Second-line chemotherapy in advanced biliary cancer: a systematic review

The randomized NCRN phase III ABC-02 trial provided level-A evidence for first-line chemotherapy with cisplatin and gemcitabine combination in advanced biliary cancer (ABC). This systematic literature review aims to evaluate the level of evidence for the use of second-line chemotherapy for patients with ABC in terms of overall survival (OS), response, toxicity and quality of life. Eligible studies were identified using Medline, ASCO, ESMO and the World Gastrointestinal Congress databases. Searches were last updated on 15 December 2013. Eligible studies reported survival and/or response data for patients with ABC receiving second-line systemic chemotherapy. This systematic review was registered in the PROSPERO database (No. CRD42013004205). Five hundred and fifty-eight studies were identified from the searches in Medline (n = 342), ASCO (n = 160), ESMO (n = 27) and World Gastrointestinal Congress (n = 29). Twenty-five studies were eligible: 14 phase II clinical trials, 9 retrospective analyses and 2 case reports. In total, data from 761 patients were reported with median number of patients included in each study of 22 (range 9-96). The mean OS was 7.2 months [95% confidence interval (CI) 6.2-8.2] [phase II: 6.6 (95% CI 5.1-8.1); retrospective analysis: 7.7 (95% CI 6.5-8.9)]. The mean progression-free survival (PFS), response rate (RR) and disease control rate were 3.2 months (95% CI 2.7-3.7), 7.7% (95% CI 4.6-10.9) and 49.5% (95% CI 41.4-57.7), respectively. The best correlations were between OS and PFS for all studies (r = 0.54; P = 0.01) and between OS and PFS (r = 0.61; P = 0.04) and OS and RR (r = 0.62; P = 0.03) for phase II studies, respectively. Biliary tract cancer is known to be a chemo-responsive disease. There is insufficient evidence (level C) to recommend a second-line chemotherapy schedule in ABC, although the available data suggest that a cohort of patients may benefit. Further prospective and randomized studies are needed to clarify the relative value of second-line chemotherapy in this setting.

Practical management of sunitinib toxicities in the treatment of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (pNETs) are infrequent malignancies which manifest in both functional (hormone-secreting) and more commonly non-functional (non-secreting) forms. The oral multitargeted tyrosine kinase inhibitor sunitinib and mammalian target of rapamycin (mTOR) inhibitor everolimus are approved as targeted therapies for patients with well-differentiated, non-resectable disease and evidence of disease progression. The recent approval of sunitinib for the management of advanced pNET is based on a continuous daily dosing (CDD) schedule that differs from the intermittent 4weeks on/2weeks off (4/2) schedule approved for sunitinib in advanced renal cell carcinoma (RCC) and imatinib-resistant gastrointestinal stromal tumor (GIST). Therefore, although clinicians may be familiar with therapy management approaches for sunitinib in advanced RCC and GIST, there is less available experience for the management of patients with a CDD schedule. Here, we discuss the similarities and differences in the treatment of pNET with sunitinib compared with advanced RCC and GIST. In particular, we focus on the occurrence and management of sunitinib-related toxicity in patients with pNET by drawing on experience in these other malignancies. We aim to provide a relevant and useful guide for clinicians treating patients with pNET covering the management of events such as fatigue, mucositis, hand-foot syndrome, and hypertension.

Gefitinib for oesophageal cancer progressing after chemotherapy (COG): a phase 3, multicentre, double-blind, placebo-controlled randomised trial

BACKGROUND

Evidence is scarce for the effectiveness of therapies for oesophageal cancer progressing after chemotherapy, and no randomised trials have been reported. We aimed to compare gefitinib with placebo in previously treated advanced oesophageal cancer.

