1) to receive pasireotide LAR (60 mg) or octreotide LAR (40 mg) every 28 days. Primary outcome was symptom control based on frequency of bowel movements and flushing episodes. Objective tumor response was a secondary outcome. Progression-free survival (PFS) was calculated in a post hoc analysis. Adverse events were recorded. At the time of a planned interim analysis, the data monitoring committee recommended halting the study because of a low predictive probability of showing superiority of pasireotide over octreotide for symptom control (n=43 pasireotide LAR, 20.9%; n=45 octreotide LAR, 26.7%; odds ratio, 0.73; 95% confidence interval [CI], 0.27–1.97; P=0.53). Tumor control rate at month 6 was 62.7% with pasireotide and 46.2% with octreotide (odds ratio, 1.96; 95% CI, 0.89–4.32; P=0.09). Median (95% CI) PFS was 11.8 months (11.0 – not reached) with pasireotide versus 6.8 months (5.6 – not reached) with octreotide (hazard ratio, 0.46; 95% CI, 0.20–0.98; P=0.045). The most frequent drug-related adverse events (pasireotide vs octreotide) included hyperglycemia (28.3% vs 5.3%), fatigue (11.3% vs 3.5%), and nausea (9.4% vs 0%). We conclude that, among patients with carcinoid symptoms refractory to available somatostatin analogues, similar proportions of patients receiving pasireotide LAR or octreotide LAR achieved symptom control at month 6. Pasireotide LAR showed a trend toward higher tumor control rate at month 6, although it was statistically not significant, and was associated with a longer PFS than octreotide LAR.

Multicenter Phase II Study of Sequential Radioembolization-Sorafenib Therapy for Inoperable Hepatocellular Carcinoma

Background The safety and tolerability of sequential radioembolization-sorafenib therapy is unknown. An open-label, single arm, investigator-initiated Phase II study (NCT0071279) was conducted at four Asia-Pacific centers to evaluate the safety and efficacy of sequential radioembolization-sorafenib in patients with hepatocellular carcinoma (HCC) not amenable to curative therapies. Methods Sorafenib (400 mg twice-daily) was initiated 14 days post-radioembolization with yttrium-90 (90Y) resin microspheres given as a single procedure. The primary endpoints were safety and tolerability and best overall response rate (ORR) using RECIST v1.0.Secondary endpoints included: disease control rate (complete [CR] plus partial responses [PR] and stable disease [SD]) and overall survival (OS). Results Twenty-nine patients with Barcelona Clinic Liver Cancer (BCLC) stage B (38%) or C (62%) HCC received a median of 3.0 GBq (interquartile range, 1.0) 90Y-microspheres followed by sorafenib (median dose/day, 600.0 mg; median duration, 4.1 months). Twenty eight patients experienced ≥1 toxicity; 15 (52%) grade ≥3. Best ORR was 25%, including 2 (7%) CR and 5 (18%) PR, and 15 (54%) SD. Disease control was 100% and 65% in BCLC stage B and C, respectively. Two patients (7%) had sufficient response to enable radical therapy. Median survivals for BCLC stage B and C were 20.3 and 8.6 months, respectively. Conclusions This study shows the potential efficacy and manageable toxicity of sequential radioembolization-sorafenib. Trial Registration ClinicalTrials.gov NCT00712790.

Dynamic contrast-enhanced CT imaging of hepatocellular carcinoma in cirrhosis: feasibility of a prolonged dual-phase imaging protocol with tracer kinetics modeling

Dynamic contrast-enhanced (DCE) CT imaging of four patients with hepatocellular carcinoma (HCC) was performed using a dual-phase imaging protocol designed with initial rapid dynamic imaging to capture the initial increase in contrast medium enhancement in order to assess perfusion, followed by a delayed imaging phase with progressively longer intervals to monitor subsequent tissue enhancement behaviour in order to assess tissue permeability. The DCE CT images were analysed using a dual-input two-compartment distributed parameter model to yield separate estimates for blood flow and permeability, as well as fractional intravascular and extravascular volumes. The HCCs and surrounding cirrhotic liver tissues were found to exhibit enhancement curves that can be appropriately described by two distinct compartments separated by a semipermeable barrier. Early contrast arrival was also found for HCC as compared with background liver. These findings are consistent with the current understanding of sinusoidal capillarization and hepatocarcinogenesis.

Triplet combination of gemcitabine, paclitaxel, and carboplatin followed by maintenance 5‐fluorouracil and folinic acid in patients with metastatic nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a disease that is highly responsive to various chemotherapeutic agents. In the metastatic setting, 2‐drug combination chemotherapy generally provides a response rate of 55% to 75%, and median survival of 10 to 12 months. The objective of the current study was to assess the efficacy of a 3‐drug combination followed by maintenance treatment in patients with metastatic NPC.

A Randomized Phase II Trial of Single-Agent Gemcitabine, Vinorelbine, or Docetaxel in Patients with Advanced Non-small Cell Lung Cancer Who Have Poor Performance Status and/or Are Elderly

Background: Patients with poor performance status and/or are elderly are frequently considered a compromised group at high risk of chemotherapy-related morbidities and less likely to benefit from treatment. We aimed to evaluate tolerability and efficacy of three single-agent regimens in these patients. Patients and Methods: Patients with advanced non-small cell lung cancer who had performance status 2/3 and/or were aged 70 and older were randomly assigned to receive gemcitabine, vinorelbine, or docetaxel. Objective response, toxicities, and quality of life were evaluated. Results: One hundred thirty-five patients were registered, of whom one was ineligible. Of the 134 patients, 43 received gemcitabine, 45 vinorelbine, and 46 docetaxel. The response rate was 16%, 20%, 22% for gemcitabine, vinorelbine, and docetaxel, respectively. The main grade 3/4 toxicities were fatigue (18%) and neutropenia (16%). There was improvement in global health scores, cough, and dyspnea for all treatment groups. The improvement in dyspnea was most marked in patients with performance status 3. Conclusion: There was no significant advantage of any of the treatment arms over the rest. There was benefit seen with improvement of quality of life in patients who were able to receive more cycles of chemotherapy.