Rachel Midgley

Vascular and upper gastrointestinal effects of non-steroidal anti-inflammatory drugs: Meta-analyses of individual participant data from randomised trials

Summary Background The vascular and gastrointestinal effects of non-steroidal anti-inflammatory drugs (NSAIDs), including selective COX-2 inhibitors (coxibs) and traditional non-steroidal anti-inflammatory drugs (tNSAIDs), are not well characterised, particularly in patients at increased risk of vascular disease. We aimed to provide such information through meta-analyses of randomised trials. Methods We undertook meta-analyses of 280 trials of NSAIDs versus placebo (124 513 participants, 68 342 person-years) and 474 trials of one NSAID versus another NSAID (229 296 participants, 165 456 person-years). The main outcomes were major vascular events (non-fatal myocardial infarction, non-fatal stroke, or vascular death); major coronary events (non-fatal myocardial infarction or coronary death); stroke; mortality; heart failure; and upper gastrointestinal complications (perforation, obstruction, or bleed). Findings Major vascular events were increased by about a third by a coxib (rate ratio [RR] 1·37, 95% CI 1·14–1·66; p=0·0009) or diclofenac (1·41, 1·12–1·78; p=0·0036), chiefly due to an increase in major coronary events (coxibs 1·76, 1·31–2·37; p=0·0001; diclofenac 1·70, 1·19–2·41; p=0·0032). Ibuprofen also significantly increased major coronary events (2·22, 1·10–4·48; p=0·0253), but not major vascular events (1·44, 0·89–2·33). Compared with placebo, of 1000 patients allocated to a coxib or diclofenac for a year, three more had major vascular events, one of which was fatal. Naproxen did not significantly increase major vascular events (0·93, 0·69–1·27). Vascular death was increased significantly by coxibs (1·58, 99% CI 1·00–2·49; p=0·0103) and diclofenac (1·65, 0·95–2·85, p=0·0187), non-significantly by ibuprofen (1·90, 0·56–6·41; p=0·17), but not by naproxen (1·08, 0·48–2·47, p=0·80). The proportional effects on major vascular events were independent of baseline characteristics, including vascular risk. Heart failure risk was roughly doubled by all NSAIDs. All NSAID regimens increased upper gastrointestinal complications (coxibs 1·81, 1·17–2·81, p=0·0070; diclofenac 1·89, 1·16–3·09, p=0·0106; ibuprofen 3·97, 2·22–7·10, p<0·0001; and naproxen 4·22, 2·71–6·56, p<0·0001). Interpretation The vascular risks of high-dose diclofenac, and possibly ibuprofen, are comparable to coxibs, whereas high-dose naproxen is associated with less vascular risk than other NSAIDs. Although NSAIDs increase vascular and gastrointestinal risks, the size of these risks can be predicted, which could help guide clinical decision making. Funding UK Medical Research Council and British Heart Foundation.

Genetic prognostic and predictive markers in colorectal cancer

Despite many studies of the likely survival outcome of individual patients with colorectal cancer, our knowledge of this subject remains poor. Until recently, we had virtually no understanding of individual responses to therapy, but the discovery of the KRAS mutation as a marker of probable failure of epidermal growth factor receptor (EGFR)-targeted therapy is a first step in the tailoring of treatment to the individual. With the application of molecular analyses, as well as the ability to perform high-throughput screens, there has been an explosive increase in the number of markers thought to be associated with prognosis and treatment outcome in this disease. In this Review, we attempt to summarize the sometimes confusing findings, and critically assess those markers already in the public domain.