METHODS

For this phase 3, parallel, randomised, placebo-controlled trial, eligible patients were adults with advanced oesophageal cancer or type I/II Siewert junctional tumours, histologically confirmed squamous-cell carcinoma or adenocarcinoma, who had progressed after chemotherapy, with WHO performance status 0-2, and with measurable or evaluable disease on CT scan. Participants were recruited from 48 UK centres and randomly assigned (1:1) to gefitinib (500 mg) or matching placebo by simple randomisation with no stratification factors. Patients, clinicians, and trial office staff were masked to treatment allocation. Treatment continued until disease progression, unacceptable toxicity, or patient choice. The primary outcome was overall survival, analysed by intention to treat. This trial is registered, number ISRCTN29580179.

FINDINGS

Between March 30, 2009, and Nov 18, 2011, 450 patients were randomly assigned to treatment groups (one patient withdrew consent; 224 patients allocated gefitinib and 225 allocated placebo included in analyses). Overall survival did not differ between groups (median 3·73 months, 95% CI 3·23-4·50, for gefitinib vs 3·67 months, 95% CI 2·97-4·37, for placebo; hazard ratio [HR] 0·90, 95% CI 0·74-1·09, p=0·29). Among the prespecified patient-reported outcomes (110 patients on gefitinib and 121 on placebo completed both baseline and 4 week questionnaires and were included in analyses), odynophagia was significantly better in the gefitinib group (adjusted mean difference -8·61, 95% CI -14·49 to -2·73; n=227; p=0·004), whereas the other outcomes were not significantly improved compared with placebo: global quality of life (2·69, 95% CI -2·33 to 7·72, n=231, p=0·293), dysphagia (-3·18, 95% CI -8·36 to 2·00, n=231, p=0·228), and eating (-4·11, 95% CI -9·96 to 1·75, n=229, p=0·168). Median progression-free survival was marginally longer with gefitinib than it was with placebo (1·57 months, 95% CI 1·23-1·90 in the gefitinib group vs 1·17 months, 95% CI 1·07-1·37 in the placebo group; HR 0·80, 95% CI 0·66-0·96, p=0·020). The most common toxicities were diarrhoea (36 [16%] of 224 patients on gefitinib vs six [3%] of 225 on placebo) and skin toxicity (46 [21%] vs two [1%]), both mostly grade 2. The commonest grade 3-4 toxicities were fatigue (24 [11%] vs 13 [6%] patients) and diarrhoea (13 [6%] vs two [1%]). Serious adverse events were reported in 109 (49%) of 224 patients assigned to gefitinib and 101 (45%) of 225 on placebo. 54 (24%) of patients in the gefitinib group achieved disease control at 8 weeks, as did 35 (16%) of patients on placebo (p=0·023).

INTERPRETATION

The use of gefitinib as a second-line treatment in oesophageal cancer in unselected patients does not improve overall survival, but has palliative benefits in a subgroup of these difficult-to-treat patients with short life expectancy. Future research should focus on identification of predictive biomarkers to identify this subgroup of benefiting patients.

FUNDING

Cancer Research UK.

Somatostatin receptor expression in hepatocellular carcinoma: prognostic and therapeutic considerations

Sorafenib is the only systemic therapy to demonstrate a significant survival benefit over supportive care in robust randomised controlled trials for advanced hepatocellular carcinoma (HCC). In the context of an intense search for prognostic and predictive factors for response and efficacy of different systemic therapies (including sorafenib), a number of molecular targets have been identified, paving new avenues for potential therapeutic opportunities. Such molecular targets include somatostatin receptor (SSTR)-related alterations. In this review, we provide an overview of the various considerations relating to SSTRs as potentially novel prognostic and predictive biomarkers for HCC with special emphasis on the therapeutic potential of somatostatin analogues in HCC management.