Meta-analysis of three genome-wide association studies identifies susceptibility loci for colorectal cancer at 1q41, 3q26.2, 12q13.13 and 20q13.33

Genome-wide association studies (GWAS) have identified ten loci harboring common variants that influence risk of developing colorectal cancer (CRC). To enhance the power to identify additional CRC risk loci, we conducted a meta-analysis of three GWAS from the UK which included a total of 3,334 affected individuals (cases) and 4,628 controls followed by multiple validation analyses including a total of 18,095 cases and 20,197 controls. We identified associations at four new CRC risk loci: 1q41 (rs6691170, odds ratio (OR) = 1.06, P = 9.55 × 10−10 and rs6687758, OR = 1.09, P = 2.27 × 10−9), 3q26.2 (rs10936599, OR = 0.93, P = 3.39 × 10−8), 12q13.13 (rs11169552, OR = 0.92, P = 1.89 × 10−10 and rs7136702, OR = 1.06, P = 4.02 × 10−8) and 20q13.33 (rs4925386, OR = 0.93, P = 1.89 × 10−10). In addition to identifying new CRC risk loci, this analysis provides evidence that additional CRC-associated variants of similar effect size remain to be discovered.

Common variation near CDKN1A , POLD3 and SHROOM2 influences colorectal cancer risk

We performed a meta-analysis of five genome-wide association studies to identify common variants influencing colorectal cancer (CRC) risk comprising 8,682 cases and 9,649 controls. Replication analysis was performed in case-control sets totaling 21,096 cases and 19,555 controls. We identified three new CRC risk loci at 6p21 (rs1321311, near CDKN1A; P = 1.14 × 10−10), 11q13.4 (rs3824999, intronic to POLD3; P = 3.65 × 10−10) and Xp22.2 (rs5934683, near SHROOM2; P = 7.30 × 10−10) This brings the number of independent loci associated with CRC risk to 20 and provides further insight into the genetic architecture of inherited susceptibility to CRC.

A phase II study of adoptive immunotherapy using dendritic cells pulsed with tumor lysate in patients with hepatocellular carcinoma

This is a phase II clinical trial investigating the safety and efficacy of intravenous vaccination with mature autologous dendritic cells (DCs) pulsed ex vivo with a liver tumor cell line lysate (HepG2) in patients with advanced hepatocellular carcinoma (HCC). HCC is an attractive target for immunotherapy as evidenced by an active recruitment of tumor‐infiltrating lymphocytes that are capable of lysing autologous tumor cells in ex vivo studies. DCs are the most potent antigen‐presenting cells, with the capacity to take up, process, and present tumor antigens to T cells and stimulate an immune response, thus providing a rational platform for vaccine development. Thirty‐five patients with advanced HCC and not suitable for radical or loco‐regional therapies received a maximum of six DC vaccinations each at 3‐week intervals. In total, 134 DC infusions were administered with no significant toxicity and no evidence of autoimmunity. Twenty‐five patients who received at least three vaccine infusions were assessed clinically for response. The radiologically determined disease control rate (combined partial response and stable disease ≥3 months) was 28%. In 17 patients the baseline serum α‐fetoprotein (AFP) was ≥ 1,000 ng/mL; in four of these patients, it fell to <30% of baseline following vaccination. In one patient there was a radiological partial response associated with a fall in AFP to <10% of baseline. Immune responses were assessed using an ELIspot assay of interferon‐γ (IFN‐γ) release. In several cases there was induction of T cell responses to the vaccine and/or AFP following vaccination. Conclusion: Autologous DC vaccination in patients with HCC is safe and well tolerated with evidence of antitumor efficacy assessed radiologically and serologically, with generation of antigen‐specific immune responses in some cases. (HEPATOLOGY 2009;49:124‐132.)

Evaluation of PIK3CA Mutation As a Predictor of Benefit From Nonsteroidal Anti-Inflammatory Drug Therapy in Colorectal Cancer