Sunitinib for advanced pancreatic neuroendocrine tumors

Recent recognition of the high prevalence of neuroendocrine tumors in combination with a sustained failure to improve outcomes for patients with advanced disease has elevated their priority for research and drug development. Sunitinib (SU11248, Sutent; Pfizer Inc. NY, USA) potently inhibits multiple-receptor tyrosine kinases, resulting in antiangiogenic effects. A growing body of evidence indicates angiogenesis is a clinically relevant therapeutic target in pancreatic neuroendocrine tumors, culminating in a Phase III randomized study of sunitinib in patients with advanced progressive pancreatic neuroendocrine tumors. Sunitinib has recently gained regulatory approval as a single agent in this setting, and future studies will investigate most appropriate patient selection, and sequencing and combination with other targeted and cytotoxic agents. Here, we discuss in detail the molecular properties, clinical efficacy and safety of sunitinib in the context of pancreatic neuroendocrine tumors.

Ornithine decarboxylase G316A genotype is prognostic for colorectal adenoma recurrence and predicts efficacy of aspirin chemoprevention

PURPOSE

The chemopreventive activity of aspirin in colorectal neoplasia may be explained in part by its effect on polyamine metabolism. The ornithine decarboxylase (ODC) G316A polymorphism affects polyamine metabolism through altered expression of ODC. We investigated the influence of ODC G316A on the chemopreventive activity of aspirin in colorectal adenoma (CRA) recurrence.

EXPERIMENTAL DESIGN

We genotyped ODC G316A in 546 individuals in the United Kingdom Colorectal Adenoma Prevention trial of aspirin for CRA recurrence prevention and pooled our findings with data from two other randomized intervention trials.

RESULTS

The United Kingdom Colorectal Adenoma Prevention participants with homozygous ODC 316AA genotype were at reduced CRA recurrence risk [relative risk (RR), 0.43; 95% confidence interval (95% CI), 0.16-1.15], particularly if also exposed to aspirin (RR, 0.24; 95% CI, 0.03-1.71). In the pooled analysis of 2,207 individuals, those with homozygous ODC 316AA genotype were at significantly reduced CRA recurrence risk (RR, 0.68; 95% CI, 0.47-0.99). Following stratification by genotype and aspirin exposure, individuals with homozygous wild-type or heterozygous genotypes derived modest benefit from aspirin (RR, 0.85; 95% CI, 0.72-1.01), whereas in those with both ODC 316AA genotype and aspirin exposure recurrence risk was halved (RR, 0.52; 95% CI, 0.29-0.91).

CONCLUSION

The ODC G316A genotype is prognostic for CRA recurrence and predictive of an enhanced response to aspirin in preventing recurrence. This variant has the potential to be a clinically useful genetic marker to identify individuals likely to derive the greatest benefit from aspirin chemoprevention.

Polymorphisms in PTGS1, PTGS2 and IL-10 do not influence colorectal adenoma recurrence in the context of a randomized aspirin intervention trial

Regular use of aspirin and other nonsteroidal antiinflammatory drugs reduces both the development of colorectal neoplasia and recurrence of colorectal adenoma (CRA). Modulation of the effects of aspirin by genetic factors has been reported, potentially allowing targeting of treatment to individuals most likely to gain benefit. Prostaglandin H synthase 1 (PTGS1) and PTGS2 are key enzymes in prostaglandin synthesis and are inhibited by aspirin, whilst interleukin-10 (IL-10) is an important antiinflammatory cytokine. We investigated whether functional genetic polymorphisms in the PTGS1, PTGS2 and IL-10 genes influence CRA recurrence in individuals participating in a randomized aspirin intervention trial. DNA was available for genotyping from 546 patients who received aspirin (300 mg daily) or placebo for a mean 41-months' duration. Homozygote carriers of variant alleles for the PTGS1 50C>T, PTGS2 -765G>C and IL-10 -592C>A polymorphisms did not have a significantly altered risk of CRA recurrence (relative risk [RR]=0.91; 95% confidence interval [CI]: 0.14-6.07, RR=1.32; 95% CI: 0.66-2.62 and RR=1.24; 95% CI: 0.74-2.07, respectively). There were also no significant interactions between aspirin intervention and genotype in determining recurrence risk. These data indicate that these polymorphisms are unlikely to influence CRA recurrence and cannot be used to identify individuals who derive benefit from aspirin intervention.

Should folic acid fortification be mandatory? No

The UK's Food Standards Agency recently recommended mandatory folic acid fortification of some foods. Nicholas Wald and Godfrey Oakley argue that it's a safe effective way of preventing spina bifida and anencephaly—but Richard Hubner and colleagues say that more research into the harms is needed

MTHFR C677T and colorectal cancer risk: A meta-analysis of 25 populations

The common functional methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism may influence the risk of colorectal cancer (CRC), but data from published studies with individually low statistical power are conflicting. To clarify the role of MTHFR C677T genotype in CRC, we considered all available studies in a meta-analysis. Studies reporting on MTHFR C677T genotype and CRC were searched in PubMed up to April 2006. The principle prior hypothesis was that homozygosity for MTHFR 677TT would be associated with reduced risk of CRC. Data were available for 29,931 subjects, including 12,243 with CRC, from 25 independent populations. Compared to the homozygous CC genotype, the MTHFR 677TT genotype was associated with a reduced risk of CRC (odds ratio (OR): 0.83; 95% confidence interval (CI): 0.75-0.93; p = 0.001). There was some heterogeneity among the results of individual studies, but this was not statistically significant (heterogeneity p = 0.12; I2 = 25.8%). Heterozygosity for MTHFR 677 did not influence CRC risk (OR: 0.99; 95% CI: 0.94-1.04). These findings indicate that individuals homozygous for the MTHFR 677TT genotype are at moderately reduced risk of CRC, and support the proposal that common genetic variation in the MTHFR gene contributes to CRC susceptibility, probably accounting for at least 9% of the total incidence.

MTHFR C677T has differential influence on risk of MSI and MSS colorectal cancer

The majority of colorectal cancer (CRC) exhibiting the micosatellite instability (MSI) phenotype is due to hypermethylation of the hMLH1 gene promoter. We aimed to test the hypothesis that polymorphisms in genes coding for enzymes involved in folate metabolism play a role in altered promoter-specific hypermethylation and thus predispose to MSI CRC. Analysis of MSI was performed in 1685 CRCs, and polymorphism genotypes were determined in germline DNA for all cases and 2692 cancer-free controls. MSI was observed in 171 cancers (10.1%). Compared to homozygous wild-type individuals, those with MTHFR 677TT genotype were more likely to have MSI than microsatellite stable (MSS) CRC [odds ratio (OR) 1.90; 95% confidence interval (CI): 1.09-3.31]. When MTHFR C677T genotype frequencies in MSS CRC cases were compared to controls, individuals with homozygous variant genotype were at 19% reduced risk of cancer compared to wild type (OR = 0.81; 95% CI: 0.65-1.02). Conversely, when MSI CRC cases were compared to controls, individuals with one or two MTHFR 677T alleles were at 42% increased cancer risk (OR = 1.42; 95% CI: 1.02-1.96). Our observations indicate that MTHFR 677TT homozygous individuals are more likely to develop MSI CRC than those with wild-type genotype, and this common polymorphism has differential influences on MSI and MSS CRC risk. Stratification by MSI status should aid future studies investigating the complex relationships between genotype, environmental factors and CRC risk.

Genetic variants of UGT1A6 influence risk of colorectal adenoma recurrence

PURPOSE

The UDP glucuronosyltransferase 1A6 (UGT1A6) and cytochrome P450 2C9 (CYP2C9) enzymes participate in the metabolism of nonsteroidal anti-inflammatory drugs, endogenous substances, and carcinogens. Functional polymorphisms of UGT1A6 (T181A and R184S) and CYP2C9 (R144C and I359L) have been reported to modify the protective effect of aspirin on colorectal adenoma risk. We aimed to further investigate the effect of these genetic variants on the development of colorectal neoplasia.