PURPOSE Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) protect against colorectal cancer (CRC) and are associated with reduced disease recurrence and improved outcome after primary treatment. However, toxicities of NSAIDs have limited their use as antineoplastic therapy. Recent data have suggested that the benefit of aspirin after CRC diagnosis is limited to patients with PIK3CA-mutant cancers. We sought to determine the predictive utility of PIK3CA mutation for benefit from both cyclooxygenase-2 inhibition and aspirin. METHODS We performed molecular analysis of tumors from 896 participants in the Vioxx in Colorectal Cancer Therapy: Definition of Optimal Regime (VICTOR) trial, a large randomized trial comparing rofecoxib with placebo after primary CRC resection. We compared relapse-free survival and overall survival between rofecoxib therapy and placebo and between the use and nonuse of low-dose aspirin, according to tumor PIK3CA mutation status. RESULTS We found no evidence of a greater benefit from rofecoxib treatment compared with placebo in patients whose tumors had PIK3CA mutations (multivariate adjusted hazard ratio [HR], 1.2; 95% CI, 0.53 to 2.72; P = .66; (P)INTERACTION = .47) compared with patients with PIK3CA wild-type cancers (HR, 0.87; 95% CI, 0.64 to 1.16; P = .34). In contrast, regular aspirin use after CRC diagnosis was associated with a reduced rate of CRC recurrence in patients with PIK3CA-mutant cancers (HR, 0.11; 95% CI, 0.001 to 0.832; P = .027; (P)INTERACTION = .024) but not in patients lacking tumor PIK3CA mutation (HR, 0.92; 95% CI, 0.60 to 1.42; P = .71). CONCLUSION Although tumor PIK3CA mutation does not predict benefit from rofecoxib treatment, it merits further evaluation as a predictive biomarker for aspirin therapy. Our findings are concordant with recent data and support the prospective investigation of adjuvant aspirin in PIK3CA-mutant CRC.

KRAS Mutation Is Associated with Lung Metastasis in Patients with Curatively Resected Colorectal Cancer

Purpose: Oncogene mutations contribute to colorectal cancer development. We searched for differences in oncogene mutation profiles between colorectal cancer metastases from different sites and evaluated these as markers for site of relapse. Experimental Design: One hundred colorectal cancer metastases were screened for mutations in 19 oncogenes, and further 61 metastases and 87 matched primary cancers were analyzed for genes with identified mutations. Mutation prevalence was compared between (a) metastases from liver (n = 65), lung (n = 50), and brain (n = 46), (b) metastases and matched primary cancers, and (c) metastases and an independent cohort of primary cancers (n = 604). Mutations differing between metastasis sites were evaluated as markers for site of relapse in 859 patients from the VICTOR trial. Results: In colorectal cancer metastases, mutations were detected in 4 of 19 oncogenes: BRAF (3.1%), KRAS (48.4%), NRAS (6.2%), and PIK3CA (16.1%). KRAS mutation prevalence was significantly higher in lung (62.0%) and brain (56.5%) than in liver metastases (32.3%; P = 0.003). Mutation status was highly concordant between primary cancer and metastasis from the same individual. Compared with independent primary cancers, KRAS mutations were more common in lung and brain metastases (P < 0.005), but similar in liver metastases. Correspondingly, KRAS mutation was associated with lung relapse (HR = 2.1; 95% CI, 1.2 to 3.5, P = 0.007) but not liver relapse in patients from the VICTOR trial. Conclusions: KRAS mutation seems to be associated with metastasis in specific sites, lung and brain, in colorectal cancer patients. Our data highlight the potential of somatic mutations for informing surveillance strategies. Clin Cancer Res; 17(5); 1122–30. ©2011 AACR.

Systemic treatment of colorectal cancer

Palliative and adjuvant treatment for colorectal cancer has been, until recently, largely dependent on 5-fluorouracil (5-FU)-based chemotherapy. Oral fluoropyrimidines have been evaluated in the advanced disease setting and they appear to be as effective as 5-FU, but are safer and more convenient for most patients. Irinotecan and oxaliplatin are new cytotoxic agents, which are active in 5-FU-resistant disease, but which may also be combined with 5-FU as initial therapy in advanced disease. Initial combination therapy leads to improved response rates and more prolonged progression-free survival compared with 5-FU monotherapy. Standard regimens for adjuvant therapy usually involve 6 months of chemotherapy using 5-FU and folinic acid. Recent trials of capecitabine, oxaliplatin and irinotecan in the adjuvant setting are ongoing, or have recently completed accrual, and may lead to a change in future clinical practice. Biological therapies are playing an increasing role in the management of colorectal cancer. Farnesyl transferase inhibition, inhibition of the epidermal growth factor receptor (EGFR) and the vascular endothelial growth factor (VEGF) are undergoing evaluation in advanced disease. In the adjuvant setting, both passive and active immunotherapeutic approaches have been studied. In addition, a large trial will evaluate the role of cyclo-oxygenase(COX)-2 inhibitors as adjuvant therapy. Further research is required in order to define the optimal sequence and combination of these different cytotoxic and biological therapies, in order to secure the best possible outcome for various subgroups of patients with both early and advanced stage colorectal cancer.

TERC polymorphisms are associated both with susceptibility to colorectal cancer and with longer telomeres

Background and aims Shorter telomeres have been associated with increased risk of malignancy, including colorectal cancer (CRC). Telomere length is heritable and may be an intermediate phenotype linked to genetic susceptibility to CRC. Methods In a large sample, the study investigated whether candidate single nucleotide polymorphisms (SNP) in ‘telomere biology’ genes were associated with telomere length in leucocytes. SNP associated with an increased risk of CRC were searched for separately. Results Carriers of the common allele at SNP rs10936599, near the telomerase RNA component (TERC) locus, had significantly longer telomeres. It was independently found that the same rs10936599 allele was associated with increased risk of both CRC and colorectal adenomas. Neither telomere length nor CRC risk was associated with variation near telomerase reverse transcriptase or other telomere biology genes. In silico analysis showed that SNP rs2293607 was strongly correlated with rs10936599, mapped within TERC transcripts, had a predicted effect on messenger RNA folding and lay at a reported transcription factor binding site. TERC mRNA were expressed, differing only at the alleles of rs2293607, in CRC cell line HCT116. The long-telomere/CRC-risk allele was associated with higher levels of TERC mRNA and the formation of longer telomeres. Conclusions Common genetic variation at TERC is associated with both longer telomeres and an increased risk of CRC, a potential mechanism being reduced levels of cell senescence or death. This finding is somewhat paradoxical, given retrospective studies reporting that CRC cases have shorter telomeres than controls. One possibility is that that association actually results from poorer survival in patients with longer telomeres.

Phase III Randomized Trial Assessing Rofecoxib in the Adjuvant Setting of Colorectal Cancer: Final Results of the VICTOR Trial

PURPOSE Laboratory and case-control studies suggest a pivotal role for the cyclooxygenase-2 (COX-2) pathway in colorectal carcinogenesis. The purpose of this study was to test whether the COX-2 inhibitor rofecoxib could reduce recurrence and improve survival when administered in the adjuvant setting of colorectal cancer (CRC). PATIENTS AND METHODS Patients who had undergone potentially curative surgery and completion of adjuvant therapy for stage II and III CRC were randomly assigned to receive rofecoxib (20 mg daily) or placebo. The primary end point was overall survival (OS). Where formalin-fixed paraffin-embedded tumor tissue samples were available, COX-2 expression was evaluated by immunohistochemistry and correlated with clinical outcome. RESULTS Two thousand four hundred thirty-four patients were entered onto the study. The trial was terminated early because of the worldwide withdrawal of rofecoxib. At this point, 1,167 patients had received rofecoxib and 1,160 patients had received placebo for median treatment durations of 7.4 and 8.2 months, respectively. For the rofecoxib and placebo arms, median follow-up times were 4.84 and 4.85 years, with 241 and 246 deaths and 297 and 329 recurrences, respectively. No difference was demonstrated in OS (hazard ratio [HR] = 0.97; 95% CI, 0.81 to 1.16; P = .75) or recurrence (HR = 0.89; 95% CI, 0.76 to 1.04; P = .15) comparing the two groups. Tumor COX-2 expression by immunohistochemistry was assessed for 871 patients, but neither prognostic nor predictive effects were observed. CONCLUSION In this study of abbreviated therapy in the adjuvant setting of CRC, rofecoxib did not improve OS or protect from recurrence in unselected patients. In addition, COX-2 expression did not correlate with prognosis overall or predict effectiveness of COX-2 inhibitors.