EXPERIMENTAL DESIGN

We examined the relationship between UGT1A6 and CYP2C9 genotype and colorectal adenoma recurrence in 546 patients participating in a randomized placebo-controlled aspirin intervention trial.

RESULTS

Although colorectal adenoma recurrence was not significantly influenced by CYP2C9 genotype, carriers of variant UGT1A6 alleles were at significantly reduced risk of colorectal neoplasia recurrence [relative risk (RR), 0.68; 95% confidence interval (95% CI), 0.52-0.89]. This risk reduction was also evident when the analysis was confined to advanced neoplasia recurrence (RR, 0.71; 95% CI, 0.47-1.09). When patients were stratified by genotype and aspirin intervention, those with variant UGT1A6 alleles were at reduced recurrence risk irrespective of whether they received aspirin or placebo (RR, 0.62; 95% CI, 0.42-0.92 and RR, 0.63; 95% CI, 0.44-0.91, respectively).

CONCLUSIONS

These findings confirm that UGT1A6 variants influence colorectal carcinogenesis independent of aspirin intake and suggest that they may have clinical value in secondary prevention programs for patients diagnosed with colorectal adenoma.

Folate metabolism polymorphisms influence risk of colorectal adenoma recurrence

Folate intake is inversely related to risk of developing colorectal neoplasia. Associations between risk of colorectal neoplasia and polymorphisms in genes coding for enzymes involved in folate metabolism have also been reported, suggesting a relationship between genotype and development of colorectal neoplasia. To further investigate the effects of folate metabolism genotypes on colorectal neoplasia, we genotyped 546 patients participating in a randomized controlled trial of folate supplementation for the prevention of colorectal adenoma recurrence. A significantly reduced risk of recurrence was observed in patients heterozygous for the MTRR A66G polymorphism [relative risk (RR), 0.64; 95% confidence interval (95% CI), 0.46-0.90] or heterozygous for the MTHFR A1298C polymorphism (RR, 0.71; 95% CI, 0.52-0.97). Furthermore, a significant reduction in recurrence risk was seen in MTRR A66G heterozygotes who received folate supplements but not in those who did not receive folate. Patients heterozygous for the MTHFR C677T polymorphism had a nonsignificant risk reduction (RR, 0.92; 95% CI, 0.69-1.23), as did patients with one or two variant alleles for the MTR A2756G polymorphism (RR, 0.82; 95% CI, 0.60-1.12). No influence on recurrence risk was observed for the TSER, TSER 3R G>C, and TS 1494del6 variants. These findings provide additional support for the hypothesis that germ line variants in folate metabolism genes influence the development of colorectal adenomas.

Molecular advances in medullary thyroid cancer diagnostics

Germline activating mutations in the RET proto-oncogene cause inherited medullary thyroid cancer (MTC) and the multiple endocrine neoplasia type 2 (MEN2) syndrome. Identification of a RET mutation in an individual with MEN2 allows pre-symptomatic genetic testing of other at-risk family members, and guides early intervention to prevent death and serious morbidity from MTC. Developments in the understanding of downstream RET receptor signalling pathways and how activating mutations disturb receptor function has led to insights into the possible molecular mechanisms underlying the different MEN2 phenotypes. Mutation analysis of RET in individuals with MEN2 has identified a number of different mutations, and correlation with cancer biology and clinical outcome has led to tailoring of management according to the mutation detected.

Bisphosphonates' use in metastatic

Bisphosphonates already have an established role in the management of the skeletal complications of metastatic bone disease. The development of new, highly potent compounds has led to investigation into their use as preventive agents in the adjuvant setting. The aim of the paper is to evaluate the evidence for their use in prevention and treatment.

Differential tissue and enzyme inhibitory effects of the vasopeptidase inhibitor omapatrilat in the rat

Vasopeptidase inhibitors simultaneously inhibit angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP). The present study characterized the tissue distributions of ACE and NEP, and assessed the effects of the vasopeptidase inhibitor omapatrilat on ACE and NEP in rat tissues. In vivo ACE and NEP inhibition was studied by in vitro autoradiography and using the ACE inhibitor radioligand (125)I-MK351A and the NEP inhibitor radioligand (125)I-RB104 in rats that received oral omapatrilat (40 mg x day(-1) x kg(-1)) for 3 days. In vitro autoradiography was used to examine the distribution of ACE and NEP in the kidney, aorta, heart, adrenal gland, lung, intestine, liver, spleen and brain, and to assess enzyme inhibition after oral omapatrilat. Omapatrilat inhibited plasma ACE and increased plasma renin activity (P <0.01). Tissue ACE was inhibited by 70-95% (P <0.01), except in the brain, where ACE was not inhibited. NEP was inhibited by 87% in the kidney and by 20-40% in atria, aorta, adrenal gland, lung, liver and intestine; it was not inhibited in the brain, the ventricle or the spleen. Omapatrilat is a potent vasopeptidase inhibitor that significantly inhibits tissue ACE and NEP, with the degree of inhibition varying according to the enzyme and the tissue under assessment. The degree and site of tissue enzyme inhibition by vasopeptidase inhibitors may be relevant to end-organ protection as well as to the side-effect profiles of these agents.

Evidence for cardioprotective, renoprotective, and vasculoprotective effects of vasopeptidase inhibitors in disease

In both the natriuretic peptide and renin-angiotensin systems, peptidases play an important role in the inactivation or activation of the system. Angiotensin-converting enzyme is responsible for the conversion of angiotensin I to angiotensin II, while neutral endopeptidase is one of the pathways involved in the degradation of the natriuretic peptides. The vasopeptidase inhibitors, which simultaneously inhibit neutral endopeptidase and angiotensin-converting enzyme, appear to offer distinct therapeutic advantages in treating hypertension, heart failure, and endothelial dysfunction.

In-vitro and in-vivo inhibition of rat neutral endopeptidase and angiotensin converting enzyme with the vasopeptidase inhibitor gemopatrilat

OBJECTIVES

Vasopeptidase inhibitors are single molecules that simultaneously inhibit neutral endopeptidase (NEP) and angiotensin converting enzyme (ACE). The aim of this study was to characterize in-vitro and in-vivo inhibition of NEP and ACE in the rat with the vasopeptidase inhibitor gemopatrilat.

DESIGN AND METHODS

In-vitro NEP and ACE inhibition was studied by radioinhibitory binding assay using rat renal membranes and the specific NEP inhibitor radioligand 125I-RB104 and the specific ACE inhibitor radioligand 125I-MK351A, respectively (n = 3 per curve). In-vivo NEP and ACE inhibition was studied using in-vitro autoradiography in rats that received oral gemopatrilat (1, 3, 10 mg/kg; n = 4 per dose) and were killed 1 h later, or received oral gemopatrilat (3, 10 mg/kg) and were killed at time points 1, 2, 4, 8, 18, 24 and 48 h (n = 4 per time point).

RESULTS

Gemopatrilat caused a concentration-dependent displacement of specific radioligands from renal membrane NEP (IC50 305 +/- 5.4 nmol/I) and ACE (IC50 3.6 +/- 0.02 nmol/). In the dose-response study gemopatrilat (1, 3 and 10 mg/kg) caused significant inhibition of plasma ACE (P< 0.01), and renal ACE and NEP (3, 10 mg/kg, P < 0.01). In the time course experiment, gemopatrilat (10 mg/kg) increased plasma renin activity for 8 h (P< 0.01) and inhibited plasma ACE (P< 0.05), renal NEP (P< 0.01) and renal ACE (P< 0.05) for 48 h.

CONCLUSIONS

Gemopatrilat is a potent in-vitro vasopeptidase inhibitor that also causes prolonged inhibition of circulating and renal ACE and renal NEP after a single oral dose. The data suggest that gemopatrilat may be a useful addition to existing vasopeptidase inhibitors in the treatment of cardiovascular disease.